There are more variables that you are missing.  Rim width is also a factor as well as the tire "setup" itself (tubeless or tubed).  So all the variables you would be looking at are tire width and size, rim width, tire pressure and wheel setup (tubeless or tubed).  For any or the data to be meaningful, you'd need all of that data.  Generally you will get the widest footprint/contact patch by riding a wide tire on a wide rim at low pressures with a tubeless setup.


Are there any reasons why you would avoid going disc (other than cost) for racing cyclo cross?

One good reason to stick with cantilever is easier wheel swaps. Last weekend races, my son flatted and we did not put spare wheels in the pits. Neutral support had spare wheels and if my son had a disc based bike he would not of been able to use them. Even if neutral support had disc wheels, with differences in rotor size they may not work for your bike.

Full Disclosure: my next CX will be disc based, I've been through too many rims with brake surface getting dished from grit and grime.


Where can I find statistics on the growth of US & worldwide bicycle use and business?

There's some US-specific stuff collected by the LAB here: http://www.bikeleague.org/media/facts/ — click through and you'll find spreadsheets, etc.  Looks like they mostly have 2000–2009 data.

It's pretty typical for that kind of data that 2009 will be the latest year available. With the type of agencies and data involved, it can easily take a year or two to compile into a useful report.

I was looking at a recent report for data in my local area (long pdf, start at page 85) and they reference the National Bike and Pedestrian Documentation Project as the new (2009 and later) standard used for counting bicycle usage.

Looking through their documents, they mention:

Rails-To-Trails Conservancy
Institute of Transportation Engineers.
National Household Travel Survey.

The NHTS seems most promising, but they don't have a ready-made report for what you want and their data samples are roughly every decade, not annual.

Also promising: US Census Commuting Data, but it looks like you'll have to dig down into the more raw data to get what you want, since the easy to find report only has the latest census and puts bicycling in an "other" bin.


Originally I had a wind trainer which was very loud and the resistance felt weird. You could pedal really quickly and it would get really easier. I've had a Kurt Kinetic Road Machine for a couple of years and have road it about 40 times, putting about 1000km on it. It is quite, still looks brand new and doesn't get easier the longer I pedal which is a problem with some lower end trainers. This is because the fluid doesn't warm up and become less viscous. I would strongly recommend it. Also the resistance feels similar to riding on the road. Another benefit of a Kurt Kinetic is that you can translate your speed into watts. I bought a power meter and have compared the numbers and they are about 5% difference, so pretty close. Hope this helps


By looking on the shape of the tooth on the biggest cog, it looks worn out and a time for a replacement. Grinding feeling on a clean chain is always a sign of wear.

Also worn-out cassette will will wear out chains much quicker. And you already feel that - second chain got only 50% of usage from the first chain.

I would just replace the cassette, before the new chain is also stretched out.

p.s. you are far too precise with your mileage!


Can I swap my 49cm fixie frame with a 47cm, with every other part fitting right on the new frame?

Just had a quick look at their site, there doesn't appear to be anything too special about these that'd cause problems.

However, it doesn't look like they sell frames on their own.

If you're changing to a frame from another brand then you'll have to make sure the following things are the same.

Bottom Bracket

There are a variety of styles for these, your's is most likely BSA threaded and 73mm wide. You need to make sure a replacement frame matches this to just swap the parts over. You can replace the cartridge in the middle, as this looks like a fairly standard square taper crankset, but finding the right one can take some thought.
Seat Tube Diameter

Seat tubes come in all kinds of sizes. Your's could be anything. To fix a mismatch here all you need is a new seat tube though, and these are pretty cheap.
Rear OLD, or spacing.

The space between the fork ends on the rear could be either 120 (almost certainty on a fixie) or 135mm. This should match, but you can bend a non matching frame or space out your hub to make it match later. This can affect your chainline.
Headset

Often frames come as a set with forks & headset, often not. If the new frame doesn't include a fork & headset the head tube of the frame will either need to match, or you'll need a new headset.

This bike looks like it has threadless headset, most are these days, be sure to get a matching frame or you'll need to replace forks & stem too.
Steerer

The steerer of your current fork may not be long enough if it's cut to size and the new frame has a longer head tube.

Other than that, most things should be ok. There's no guarantees though.

However, the easiest way to sort this out would be to sell this one to someone taller and buy yourself another in the correct size.

Buying bikes whole is always much better value and you're not going to have to buy a hundred new specialist tools to get the job done.


When building frames high quality tubing, such as Reynolds 531 is often only used on the main tubes (i.e., main triangle) and if you are lucky the rear triangle.  Less critical tubes, such as the cross-brace, will typically use a lower quality steel, such as a mild steel, which is more susceptible to rusting and will show earlier signs of deterioration. Therefore, there is still a chance that while the cross-brace has severely deteriorated,  the main structural frame may have remained relatively intact.

There is of course no way to know for certain until you strip off all the components and paint and really have a close inspection of the main structural tubes.  Once the paint is off you can can see how deep the surface rust goes. You can also try tapping the tubes lightly with a small hammer to see if you hear tone changes (i.e., severe thinning due to interior rusting). Careful inspect the chain and seat stays as some frame builders use cheaper steel here, which may not have faired as well. Finally, the cross-brace was often used for fender mounting and was usually drilled, paint damage at this point is also common which could have further accelerated the rusting.

Even if you do all this and the main frame seems reasonable intact, I would still be cautious in use as there is no way to determine with absolute certainty the safety of the frame without pressure testing it (i.e., ridding it). This is a delicate proposition as you want to ride it as lightly as possible until you see how it reacts and slowly build more confidence as you use it in differing situations. One of the things working in your favor is the failure mode of steel is a lot better than other frame materials such as aluminum and especially carbon, which you should generally avoid riding if you have concerns over structural damage.


Is it possible/sensible to add a suspension fork to an old mountain bike?

I would consider looking at a used later model bike.The improvements made in the last 18 years are worth the money.A decent fork can run hundreds of dollars not including installation. Check with your local bike shop for used bikes or craigs list if you keep it local so you can see before you buy.Bikepedia is a good reference to make sure you have an idea what the bike cost new. Also check the minimum inflation recommended for your tires and run them softer than you have been,this will cushion some of the bumps.An alternative might be to install the biggest 26 inch tires you can fit in your frame and lower the tire pressure to get more shock absorbtion.Be careful of really lowend bikes from the big box stores Walmart etc. a really cheap shock with no dampening or adjustment is worse than no shock.


Generally, you attach a bike computer or a power meter to a bicycle to collect statistics, and/or some sensors to yourself.

A bike computer measures the revolutions per minute of a wheel, typically by attaching a magnet to a spoke of the wheel and using a detector attached to the frame which tells the computer every time the magnet passes the detector (so the number of times the magnet passes the detector per minute is the revolutions per minute; the circumference of the wheel gives distance). This gives you information like speed. These are cheap -- maybe 10-20 dollars on the low end, and various exercise apps can estimate calories burned based on the speed data (sometimes automatically from things like ride logs, and possibly with additional parameters you can estimate). A GPS can also take position and time measurements and do calorie estimates, albeit probably less accurately than a bike computer.

A power meter is often built into a special crankset (or occasionally bottom bracket or hub or pedals). It uses strain gauges to measure your power output based on your pedaling. This gives you watts that are delivered through your drivetrain. These are often quite expensive -- on the order of 1000 USD, typically. Using data from this, you can approximate the power you're using (under some appropriate models), which would give you the rate of calories burned.

You can also attach things like heart rate monitors and O2 sensors and other sensors to the person's body. From these, again,  with appropriate models, you can estimate the calories burned. These are in the middle in price -- my bike computer came with a heart rate monitor strap, and bike computers that have this feature are available in the 100 dollar range (probably less; mine came with my trainer). Generally, this calculation will come up in terms of VO2 max (which you can estimate based on how quickly you can run), age, gender, weight and the heart rate. This can be supplemented with other sensors as well.

I'd venture in terms of accuracy, combining a heart rate monitor (and maybe other sensors) and power meter would be most accurate. However, in terms of cost, just using a decent heart rate monitor (i.e. with a chest strap; not something like a FitBit) is probably the best for budget. The cheapest option would likely be using the bike computer and entering the speed data into some app, but this is likely the least accurate option.


This appears to be the one in the diagram you linked:
http://www.amazon.com/D-Toplight-Rear-Light-Design-backlight/dp/B000NW65U4/

That one requires external power from a dynamo hub, though I have seen references online to a battery-powered version of the same light.  The same company, Busch & Müller, makes a few others with the same mounting system.  In general you can find these things by searching for "European" style taillights, as they are popular in that region (but not in the US).  Here's one that works on batteries: http://www.amazon.com/4D-Toplight-Permanent-Tail-Light/dp/B0051WTS0A/ (the Senso model is similar but adds an auto on/off capability based on ambient light level).

Here's another that fits the same mounting holes but with a very different design (for use with a dynamo hub only): http://supernova-lights.com/en/products/e3_tail_light2.html

Finally, some taillights have available mounting plates for 50mm rack mounts, such as this: http://ecom1.planetbike.com/3108.html or this: http://www.amazon.com/Cat-Eye-Tailight-Rack-Mount/dp/B002P793U4


Why 9 speed front derailleur cannot handle 10 speed rear derailleur?

The front derailleur doesn't care what the rear derailleur is and vice versa. The front derailleur is matched with the front chainring sizes, number of chainrings, mounting type of the front derailleur (a property of the frame) and the front shifter.

The rear derailleur is matched to the shifter (for indexing; the shifter is matched to the cassette), and the capacity required (which is dependent on the amount of chain slack it needs to absorb).

The point of saying that is so that you can get someone to buy a new front derailleur unnecessarily.


No, you can't broadly say "Bridged suspensions are stronger".  It's depends on many things, including the design of the system, materials used, build quality, etc.

As Batman mentioned, Cannondale's Lefty suspension is stronger than most traditional systems and isn't bridged, or even bridgeable.

