Using WD40 for cleaning (not lubricating..)

I clean my stuff with Simple Green. Rinse. Simple Green. Rinse until clean.

I wouldn't use WD-40 if I were you though. I am not sure about the chemistry behind it but it is not a degreaser and there are plenty of other better options out there.

Don't use grease either. Use a light oil. And remove the excess. I keep an old toothbrush around to brush in all of the oil to make sure I have all the little pieces coated then wipe off any excess. Anything dripping or about to form drips is excess.

With grease and excess oil comes accumulation of dirt which is abrasive. By not using grease with is sticky and wiping excess oil you are effectively limiting the abrasives that stick to your chain.

I am not super sure of what you mean by 'Dry Lube' I think you mean either a Teflon based lube or lube that is meant for dry conditions. I have used Teflon-based stuff before and it was a pink, waxy mess. That could just be the brand though. All the bike shops around me use Tri-Flo. Thats what I use. I have a small bottle that has lasted for years.


How does a chain get filthy and how can you stop it from getting filthy?

The "filth" is a composite material. It is a mixture of chain lube, road grit, and the metal filings from gear and chain wear. The road grit is composed of sand, tire bits, asphalt, trash, etc. The issue is when you mix them all together it forms a thick, pasty sticky mess.. The goop tends to collect more material. The  grit in the sticky residue acts like sandpaper accelerating wear. You can minimize but not eliminate it by using the correct lube. This generally means a dry type lube when the conditions are dry and a wet lube when the conditions are wet.


Low tire pressure causing fall in corner?

I presume you were riding in the direction you came across the bridge and down the ramp.
I doubt tire pressure had anything to do with it. On a moutain bike sized tire, unless rolling tires of rims, too low tire pressure tends to cause imprecise handling and a general 'sloppiness' in the front end. "wiping out" as you did is not typically caused by low pressures.  Check the rim for scrapes that would indicate you rolled the tire off the rim and had the rim hit the ground.

The weight on the back of the bike, and the change in angle that coincides with the corner probably unloaded the weight off the front wheel. The amount of friction you get is directly proportional to weigh, so the wheel 'wiped out' from under you because it was not far off hanging in mid air.

When learning to mountain bike one of the first skills you need to learn is to load the shock before the corner and maintain pressure on the front wheel though the corner, letting the shock do its job of maintaining wheel contact with the ground. In this case if you had loaded the front shock, the change in angle coming onto the ramp would have be absorbed by the shock as it extended to maintain wheel contact pressure with the ground.

Things that could contributed to the crash are rider position - too much weight too far back into and though the corner. This means not enough weight on the front wheel to maintain traction and not enough preload on the fork for it to hold the front wheel on the ground.  The solution to this problem is enter the attack position, move body weight forward (not lean) to load the front fork with plenty of weight to hold the front wheel down.  With 30kg on the rear, there is very little risk of putting so mach weight too far forward you go over the bars. Just how far forward you can go is much further than most people think, and is very unnerving for a novice until they have practiced doing it many times.

The other thing that could easily contribute to the crash is the fork settings - damping, rebound and air pressure are all available on the Reba. Getting this set correctly will make a big difference to hold the front wheel on the ground. With these set correctly, maintain a good weight distribution with you body well forward becomes easier as you learn to trust the fork to work for you. With these set wrong, the fork can feel like its working against you and you are less included to load it.

All that said, the speed you went though the corner with that bike setup and weight was fairly ballsy, and the outcome not entirely unpredictable. If you don't want to crash, you may need to slow down.


Problem setting up Shimano 5800 levers for the first time

I managed to fix this, but I'm not completely certain why it started working. I believe the fix was a combination of three things.

Repulling the cable and being firm about pulling it horizontally
through the lever. I don't believe I got it deep enough into the lever before
putting the hood back into place for extra pressure on the cable helped it engage
making sure to start with a fair amount of cable tension before working the levers


The Sunlight tubes I was using have a "ribbed" area near the valve stem. Patches just did not hold in that ribbed area.
Inside the rim no sharp areas or spokes protruding, but I added an additional cloth rim strip and a Continental brand tube purchased from a different shop.
It is holding for now, although this problem sometimes doesn't show up immediately.
Here's hoping it is a good fix.

(later) I am happy to report that changing to a different brand of tube (continental) and adding a second rim strip has solved my problem of multiple flat tires.


Unfortunately, there is a fairly straight forward reason why you actually need to ride hills in order to get faster at them: crank inertial load.

We have two main types of skeletal muscles. (Skeletal muscles are responsible for our locomotion and movements, cardiac and smooth muscles make up the other muscle types in our the body). The two main skeletal types  are slow twitch which has slower contractile speed, lower force, but higher endurance and fast twitch which has a faster contractile speed, higher force, but lower endurance. Fast twitch can be further broken down into an additional 3 sub-types, which again vary from each other by contractile speeds and forces generated.   Each person has a unique make-up of these skeletal muscle type which is controlled largely by genetics, but the relative strengths of each type can also be trained plus there is some evidence for inter-conversion of the fast twitch muscle types through training.

This gets us to hill climbing.  The conditions experienced by your skeletal muscle when climbing is very different from riding on the flat. On the flat you are typically carrying a lot of momentum (kinetic energy). If you stop pedalling you will still be carrying a lot of speed and will not slow down much immediately after you stop. As such you have all this energy which helps to overcome the drag and rolling resistance. In order to accelerate you will need a quick burst of work which means you need to fire your muscles more quickly in order to perform sufficient work in a short enough time period. These conditions are more favourable to including more fast twitch fibers (although all fiber types will still be contributing).   Conversely, when climbing you have less kinetic energy. If you stop pedalling you will slow down much quicker. These conditions are more favourable to longer contraction times, which in turn favours the use of slow twitch muscles over fast twitch.

This all has important consequences when looking at replicating riding conditions with indoor trainers. This quote from R Chung (who is a frequent contributor on bicycles.se) summarizes nicely why this is the case:

  No turbo currently on the market can adequately replicate the forces you experience while climbing. Mostly, that's because hills vary in steepness, so the power and inertia vary, while most turbos (all mechanical turbos and many electronic turbos) have a fixed relationship between wheel speed and power, and all have fixed inertial load. Some electronically-controlled turbos can vary the relationship between wheel speed and power (typically, by something they might call "slope") but none vary the inertial load.

  So when you're training on a turbo, forget about cadence, or climbing. You can't replicate it. What you can replicate is the range of power you need to produce. So just focus on that. If you have a power meter this is easier but if you don't just focus on wheel speed, even if the wheel speed isn't representative of the wheel speed you'll use while climbing.

Unfortunately, its not just "Turbo trainers" most trainers on the market cannot sufficient replicate the inertial loads experienced when climbing. These are better suited to replicating riding flats and as such provide a poor substitute for actually getting out and climbing real hills because you are training muscle firing patterns that are much different than what is needed to climb efficiently.

Finally, Cycling Tips has a good article summarizing the differences in how our muscle work when climbing versus riding flats.


Disc brakes making a banging sound on steep descents

Possibly calliper alignment. Manufacturing variation in hub or badly faced rotor mounts can move the rotor plane in or out a crucial tiny amount which combined with a odd calliper shape can result in some of the arms of the rotor bonking the calliper under the right conditions. Hence the thunk, thunk sound. Not dangerous but annoying.
Moving the callipers a touch to one side (e.g use a paper width as a gauge) might fix the issue without significantly affecting the centering.


Effects of longer and higher stem on rider position/comfort and handling

There is no magic formula for handlebar position, so some experimentation is necessary.

If you feel your hand should be further forward, get a longer stem. Think about where your hand want to be on the drops and decide if you will go 1cm or 2cm longer.

You can experiment with bar height. If you have spacers on the steerer you can move the stem up and down. If you want the bar higher still you can flip the stem.

By the way, many riders find the drops uncomfortable for long periods of time. Spending time in the drops, stretching and core strength exercises help.

With regard to handling a longer stem moves mass forward which makes the bike a little more stable and slows steering due to the longer radius between contact points on the bars and the steering axis.


How can I use a bent seatpost to move my cruiser's seat farther back?

After some more searching, it looks like I'm looking for a layback seatpost, and they're available for purchase on eBay.


What are the brake housing stoppers on the end of the brake housing called (see pic)

They're essentially part of the brake lever. They don't really have an agreed-upon name. Probably the closest is "mushroom ferrule," which appears to be what Dia-Compe calls them.

They're not totally universally sized. Different brake levers have slightly different bits that go there but do the same thing. That said, the ones on the great majority of bikes with applicable levers are all the same size, which I believe is basically Dia-Compe and clones.

You can just buy the common size ones new. In the US, J&B Importers (one of the largest parts wholesalers) has a house brand one they call a "Cable End Button" and UBS has one they call "UNIV BRAKE CABLE ADAPTER." There's also Dia-Compe part 94, same thing. You can just order any of them from an online reseller, or find a shop that has them. Some shops will also have old levers around to cannibalize.


Can I replace a Shimano Deore SL-M590 3speed Left shifter with an Acera SL-M310?

Short answer - yes it will work, its a 3 speed Shimano "mountain" shifter so the amount of cable pull should be identical.

Long answer - You get what you pay for.

Acera is the cheapest of the M series groupsets. Above it you have Alivio , then Deore. In saying that, Shimano's trickle down development tends to send improvements down the production line over the years so a 2018 Acera won't be much worse than a 2009 Deore.

You won't (initially) notice much difference in shifting quality. It'll probably feel better for a while.

Yes it will be plasticky. yes it will break faster than a new Deore part. YMMV depending on what sort of riding you do.

You can find many tutorials on YouTube on how to do this ("replace front shifter bike"). With luck you just need a 4mm and 5mm Hex and to be able to get the left grip off. Worse luck, the cable housing has degraded and needs replacing too.