Inverted, or "upside-down" systems, like the one in your photo, have other considerations as well, outlined in this question.  To your question, the thru axel keeps the stanchions bound together, preventing different rates of compression.

I think we will see fewer front forks with suspension bridges in the future and more inverted systems, as the technology trickles out to less expensive builds and the cost of manufacture drops.


Yes, straight pull spokes are technically superior to traditional J-bend spokes.  The only reason that J-bend spokes are relatively more popular is because it's cheaper to machine a hub with simple flanges on a lathe.  Well-designed straightpull hubs typically cost more.

Note that a straight-pull spoke in generally can and should be tensioned higher than the equivalent J-bend spoke.  As always, build quality is key, and the average bike shop won't necessarily have the experience to do it well.  Nevertheless, in comparison to a J-bend, a straight pull spoke properly assembled onto a properly designed hub will:

Not fatigue as fast -- especially if a J-bend is not kept adequately tensioned. in other words, a straightpull spoke will not relax as quickly.
Eliminate spoke rubbing typical in most traditionally laced wheels.
be stiffer radially AND laterally than most traditional lacing for the same spoke gauge (though it is hard to do a direct comparison because hub and rim geometry varies widely)
Be lighter for the equivalent capability -- or, more importantly, will have less inertia due to the ability to use fewer spokes and/or narrower gauge butted spokes with no loss in stiffness & strength
Will last longer -- the J-bend spoke beds in, then frets and ovalizes the spoke hole, losing tension as the wheel wears in, as well as wearing out the hub.  In a straightpull spoke, there is much less motion & wear at the hub and nipple.

Bottom line: straight pull spokes, properly designed and built, will be lighter, stiffer, and require less truing than a conventional wheelset with the same number of spokes.

What are the advantages of J-bend spokes?  Price and parts availability.


It is not unusual to have a very small range of position which allows for your most efficient pedaling position.

It is a little unusual for it to be quite that drastic a change. Are you accounting for the change in saddle extension by adjusting your seat height as you move the saddle for and aft?

If not, I expect that it is more the extension length than your fore aft positioning which is affecting you.

By the way, 7-9cm behind the BB center is fairly far back when measuring from saddle tip. Most people are in a 2-5cm range, unless they are unusually tall or have unusually long femurs for their height. You may want a professional to take a look at your fit.

I hope that is helpful.


This Orbea Logo was used from around 1995-2004 however in the early 2000s the started changing the rear seat stays and chain stay to be black. the biggest way to know the exact year would be to see the tube shapes. starting in 200 they started going to more of a triangular tube and going away from round and oval. It looks like you have a a 2000-2003 frame. that being said, I highly doubt it is an original team frame, they did make many replicas. That said it doesn't make the frame not as good as an original. These bikes came with DuraAce components, I can't tell what you have on there.


Newer versions of Tiagra brifters route the shift cable under the bar tape. Do be careful though because Shimano has changed their cable pull on some versions. The 4700 series Tiagra uses a cable pull ratio that is different from any other Shimano models. If you get 4700 brifters you would need to replace your derailleurs to be compatible.


How can I keep my chain from derailing from the front sprocket under load?

I don't like to be the bearer of bad news, but I've been down this road once or twice.  As a hobby, I sometimes pull bike frames out of dumpsters and rebuild them to sell for my cost on Craigslist.  I have learned over the years that bicycles, when new, really cost at least $300-400.  "Bicycle-Shaped Objects" (BSO's) are sold at stores like Wal-Dart and Cost-Mo for much, much less.  These BSO's are, though, just that.  They are a loss for everyone except the manufacturer and the store.  And I doubt the stores are making much on them.

If I find a box-store BSO and seek to rebuild it, I will usually remove and discard that whole front assembly--chainrings, cranks, bottom bracket.  They're usually toast anyway.  WHen I get to this point, I am about to put into the bike probably near what it was worth new at Cost-Mo.  The bottom bracket (bearings between the cranks) will probably run $30 (UN54 baby!).  The cranks I can often get decent ones used for $20-30.  Chainrings another $5-20 a piece, depending on what I am trying to build.

None of these things is really expensive, but it adds up.

WHY AM I TELLING YOU all of this?

Why don't I just say, "get some used quality parts for $5-20?"  Well.  If you're putting that much torque on this thing to bend the chain rings, I wouldn't be surprised if the bottom bracket were screwed up, too.

Sometimes you can get decent used parts at a pretty low price, but I think it is unlikely that your crank-arms will accept replacement chainrings (sprokets).  Usually on box-store bikes, these are riveted-on.  They are disposable. That means replacing the cranks, too.  So.  You're going the whole monte.

So figure, cheapest-possible solution, we're looking at about $100.  What did the bike originally cost?  Maybe $150?  If that's worth it to you, go do it.  It's not all that hard to do yourself.

In my experience, though, when you find one thing wrong... then you find another... and another... pretty soon you have $250 invested in a bike that's worth about $150.

If the bike is "Your Bike" and you have sentimental attachment to it, I understand (I own that bike and continue pouring parts into it).  Otherwise, I'd say look for a quality used bike.  A mid-90's Specialized Rockhopper will run you about $150 and will come with good quality parts that can be more easily worked on.


You don't need a new wheel, and the repair is cheap if you have the correct tools.

Here's a guide if you want to try it yourself, or I reckon it would cost 0.5 - 1hr labour at a bike shop (plus the price of a single spoke).

edit - just read that it's the front wheel, which makes things easier still. No need to remove any cassettes!


Best advice for buying a replacement spoke

It's worth asking at your LBS. If you've got more than one LBS, try asking them all.  :)

I don't know if most bike shops have it, but I know at least one of my LBSs has a piece of equipment that cuts a spoke and puts a thread on it at the same time. They routinely cut (and thread) spokes to length. From talking with one of their employees, I guess it was a better deal for them than trying to stock a ton of different length spokes.

Rims might be a few fairly standard sizes, but there's a lot of variety in hub flange diameter. Spoke lacing pattern also affects the needed lengths. In other words, even your unusual size might be something they already stock. Or if they've got something that's just a millimeter or two too long, it's probably possible to cut it without putting thread on it and still have a useful spoke.


Yes you can ride home with a broken spoke. I'd probably unscrew the spoke from the nipple before doing so, so that it doesn't wobble around and get caught in other bits of the bike. Bike wheels are wonderful things that can easily put up with having a few spokes missing.


How to fix new chain that switches gears when pedaling backwards

I consider it standard practice to replace the rear cogs at the same time as buying a new chain. If you don't the rear cog's teeth start to look like shark fins after a while and your chain will "climb". Esp. when pedaling backwards.

Edit: worn cogs, even if they don't cause immediate problems, will stretch your chain causing it to wear out quickly.


Broken shifter cable in Shimano Ultegra 6600 10-speed shifter

This is fixable, but may be any level of difficulty.   It depends on how the strands of cable have moved and whether the cable head is caught.

Given its your rear shifter, its on the Right side of the bars, and there's a port for the cable outer to seat in on the left side.   When you shift down (to an easier gear/bigger rear cog), the whole brake lever rotates, and holding the lever there will show the access hole on the right/outboard side.

Moving only the upshift lever (the smaller one behind the brake lever) won't show the hole.

Your next task is to hold the lever across, and try to make the cable head fall out the right hand side access hole, by hook or by crook.   The head may not fit through the hole sideways, it may have to come through flat-face first.

Some ideas to help manipulate it...

More Light!  You need to see, so use at least two bright lights.  I have a pair of 200W desk lamps over my bench, which helps avoid shadows.
A thin and stiff wire in the left side port to push the head from underneath
A tiny magnet - depends if the head is steel, or if the cable has enough steel to react to a magnet.
A tiny sharp pick to help manipulate whatever you can see through the holes.
Slack off the clamping bolt to rotate the lever hood, get gravity on your side
Undo the stem to let the bars rotate, again for gravity
Untape the bars, get the whole shifter body off the bars for easier access.

You might try flushing the mech with light degreaser, in case theres a blop of grease holding it down.  However this might have the opposite effect

If that doesn't work, you're probably up for disassembly.   Since Shimano shifters are not intended to be serviceable, this can ruin the shifter if done wrong.  There's no shame taking the part to a good LBS bike shop for repair.

Have a read of https://bicycles.stackexchange.com/a/35662/19705  where I did a similar recovery on my 7 speed RSX shifter.

There was a useful video at

Gear cables should be replaced whenever shifting starts feeling "a bit weird" or every 10,000 km of road riding, or 5000 km of off-road.  It would have been impossible to see this cable fraying in place during inspection though.   You should probably replace the left-side cable too, and check the brake cables as well.

Sadly 6600 and 6700 and 5700 shifters were known for munching through cables quite quickly.  If it were my bike, I'd replace the shift cables annually whether they need it or not.   Cables are cheap.


Protecting bike attachments such as lights against theft

Take the lights and anything else thats likely to be stolen off your bike.

For things that can't be removed easily, you may want to use something like Pitlock security skewers (or security bolts) or glue in ball bearings or similar into the head of the bolts (which will make them hard to remove when you need to remove them, but a casual thief can't remove them easily). Also, make sure you know how to properly lock up your bike (which has been discussed at length in other places on this SE).


Yes, it is possible. Just be prepared to replace every single drivetrain component. If you go 11-speed you will also need a new rear wheel because 11-speed cassette needs a wider freehub body and possibly new brakes because cable pull changed slightly with 11-speed.

The standard advice here is to not do it because the cost will be close to new bike, but Look frames are quite high end and new bike with similar quality frame would be far more expensive than any random Ultegra bike.


Bicycle's inner-tube got puncture right next to the valve, How to patch it there?

That's a very hard area to patch properly (if its even possible), and I'd recommend putting a new tube in instead of trying to patch it. .

I'd also check that the rim tape on the rim is intact and in good condition, cause otherwise if its busted, you're going to get another cut. Also, as pointed out by ChrisH in the comments, rough edges on the rim hole can also cause this problem (you can use a small file to smooth them out, if that is the case).