Possible causes:

Deformation of the steerer around the clamp area, possibly from overtorquing.
The steerer is cracking and hence lacks dimensional stability. I've seen this cause the exact issue you're talking about and it's scary, so I recommend looking very closely for it. Take off any spacers below the stem to get a better look when doing so.
Using a plug and topcap assembly that doesn't provide as much internal support as the fork is designed to need. Sometimes plug assemblies are treated as totally interchangeable and in practice this isn't really the case. If this is what's going on it can easily have already caused cracking. If it still looks good and the plug assembly isn't snug inside where the stem clamps, try getting one that is.
Plain old poor fit/tolerance between the stem and steerer. This is pretty unlikely.
Using a single-bolt stem with the carbon steerer. This is a big no-no and could have caused the sort of deformation mentioned above.

Bear in mind that 5Nm, with or without carbon prep in most cases, really is plenty when things are working right (given common lightweight stems that call for 5, of course). It sounds like something else has gone wrong and I doubt that more torque is going to be the fix.


It could be the freewheel or hub bearing causing the squeak but this should not be the case as both are lubed,  or should be. More likely is as you mention a spoke.
Sometimes spokes squeak at the hub end as they flex.. Try rubbing in some grease or putting on a drop of oil on each spoke fitting at the hub end to see if it cures it,  just ride the bike and let the lube take effect.
Of course a spoke could also squeak at the nipple end too as it flexes slightly in the wheel,  the only way to address/lube this end properly is by removing the tyre etc and applying a tiny drop of oil to each nipple. Don't let it get near your braking surfaces though.


Buying parts for an extra set of wheels: will a an 11 speed freehub body accept a 12 speed cassette?

You can put 12 speed on any of the freehub body types found on mountain bikes (HG, XD, or Micro Spline), but if you want to use a 10t small cog you can't use HG.

The spacing from the rotor mount surface to the dropout is standard, but the tolerance is big enough to make this the spot where alternate wheelsets can be tricky to make work with no adjustment. In other words, between two hubs of rhe same OLD spec, with the same rotor on each, the rotors will wind up close to the same plane, but possibly not close enough to center them given you're working with so little margin for error. The first thing to do if you can is get another one of the exact same hub, although I understand that may not apply here.

With 6-bolt you can use micro shims to build up the rotor mounting surface of whichever hub is more inboard to achieve drop-in interchangeability as best as possible. It will still be subject to rotor wear and trueness. There's no equivalent trick if one of the hubs is centerlock and it happens to place the rotor more inboard.

You need to use the same hub OLD your frame takes, like 142x12, 148x12 (Boost), etc.

Hubs usually put the cassete in close enough to exactly the same position for wheel swaps without adjustment. In the road world this is important because rapid wheel swaps are so integral to the sport. As you can imagine, it's still possible for tolerance considerations to make it not work, and a cheap MTB hub with 12-speed is probably about the most likely place for that to occur. There aren't any shims small enough I'm aware of to tune it the same way as above.

Many wheels don't come with rim tape or strips. And from your list you'd also need tubes or valves and sealant as applicable.


I think what you have is a lower end carbon fork where cost has been saved on the finish.

Carbon fiber composite is made from carbon fiber cloth in an epoxy matrix. The cloth weave often shows through the finish of CFC products. The finish in this fork seems to be somewhat variable. I think you are right that the lines on the inside are mold junction lines. Notice that are all on the inside surface to try to hide them.

What I would be more concerned about are the two vertical crack lines visible in the first photo, running parallel to the mould line above the cable exit. They may just be in the finish but I would have a bike repair shop check them out.


You are not alone. These brakes require constant adjustment and are not fit for purpose. The recommendation is to upgrade to Avid BB7's or a hydraulic system. Read the litany of complaints:

http://www.mtbr.com/cat/brakes/disc-brake-system/avid/bb5-mechanical-disc-brake/prd_414627_1507crx.aspx

Before you tear them off the bike in disgust you may want to take a read of the Park Tool instructions for adjusting Avid mechanical disk brakes:

http://www.parktool.com/blog/repair-help/avid-reg-mechanical-disc-adjustment

This explains quite clearly how the brakes actually work - the outer pad moves whereas the inner pad does not. The disk gets pushed across by the outer pad to hit the inner pad. Note that the more expensive BB7's allow more adjustment and that the even more expensive hydraulic systems work differently, pushing both pads out to meet the disc rather than just 'bending it across'.

Good rim brakes are better than cheap disc brakes and your bike unfortunately has the latter. I recommend that you upgrade the brakes to the best mechanical system you can afford rather than spend any more time trying to adjust what sounds to me to be a flawed product.


Is a tri frame suitable for track racing?

I wouldn't. Track frames are purpose-built for racing at a velodrome.

Your tri frame will have a much lower bottom bracket. This can easily result in a pedal strike on the banked corners of the velodrome. Pedal strikes on corners with a fixed gear are bad; since the drivetrain is always turning, it will cause your rear wheel to jump perpendicular to the track surface. This will throw you into the bike on your left, and cause a spectacular crash.

Not as bad is that your frame has vertical dropouts instead of horizontal ones. Horizontal dropouts are made such that any loosening of your rear skewer bolts can only cause the wheel to move further into the dropouts. With vertical dropouts, any slip can potentially result in you losing your wheel.


You're asking a question that cannot be answered.  Sorry - the plethora of tyre size measuring systems means there is no good answer.

Diameter could be 29 inches, it could be 28 inches, it could even be 27 inches.  But the bead seat IS 622 millimetres without exception.

The width likewise varies - there are fractional inch measurements that do not line up with the decimal inch of the same size - IE 1 1/2 inches is not the same width of tyre as 1.5 inches.  But 23mm is 23mm without exception.

This is why the ETRTO measurement system is simply superior to all that went before.  Not that its based on metric, but ETRTO is consistent and accurate.

A "700c" tyre in a width of 23 is a ETRTO measurement of 622-23, which is sometimes written as 23-622.

You might glean some more information from How do I know what size tyres can I fit on my rims? and from How do I determine my wheel size

Or consider asking about what you're trying to achieve - this sounds like an XY problem.


As far as I can tell the 2015 Carrera Vulcan came with SRAM X4 all round. If the front derailleur is a Shimano unit it definitely was not original. I would guess the previous owner swapped it in. A Shimano unit will have 'Shimano' and 'Tourney' written on it. A picture of the derailleur added to you question will help us provide a good answer.

In general SRAM and Shinano derailleurs and shifters are not compatible because they use a different cable pull ratio (how much cable is pulled to move the derailleur a certain amount).

You options for replacement depend on what front shifter you have. If the shifter was also replaced with a Shimano unit you'll need a Shimano derailleur replacement. I'd avoid the Tourney range and upgrade slightly to something in Altus or Acera ranges. The exact model you want depends on if the the cable routing comes from the top or bottom of the frame.

If the shifter is still a SRAM unit you the obvious choice for a replacement is a SRAM X4 unit as was originally fitted. I don't think SRAM makes these anymore but they are available from Ebay, Amazon etc.


I've never heard of a galvanized frame. Galvanizing involves dipping steel in molten zinc, which I'm pretty sure would mess up the heat treatment state of the steel tubes.

Frames are just painted to protect from corrosion.


answers for why the bike wobbles back and forth when standing on the pedals and working it

The way he's riding is bad because it damages your bike. That in itself ought to be enough reason to stop. You could point out that all the effort spent pushing the bike from side to side is wasted; he could use he energy more effectively to push the bike forwards using the pedals.

I suspect that if your friend was riding his own bike, he'd be less cavalier about his treatment of it.

I'd be inclined to say one of the following things to him:

"Please return my bike in the condition it was in when I lent it to you; either don't damage it, or get it properly repaired before you give it back", or
"You're not borrowing my bike any more"

Note that different types of bike are designed for different purposes. You've tagged this as "road"; we generally want road bikes to move forward efficiently, but BMX riding (for example) is very different. It sounds a bit like your friend isn't used to this kind of distinction.


Having restored a number of old cheap bikes, I can tell you that the biggest problem is almost never the derailleurs/shifters. Usually these bikes have not been ridden much and have spent most of their time in a garage exposed to the elements. The biggest problems are rusted parts, poor lubrication, and horrifically bad tuning. Frequently, on a bike like this you're likely to find that it was never properly put together.

Here's a quick checklist of things to go over that can be fixed economically:

Buff all rusted parts with steel wool, regrease all bushings on derailleurs & brake calipers/levers.
Clean/lube chain & freewheel or replace with similar if worn out (unlikely).
Replace cables and housings for brakes and shifters with inexpensive new ones (example) ~$10-20
Replace brake pads ~$10
Adjust brakes-- following readily available instructions
Adjust shifters-- following readily available instructions
disassemble/re-grease/re-pack hubs, headset, bottom bracket-- following readily available instructions
True the wheel, tighten spokes if needed.
Replace inner tubes, tires, rim-tape (If they're in bad shape) ~$30-50

If you have to replace the shifters or derailleurs, just try to find cheap replacements or used parts that are similar. You'll want to stick with 5-speed stuff, you aren't going to be upgrading to a 10 speed freewheel (they don't exist!).


Could I have deformed the wheel of my new bike by being too heavy?

220 pounds (100kg) is not that heavy.

At £459 or about US$600 retail, the Saracen is also not an inexpensive bike. It should be more than able to handle your weight unless you're doing very aggressive biking (such as hopping on and off curbs or doing wild jumps without the proper technique). Riding on rough roads is well within the design parameters of this "hybrid" bike.

If your wheels are deforming**, it is likely either a manufacturing defect in the rim or your spokes were not properly adjusted/checked by the dealer. As @Orb notes, you should have also gotten a request from the dealer to come in after the first week to tighten things up as part of the new bike service. I would immediately go back and demand that it be fixed or replaced. I would myself insist on new wheels and insist that the spoke tension and hubs be properly checked before they are reinstalled.

** Note that I'm assuming your wheel (the metal bits) are deforming. Your description is vague. If your tire (the rubber bits) is bulging, then that could be caused by a local weakness in the tire wall. In either case, take it back to the shop to get it replaced.

The UK has good retail trade laws so you should be well within your rights to demand resolution.

ps. I do hope you bought it from a local bike shop rather than online. It's much harder to yell at people online, I've found.


The bottom bracket spindle is for cottered crank.

The bottom bracket looks like threaded one, so it is likely that it can be replaced with square taper or external cup bottom bracket. To tell which thread the bottom bracket has, we'd need to know the exact dimensions.


The subject of stretching is controversial and there is ongoing debate within the scientific community. There is actually no absolute answer until there is further research. Here is what current and on-going research indicates as to the question, "Is there any factual basis for the claim that increased flexibility leads to less power?".

Stretching and obtaining flexibility beyond your sport specific optimal range of motion is likely to decrease performance.
Stretching to optimize range of motion is beneficial, if tight muscles are the cause of sub-optimal range of motion.
Stretching may be necessary for individual cyclists in order to optimize aerodynamic positioning and/or to enhance riding comfort.
Stretching to prevent injury is not shown to be beneficial.
The timing of static stretching is shown to influence muscle power and therefore performance.
The benefits and drawbacks of stretching are sport specific.
Benefits of dynamic stretching/warm-up routines are inconclusive at this point.

More interesting studies from PubMed searches:

This one: "Overall, the evidence suggests that increasing range of motion beyond function through stretching is not beneficial and can actually cause injury and decrease performance."
And another: "...for sports with slow stretch-shortening cycle such as jogging or cycling, there is no scientific data showing a positive effect of stretching." However, negative effects are not showing up other than where one is increasing range of motion beyond what is necessary for a specific sport.

I did some searching on PubMed and other biomedical databases, using the search terms: flexibility, stretching, cycling performance, muscle power, etc, in various combinations.

There are no research papers coming up in searches that say a regular stretching program reduces sprinting power.
There is research saying that the timing of static stretching influences muscle power. See below.
There is also research saying that cycling performance can be enhanced by a flexibility program in cases where flexibility improves range-of-motion and/or cycling position. Such as time trials.

As a cycling and fitness enthusiast I feel compelled to figure this out. Since my last revision I found a recent, well documented book on the subject of stretching. The book is 'Dynamic Stretching' by Mark Kovacs, Phd. (The Phd is in exercise physiology).

The gist is:

Pre-event static stretching - Research shows that it can decrease performance in strength, speed and power activities. Some studies have shown decreases in performance by as much as 30%. (Pre-event meaning within 60 minutes of the event)

Static stretching as part of an ongoing training program - Improves range of motion and flexibility in the major muscles and joints of the body. Does not influence strength, speed or power except as to enhancing range of motion. However, there are performance benefits depending on the specialty of the competitive cyclist. For example, a time trialist needs to achieve and maintain an optimal aero position; a cyclocross competitor needs to get on and off the bike a lot; individual sprinters may need to improve range of motion, etc, etc...

Whew! A huge amount of misinformation and mythology on stretching is available. The book cited is focused on dynamic stretching, however the sections on the science of flexibility are well documented from numerous scholarly sources.


Converting bike from rim brakes to disc brakes

Your frame and fork already have disc tabs, which is the first step.  The second is a disc wheelset, which it does not appear that the stock wheels are.  Disc hubs come in two varieties: the common six-bolt ISO and the proprietary Shimano Centerlock, the former are identifiable by a large six-bolt-hole protrusion on the left (non-drive) side of the bike.  The latter have a rubber cover over a smaller splined mount.

Once a new wheelset is selected, you'll need a set of calipers and disc rotors.  The Avid BB7 is a popular mechanical disc caliper, and will work with your existing linear-pull brake levers.

Installation is fairly straightforward, but since it involves braking it's worth involving a professional if you're at all in doubt of your mechanical aptitude.  The disc rotors bolt to the wheel, the calipers to the frame.  The old v-brakes are removed.  New cables and housing are routed from the levers to the calipers and the calipers are adjusted.

Cost-wise, if you're happy with the bicycle otherwise it's not a poor investment - good wheels and brakes can be moved to future bikes if you later decide to upgrade the frame.  The ideal time would be to consider when the wheels already need to be replaced due to wear, since the new wheelset will represent the majority of the upgrade cost.


Is it best to put oil on the inner or outer of the chain?

If you think about it, the purpose of oiling is to lubricate where you have metal moving against metal.

So in the diagram below:

you need to oil the pin/roller area. There's no point oiling the face plates (which I think is what you're saying?).

When you oil, know how many links are in the chain (or mark your start link), and go around the whole chain once, oiling each roller. That's all you need to do. No need to do quarter turns or repeat three times.

Then, when you've done, wipe off the excess oil with something dry. A bit of rag or kitchen towel will do.


Bike not changing correctly between two gears

How many miles on this bike?  If over 5000 miles (8000km) then your rear gear cluster may be worn out.  Your symptoms are most strongly suggestive of that.

Otherwise, the first thing to do is to clean the derailer real well.  Lean the bike against a wall (derailer facing you) outside somewhere where a few oil stains won't be a problem.  Shove some newspaper or cardboard up behind the derailer and drape it over the tire, to keep stuff from dripping on the tire.  Then spray the derailer well with a spray solvent (WD40 in the US) and scrub it with an old toothbrush.  Dry the derailer well with an old rag, and lubricate with chain oil.

With the derailer clean, swivel it back and forth by hand and notice if it seems to be twisting in parallel with the chain and sprockets or is perhaps bent so that it goes at an angle.  If it seems bent (which happens from dropping the bike on its side) then the "derailer hanger" probably needs to be straightened.

Also, pay attention to the shifters and cables.  A little spray lube in the shifters and down the shifter cable housings is generally all that's needed here, unless the cables are badly corroded or beginning to fray, in which case they need to be replaced.  Be careful, though, about what sort of lube you put on the shifters as most now have plastic components that can be damaged by strong solvents.

And, of course, it's probably time to adjust the derailer, but that a whole different post.


If you noticed the chain chattering on the sprocket, then yes, it could be caused by using an 8-speed shifter with a 6-speed freewheel. With indexed shifting, all the drivetrain parts are designed to work together, and if you've got a mismatch--as you do here--you can expect the shifter to pull the chain out of alignment with the sprocket.


Tadpole Recumbent Bike Correct Fairing Position

Fairings are external body panels that help shape the airflow over you and your ride, whether it be an upright, or a recumbent, bike or trike.

So if you're aiming for more speed via better aerodynamics, then the fairing should be as small as possible AND smooth the airflow over you as much as possible.  This means as narrow as possible while not interfering with your pedalling.  It should also be high up so there is less vertical surface presented to the airstream (ie your face)

If you're aiming for comfort while commuting, then visibility is important, so a lower trailing edge allows you to see more.  Yes it will be not quite as good for slipping through the air, but a crash or an avoidable incident will slow you down more.

Length isn't really that relevant to aerodynamics unless you're getting side winds, where the surface area is larger because the wind is from the side.  There's a rule of thumb about the length of any tailbox which should be 6x longer than its maximum width to avoid stalling the windflow as it comes back together.

A final thought about trailing edge height - if you have a sudden stop that throws you forward, will you be better off with the trailing edge inline with your head or your chest?  Obviously not stopping suddenly would be best, but we don't always have that option.


How to slow yourself down (for playing nice with others)

Focussing on the "training harder" aspect of your question:

A simple way for training hard while keeping your speed comparatively low would be to increase your cadence.

The easiest approach: Try switching a gear or two lower than you normally feel comfortable with, meaning you will have to pedal faster to keep the same speed.

One of the advantages of high cadence cycling is less force on your legs, and therefore accumulated fatigue,  leading to a faster recovery after a long ride.

There is actually a nice GCN YouTube video on this topic: GCN: Improve Your High Cadence Cycling.

Focussing on the "playing nice" aspect of your question:

You could offer to carry a bigger share of supplies and equipment. Collect those spare tubes, an emergency pump, patches, and maybe an extra water bottle, and the additional weight will make it certainly more challenging for you (and easier for your companions), especially if your tour includes some nice climbs.


What is the recommended tension for my AlexRims X2100 rim?

Some manufacturers have published recommended spoke tensions for their rims. For two examples, Mavic recommends 70 to 90 kg (700 to 900 N) in front and drive side rear and Velocity claims 110 to 130 kg (1100 to 1300 N). Non-drive side tension should be set so that drive side is at recommended tension and the rim is centered.

For high spoke count road wheels there is a workaround where you increase the tension until the wheel turns slightly taco shaped and then back off until it is true. This works for narrow rings like Open Pro, but can result in excessive tension for smaller and stiffer MTB rims.


Will a 9 speed crank work with 10 speed groupset?

10 is a little bit narrower, but generally a crank with 1 measure narrower chain will work pretty good.


Buying a new bike for under $1500 - best option for hard terrain on a budget

At 1.5k it has to be a hardtail. Rear suspensions need to be done right to be worth having in the first place. If I was a long-travel guy (I'm not) I would start looking at FS bikes once my budget passed 2k.

As to the frame, 1.5k would get you a cheap/heavy carbon frame or a top quality aluminum frame. I'd go aluminum.

The above assumes that you are buying new...  I would consider buying used.

If I were you, I would get a used aluminum FS. I wouldn't mess with a used carbon bike, that can be risky.

Brand and model really doesn't matter if you know your components. If you have no clue how to identify good components, you should stick with big, well-known brands like Trek, Cannondale, Giant, Specialized, etc.

Good luck!


MTB vee brakes have a different pull ratio than road caliper pull ratio.
They make specific levers for each.
I've used normal mtb vee levers on road bikes before and it was fine, when I used the brakes, it just felt like it stopped with small amounts of movement of the lever. So modulation wasn't great. But it worked.
Alternatively, you could use "cross top" levers which should work better than normal MTB levers.
Cross top levers, used a lot in CX and touring bikes.


Should I use a narrower saddle on a road bike than I would on my hybrid commuter?

Yes, a more aggressive stance requires a narrower saddle.

Your pelvic bone is a fairly complicated structure, but there's basically a triangle that you sit on with a saddle.  There's two bumps ("ischial protrusions") at the back end that take your weight if you're sitting with your back straight up (such as on a chair or the saddle of a cruiser or dutch bike). The front point of the triangle is the "pubic symphisis" which you don't sit on. Between there it's basically slightly curved like the bottom of a rocking chair.