Can I reuse an old rim to build a new wheel?

Yes, absolutely, and it can make plenty of sense sometimes. Hubs failing early is one case. It has also become more frequent, although maybe not common, for people to want to swap carbon rims around, especially on disc brake wheels, because they have so much invested in the rim, and they can go a long time. I've rebuilt a handful of carbon rims in recent years for people playing with different hubs who wanted to keep their big dollar rims.

When you unlace the old rim, you want to do so in a fairly gentle, gradual way, especially at first when the spoke tension is still high. It's not good for rims of any material to be bent around unnecessarily, which is what happens if all the tension gets released at once on a spoke while the others are still tensioned. In other words, cutting the hub out like one does to re-lace a hub is not what you want to do here. What I do is go around doing detensioning layers of a half turn per spoke until I have quite low tension, then go to full turns. As soon as the spokes are sloppy loose, there's no tension and you can cut them or use a nipple driver in reverse from there.

Once you have your bare rim, it's a good idea if possible to check what kind of shape it's in without being acted upon by spoke tension. I always do this by taking a good quality new machined sidewall rim of the same size, laying it on the bench or ground, and laying the rim to be reused on top of that. You're essentially making a surface table out of the new rim, and it works well. Any lateral kinks or distortions will reveal themselves easily. Major radial dips or rises can be felt for this way too, but it's more subtle. If there are any radial distortions, the old rim probably isn't worth messing with. If you find lateral waviness inside of 2mm total gap or so it's probably fine; it will create some amount of tension imbalance, but only on the order of a couple quarter turn adjustments.

As far as fatigue, if you're gentle with taking the old wheel apart, there's not much difference between reusing the rim and continuing to ride the old wheel.


Sprinter

A sprinter is a type of rider who is known for explosive power and acceleration.  They often have a large build, usually with massive quads and strong upper bodies.

Since they are relatively heavier than other riders their speed advantage is often limited to flatter sections and they can and are often dropped in hilly terrain.

Sprinters are know for drafting in the slipstream of teammates (usually the domestiques) who are sheltering them, before launching into a sprint in the final meters of a race.

Some sprinters are stronger in hillier terrain and cobblestones, and are sometimes categorized to be Puncheurs.  They often excel in the classics races.

Mark Cavendish

considered one of the best contemporary sprinters, he has 43 stage wins in Grand Tours, 25 of which were bunch sprints in the TdF going head to head with the best sprinters in the world.


Avid juicy three piston popped out when bleeding without block

You should just need to re-bleed them. Happened to me a few weeks back late at night before an Enduro the next morning. Bled them and they were good as new.


That size looks like an EC34 (external cups, 34mm inner head tube diameter for forks with 1.125 inch steerer tubes).

You'll either have loose balls, balls with a retaining cage (metal or plastic), or cartridge bearings.

If you have caged bearings, loose bearings will work fine but be more fiddly to install. Take one to your LBS or hardware store.

If you have cartridge bearings, the size will be moulded into one of the rubber seals or be laser-etched on the side of the casing. Your LBS may stock one or two common sizes if you're lucky. Otherwise either buy a complete headset which uses the same size, or buy a complete headset and get it fitted or press it in yourself. Complete headsets can be cheaper than replacement bearings but the cost of paying a mechanic to install it will exceed the part cost.

TH Industries make the bearings used in many headsets. Their brand FSA offers a variety of affordable good quality headsets.


Pinch flats are due to under-inflation of tires.  On a road bike you should be inflating your tires to 120-130 lbs.

Also, you need to check and re-inflate your tires every time you ride.  I just keep my pump right next to my bike, and wind up adding air every 2nd or 3rd day.

I see you added tire size - those are older bike tires, they don't inflate as high as road bike tires, I'd try pumping them to 65 lbs, and if you are still getting pinch flats, go up 5 lbs at a time until it stops.

You can tell a pinch flat because it will look like a snake bit, 2 small holes close together.

If you do not get any pinch flats at 65 lbs, you can try going down 5 lbs at a time until they return, then you know the range your tires need to be at to be properly inflated.

The most important thing is to check tire pressure every time you ride, as bike tires can lose up to 5/lbs a week from just sitting.  These are high pressure tires, so they lose air much faster than low pressure car tires.

Cheers,
Mike


I figured out a way to do it which was actually fairly easy. This only worked because it was in my garage, trying to steal someone's bike like this would be crazy...

I took a hammer, and pounded on the bar. The first thing that happened was the plastic broke away. I kept pounding on it, until the lock just fell apart. It took about a minute...

Note to self, don't buy a cheap lock next time...


Replacing broken road fork with same model but shorter steerer tube. What can I expect for handling issues?

Steering will not really be directly affected at all, because you are not changing the steerer tube angle, fork length or rake, or the stem length.

What will be affected is your riding position. Dropping your bar 30mm is a big adjustment. (BTW, standard steerer tube spacers are 5mm, so you may want to check that you can actually drop your stem 30mm.)

You really need to ask yourself if you can tolerate such a big drop in your handlebar position, or even if it would be desirable.

You could possibly replace the stem with one with a greater rise angle to bring the handlebar back up.


Manufacturers recommend a strap to stabilize a (class 1) hitch-mounted bike rack so it doesn't bounce or sway.  For example see Stabilizing Strap for Hitch-Mounted Accessories, and especially the review video lower on the page.

(This is not a product recommendation, just the first thing that popped up in a search.)


Can I put a 9mm axle hub with a Shimano roller brake into a 3/8" fork?

Any free space between axle diameter and clearance width of dropout sides can exacerbate problems with maintaining the correct tension between the dropouts when the wheel is installed. The last thing you'd want is to hit a bump, pothole, etc... have the front wheel fall out of those dropouts and put you into a faceplant or worse. Bikes are subjected to immense levels of vibration on every ride and those vibrations will work to loosen any weak fasteners. BTDT

There are aftermarket spacers designed for MTB applications that will adapt a 9mm skewer to a 10mm hub/dropout (typical of rear dropout clearance) and that 10mm converted to inches is .394" (3/8"=.375")

You might also find some aluminum or steel spacers at a local hardware/home improvement store. Measure out your skewer diameter and dropout width to be sure of what you're looking for.


Product compatability (bottom bracket and frame)

Bottom bracket standards are numerous and confusing. Have a look at https://wheelsmfg.com/bb-standards. That's the best online resource I have found so far that explains them.
PF30 bottom brackets are designed for a 30mm crank axle. Shimano cranks have a 24mm axle. What you need is a bottom bracket that adapts between the PF30 specification frame and the Shimano crank. An example is https://wheelsmfg.com/pressfit-30-to-outboard-bottom-bracket-for-24mm-cranks-shimano-black.html. Other manufacturers make similar products.


Partly reinstall crank opposite nut.
Remove nut.
Update with new photos as necessary.


According to this Tokyo Metro Police Department (警視庁 Keishichō) web page on bicycle rules, the pet peeve of the authorities in Japan with regard to right turning cyclists is the practice of just going like cars through the turn.

Three cases are specified, which all share the common theme that the cyclist, second class creature that it is, must turn right by crossing the intersection twice, like a lowly pedestrian, and not like a vehicle.

The diagrams are self-explanatory.

At an intersection with no signals, look both ways, and proceed straight through. As you approach the other side, then turn right and cross again.
At an intersection with signals, but no pedestrian/cyclist signals, proceed through the intersection (and swerve a bit toward the pedestrian crossing, according to the diagram). The accompanying text says you should walk your bicycle if the crossing is busy with pedestrians. Then wait, on the road, for the signal to change for the second crossing and then proceed, similarly to a vehicle (away from pedestrians).
At an intersection with pedestrian/cyclist signals, cyclists are expected to similarly cross twice, obeying those special signals, sticking to the bicycle section of the crossing.  The main difference is that waiting for the second crossing is done off-road, and then the crossing is carried like the first, with the pedestrians.

It's not clear whether the page incorporates any 2015 changes in rules, but it was modified in April 2015.

The very last diagram makes it clear that bicycles are not to behave like motor vehicles. They should stick to the left. Even if there is a left-turning lane and they wish to go straight through the intersection, they must do so from that left-turning lane, and not from the adjacent lane which goes straight. Likewise, they must not occupy the right lane (from which it would be possible to turn right like a motor vehicle).


Why the adjustable spring tension on the cage of Shimano rear derailleurs?

It's a way of mitigating chain slap and chain retention issues, primarily for more aggressive riding styles. The tradeoff is drivetrain efficiency and shifting smoothness. It's a feature that's basically been supplanted by rear derailer clutches.


Building up a 1988 Schwinn Circuit frame with new parts

It's certainly possible to build late 80s frames up with modern components. The two biggest issues you may run into are the rear dropout spacing and wheel size.

Older bikes with fewer rear gears had narrower rear dropout spacing than modern ones designed for 10 and 11 speed drive trains. A frame designed for a 7 speed drivetrain very likely has a 126mm rear. These can easily be widened to 130mm. Detailed instructions can easily be found RJ the Bike Guy has a good instruction video on his YouTube Channel.

Older road bikes were designed around '27 inch' wheels with 630mm diameter rims. Modern bikes are designed around '700c' wheels with 622 diameter rims. I'm not sure what wheel size 80s bikes used. Tf your frame is designed for 27" wheels, new wheels and tires are available, but if you want to switch to 700c for a vastly wider array of choices you have to fit long reach brake calipers as obviously the brake mounting holes are 4mm further from the axle axis.


Is gasoline an effective restoration material to use?

Gasoline aka petrol, is a volatile fluid that will dissolve grease and oils.  It will penetrate, soften, and loosen impacted and congealed dirt and dust.

Petrol / Gasoline will NOT fix your rust, nor remove your rust. It will not restore chrome.

Petrol is not terrible for rubber parts, but I wouldn't leave them soaking in the fluid.