Look here: http://en.wikipedia.org/wiki/File:Gray237.png
Here: http://en.wikipedia.org/wiki/File:Gray235.png
And here: http://en.wikipedia.org/wiki/File:Skeletpelvis-pubis.jpg

As you rotate your hips forward (for a more "aggressive" position), your hips should be rotating forward and your back staying relatively straight. Because of that, the part of that ischial/pubis structure that you sit on is more towards the narrow front part and the saddle should be narrower. This can also affect the desired tilt of the saddle.

Also, in general, if you're riding more aggressively, all that pedaling removes some of the weight from the saddle and makes any kind of rubbing against the saddle more of a problem, which are additional reasons aggressive road riders may want a narrower saddle.


I think first you should read up on the price point people recommend staying with a hard tail. Below that figure (about $US2000 depending who you speak to) Soft tails are heavy with poor rear suspension performance.

Almost always, the most economic way to upgrade is to sell the current bike and buy a second hand one. The BD (if its the bike I am thinking of $500ish price point) does not have components worth putting onto a a ST frame worth riding.

If you are new to MTB, and enjoy the bike you have, stick with the bike you have and start saving until you get a bank balance that lets you truly upgrade - not just a sideways or downwards shift. Riding a HT needs skills that you can get away with not having on a ST. These skills make you a better rider and a HT is the best way to learn them. Don't upgrade till you are sure its the bike limiting you riding - most riders get much more improvement for a lot less by upgrading themselves rather than the bike - get some training - a coaching session or four, read mags and books, or watch few MTB coaching videos.


The most likely problem is that the brakes are rubbing.  If you pick up the front of the bike, hold your head near the brakes and spin the wheel you shouldn't hear any noise from the brakes.  If you do, then the brakes are rubbing and that's the first problem to be fixed.  To be honest, I'd guess that's 99% likely to be your problem.

If you have fenders, and the new tire is larger in size than the old one, then there may not be enough clearance for it; that can also be detected by listening for rubbing sounds.

If the brakes are fine and nothing else is rubbing, pop the wheel off the bike and try spinning the axle; if it doesn't spin freely then that means there's too much pressure on the bearings.  (Note this is really unlikely if the shop only changed the tire.)


It certainly does look like you have ample clearance for fenders.

Those look long deep drop brake calipers too.

If you don't have fender mounts on the rear - you can always use P-Clips.


I would say it depends on your riding style and the geometry of the specific bike you are looking at.  29'r is definitely not to big for you (I am 5'10" and my 29'rs are just fine).  However, there are reasons that a lot of all mountain, freeride and almost all downhill rigs are still 26".  29'rs are less suited for highly technical riding, but much better suited for cross country and trail riding.  As always, tailor your bicycle choice to your riding style.

If you are into flowy single track and aren't hitting drops, ripping through rock gardens and generally abusing the landscape with your rig, then 29" is probably a better choice for you (with the right size frame).


My chain slips when I use an inappropriate gear, and the chain loosens when changing gears (most of the time). What should I do?

Sounds like you need a new chain and cog. It is badly worn and can result in your injury.
As well as a service on the derailleur ( whole bike service would be best).


Do all or virtually all rear derailleurs actually have linear actuation ratios?

Over the last decades, virtually all rear derailleurs have been based on the same parallelogram geometry. Its movement is close to linear over the cogs, but when you draw the half-circles different parts move in, it is clear that the actuation ratio changes near the edges of the range.

Calculating the actual position of pulleys from cable position is quite complicated, since there are three fixed and three moving pivots (one of each for cable, two for parallelogram. The dimensions of different derailleur are quite close, so the small non-linearity behaves in similar way between different brands.

On the other hand, 10 and 11 speed Campagnolo cassettes have slightly uneven spacing between cogs. This means that even perfect conversion from a system with even spacing would not be perfect match. The varying spacing is documented in Sheldon Brown's crib sheets and this photo.


Is the real world experience of riding a light bike understated by physics-based calculators?

The physics model of cycling power and speed has been validated in the real world. Two examples are this and this. The model embedded in Analyticcyling.com's online calculator is based on these two papers.

Whether the amount of difference calculated by the validated models is worth it to Joe and Billy is a question that can't be answered by the physics.


Replacement brake pads for SRAM Force 1/CX 1

Should be OK, I have not heard of problems changing to different types.
Organics are normally quieter and less prone to squeal than metallic pads, in fact its one of their main advantages.

I would go though the normal steps for dealing with squealing brakes. Align the calipers, clean and bed in. As the pads are new, and you cleaned the rotors, I would align and see it if goes. If that does not work, very lightly surface the rotors and discs with fine emery paper and redo bedding in.

In some cases its just the  combination of pads, disk, brakes and frame don't work. If you can't live with it, changing to a different pad will often fix it.


Derailleur adjustment: front or rear first?

If the derailers just need minor tweaking (they are basically in adjustment but are "not quite right") then you adjust the one that is obviously wrong, check the overall adjustment again, then again adjust what needs adjusting.  Often only one derailer needs adjusting and often the adjustment is just a half-turn of the barrel adjuster.

If they are completely mucked up (but nothing visibly bent/broken), I usually first check the front for parallel and sprocket clearance (they often get knocked out of alignment), get it on the center sprocket, then address the rear.  Once the rear is basically correct, get the front to where it will shift to all rings with modest accuracy, then, trying all combos, adjust the rear some more.  Finally, fine-tune the front, then fine-tune the rear.

But it varies with the bike, how recalcitrant the derailers are, and specifically what is out of adjustment most.


Is it possible to use a MTB with rear Boost hub with a Tacx E Blue Twist T2675 E trainer?

I think it's likelier than not that the one you link to won't work with boost.
Boost/148 isn't listed in what it's compatible with. If it was made with 142 in mind it's not likely to work by coincidence, because of trainer thru-axles that are adaptable to different spacings, they do it by swapping spacers around on an axle that's long enough to accommodate whatever. I'd be suspicious of that one being long enough. And, playing games with barely sufficient thread engagement is the main way for the whole thing to go wrong.
Get a Kinetic Traxle Fine T-2100. I've yet to see one not go into whatever trainer. Remember that no matter what you do, the deal with X12 is you must have the conical interface of the frame mated with an appropriate conical washer of some sort, or you'll ruin your frame. The above Traxle has one.


Can I leave headset spacers above and below the stem

Yes. I do this on most of my bikes so I can do a quick fit for a friend when needed and to broaden the appeal for resale. Just make sure to snug up the compression like normal prior to tightening the stem and you will be good.


3x8 to 1x8 (with expansion to 1x10/1x11 in the future)

It's unclear if you mean versus other standards, or if there are
different kinds of BSC/ISO (BSA is kind of a misnomer, and in
my opinion it's clearer just to call it all ISO, because that's the
standard that current examples are actually made to). Some road
bikes are still made with Italian, but only a couple brands, and
bottom brackets can still be had for all the old national sizes.
Other than that, yes ISO is the only threaded standard left. Each ISO
BB is made for a certain shell width, or widths in the case of the common 68/73/e-type ones that come with 2.5mm spacers you use as needed, but there aren't shell
interface differences within ISO beyond that.
Yes, no problem.
Chain retention tends to be acceptable with just a narrow-wide ring and nothing else helping it, but it's something I'd be looking at when test riding the new setup. Of all the many rear derailers in the world, you could probably come up with some that didn't pull on the chain adequately. It's also good practice to start a new chainring out with at least a new chain and ideally also a new cassette. (This is now less true of the cassette since suddenly it's much more common for people to have extremely expensive ones.) You could skimp on it if they're still pretty fresh, but the idea is that minimizing wear on the ring tends to save more money ultimately. Worn chains can bring a new chainring to their level of wear fairly rapidly.

Chainline is also something one should look at when putting a 1x or
any other drivetrain together, although it's perennially overlooked
and so parts manufacturers do what they can to make it work out okay
passively. Buying a dedicated 1x mountain crank with 49mm chainline
such as the one you link to and putting it on a normal 135 8/9/10
rear (which wants a chainline somewhere around there) puts you in the camp of not
having to worry about it. Other setups create some hoops to jump
through.

Yes, presuming you get the correct version of the BB. (The BSA 68/73 unless it's got an 83 or 100mm shell.) You need an external BB cup tool.


Upgrade my Rear Cassette from 12/25t to 11/28t

Usually, the up to 26t is more so a guideline than a hard limit as is the chain wrap capacity. I'd say try the 11/28t - it will probably work, and if it doesn't work you can always put a new long cage Shimano derailleur (such as a deore one - the cable issues dont matter for road vs mountain rd's from Shimano, or a Sora if you want to stick with the road group). Of course, if you don't shift properly, there is a higher risk of things not working the way they should.

Though, you probably just need to spin faster instead of higher gearing (use Sheldon Brown's gearing calculator to see the differences): http://sheldonbrown.com/gears/


Front and Rear speed shifters aligment guide

It sounds like your derailer(s), or derailleurs if you prefer, are out of adjustment. Derailers work by guiding the chain from side-to-side to shift gears. They have limit screws that are supposed to stop the movement before the chain comes off, but if the limit screws are misadjusted it will be possible to shift beyond the limits of the chainrings in the front and/or the cogs in the back.

From what you've said it sounds like you can get things back on track (so to speak) by shifting both derailers towards the middle of their range, then put the chain back on – any cog and ring that seem close – and pedal (have somebody hold the rear wheel up when you do this). The chain should settle onto the proper gear. You may hear some noise from the chain as it runs against on or both of the derailers (and may bounce around between gears if you get it just wrong). You should be able to make the front and maybe the rear quite down by making small adjustments. In any case, as long as you are towards the middle, the chain should stay on.

If you find the chain coming off as you shift towards the extremes you'll need to adjust the derailers. Start with the limit screws. Parks has a articles on adjusting the front and rear as does Sheldon Brown. One thing to keep in mind is that rear detailers are also sensitive to the alignment of its hanger.


What are good vegan diet resources for bicyclists?