The best use for petrol is to clean your parts, before doing a close inspection to decide whether they are serviceable still, or need replacement.

Downside for petrol is that right now its NZ $1.97/litre in my country (approx US $5.36/US Liquid Gallon) and that adds up.  You can't reuse the dirty petrol for anything, and the grease won't settle out so it can't even be decanted.

Petrol is also hard on your skin, so wear gloves, and clean up immediately afterward.  Moisturising your hands before starting is surprisingly good protection too.

Rust

Rust is oxidised iron, which comes from steel being exposed.  Often appears on friction points like chainring teeth, and anywhere that the paint has been damaged letting fresh oxygen to the steel.

There are options:

Leave it alone.  This uglifies your bike and makes it less desirable to thieves, as long as its still mechanically and structurally sound.
Paint over it - this is a very short-term fix and will not last more than a month before the new paint is bubbling off.
Remove the rust then paint it - this is elbow work with a file and sandpaper, or some motorised tool doing the same thing.  You MUST paint the surface within a few hours, else the virgin steel starts to rust again.
Treat the rust - There are many rust treatments which transform red rust into a more stable black oxide of iron.  Most contain Phosphoric Acid and require PPE.  The fumes are something else!  Once the rust has blackened and dried, you can sand and overpaint.

Petrol would be used as a degreaser on the rust before sanding.  Turpentine would be similar, but that's even more expensive than petrol.

Have a look at Suggestions for removal of old chrome?  where I am doing something similar to some handlebars.  That question will be updated as progress continues.


Will 10 speed cranks work with an 8 speed freewheel?

According to Sheldon Brown's website:

  New Chainrings, Old Chains
  Going the other direction, using wider chains with chainrings intended for narrower chains is not generally a major problem if there's only a one- or two- generation difference. The only problem you might run into is that the chain will be more liable to rub on the inside of the bigger chainrings in the small/small crossover gears, gears you shouldn't be using in any case.

You may run into some poor shifting performance, but the system should still function.  If you are unhappy with the performance, 8 speed chainrings will mount on your current crankset, so there's no need to change-up everything.


While I'm not a road biker, I can speak from experience with mountain bike tires. The first spot to wear is the center of the tread. Why? It's the part that is ridden on the most. Increasing the width of your tire with increase the contact patch (the part of the tire touching the ground); therefore, your wear is going to be the same because that contact patch is still hitting the ground the same amount. That said, the amount of pressure put on that contact patch can change due to width, as the mass of the bike and rider is spread across the larger area.

Tire pressures can affect your contact patch as well, lower pressures allow more of the tire to hit the road or trail. This means your going to expose more of the tire to wear, increase grip (in the case of mountain tires, don't know about road so much), and increase rolling resistance.

Other wear patterns will depend on the type of terrain and riding style. If you ride on very smooth asphalt, you probably aren't going to wear through a tire that fast, but if you ride on loose, rocky, beat-up roads, that's going to eat at the rubber much more quickly. Similarly, if you do more straight-line riding you're most likely going to see the center wear quicker than the sides, but if you turn more (or skid a lot when braking into turns) you can wear down the sides quite a bit too. There are other environmental factors to consider as well (heat, humidity, etc.) that can affect tire wear, but those are much harder to quantify.

I would look more into finding specific types of tire, maybe ones that address the hard/softness of the rubber instead of looking for wider tires. Also try experimenting with tire pressures outside of what you're doing now. If you want some hard numbers, I would recommend looking at specific tire manufacturers who may have testing data available and estimated mileage charts for certain riding conditions.


Can't shift down from 50T with clutch on, but can shift down with clutch off, why?

The RD-8000 is specified for a maximum tooth size of 46 (1x11-46).  Likely you are just exceeding its design criteria and reaping the rewards of DIY mix and match.

The clutch does not add tension. It add friction in one direction to resist a forward moving cage, but allows the spring to pull the cage back freely.  As the chain drops off a cog onto a smaller one, it has to briefly lift and this causes the cage to move forward against the clutch. The clutch is designed to slow this action - possibly in you setup just enough to keep the chain on the large cog and prevent it dropping on to the smaller cog. A longer chain will make little difference, as the clutch is friction based, so spring tension changes probably won't change the behavior.

Chainline is probably all you have left to play with. (You don't mention the bike, presume its 1x now, was it always 1x). Moving the chain ring out a millimeter or two might make a difference - or it might not.


Attaching frame pack — velcro straps or fastex sliders?

I would be more tempted to use metal slot-rings to let you double the velcro back on itself because the rings reduce the force on the velcro at a small cost in weight and complexity. Friction fasteners tend to slip when used on tubes. That is probably why they're not used for the load-bearing straps.

Those fasteners rely on friction caused in part by the pressure of the fixed end lifting the non-release side out so the other end presses down on the looped-back portion. When you wrap one round a tube they often slip because that pressure is missing.

In the diagram the orange is the strap which comes in, goes under the release tab, under the blue "wrap bar" that's actually part of the one-piece fastener, then comes back over that bar and under the tab. Pressure down where the red arrow is results in friction where the red oval is. That's what holds the strap. But if there's no matching support/pressure underneath, there's not much friction and the strap slips.


Can you identify this cheap single speed bike?

Those wheels are worn.  That would need to be a $700 bike new to be worth $250 in that condition.

Pictures don't show detail on the items like brakes, bb, crank, wheel, hub, and chainring that would give a clue. If you are not finding mid range name brand components that bike is not worth $250.

A lowest end bike is under $100.  This is picture of $300 bike new.  Assume that is a low end bike until you have evidence it is not.


Why can't a child bike seat be mounted on a carbon frame?

Carbon tubes tend to be very strong at withstanding forces in the direction they are designed for, but weak at resisting other forces (such as clamping forces compressing the tube), hence why bolts for carbon bars, seat posts etc are usually only torqued to 4-5Nm.


The minimum tool set is something that gets discussed on the framebuilders list and other forums from time to time. I think the consensus is:

a heat source, usually oxy-acetelene or arc welder but you can start with MAPP (oxy-propane) which is cheaper.
a cheap hacksaw and 32tpi blade (technically you could use a file instead but don't)
a half-round file
a drill (even a hand drill) and 3-4 drill bits
a pen or scribing tool (even a nail will do)

Ideally you'd have more than that but you could build a bike with only those tools. But that is "making a point" territory. More realistically you would add:

a vise, preferably bolted to a workbench
a decent hacksaw and several blades
several half round files and a flat file
a set of locking pliers (vice grips or similar) to hold hot metal with
a hand punch (spring punch)
a small paint brush for applying flux, and a wire brush for removing it (if you're brazing)
a grinder with cutting and grinding disks and a wire brush (easier than hand tools for rough work)
an internet search engine, for answering random questions at odd hours :)

If you want to start building bikes I strongly suggest joining the framebuilders list or some of the online forums. There's a heap of things you can do to make your life easier, and having someone you can visit to see how they do stuff will teach you things you don't even think to ask. The Atomic Zombie crew or other garage homebuilders would be perfect if there's a group like that near you. Recumbent homebuilders are often equally useful and will probably help you even if you want to build a wedgie.

The advantage is that you built it yourself, and if you want something unusual you can build it. The disadvantage is that it's an expensive, time-consuming way to get an inferior bike. The first one you build will not be professional quality, you'll be lucky if it works at all. So if you want a traditional diamond frame bike the only reason to build it is because you can (like Suzy did). If you want a weird bike then you might find you have to either pay a professional framebuilder or do it yourself. Unless you already have a metalworking shop, it's cheaper to pay someone, even if they've never done anything like your bike before (so you get a first attempt that kinda works).

The reward is that you get something you built yourself. It's especially fulfilling when someone you approached initially who refused to build it sees your version and turns it into a commercial product (Greenspeed make a tandem that converts to a solo trike now, because I showed them it could be done).

(moved from Items required to manufacture a DIY bike?)


According to Cannondales website they offer limited lifetime warranties on their frames. They also have a passage that states"The specific warranty covering your Cannondale bicycle is governed by the law of the state or country in which it was purchased, and applies only to bicycles purchased from Authorized Cannondale Retailers". That said my first stop would be the dealer that you bought it from. I would stop riding it until they check it out. You don't want a warranty denial due to the fact you rode it damaged. If you get an unsatisfactory response I would seek a second opinion from a shop that specializes in carbon frame repair. I believe most shops don't see enough frames to form a valid opinion. Or they fear litigation (rightfully so) and make a judgment for safety sake.  You may save a few coins if you disassemble the bottom bracket so they can get a look inside the shell.
  I had a Cervelo R3 with a similar looking flaw. After having it checked by a shop (Hot Tubes) that does custom builds and frame repairs. They determined it was stress cracks in the paint. That was several years ago and it has not gotten worse.


Finding my physiologically relevant maximum heart rate

The 220 - age (or any age based formula) is a myth that works well enough for roughly 60% of the population and puts the other 40% wrong. That it persists to this day with such ready access to HR monitors and reasonably accurate sub-maximal tests to determine max HR astounds me.  (I blew over 210 when I was in my early 30's and now over 50 can sustain 170 for a hour and can probably reach 190.)

Training zones based on  max heart rate percentages are based on average people and  well enough for most of the population, but they are guesstimates. You do not gain more accuracy from knowing max HR to a few beat per minute.

Presuming your HR monitor is accurate, your maximum is clearly at least 202.  For defining your training zones, use 200 - its a nice round number.


What's the difference between power meter and bike computer?

A 'bike computer' is a generic term for everything from a simple wheel sensor giving distance and speed, to an all singing all dancing computer that measure cadence, speed, altitude,  heart rate, power and anything else you can think of

A power meter measures the power you are outputting, and is one input into a bike computer.   Power meters are expensive - a basic bike computer is less than $10, last I checked the cheapest power meter was worth more than my bike. They are also useless without a 'bike computer', but come with one - the computer with all the other sensors a typical bike computer has is the cheap bit.