I don't think there's anything particularly unique to your situation to warrant specific diet recommendations. Eat carbs while on the bike, eat what your body feels like when you're off the bike.

You're not self-reporting any actual issues you're having like feeling weak or tired, or having trouble achieving weight goals (e.g., gaining, losing, or maintaining) or fitness goals. So what makes you feel compelled to change something?


Have I bought the wrong rear derailleur?

The derailleur you bought has a capacity of 43 teeth, so if you need only 24 teeth, you're fine on that count. The fact that it is marketed as being for mountain bikes is not relevant in your case--it only comes into play on bikes that have indexed shifting, which yours does not.

Mount it up, set the high/low limit screws so you can't shift past the inside/outside of your freewheel, set the B screw in back so that the jockey pulley rides a few mm below the gears, and you should be ready to ride.

I'll mention as an aside that if your other drivetrain parts are of similar vintage to your late derailleur that something else could fail at any point, and you may need to budget for a new chain and freewheel (at this age, replace both together to ensure they mesh correctly), and possibly chainrings (for the same reason).


use with SHIMANO 105 FD-5504 Front Derailleur on crankset 26/36/48t

Generally speaking yes, presuming everything else about the chain, ring spacing, and shifter play nice. What you'll tend to find is the gap with the ring will be a little wider than ideal at the tail end of the cage,  since FD-5504 is contoured for a 52. Usually this effect won't be enough to keep it from working fine.


Finding store selling SM-PD64 reflectors for the Shimano Saint PD-MX80 flat pedals?

I have no experience with reflectors but I do have experience with ordering "bit parts" from Shimano so may be able to help.

The first step was to go to the Shimano site and find the official distributors for my country (UK). I was quite surprised since I'd never heard of them, but fortunately they had a website etc. (So if you have no joy with the German distributor, you may wish to try the UK distributor).

When I contacted them, these people were happy enough to order the stuff for me, but (a) relatively-speaking they were very expensive, and (b) they took an age to arrive - it was like the distributor had to order them from Japan.

If I tell you that what I had was some SL cleats, and all I wanted was something as simple as some replacement screws (this was when I first started riding, one of mine fell out one day so I figured it would be sensible to get some spares). With hindsight I should have just bought some new cleats, which of course I ended up doing anyway eventually.

Its as few years ago but I can have a look through my old emails and find out exactly who I ordered off, if you can't find this on the Shimano site. Let me know if you'd like me to do this.

Hope this helps some.


Road bike handle bar adjustment to one weaker and shorter arm

For a small difference in reach, it could be a simple as adjusting the position of the hoods on your handlebar such that the left one sits a little higher and further back. It's a change that will often look small, but it adjusts the angle of the lever at the same time, which amplifies the change too.


Campagnolo chainring bolt stuck to crank

I would underscore taking it to a trusted local shop to remove the bunged screw.

But I would also suggest that if you've tightened the other four that your creak is NOT coming from the chain rings but probably from either your pedal, your cleat or your shoe. Also if you haven't lubed the chain for awhile you can try that as well.

A creak from the chainrings will almost always be heard when pedaling on both sides. This will also be the case with the crank bolt as well if it isn't properly torqued.

In one case it was the right LEVER that wasn't tight enough. In another the front derailleur. But shoes and cleats are the most common.


Would a recumbent bike be allowed at an ultra endurance event? & Why is no one using one?

The TCR is a race (strictly speaking a time trial).  In that specific case, Wikipedia states that recumbents and tandems are not allowed (no citation is given).  I suspect that races will either say that or have a separate category (as is the case for the race across America.  I can't find a definitive answer for the Race ACross Europe as the you appear to have to sign up to get the rule book, but I have found implications that they are allowed.

For the more generic events in your title (of which there are many more), the case is likely to be more permissive. The TransOz (certificate error) for example, is run under Audax Australia rules, which state "A  rider  may  ride  any  type  of  cycle  on  a  ride  provided  it  is  only  capable  of  being  propelled solely by human effort and complies with the road rules*." Many such events (1200km and above) are listed by the Randonneurs Mondiaux.

Wikipedia has a note of interest in the article on Ultra-distance cycling (the admittedly vague definition there includes much shorter rides than those in the question, right down to the sort of distances I ride). "There are no longer any true ultra-distance bike races (i.e., that are longer than 300 kilometres (190 mi)) that are affiliated with cycling's main governing body, the UCI" so we can't really blame the UCI directly for the lack of recumbents on such rides.  The oldest ultra-distance cycling event (Paris-Brest-Paris definitely allows them.  This isn't technically a race any more, but first place finisher is a prestigious position.

* From other context on the site, this seems to be referring to local law for road usage, rather than, e.g., the UCI rules for road bike races (which would forbid recumbents).


Saddle getting in the way when cornering on MTB - what to do?

I believe popular advice for MTB carving is to drop the outside pedal, rather than keeping the pedals horizontal.  If you then dump your weight to the outside pedal (off your bars) you can lower your center of gravity some and in the case of pumping that weight dump, increase your traction.  While keeping your pedals horizontal for obstacles increases your clearance, it isn't what you want cornering.


Brake pads from new dual pivot calipers dont reach the rim in the rear wheel

What you really need is brakes with longer reach. Reach is the measurement from mounting hole to rim, you can measure it with a measurement tape and it is listed for most of rim brakes.

If you absolutely want to install these brakes no matter the cost or reliability, there exists a component called drop bolt. These used to be more common in days of classic steel frames and single pivot brakes, but NOS parts are still available. I would recommend disassembling your brake and verifying its mounting bolt is compatible before buying anything.


Why do cable disk brake instructions say not to use the barrel adjusters?

As you dial out the barrel adjuster on the brake lever you pull more cable by effectively lengthening the cable outer (aka cable housing). By pulling more cable you change the starting position of the caliper brake arm, which if extreme enough, could mean:

the caliper brake arm may not have enough travel to get the full braking power; and,
If the caliper has some sort of progressive engagement trajectory, you start the contact point at a later point in the curve. (This was noticeable with early Shimano mechanical disc brake calipers, which would  loose initial brake bite.)

Either or both imply you are operating the brake outside of the intended design parameters, which means that the functioning can be negatively affected.

Adjusting pad engagement by using the adjustment knobs on caliper keeps the caliper brake arm in the same relative position regardless of pad wear thereby maintaining brake function throughout the life of the pad.


What's the performance difference between a front-load and top-load bike stem?

There should be no difference, other than the quality of the materials and workmanship.  One can clamp just as tightly as the other, and both will be apt to produce the same symptoms if the bar is slightly undersized or too flimsy at the mount point.  In both cases, if you do have a slightly-undersized bar you want to keep you can grind down the faces of the clamp a hair (though it would tend to deface the upper unit more).

I suspect the main difference between the above units is weight and "sex appeal" -- the upper unit appears likely to be a few grams lighter, and it's that cool black color.


Is it possible to replace the seat rails on a saddle?

High end saddles like Brooks do offer rail and frame replacements: http://www.brooksengland.com/en_us/spare-parts.html

You might google "yoursaddlecompany rail replacement"

But if your saddle cost less than US$50,
I doubt it is economic to do so. Stocking SKUs and supporting a repair/parts department costs money for the saddle company.

You're better off either just getting a new saddle or seeing if you can't buy a used saddle with a trashed seat cover and doing a transplant. Note that many saddles are riveted on so this may be a big pain.


On a SRAM AXS MTB drivetrain, can you add satellite shifters on an aerobar?

I am not, among other things, a bike mechanic, and I haven't touched SRAM's stuff. From what I am seeing, this should be possible in theory, but it may involve giving up the Eagle shifter in place of SRAM's clics.
For readers unfamiliar with SRAM, Eagle AXS SRAM’s wireless MTB groupset. I believe that SRAM designed AXS (pronounced "access") a bit like a system architecture. Physical limitations like derailleur capacity aside, components compatible with AXS should work seamlessly together, e.g. some gravel bikes have Force AXS cranks and shifters, but an Eagle AXS rear derailleur and a 10-50 Eagle cassette.
You are correct that aero bars on MTBs are not common, although some long-distance off-road riders may use this setup. Just for general interest, Pete Stetina used aero bars on an MTB to set a Fastest Known Time around the White Rim Trail in Utah, in the US. This is a 100 mile (160km) course that's not friendly to gravel bikes. Of course, he appears to have mechanical Shimano shifting, and hence his setup isn't going to help you.
SRAM offers satellite shifters for its road groups. You plug these directly into your shifters. For time trial bikes without the usual integrated shifter/brake levers, you would set up brake levers on the base bars, place satellite shifters on the bar ends and wherever else you want them, then plug all the shifters into a Blip Box. That item is a bit like a Shimano Di2 A junction box (usually mounted under the stem or in a handlebar end), only the Blip Box communicates wirelessly with the derailleurs. In contrast, the current Shimano Di2 version is wired to the battery and the derailleurs.
This Bike Rumour article about Eagle AXS says that you can replace your Eagle shifter with a Blip Box and a bunch of Blips or Clics - there are several different types of satellite shifter with different model names. The Clics (or at least the ones I linked) appear to be designed for mounting on aero bars. I believe the Eagle MTB shifters themselves lack plugs for satellite Blip shifters, probably because this setup is rare in MTBs. So, to reiterate, I think the proposed setup should be theoretically possible, but I think you would need to ditch the Eagle shifter. That, or find out if your derailleurs will work with both an Eagle shifter plus a blip box wired to your aerobars, i.e. will they correctly interpret the shift signals if both components are installed.


Where did a '95-'96 Sycamore mtb fit in the Mongoose product range?

The Sycamore could only be considered a mid-range bike. It had reasonable entry level components but nothing great.

The tange chromoly frame would make a good base for a commuter but I think this was only a part frame so it may be quite heavy as opposed to a full chromoly frame. You would struggle to find a replacement fork if you were changing that due to its 1 inch head set. Not sure on the bottom bracket if it was cartridge this would be an easy change. It doesn't have tabs for disc brakes.U


swapping crankset and chainline compatibility

Yes, that's enough to create situations where you may have chain rub that can't be adjusted out in some additional gears on most road bikes. There are other factors, namely chainstay length - bikes with "pushed" chainstay lengths, i.e. 405mm-ish or less, are notably more finicky about this kind of thing.

How important this is depends on your riding habits.

It sounds like you're looking at a power crank with a chainline that's either oriented more towards a road disc rear end (135mm as opposed to 130) or trying to do both with only one product.


From your description I would guess that your problem not about learning how to do it (you can do it, but only on one side) but more about fear and confidence.

There are two things you will need:

some quiet spot to practice with smooth surface and not many obstacles, maybe a parking ground or so,
a bike that has a preferably upright riding position.

The reason for the latter is, that your hands on the handle bar serve two purposes: the hold the bar to control the front wheel and they support your upper body. The bent over your upper body is on the bike, the more weight has to be taken by your arms to support your body and the more can your upper body influence the steering behavior (as already mentioned in webbgeek's answer). With an upright position the weight of your upper body is lasting on the saddle via your hip and the arms only have to steer.

So if you have different bikes at hand, chose the one with the most upright position you can get – chances are good that this is your grandma's bike or something similar ;-) If you have no other bike but different possibilities to place your hands on the handle bar, start your practice with the hand position that allows for the most upright position instead.

When on your safe spot now, try to ride some straight lines and circles while putting as less weight as possible on the handle bar. Also try not to wrap your fingers around the bar but only put your palms or the joints between hand and fingers on the handles while keeping your hands open, so that you have only the friction between your palms and the handles to control the steering. By trying to put as less weight as possible on the handlebar you also will sit more upright which will make it easier to use your upper body and hips for steering.

You will also realize, that you don't have to hold the handles tight like you tried to squeeze water out of them. Once you feel safe with this situation you can now try to take away the weight from one hand completely without putting this weight on the other hand and also without closing the remaining hand to fasten its grip. Maybe it helps, if you don't take away the weight by just lifting your hand but by rotating your shoulders a bit, so that the shoulder of that side, where you want to take the hand away, goes slightly away from the handle bar. Now you can again first practice going straight and then some (hopefully now intentional) wiggly lines which should give you more safety while riding with one hand.

I also would recommend to do this not only with your weak hand, but practice with both hands and watch if you unintentionally fall into some certain behavior while riding with your strong hand.


Anyone know a way to get a profile of a ride from google?

GPS Visualizer will do the job. From this thread:

  Plan your route as normal in Google Maps.
  Click on "link" above the top right corner of the map.
  Copy the top link.

  Go to:  http://www.gpsvisualizer.com/profile_input

  Paste the GM link that you copied into the field titled:  "Or provide the URL of data on the Web:"


Is 650b a better platform than 26" or 29"?

You might want to take a look a this question  which discusses the advantages of 29" over 26".

650b (or 27.5") falls somewhere in the middle and therefore performance characteristics will be somewhere in the middle of the two. For instance, 650b would be faster than 26" but slower than 29" at same chainring/cog. It would also roll over obstacles easier than a 26" but not as well as a 29".  Also, the weight would be somewhere in the middle.

It depends on what type of riding you are doing to determine which is the "better" platform.  Also, you should consider how easy it is to find parts in your area for a particular wheel.  Since 650b is only starting to gain popularity, it might be difficult for you to find the tires you want, or to find replacement tubes at your local bike store. Also, I'm pretty sure you have to have a completely different frame for all 3 options, as tires aren't really interchangeable at that large of a difference.  You could possibly put smaller tires on the frame than it is designed for, if you had disc brakes, but it might look odd, and might have weird handling.


How to deal with long pre-bled brake line?

Shortening the hoses isn't much more than a 10 minute job on most models. You'll need either a bike shop, or some nice cutters and a new olive and insert which will cost a dollar/pound or two.

Although, as these are moving to a new bike, I'd leave them be and do a more thorough job of looping them until you can measure them on the new bike. What are you using, my first stop would be zip ties and if that slips still, duct/duck tape. When you move them, a little alcohol will lift any sticky mess that's left.

You wont hurt the performance of the brakes unless you kink the hose. Don't do that. They'll want replacing if you do.


long distance touring: is high tensile steel silly?

Any steel, even hi-ten is less silly than alu for the trip you're planning and the age of your bike. The endurance strength of steel is much higher, and the material itself is not as bad as it's said to be. Also steel is easily and cheaply repairable, which is a serious advantage when you're going on a long tour with potentially few bike shops. But the problem with hi-ten frames is that these frames mostly exist in rreally cheap bikes, where the quality of manufacturing and quality control are quite poor. With a frame this old it means it could crack any time.

Comparing your frame to a new one, it would be much safer to buy a new one. Simply because it's new and the material and joints aren't fatigued (and the fatigue would be much quicker with you and racks full of luggage). But comparing a new cr-mo to a new hi-ten frame, there's not too much of a difference in terms of what they offer for touring bikes. Hi-ten steel has lower tensile strength, but higher ductility, so it's more prone to damage at extreme loads, but will bend rather than crack.
Well in the end it's all a matter of compromise and in case of this specific tour, it would be largely opinion-based, thus out of scope of this site.


Start by exploring some of the identifiable items:

Campagnolo triple crankset, Campagnolo Athena brakes, and Campagnolo Centaur front derailleur - all from different groupsets.
Shimano Deore MTB derailleur - from a different manufacturer
Squishy gel saddle
The sheer quantity of spacers under the stem.
Panasonic Panaracer all-round touring/commuter tyres
Completely unbranded rims and frame, but apparently carbon fibre
7 speed block
Suspension seatpost - not ever found on fast bikes.

I can't see anything on the brifters or the wheel hubs, but based on the pictures that is a mongrel bike made of random items.

Now don't take that badly, it is not an insult.   It just means there's no big decal on the frame with a brand.   You would be quite justified getting a decal professionally made that says "Drew'sBro" (or his name) and putting that on.

As for worth, well that's outside the scope of this website.  Just list it on craigslist or ebay with "pickup only" and see how the bidding goes.  It is worth what someone's prepared to pay for it.   Your other option is to simply ride it, perhaps in his memory.


What is air pressure on Marzocchi forks?

Air pressures in Marzocchi Bomber All Mountain forks are between 2.0 & 4.5 bar.  The range is suggested and based on rider weight.  Obviously, desired sag is a factor in your choice of pressure as well.   I've copied the chart from a 2006 Bomber AM maintenance guide.  I can't find the web link at the moment.  The use of commas and periods is confusing to me, but this is exactly how it's written in the book.  The commas are like a decimal point in the U.S.

(User weight ) Air pressure

(kg.) (lb.) bar | psi

(55 - 70)(121 - 154) 2,00 - 2,75 | 2.900,00 - 3.987,50
(70 - 80) (154 - 176) 2,40 - 3,10 | 3.480,00 - 4.495,00
(80 - 95) (176 - 209) 2,90 - 3,80| 4.205,00 - 5.510,00
(95 - 110+) (209 - 242) 3,60 - 4,50| 5.220,00 - 6.525,00

The maintenance guide I have deals with 110, 130 & 150 mm of travel AM forks and there is only one air chart for all three.


Can you ride a bicycle at 90 km/h on a flat road?

In my younger foolish years I actually did this exact scenario, except at a slightly lower speed 85 kph (speed limit was 80 km/hr), but for a distance of nearly 10 km (between two suburbs).  In my case I drafted a double trailer gravel truck which was very slow to accelerate making it easy to keep pace. This was only possible due to the massive low pressure wake at the rear of the vehicle.

I was on a road bike with a max gearing of 53-11.  When we were at speed I remember spinning like crazy to keep up, typically I would have to do it in pulses where I would bridge up a foot or two to secure a better position in the draft, then take a quick rest.  Adrenaline really keeps you motivated in this type of situation.  I even remember a few cars driving up beside and staring in amazement or disbelief - I am not sure which one.

  The road is flat, so it keeps puzzling me: how could he reach and maintain such a high speed?

It really depends how fast the vehicle accelerates. It needs to accelerate slow enough so that you can keep pace and remain in the draft. At the time I had no trouble hitting 50 kph on my own for short periods so I had the acceleration needed to keep pace until the draft really started to kick in.  At higher speeds it is amazing how much the draft really sucks you along, you really don't need to generate crazy power, just have enough leg speed so that you can keep pace in your largest gear.

At 80+ kph you need at minimum 53-11 gearing.  Even then I could barely stay on top of the gear, I had to spin incredibly fast.  I had a bike computer at the time, but I never checked the cadence, just my speed which was 80-85 kph.  At that time (late 1990's) you didn't have many data loggers, which record every moment in detail for posterity like we do today, so I can't offer any more detail than this.

  Is it even possible to do this without any external help, e.g. grabbing the truck? Is it the "air-dragging" effect of the truck is what makes it possible?

As long as you keep close to the back of the truck the draft literally sucks you along. Once in the draft you really don't need a ton of power, just the ability to spin fast so you can keep nudging yourself back up into the sweet spot of the draft. I tried to minimize my risk exposure by drafting to the side of the truck, so I had a shot of getting over to the shoulder quickly if the truck suddenly braked. This meant I lost a bit of the draft, but given the insanity of the situation I felt it was a reasonable compromise.  Others seem a bit more brave drafting in the dead centre (pun intended).

WARNING: All this is of course incredibly foolish and could quickly descend into disaster.  At the time I was young and clueless.


You don't say what brand of hub it is so I'm assuming it's a could-be-anything OEM singlespeed MTB cassette hub.

There is no universal answer. If you want to figure it out yourself and you have no other real information about the hub (which would usually be the case unless it's from an aftermarket hub maker), you have to take it all the way apart and see what there is to see. Some hubs, for example most Shimano cassette hubs, can be tuned for freehub play by permanently removing one of a set of very thin shims inside that are there just for that purpose, but one has to take the unusual step of completely disassembling the freehub body. It's also possible that play is occuring because a freehub cartridge bearing is destroyed, in which case can just replace the bearing.

Depending on the design of the hub, it's possible that this could be a simple adjustment, but that's not usually the case.