Power meters, like HR monitor in the 1990's are a great tool, but that is it, they are only a tool. Think of TV sales channeled selling fitness gear -'but wait, there's more.... You too can have a 6 pack and a gorgeous girl with just one ride a week with your power meter.  *In conjunction with a nutrition program *Result will vary, Not all users will achieve the same outcomes shown in the advert.'

If you don't know how to use them, have no interest in sports science and physiology  and no desire to learn this stuff, they are expensive paper weights that slow you down.  If you are prepared to learn and interpret the results they provide, they can be a great benefit.


Does going faster always result in more calories burnt

All other things being equal, yes. The increase in effort more than makes up for the decrease in ride time.
Consider two scenarios where one rides 20 km: first at 25 km/h, second at 30 km/h. In the first case, riding at 25 km/h takes 96 W of power, in the second, riding at 30 km/h takes 150 W according to this web page (using my own stats).
 96 W * 20 km / 25 km/h = 276 kJ over 48 minutes
150 W * 20 km / 30 km/h = 360 kJ over 40 minutes

Thanks to a lucky mathematical coincidence, kilojoules of work is almost exactly equal to calories burned. Some estimating tools treat calories burned as 10% above kJ of work.


Did i buy the wrong derailleur? (mech hanger/direct to frame)

It appears from your photo that you indeed have the wrong style derailleur. Your frame appears to have vertical dropouts and a frame derailleur mount. The derailleur you purchased is designed for a frame with horizontal axle slots. Since the derailleur hanger mounts under the axle nut your frame doesn't have a slot big enough for it to fit.


Descending without braking: where's the sweet spot?

You are going at constant speed when the driving force from gravity Fg is equal to the drag (air resistance) Fd plus friction (rolling resistance) Ff:

Fg = Fd + Ff

When coasting down a hill, the driving force is the component of the gravitational force parallel to the road:

Fg = m g sin(a)

Here, a is the slope (angle with the horizontal), m is the mass of bike and rider, and g is the gravitational constant. Slopes on roads are often measured in percent, and for small angles sin(a) is equal to the slope in percent. e.g. for a slope of 10% (100m descent on 1km of road) sin(a) = 0.1.

Drag is proportional to the square of the velocity v, the projected frontal area A and a drag coefficient cd, and the density of air rho:

Fd = 1/2 rho v^2 cd A

The drag coefficient cd depends on the shape of the object - streamlined bodies have a low cd, but for a bicycle with rider I find approximately cd = 1 in Wikipedia. I'd estimate the frontal area of a cyclist to about 0.4m^2.

Friction (rolling resistance) is proportional to a coefficient cr and the normal force (the weight component perpendicular to the road) Fn = m g cos(a):

Ff = cr m g cos(a)

The coefficient of rolling resistance cr will depend on the bike (lubrication, tire pressure, surface roughness etc.). For car tires on concrete, Wikipedia gives cr=0.01, so the Ff would be about 10N. That's about a tenth of the driving force on a 10% slope (see above), but on a rough road surface it might well be much more.

So we end up with

m g sin(a) = Fg = Fd + Ff = 1/2 rho v^2 cd A + cr m g cos(a)

Solving this for v gives:

v^2 = 2 m g (sin(a) - cr cos(a) ) / (rho cd A)

Putting in g=10m/s^2, rho=1.2kg/m^3, cd=1, A=0.4m^2, and m=100kg (nice round number for rider and bike), I get

v = sqrt( sin(a)-cr cos(a) ) * 64 m/s

The rolling resistance cr essentially is like reducing the slope somewhat, so a slope of 10%=0.1 with cr=0.01 is the same as a slope of 9% on a perfectly rolling bike. So, for a slope of 10%, the sqrt becomes 0.3, and I get a speed of 19m/s = 70km/h

It's not unrealistic, but perhaps a bit faster than I would have expected. However, there are simplified assumptions, friction and rolling resistance is probably higher and cd and A have a big effect, they all depend on the bike and the rider.

From the drag equation you can see why the racing position is with the head down. This position decreases the frontal area A considerable, compared to an upright position, and it makes the body somewhat more streamlined (reduces cd). As the drag goes with the square of the velocity, this gets more important at higher speed.


Is there Rack (luggage carrier) for Ragley Blue Pig?

On a Blue Pig MK1 you could probably use the threaded fender mounts to attach any normal rear rack to it, since the rear disc caliper is mounted out of the way on the chainstay. The upper rack stays can be attached to the seatstays with p-clamps.

The Blue Pig Mk2 doesn't have any such mounting points, so it's more complicated. You could possibly rig something up with p-clamps or hose clamps around both ends, but the possible weight you could haul will be greatly diminished.  You'd probably want to look at a rack that mounts to the axle, such as the ones made by Old Man Mountain.  Alternatively, you could get your local framebuilder to braze on some threaded barrels to fit the rack of your choice - it shouldn't be too expensive, but you'll either need to repaint it afterward or deal with some ugliness.

Depending on how much work you want to do in swapping the frame to "adventure" mode versus aggressive mountain biking mode you might look at a rigid fork, such as one from the Salsa Fargo or the Surly Ogre, and hauling front-end loads.  Riding long distances loaded and with a 140mm travel suspension fork is in itself not going to be particularly enjoyable.


A typical road frame could have these issues for cyclocross (CX):

tire clearance -- cyclocross tires are a bit bigger than typical road tires (especially with the small knobs typical on CX tires)
brake style -- you'll want some kind of brakes that aren't clogged up by mud. Road bikes often have caliper brakes that hug the wheel fairly closely, while cyclocross bikes usually have cantilever (or sometimes V-brakes).  Disc brakes are recently allowed in CX and seem popular on the higher-end bikes.
frame style -- a lot of newer road frames have a compact geometry where the top tube slopes down to the seat cluster.  Cyclocross bikes generally have a straight top tube so that it's easier to pick up the bike and carry it with your shoulder under the front of the seat cluster.
handlebar height -- not as important, but cyclocross bikes generally have slightly higher handlebars since aerodynamics aren't very important in cyclocross
gearing -- typically run a little lower.  singlespeed is popular (but probably puts you in a different class than geared racers)

There's some even more minor things, like some CX bikes have a slightly higher bottom bracket than road bikes to make it easier to get over rough terrain and cables are probably routed away from the muddy side of the bike.

I wouldn't go with the smaller frame, as that'll likely be less comfortable, effectively lower handlebars, and probably less room for your shoulder if you need to carry the bike.

If you don't already have a bike you'd be better off getting a cyclocross bike with two sets of tires (one knobby and one smooth) and a second set of gears and converting it to a road bike part-time, instead of getting a road bike and using it for CX.

(I haven't raced cyclocross, but have watched a few races, including one a couple days ago and am starting to consider trying it out)


I can't track down the source of chain skip - what might it be?

Does the large chainring show much wear? I don't think it is the culprit but it needs replacing when it is worn. If the old chain was very worn like that it could have caused wear here too. You could think about chain suck but IME this is quite violent and it jams up the drive by pulling back on the chain; if you look for it you can tell when its chain suck. Check it out, but to rule it out.

As you say the problem is bad moving off from a stop, I would strongly suspect the pawls of the freewheel mechanism in your hub as this is when torque is high on the cassette. I've had the same problem before, it's pretty terrifying when the pedals slip and you lose your balance in traffic. I had mine replaced and instant fix.

You did explore this with club mate's wheel, but I would be pursuing it again with another different wheel and you should at least get into the hub and clean, inspect, grease. Check the wear on the rim and see if it isn't time for a new wheel anyway, otherwise check out the cost of replacing the freehub. You've done the chain and cassette, good, but now you need to take it further.

I think (from reading your post) you can judge the indexing and RD behaviour competently enough and this problem isn't super common despite all noisy, badly adjusted, worn out drive trains there are in the world.


What tool can I use to tighten SRAM GXP bottom bracket without removing the cranks?

The short answer? No.

Threaded GXP uses the Hollowtech II style dimples for tightening, these aren't deep enough for a C-Spanner style or for a wrench the has less than 180 degrees of contact.

Even if a tool existed, most chainrings are going to get in the way, my 1X is GXP and there's not a lot of room, a double or triple is going to make this worse.

And finally, GXP works by clamping the non-driveside bearing between a flange on the spindle and the back of the crank arm. There's no preload adjustment, so tighten it down and leave it alone.

PS. What style is your eccentric BB?


What wheels can I buy that fit this Shimano UG 5 speed freewheel?

A bicycle of that era will likely need 27" wheels and 126mm rear spacing.

To confirm this, you could put a quick release or other straight small object through the dropouts (as if it were an axle) and measure the distance to the brake pads. A 27" is going to be around 630mm/2 = 315mm in radius to where the tire sits, so the brake pads should be able to extend a little bit closer to the dropouts than this (this is not exactly a way to determine what size wheels the frame was designed for, but just determine that they will work). Depending on exactly when it is from in that era and the quality of the bike, its possible that it would use 700c wheels (which have a very similar 622mm diameter) but very unlikely.

The spacing is the distance inside the dropouts:

from http://farm3.static.flickr.com/2061/1819835696_836e18f8ea_o.jpg

The rear should measure 126mm I would expect, and the front should almost certainly be 100mm (any wheelset that meets the specifications for the rear should also fit the front)


For what kind of bike and under what riding conditions would a Biologic FreeDrive Chain Cover be suitable?

I'd say "when there's no rain, mud or grit on your route". That thing looks as though it's designed to collect any loose material that falls into the open lower section and make sure it stays on your chain forever.

Recumbents commonly use sections of poly pipe (cheap black flexible plastic pipe) to cover their very long exposed sections of chain, and that works fairly well. You could do the same on the shorter chain of an upright and get most of the benefit of the solution above without the penalty. Easier with a singlespeed or hub geared bike, but possible with derailleurs (the attachments need to be flexible).


What is it called when you ride around on your front wheel?