If you do find that you need a replacement freehub body, and it is an OEM wheel, they can be tricky to get hold of but it's possible more often than some might have you think. If it's branded by a bike company then the first place to start is a call to that company's warranty department, which in some cases might just have it laying around, especially if you know the exact model and year of the bike. If that doesn't get you anywhere, which is entirely possible, then it becomes a matter of pouring through images of all the Novatec, Formula, KT, King Kong/KK, Chosen, etc hubs of that genre that have ever been made, getting the model, and making contact with a representative of that company that speaks your language. At that point arrangements can often be made to get hold of a replacement freehub body. Since this is a singlespeed it's probably more of a longshot than usual that this plan will work, but it's worth trying.


If you want to improve your efficiency and endurance on your bike there are several strategies that you can use to accomplish that.

The "Spinning is winning" concept is only partly about when and how you change gears for a given situation. It is about making sure you use the mechanical advantage of your bike's drivetrain to ensure that every bit of energy you burn goes into making you move forward, faster.

For most cyclists, 90 RPMs cadence is an efficient balance point between speed and energy loss. And it can be remarkably hard to maintain that cadence in all situations. The "Spinning is winning" concept pushes that even farther. 100 to 110 RPMs is common for those cyclists following that track, and Lance Armstrong was well known for staying in 120 to 130 range.

In order to improve your metrics in this area, you need a way to measure them. If you don't have one, get a good wireless cadence capable cyclometer. Preferably one with training software included. I usually recommend the Garmin products, but they aren't cheap.

Then ride your bike. Try to maintain a cadence of 90 RPMs, regardless of your riding situation, once you're up to speed. That means when downhill, on flats, or uphill, your legs should always be moving at about the same rate.

This can only be accomplished by shifting your gears efficiently. As we move into the base of a hill, there is a natural tendency to set the body to engage with more power, to slow the cadence, and grind it out. Instead of doing this, increase your cadence slightly to build momentum for the hill, and as your cadence drops 10 RPMs below your goal (approximately) shift to a lower torque gear, and it should rise back up to your goal cadence, or slightly higher.

If you always pattern your shifts to keep your cadence consistent, you will find better aerobic fitness, and better efficiency on the bike, come naturally.

And once you can do it easily at 90 RPMs, move up to 100 as a goal, then 110. It will work.


Can double chainrings be used with a clutch-type rear derailleur?

This does not work in the specific case of a Sram CX1 rear derailleur, or the case of any other X-Horizon™ mechanisms.

I purchased the CX1 derailleur and attempted with a 46/39 front chainring combo. The CX1 RD allows the front shift to occur, but has no tolerance for changes in chain length (e.g. front shifting).

The change in chainring size impacts the upper-pulley distance from the cassette cogs. Adjusting the B-limit for one chainring size results in a bad configuration with another chainring size.


The first paragraph is hard to understand. It sounds like you're saying you have an 11-42 cassette and 36/26 chainrings, and you want to know what sort of RD you need. If this is true, then manufacturers will state a chain capacity for their RDs. If not, please rewrite the question more clearly.

Chain capacity is the sum of your largest minus smallest cassette cog and the largest and smallest chainring. You need a capacity of (42-11) + (36-26) = 41 teeth. I suspect this means a long cage RD, but check the specs.

I think that "chain guide" usually means some sort of guide to prevent the chain falling off a single front chainring. You do not need one for a 2x system (and you might not even need one for a 1x system, although mountain bike readers might want to read the addendum to the answer). In any case, this sort of chain guide isn't relevant to sizing your chain. (Pro tip: if you drop your chainring off the inner ring, shift to your outer ring and keep pedaling; this will often derail the chain onto the small ring. The same can work if you drop the chain off the outer ring, provided it hasn't got wrapped around anything).

If your old chain was correctly sized, then you could just break the old one, then put the new one alongside it, and cut the new one to the same length as the old one. Otherwise, Park Tools has a good explanation of how to size a chain.

I don't know what your third question means. Please clarify.

Bonus: I have not paid attention to chain retention devices for 1x drivetrains over the years. However, a recent article on the Cannondale Slate reminded me that chain guides were a mechanism to aid chain retention for 1x systems. A chain guide can be seen in this 2016 review of the Cannondale Slate, which was arguably a precursor to modern gravel bikes, with an earlier version of the SRAM Force 1x drivetrain.

I don't believe these chain guides ever became popular on drop bar bikes. On 1x CX race bikes in the 2000s, my recollection is that riders would sandwich their chain in between chain guards mounted to the crank. That was considered the gold standard. I recall an alternative standard being an outer chainguard and a chain guide mounted on the seat tube, but I don't recall this being that common; you might as well get the second guard.

By the 2010s, I believe that 1x drivetrains had become common on mountain bikes. When drop bar bikes imported them, I believe the technology was already developed enough that chain guides weren't widely used. The 2016 Slate in the link had a narrow-wide chainring and a clutch rear derailleur, both of which are currently considered sufficient for chain retention without a guide. Indeed, the review article already alluded to this, and I saw one other review of the Slate from that era without a chain guide.

I'm not familiar with mountain bikes, but it seems like chain guides may be popular on downhill bikes. Some cross country or enduro mountain bike riders may opt for the extra protection of a chain guide. Two recent cross country world champions, Nino Schurter and Kate Courtney appear to have chain guides mounted.


Why do consumer battery powered LED lights fail mid ride

In my experience cheap lights die, and some more expensive designs are prone to failure. Bike shops sell cheap lights because that's all some people will buy, and better they have a dodgy light than no light (there are enough cyclists without lights already).

All the factors you list come down to one or two factors, depending on whether you consider "built to an excessively low price point" to be a factor. The other is poor design. It's not easy to make a bike light that works, and doing so costs money. If you search for bike lights on kickstarter those projects often document the design and testing (which is one of the few places you can read about it).

I've had lights intermittently turn themselves off while riding, and that's either something hitting the on-off button or the batteries momentarily disconnecting when bumped. Rather than reproduce the latter I prefer to add conductive spacers with the batteries and see whether that solves the problem - add a chunk cut from a tin can or 5-10 thicknesses of aluminium foil at one end of each battery.

I expect to pay ~$40-$60 in Sydney for a decent rear light, maybe $30 online, and if they don't last at least a year I take them back. And I do take them back. Maybe 5% fail within a month. For front lights I pay the same as a rear one for a blinky, ~$100 for a "to see by" light. But I also DIY and use dyno lights (more expensive up front, heavier, but cheaper in the long term).

This is easier if you're running multiple bikes, whether for yourself, your household, or your group of friends. Or you have a decent LBS. Buy 2-3 different lights to test, pick the one you all like the most and buy one (or more ) each, plus a couple of spares. That way you know you're getting something that works, and have a communal spares pool. You can get a similar effect by buying what everyone else has. But buy exactly what they have, a lot of bike lights look very similar and a cheap clone is not the same as the real thing.

I have lights regularly last until the LEDs are so dim the light is worthless. Specifically, I have a box full of "bike lights and bits" in the garage that contains 5-10 rear lights and 3-4 front ones, none of which I would use today as my primary light (I use them on trailers and take them to group rides to lower the suicide rate). The front ones I expecte to fail, white LEDs have a finite, short life that in a "every weekday in the winter" light means 2-3 years. Rear ones mostly just fall to the progression in LED efficiency, in that "the same" light bought next year will be noticeably brighter (front ones too, obviously).


can i use a 700c tire (Gatorskin 700c x23) on a 650 wheel

No you will not be able to use your 700x23c tire on a 650c rim. The bead seat diameter of 700c rims is 622mm, this will also be the bead diameter of the your 700x23c tire.  The bead seat diameter of a 650c rim is 571mm (see Velocity's Spec section). Your 700x23c tire will be 51mm too wide.


How do I change a road bike into a commuter bike?

You can probably change the stem to something shorter with more rise and not have anything else to change. This may be enough to relieve the back pressure and the drop bars will give you more hand positions which I've always found easier on my carpal tunnel.

Changing the handle bars to flat bars will mean you have to get a set of shifters and brake levers to go with the new handle bar style.

I'd also recommend that you get a set of full wrap fenders so you can keep the road spray to a minimum.

I'm a designer and programmer so I understand the issues around sitting all day. A better investment may be in your chair at the office and your desk. You're spending way more time sitting there every day than you are on your bike. That is the place that you can most likely get the most benefit by setting it up for a proper ergonomic workspace.


You'd need to replace the hub (i.e. build the wheel with a new hub -- typically, its better to just get a new wheel), and then respace the frame (i.e. coldset) to take the new hub.

It's easy still to find freewheels, so I'd recommend you just replace the freewheel.


Gears on left are inverse to gears on right?

Don't stress about having a Target bike. If it meets your needs it's all good.

I think the answer to your question is - yes, you are right. If "H" is at the top on the left side and 7 is at the bottom on the right side then they are inverse of each other.

On the left side if you twist toward the "H" (High range) the front derailleur will shift the chain onto the large chain ring. Twist the left side to "L" (Low range) and the shifter will move the chain to the small chain ring.

On the right side if you twist toward the "1" the rear derailleur will move the chain toward the large gear and toward "7" will move the chain to the smaller gear.

Shifting should be done while pedaling.
This guy shows a bike shifting gears in his video
https://binged.it/2U02q6t

People have different strategies for using the gears on their bike.
I like to leave the left side in the low range and shift only the right side. I move to the high range when going down hill.


Tire and rim sizing, tubeless conversion?

Can't speak to the tubeless conversion kit, but pretty much any 559xwhatever tire should fit those rims. A given rim width can accommodate a wide range of tire widths. Seeing as how your desired tires are only 2 mm different, you'll definitely be OK.


There is a nice instruction video from RJ The Bike Guy on youtube on how to convert from downtube shifters to brifters. Perhaps that can be some idea for you.

In case the video is taken down, I'm posting a written answer.
Yes, it is possible to convert from downtube shifters to brifters. Here's what you need:

brifters compatible with the cassette and front chainrings on crank you already have, or
brifters, cassette, front chainrings with crank, probably derailleurs in case your current are not compatible with new cassette and front chainrings
new brake cables with housing, new shifter cable housing (shifter cables are delivered with the brifters usually)
"downtube cable stops" (can be found in the internet) - the cable stops that allow the shifter cable to go pass the current shifter bosses to the steering bar and the brifters.

The procedure is pretty straightforward:

you remove the components you need to remove (at least the bar wrap, current brake handles, cables, downtube shifters),
install the new components,
install the cables,
adjust and finetune everything,
and enjoy your upgraded bike.


Crank Compatibility for my Orbea Hydro 2012

You cannot use a GXP bottom bracket to "fit it all together".

BB30 cranks do not fit in a GXP bottom bracket. A GXP crank can be made to fit a BB30 bottom bracket with an adapter, like one from Praxis.

If your Orbea is a GXP standard (24mm) the cranks are no good to you as they will not fit.  If it's a BB30 they will work without the need for any type of GXP bottom bracket.


The pitch is a pretty good AM bike; I ride the enduro and I love it. It climbs ok, but can destroy really rocky, nasty trails. It also does really well on the FR terrain. While the enduro has evolved from when it was the same frame as the pitch, I think they would still be fairly comparable experiences.

You might also want to check out the heckler (you can set that up to be just about $2k) or there's also the Giant Reign which is a great bike.


How can I tell which size chain my bike uses?

If you are using a bike with a derailleur the number of cogs on the rear hub will determine the chain size you will need.  They are always 3/32" chains.

You can get a 5/6/7-speed, 8-speed, 9-speed, or 10-speed chains.

If you can't find a chain that matches your cluster pick a chain for a larger number, for example if you have an eight-cog cluster you can use a eight, nine or ten-speed chain, but you shouldn't use a 6 or 7-speed chain.

Internally geared hubs will have their own specification for the size chain they require, and single-speed, fixie, BMX bikes, and probably some older bikes use 1/8" chains.


Hex bolts on bicycles are usually metric, and it seems that the bolts holding the cassette together are too. Inch based hex key sizes fall just in between so that none fits.


Replacing grip shift shifters on department store bike with thumb friction shifters?

I've done it, on donated bikes we were rehabbing for Christmas Anonymous.  (Those twist grip shifters seem to fail pretty quickly.)  Don't recall any special problems, other than you have to refigure the cable routing, and you may need a different length cable.


Are Shimano 105 R7000 STI levers compatible with the older R5800 deraillers?

Short and easy answer - yes.

Shimano compatibility charts show ST-R7000 shifters are compatible with FD-5800 front derailleur and RD-5800 rear derailleur. All Shimano road rim caliper brakes are compatible with each other.

http://productinfo.shimano.com/#/com/3.7?cid=C-453&acid=C-455


Are U-lock "wheel extenders" sold separately?

Kryptonite does not sell that separately right now(source: am a Kryptonite distributor), but I'll bring it up to them, see if they are interested in offering it.


Problem with chain skipping when pedaling hard

Since the rings, cogs and chain are new, and decent components we can safely eliminate the possibility that there is a problem with the chain grabbing the rings or cogs.

Here is what I suspect might be happening: it's your derailleur: due to wear, damage or perhaps weakened springs.

Here is how: as you pedal, the chain temporarily catches in the derailleur cage. The next thing that happens is that, since the chain is not moving through the derailleur, the entire derailleur is pulled by the chain and rotated backwards, which basically peels/unwraps the chain from the cassette until it loses grip.

You only notice this when there is significant load on the chain, like going uphill. Under light load, you just need one or two teeth of grip, if the chain and cassette are new.

There is no substitute for having someone watch what is going on. Or attaching a camera to a chain stay or seat stay to record what is going on.

If the derailleur is the culprit, you probably wasted money on the new crankset. Two-year old rings are probably still okay, and in any case, individual rings can be replaced, not the entire crankset.


The bike shop won't fix my newly bought bike

Your new bike doesn't work properly: of course this isn't normal.

At this point, your best option is surely to return the bike to the shop for a full refund and buy a new bike from somewhere else. If there are no other Trek dealerships nearby, buy another brand.

You exact legal rights in this situation will depend on where in the world you are but I would expect that the right to return faulty goods for a full refund should be pretty much universal. One would hope that the shop will just accept your request for a refund. If they don't, you'll need to find out about your rights, and maybe ask on Law Stack Exchange.


52/36 Chainrings for Ultegra 6750 crankset

Yes, there are. Any 110BCD 5 bolt chainring except Campagnolo will fit. If you want to keep the smooth appearance with hidden chainring bolts, at least Specialites TA and Stronglight make compatible chainrings at wide range of sizes.


Are there any cleats (for SPD-SL) that convert the pedal to a regular flat platform for regular shoes?

For a ready made part, see Fly Pedals.

This is essentially just a metal platform, which you bolt cleats onto, then clip them into your pedals. They are threaded with holes for 2-bolt or 3-bolt cleats, so should work with most mountain bike or road bike clipless pedals (including SPD-SL).

Note these are not yet available, but you can pre-order them from the Fly Pedals website. Some more details on Fly Pedals on Kickstarter - that page says delivery from end of July 2014.


Rear wheel replacement: freewheel -> freehub and cog size changes

Yeah you're entering a world of hurt by changing one thing, and the slippery slope of knock-on upgrades start...

6/7/8 speed cassettes all use about the same spacing between gears, so they get wider as you add cogs.
8/9/10 speed cassettes all use the same width of cassette, so the cogs get closer together as you add more cogs but all fit on the same width of freehub.

Bending the dropout more sounds like a bad idea.  It should be parallel to the other dropout, and have the correct OLD spacing for your hub.

I've had to file off the backside of the derailleur hanger on a couple different bikes, but that bolt is anti-rotation and isn't doing much to hold the derailleur on.  So it can be thinned down successfully.  Its not hardened steel so a normal file should do the job fine.

Your other option is to adjust any spacers you have on your wheel to re-center it, and possibly adjust every spoke nipple to move the rim over a bit and keep it centered.

7 speed casssettes are totally available from a decent LBS, or you can order them from wiggle or CRC online.  There's not a huge amount of choice, but 12-28 is not uncommon.


If the 30 is worn to the point its slipping and jumping, I would my guess the others must be due for replacement, along with the chain.

Individual cogs tend to only be available in high quality gear, so a new cluster will probably cost less than a single cog.

Replace the cluster and chain if you can afford it. If not, the cheapest way would be to get a beater from the tip, side of road etc, and take the 30/32 off that. Its rare that the largest cogs are worn out more than the others  (more teeth per rotation, lower torque) so even a really old bike is likely to have a useable large cog.


Does "speed" of a replacement chainring matter?

Will the "speed" of a single chainring make much difference?

Chains typically have approximately the same internal width (with very small differences so not exactly the same). The external width of a chain however varies. So higher speed chainrings for multi-chainring systems typically have the teeth slightly offset so that the chain can't "skate" over the inner ring teeth when first shifting all the way up in the rear and only then shifting to the small ring in the front. It isn't reasonable to shift that way, so in practice you can have a mismatch of about one generation in the "speedness" of chainrings. So 9-speed ring on a 10-speed system or 10-speed ring on a 9-speed system works fine.
Actually sprocket thickness for 10 and 11 speed systems is the same, 1.6 mm. For 9 speed you would use 1.78 mm and for 8 speed and smaller than that you would use 1.85 mm. So the mismatch of 0.18 mm is very minimal and shouldn't prevent operation. In any case, the mismatch is in the correct direction (too loose as opposed to too tight) so it would be very unlikely for it to not work.
Since the difference between 10 speed and 9 speed is one generation only, it's very likely to work. The absolute worst thing that can happen is that if you use some chainring other than the biggest one and smallest rear sprocket, at the same time, the wider 9-speed chain could rub on the bigger chainring. It isn't reasonable to cross-chain in that way.
So use your gears in a reasonable manner and it should work.


Ancheer electric mountain bike cuts out under load

Your battery pack is failing under load and your battery management system is shutting off to prevent your pack from going up in flames.

A voltage drop like this is often a sign of one or more cells in your pack has gone bad - whether due to age, too many charge cycles, improper battery management, or a manufacturing defect. Or the pack could have simply been sized, engineered or manufactured without enough high current capacity for your motor’s maximum current needs.

You could also try to eek more life out of the pack by dropping the assist level when going up hills. Cells often fail when under severe load like this. Cheap ebikes are occasionally cheap because the battery packs are made by recycling old laptop cells, so your pack may have arrived already pre-aged.

If you’ve had it for a year and have ridden it every day, it may just be the natural end of life for the pack. Getting a new pack from the vendor may solve some of your problems. Your bike isn’t that powerful (250w nominal) and the hill you describe is quite steep (10 degrees) so even in the best of circumstances you might have to pedal hard while turning down the assist level.


Why does my back tyre wear so much more quickly than the front?

Kerry Irons put together an impressive breakdown of tire wear data.

His read on it is the fact that the rear tire is the primary driving force and thus the main point of power dissipation is the reason for the increased wear:

  Force per unit area grinds off the rubber, so higher rider power and lower contact area increase the rate of wear.

This makes more sense than the weight ratio, when you consider the weight distribution is perhaps 20% higher on the rear while the ratio of wear is significantly larger.


aluminium fatigue how to know if some thing is going wrong?

I have a 1998 aluminium road bike, and it made creaking noises in the stem when pedaling hard.  Could replicate this by siezing the bars while stopped and wiggling.  So I tightened the quill stem and the noise went away.  Its just a bit of play in the steerer tube/quill stem fixing.

Since you're asking, a frame should outlive you, assuming no crash damage and its garaged/treated well.

Give it a good wash and then look over the frame for any cracks... but try and see if they're paint cracks or frame cracks.

Then run your bare fingers over the surfaces - you should feel only flatness, no ripples or bends.

Your bike is probably welded, not lugged, so have a close look at the welds.  Ideally they should be smooth and flat, but some bike welds look like beginners (cheaper MTBs are chronic for the industrial weld look)

Forks can be measured to make sure they're not bent too, but this is fiddly and normally only done if the bike doesn't track right, or there was a frontal impact.