Rolling along balancing on the front wheel is called a "nose manual".
If it's braking to a stop while balancing on the wheel it's a "stoppie".
If it's braking to a stop suddenly with the rear wheel lifting and no front wheel rolling it's called an "endo".


Thoughts about tri bar / trekking bar on hybrid bicycle

Aero bars (this is the actual name of what you call "tri bar") is surely a comfortable and affordable solution. In the Netherlands you see people with aero bars on hybrid bikes quite often - it is very common way to use the bike for a long commute and ease of manoeuvrability in the city traffic.

The only disadvantage of a simple version of aero bars is that you don't have the shifters and brakes there. For the shifters it's just inconvenience, for the brake handles it is also safety issue.

Bear in mind that aero bars have some pads designed for the elbows (or actually forearms) support and nothing (even thick wrapped bar) will beat it.

Don't forget that the distance between the saddle and the bars should not be too long - when your body leans forward you shouldn't be stretching too much to reach for the handlebars. Otherwise you risk lower back pain on longer (in my experience >40km) journeys.

Concerning the bullhorn bars - in my opinion there won't be any added value for you except for the looks of the bike. And whether the brake handles and shifters are compatible depends only on the diameter of the bar you are replacing.


How much range can I get with two separate cassettes without changing chain length?

It will "work" although shifting will likely be compromised, which could include slow or even ineffective shifts on the upper half of the cassette when running the 11-23 cassette.

Rear derailleurs are designed to move in an arc that follows the cassette profile. As such different derailleurs are designed to work with different ranges of cog sizes. If you go to Shimano's technical documents the Claris RD-R2000-GS  derailleur ("long" cage) has a specified min and max low gear range of 28 to 34, while the "short cage" version  (RD-R2000-SS) has specified min/max low gear 25 to 32.  Neither were designed to work explicitly with a 11-23 cassette, although 25 is very close to 23 so in this case the "short cage" version would probably work just fine.

The problem in your case is that once the long cage derailleur is set up to work with an 11-34 cassette, swapping in a 11-23 cassette will effectively move the derailleur away from the cogs in the upper half of the cassette resulting in poor and potentially missed shifts. As you move from a cassette with larger range (i.e., 11-34) to a cassette a smaller range(i.e., 11-23) the distance from the cog to the top derailleur jockey wheel will have increase greatly for the upper half of the cassette. If you have set up a modern derailleur according to the supplied documentation this distance is often quoted as being critical to precise shifting as the top jockey wheel drives the derailing of the chain.  Once the distance becomes excessive the derailleur loses the ability to quickly and precisely change gears until its kinematics brings it in closer to the cogs in the bottom half of the cassette.  If you were running friction shift, this wouldn't be an issue as you could simply move the derailleur further to initiate a shift, but if you are running indexed shifting, you will likely find that shifting will have deteriorated for the upper half of the cassette.


Life expectancy of a cycle tube and tire?

The tube will last the life of the tire, and more, if not punctured too much.

The tire will last until it wears too thin and starts puncturing a lot, unless damaged.

Tires do, however, become brittle and crack in the sidewalls from UV and ozone exposure, and will need to be replaced every 10 years or so if not worn out first. White wall and gum wall tires crack faster.  Tubes also will crack with age, around the valve stem.

Running too low of a pressure can also destroy a tire.

1500km is nothing, if the tires are kept properly inflated.


Answer Its a late 80s bike, maybe an early 90s. The frame is a mixte, so probably sold as a woman's bike.  Almost certainly a steel frame.

The brake hoods have sissy bars, which were common in the 80s for those who didn't ride on the hoods and preferred to ride on the tops.

Shifter levers are up on the quill stem, so its more recent than downtube shifters.

The metal dork disk on the back wheel dates it to late 80s as well.  Plastic was more common later.

Can't see a lot of the transmission, but it looks like a 2x5 or a 2x6, which means a freewheel not a freehub.

The mudguards / fenders are not original, and maybe the saddle is a replacement as well.

If you test-ride it, particularly check out the tyres before riding.  Gumwalls like that could easily be 20 years old now, and haven't been commonly sold, so they're a minimum of a decade old.

DANGERS  It might be the photo but the left hand handlebar looks odd.  Almost looks like its a sharper curve than the right hand side, which makes me wonder about crash damage.  Inspect it closely.

Valuation We don't do valuations here.  You need to compare it to other similar bikes in your vicinity and see if its in-line with other local offerings.  Something's value is determined by what one person will pay for it, which is related to scarcity.   Don't just buy it because you like the colour.


All jackets have to do two jobs:

Stop the water (rain) getting in.
Let the water (sweat) get out.

While being easy to transport when not in use.

£70 is unlikely to buy you a jacket that works well doing both if you pay full price.  I would look out for a Paclite in a sale, as they are light and take up very little space on wqhen not in use.

However remember that the jacket is as much about keeping you warm when you stop for a break as it is about keeping you dry while you cycle.  So maybe just have a wind proof top for when you are riding and a cheap none-breathable jacket for when you are resting.


Why do my bicycle brakes get worse and feel more 'squishy" over time?

On most cable disc brake systems there's a moving pad and a fixed pad.  The moving pad presses against the rotor and bends it slightly towards the fixed pad.  The rotor is made of rather springy steel, and is probably where the feeling you experience comes from.

The barrel adjuster only addresses wear to the moving pad, but the fixed pad also wears in use. The rotor has to bend more to contact the worn fixed pad. This means that tightening up the fixed pad is necessary (about every other time I tighten the barrel adjuster on mine, but it depends on the pads and mechanism).  It can be a bit of a pain as it's not very easy to get at.


The 2009 edition will have 'V' brakes, although they may be called 'cantilevers' or something else that describes roughly the same thing. This is base specification for an MTB, to be assumed unless stated otherwise.

Disk brakes are better in the wet because the braking surface stays nice and dry, however, you can still stop in the wet with V brakes. We have already had this question:

Why are disc brakes rare on road bikes?


Greasing a roller brake in a difficult spot!

According to this answer in reply to a question about what grease to use with Shimano roller bakes, it's important to use the proper Shimano roller brake grease and to apply it into the hole properly. The Shimano grease comes in a tube with a nozzle that facilitates proper grease application.

  Very important to follow the instructions that come with the grease - main point is to insert the grease tube nozzle at least 12mm into the hole otherwise the grease will not reach the actual braking surface.

Simply pushing grease into the hole will not be effective. Some sort of extension made from rubber or flexible plastic tube would work as long as it can be inserted into the hub far enough.

I don't think you are correct in the assertion that roller brakes need to be greased often. According to the Shimano instructions grease only needs to be added when the brakes are not working well or are making noise.


What is the life expectancy of aluminum alloy frames?

Material fatigue does happens, it is not caused by time, but due to excessive stress on usage, and/or manufacturing process and/or design fault. If all done under optimal condition, no over stress(e.g. a 120kg person ride it without suspension and under inflate tyre), a aluminium bicycle may last forever.

A bang, a fall, can generate impact that stress the frame weak point. If you are not using it for long time, then the stress is little to none, discounting the stress from introduced from bolts/screw/welding joints/mounting temperature contraction/expansion.

If you search around stackexchange on the same topics, there is advice that you don't put your bike under the snow : i.e. a concern about welding material contraction different than the frame. But this shouldn't be an issue as long as you didn't move the bike from very cold place to very warm place (i.e., temperature different ~ 20 degree Celsius).

Consumer association with loaded funds, such as the German Stifftung Warentest, does indeed test consumer bicycle from time to time, especially for Ebike, due to ebikes are more susceptible to weight stress (the additional motor and battery weight).  As some report I read, in 2013, series of ebikes are not satisfied due to the stress test. However, in 2016, many passed the stress test, except for one bike that had a cracked aluminium seat post.

So it is all about how the manufacture learn to build the bike better.

In addition, it is a myth that titanium will fair better when put on stress : it is all about manufacturing process and design.

About the "metal deteriorate issues"
- A proper maintain steel frame will not rust. Lube and oil them, you will never see the oxidisation
- Aluminium "rust" will stop when oxidation form on the outer layer.

In addition,  steel frame WILL NOT rust, if you maintain it properly.

Update from @Barny :
** Having been the owner of a marin larkspur hybrid 6061 alu frame that has been replaced no less than three times under warranty, each time due to fatigue failure ( i am 5'8'' @ 77kg ) and each frame lasted between 12k - 18k miles, i am of the opinion the lifespan of a 6061 alu frame is around 15k road miles. First failure driveside chainstay split apart halfway along, second failure driveside seatstay split halfway along, third failure crack around downtube / bottom bracket. **


Pain on pinky toe joint from cleat setup?

Assuming that your shoes are wide enough and your front strap is not too tight, try moving your cleat sideways towards the crank arm.

This will move your foot out a little towards the outside of the pedal and reduce outward pressure. It worked for me when I had a similar problem.

Also make sure that cleats are not too far forward. They should usually be positioned so that the pedal axle is under or slightly behind the ball of your foot.


Can 26 x 1.5 inner tube fit 26 x 2.0 tire?

Yes it can but the slightly overstretching of the tube can increase your risks of puncturing.

Tubes marked with the same size as the tire are always slightly smaller than it and stretches upon inflation, so I always suggest going for an inner tube with its width size one step or level higher than the tire so that it won't have to stretch as far to conform to the tire's size, possibly making it more resistant to flats.


To answer this question, you need some measurements.
The rim ERD, from the Ryde website.
The centre-to flange (left and right) measurements of the hub and the spoke hole circle diameter. These you may need to measure yourself as they are not always published.
This information is then entered into software (or a website) that performs the spoke length calculation for you. You could do this manually if you prefer but I often use the EDD spoke calculator or the one at kstoerz.com
Would you like any help making the measurements?


Rear wheel odd shape (goes up and down) fixit or buy new?

Your description sounds like the wheel is out of true, out of round, or some of the spokes are so loose that they're flexing as the wheel rotates. However, for it to be as severe as you describe I would expect it to be visible on spinning the wheel and watching it, even to a novice mechanic.

Whatever the case, you should take your bike to a qualified mechanic. The problem may be fixable, possibly as simple as tightening and loosening the appropriate spokes. This is a relatively difficult job for a novice mechanic though. It is also perfectly possible that you need a new wheel. An experienced mechanic would have to visibly inspect the wheel to be sure.

If it's a simple fix, it could be as low as $15 US. If you need a new wheel, I would expect it to be around $75-125 for a bike that age depending on what quality you would like to get.

I would also recommend checking with a couple mechanics. Some are quick to sell new parts when an older part is serviceable.


I found it! After careful inspection of the tire I found a small piece of glass stuck into it:

It's sharp side was facing the tube.

Here is the place where it was stuck:

On the internal side of the tire you can see a little hole:

It was hard to feel this little thing by hand. But when I pumped the tire and rode, creating high pressure, this sharp edge has eventually punctured the tube.


It says Harrods (which doesn't have much to do with bicycles).
The text is a bit worn, but you can compare it to the logo at https://en.wikipedia.org/wiki/Harrods.


I've worked on a number of Marin bikes and they are impressive IMO.  Simple, straightforward design.

Here's the bottom line.  In this price range, regardless of what you get, you are looking at a Chinese-made frame built to "spec" (what the company wants).   Then, various major-manufacturer components are bolted on and the bike is shipped.

They are all really rather similar; variations in frame geometry are minimal, variations in component spec are also minimal.  It's common to throw on an "upgraded" rear derailleur as this catches the consumer's eye... Costs the manufacturer only a few bucks more.

Not that these are not perfectly fine bikes... The main thing you are looking for is fit, which you already recognize as important, and the best components you can get for your money.
Most hybrids are made with a frame that leans more to the "road" type, with a straighter top tube.  Most mountain bikes have a more compact design with a sloping top tube so that the rider can maneuver on the bike while off-road.
The old "standover height" or "inseam" height measurements date to when road bikes were built with the standard diamond frame with a flat top tube.
Modern bike design is a little more flexible.


What types of BB-axle to crankarms interfaces are there?

When comparing BB types, a significant factor to consider is the longevity of the bearings, and serviceability. Outboard bearings have the most longevity but are essentially unserviceable. When they go, or when the splines are too damaged by bad installation/removal or inferior tools, then toss them and buy replacements. Outboard BBs are used with Hollowtech (Shimano) and Ultra Torque (Campagnolo). Then there are press-fit BBs, in which the cups (or a sleeve into which the cups are fit) are pressed directly into the BB shell, which is now made without any threads. These need specific tools to install and remove, but are preferred for high-end bikes.

The BBs with the least longevity and least serviceability are ISIS (ten-splined). These are also a pain to remove the cranks from, since you need a special attachment on your crank puller (similarly with octalink, incidentally). The reason these have such little lingevity is that the diameter of the spindle means that the bearings contain much narrower balls. I'm not sure what gauge, but if you've ever taken apart bearings on a bike, there are three main sizes: BB, wheels and headset, in order of size from largest to smallest. The BB should have the largest because there is significantly more torque applied to the BB that anywhere else on the bike. The headset for example endures comparatively little. Isis BBs have to fit the bearings and the thicker spindle in the same shell size, and so they use smaller bearings that can't endure as much torque.

As for the most serviceable: older bikes, before they invented cartridge BBs (of which all the above except outboard bearing style are examples), had loose bearings (or at most inside one-sided cages) sitting between the cups (the sides that screw into the BB shell) and the cones (raised smooth edges on the spindle itself). These cup-and-cone BBs are analogous to the internal design of the wheel axle and bearing setup. These require frequent (every 1000km or so) disassembly, cleaning and reassembly as they get fairly full of crud. On a recent clean of an older fixie I run, I found that I had split several of the bearings into chunks, explaining the crunchy feeling of my rotation. As loose bearings are readily available, these older style BBs can be continued to be serviced right up until the cups and cones themselves get too degraded on their inner surfaces to function properly (pits in the grooves for example, where the ball bearings will naturally sit in, and which come about through over-tightening) will mean that ball bearings will wear out quicker.

Square taper BBs, as the commenters note, come in several incrementally different types. The main difference between ISO and JIS is the length of the tapered section of the spindle. ISO is shorter. The angle of the taper is the same (I believe), so you can fit an ISO crank on a JIS taper (and I have done this) but the cranks sit a couple of mm further outboard than ISO > ISO or JIS > JIS. Conversely, you could fit a JIS crank onto an ISO BB, but depending on the spindle width, it may rub against the BB shell as it would sit a few mm inboard.

As far as ease of installation, longevity, ease of crank installation and interchangeability, I would definitely suggest that outboard bearings, either hollowtech or ultra-torque, are the best balance of cost and benefit.


Recommendations on how to buy clipless bike shoes

You need shoes, cleats and pedals all to be compatible.
(There's also an implication that you have two feet, and nothing unusual there.)
Shoes have to fit your feet comfortably, with a close fit around the rear and across the instep.  Personally I find a slight roominess around the toes to be ideal.   You can get shoes with laces, velcro, ratchets, elastic and weird string systems, none of which makes a big difference.
The shoe has to fit the cleat, and there are two main interfaces being 2 bolt and 3 bolt.  Some shoes have 5 holes to fit both styles, but they're relatively uncommon.  2 bolt shoes often recess the cleat into the sole a bit, so that walking is mostly normal, whereas 3 bolt cleats are totally below the sole and walking in the shoes is unpleasant, and only for short distances.
The pedal you choose has to match the cleat - most new pedals come with a starter pair of cleats in the box.
3 bolt cleats tend to be made of plastic and are good for 3-12 months of usage, depending on how much you walk and how often you put your foot down.  I found my left foot wore twice as fast, mostly due to my habit of rotating onto the bike.
2 bolt cleats tend to be made of metal, and they last much longer.  However the walkable shoes tend to be softer and less "efficient" at transferring power.  So fast roadies still go for the cloppy 3 bolt road cleat.   2 bolt cleats are reputed to cope better with mud, so are more the domain of the MTB and the cyclocross runner.

You can ride a road clipless pedal while wearing flat shoes, provided the sole is stout.  There's less platform so its a lot more slippery, but it can be done.  You can also slip some old cleats into the pedal to make it better, or purchase some "platform adapters" in case you want to ride the road bike to work/shops but wear normal shoes.
It is totally okay to ride road 3 bolt pedals on a MTB, or 2 bolt pedals on a road bike.  Noone changes their shoes between the different sorts of cleats regularly, instead they'd buy two pairs of shoes and leave them set up.  Given pedals are cheaper than shoes, it is acceptable to have several bikes with the same style of pedal.

I got some clipless shoes ~5 years ago, and I have never fallen due to the shoes.  That you have to fall a couple times is a myth.  While it might happen from a moment of inattention, just learn to unclip while coasting up to a stop and you're generally fine.
I've had minor slips (not a fall) when walking in cleats, and sometimes while stopping because the cleat didn't give great traction on the road surface especially when wet.


Canyon Strive AL 6.0 - SRAM GXP or a Pressfit GXP bottom bracket?

It's a SRAM GXP in a threaded bottom bracket shell.

Here's how I found out:

The Canyon web page says just 'SRAM GXP', so I looked for some reviews thinking they might provide info about the BB. This Mountain Bike Review page has a picture that clearly shows the BB area, and you can see the bearing is an external type, not a press fit type.


Rear derailleur moves to much for each click - tried everything

So you originally had a have a SRAM 1x11 derailleur and matching shifter then swapped the rear derailleur for a Shimano 105.

That is your problem right there. Shimano derailleurs are not compatible with SRAM shifters. The length of cable the shifter pulls for each gear change is different between SRAM and Shimano (and between Shimano road and mountain groupsets at 10 speed and above). That's why the derailleur is moving the incorrect distance for each gear shift.

You need a SRAM derailleur that is compatible with your SRAM shifter. You can replace the guide wheels in all but the cheapest derailleurs, so you could fix your original SRAM derailleur and re-install that.

Or you could of course replace the shifter with one compatible with whichever Shimano derailleur you choose to run.


Mismatched rims, and tires that may be too wide?

The thing that confuses people about all the newfangled inner rim width to tire width compatibility charts is that while the effect they're trying to steer you away from is real, it's not binary. It gets more squirrelly, floppy, and prone to blowing off the narrower you go. The point where there are major issues in practice depends on rider weight, inflation pressure, riding style, the fit of the tires, and other factors.
A 2.1 on a 16mm inner width rim is somewhat extreme by rational standards, but when rims like that were trendy there were a lot of bikes running around with such a combination. It will probably be fine, but it's on you to decide whether you want the risk, and how reasonable it is depends completely on your application.
Transplanting the hub makes sense as wheelbuilding practice if that's what you want and if the rim and hub in question are in good condition. That kind of job makes little sense from a time/money perspective if all you want is a functional bike, but it's also how skills are built. Use new spokes and nipples.
There are many times when using a rim that narrow creates some hoops to jump through when setting up the brakes on a frame that predates the trendiness of super narrow 26" rims. Eighties and early nineties MTB frames often had rims and post spacing that were about as wide as they should have been. Brake and pad models differ in their ability to get the pads in so far. That in practice is a thing you need to try and see.


How to secure and transport panniers when on foot during a bike trip

I use two different strategies for the short and long absences.

  visiting a city by foot

When I'll be away from the bike for a long time I take the valuable stuff (cash, id, small tool kit, phone, charger, camera) and leave everything else. If I'm in a formal camping area or in a secluded location I'll leave the tent pitched and my sleeping bag and clothing inside the tent. In most of Europe you should be able to do this if you're officially camping, but seclusion seems unlikely (in Australia and NZ we have public wilderness areas where there are few people, so camping where no-one goes is possible).

If I'm not camping or otherwise need to leave the gear with my bike I'll look for somewhere that I can lock the whole thing in a room. Either the luggage area of a train or bus station, a backpackers or hotel, or a bike shop. Those will generally cost a small amount of money, but it's cheaper than losing easily-removed stuff or discovering that someone has opened everything up and left what they don't want scattered all over the place (has happened to a customer in India).

  going to buy groceries

For short absences I usually just take my chances. I lock my bike using a small D lock and leave it (I have pitlocks so the wheels are locked to the frame, so that's fairly easy). However, unlike the picture above I tie/strap my panniers onto the bike using bungee cords/ocky straps. That reduces load wobbling while I'm riding and makes things less likely to fall off the bike, but it also means that actually opening the panniers is slower.

I will try to park the bike where I can see it, and if it looks as though there's space in a supermarket or mall I will wheel the bike inside and lock a wheel to immobilise it in the actual shop. I've occasionally been stopped from doing that and I just politely accept and park it outside, but more often staff just look at my bike and accept me.

Edit: I also have a vaguely-related technique that I use mostly for city-fringe camping and once in the wilderness when I left my bike for several days. Since I usually sleep in a hammock and carry a few lengths of lightweight rope, I can if necessary hoist everything up a tree. I'll tie my luggage and/or bike to the rope, climb some distance up a tree and haul the stuff up, then lock it to the tree. Even fewer people will notice it if it's above head height, but it takes time and is hard work to do (lifting significant weight using a 3mm line is hard on my hands).

Edit: As @jqning reminds me below there are metal mesh wraps you can buy that might help here (I have too much to say for a comment). I've only used those for backpacks, and my experience was sufficiently poor that I gave the thing away after one trip. While it might have worked as a theft deterrent, it was sharp, bulky and hard to use. Packing it was problematic, as it had to be folded carefully then stored in a bag to protect the rest of my stuff from the sharp metal edges. It was the size of my stove, only less useful.

BUT on a bike that might be less relevant. When touring I'm willing to carry more weight than a backpacker will, and I have spare nooks and crannies on my bike where the ugliness of the shape doesn't matter. You could hang the mesh bag across the front or your handlebars, cram the wrapped mesh in behind your seat tube or under your rack, and so on. The way it would be accessible when you want it but not in the way the rest of the time. With care you could not only draw the bag tight and lock it, you could put your bike lock through it to prevent someone just removing the whole "locked" bundle. The problem might be locking the bag around your panniers, as they're usually designed as drawstring bags and they're not big enough to close around a whole bike. So you'd be drawing it tight around the rear half of the bike, or taking all your panniers off and locking them inside the bag nearby. Or using one per pannier. Still, I think it's worth considering.


Third eye helmet mounter mirror swivels too much

Chewing gum, or putty. You do not need to put the friction-increasing substance inside the joints - you can put it outside. Easier to remove later. You can also wrap sticky tape around the joints (if it's not supposed to move, but does, use duct tape; if it's supposed to move, but doesn't, use WD40 :) ).


You can buy basic 3 speed freewheels on eBay. With that and a claw-style derailleur you should be able to set up a 3 speed system. You might want to just get a different bike instead though.


Can chain-slap cause damage to a chainstay that is beyond superficial?

YES and NO

Depending on the type of frame and type of riding you are doing it could be a problem.

YES (you might have a problem)

If you have a steel frame slapping of the chain can damage the paint which is very important in keeping oxidants like water and air away from the bare steel. Steel will rust and eventually fail catastrophically.
If you have a composite mountain bike frame, chain slap can damage the outer layers of fiber which generally carry the most load. Nicks made by the chain in the frame's resin could be propagation sites for cracks that can lead to delaminating and failure. If you are missing or have worn through the factory included sticker guards, I would apply some type of wear guard.

NO (It won't be a problem)

If you have aluminum, stainless steel or another relatively non-corrosive metallic frame, no amount of beating with a chain is going to cause the thing to break. Aluminum and stainless steel are ductile materials and are very hard to damage without hitting them very hard with a large mass or by using some type of lever to bend them.

Probably No...

If you have a composite road bike, chain slap can damage the outer layers of fiber or could cause cracks in the frame as well, however the likelyhood of this happening is very small. Composite frame manufacturers generally include one ply of weave fiber on the lower chain stays to increase the durability along with a plastic sticker which should be more than adequate for many years of riding.

For what it’s worth I have <14 lbm composite road bike and I would never think of adding electrical tape (I’m counting grams here) for something as silly as chain slap.


2014 vs 6061 vs 7075 aluminium components

Aluminum alloy 2014 is often used in the aircraft industry for structural support beams and the auto industry for truck frames.
See metallurgy reference.  It outta be just fine for a chainring.

Alloy 2014 T6 has a Tensile strength (ability to resist stretching forces) of about 483 MPa which is comparable to structural steel and much higher than 6061 T6 aluminum's 300 MPa.  This strength is achieved with a tremendous weight savings (as opposed to steel).    All this is to say that it appears the 2014 aluminum is stiffer than some other possible materials which is beneficial in a crankset so that more pedalling power goes to crank rotation and not lost through material flex.

Regarding cracking, that increased susceptibility of 2014 is confined to manufacturing processes such as welding, where special support of the piece is required, or where bending the alloy is needed, avoiding sharp turns is necessary.    Oxidation prevention in pieces made of 2014 alloy is carried out by bonding a thin layer of pure aluminum (a "skin") or some form of painting, anodizing or powder coating to the outside.


Do indexed 3x downtube/barend front mech shifters exist?

The front mech shifters were generally not indexed.
The front gear change is agricultural compared to the rear derailleur. With so many gears (up to 13 now) so close together, getting the shifting right is critical, but on the front, the gear spacing hasn't changed forever, so the degree of accuracy is not the same.
Basically it's still in the days of change and trim until it is quiet


Depending on your rim (bore diameter) you don't have the choice unless you are willing to tweak your bike a bit (or use an adapter). Cross-Country or Marathon Hardtails and racing bicycles usually use Presta aka Sclaverand or French Valve (at least we call it like that in Germany). This type of valve opens when you put the pump on it (after you opened the screw). This allows for measuring the pressure but unfortunately it can be really annoying because you normally release some air when trying to set the pump correctly. Still, Presta allows for a pressure up to 15bar. This is required by racing bicycles. A disadvantage is the thin and long shaft which makes it more likely to bend the valve unwanted. Still this can be an advantage because this more elegant design reduces weight and therefore dynamic unbalance.

Schrader only allows up to 10bar pressure. Because the valve opens mechanically, we can measure the air pressure just like for Presta. The risk of loosing air/pressure at the beginning is lower because you first set the pump on the valve and just afterwards open the valve with a lever.

The biggest advantage of Schrader is that you can use pumps at gas stations without an adapter. Those adapters are really cheap and small, I always carry one in my purse between the change. But still you don't have the risk to loose that adapter when you are using Schrader valves.

The biggest disadvantage of Schrader is the relatively small pressure you are able to establish using hand pumps due to the bigger cross sectional area (p=F/A). Because of the differences in the mechanical construction and therefore the sealing, also with automatic pumps you can't achieve the big pressures compared to tires with Presta valves.

As you can see both valves have their pros and cons. Simplified, If you have

thin rims and/or
don't want to disturb the stability of the rim and the dynamics of the tire and/or
need big tire pressure and
don't care about the issues of maintenance

you should use Presta. For all other cases, use Schrader.

By the way there are more than two types of valves used for bicycles but I think the two mentioned are widest spread


(Dis-)Advantages of "push-in" to expandable handlebar end plugs

All the simple plastic bar end plugs I've ever used simply fell out at some point.

On a road bike drop bar I find it utterly impossible to tuck bar tape into the end of the bar and secure it with a simple plug.

There are better designs of expansion plug than the ones you had trouble with. In some expansion plugs the wedge is built into the cap. The bolt pulls the plug against the cap/wedge. When removing, pulling on the bolt does not tighten the plug.


The width difference of 10 and 11 speed chains is very close (5.88 vs 5.62mm) so usually this works without issue. There is always some possibility that even this difference will cause rub against the large ring in some of the small/small combos. Very short chainstayed bikes like yours increase the likelihood. Chainring micro spacers such as the 0.2mm FSA are the fix if there are issues. You'll also need to make sure your FD can be moved up a little, but that shouldn't be a problem.

You haven't said what kind of BB shell your frame has. If it's threaded you need any ISO/BSA threaded Shimano road bottom bracket. If you've got FSA cranks with a 24mm spindle now then you can use your existing BB if it's not worn out. If it's BB30 you have the option of using any of the myriad adapter systems for 24mm cranks, which consist of reducer bushings, press-in shell adapters, and screw-together adapter bottom brackets. There are many questions here about the pros and cons of these systems. Your bike's cable routing arrangement in some cases can inform which is best.


Your frame came kickstand ready. The bracket and hole are part of the frame. On your installation it appears they installed the top plate for a frame that is not kickstand ready. Not only did they use the unneeded plate but it is in the wrong place. I would remove the kickstand remove the rectangular silver colored plate. The kickstand should line up with the bracket on the frame. Tighten the allen head screw and you should be fine. If need be a drop of thread locker on the screw will keep it from loosening.


Generally, you can use any 700c trainer tire like the Continental Hometrainer , Vittoria Zaffiro Pro Home Trainer, Kurt Kinetic's Trainer tire, etc. Most come in 700x23, but some come in larger sizes (700x32 for example for the Continental Hometrainer). You can also just use a regular tire on a trainer, but the tire will wear out faster due to the additional heat versus the road. On a road, you don't want to go too far from a particular range of widths due to either flats or handling issues, but since you're bolted into a trainer, theres not a problem in using a smaller 700c tire on the wheel.

As for trainers you can use, pretty much any trainer supports 700c, but as always, check the specifications for the one you're going to buy.


How do manufacturers designate women specific designs on their bicycles?

Generally, it's impossible to tell anything from bicycle serial numbers. Manufacturers do not provide a way to look up serial numbers and get a model name or a description of the original configuration.

Some women's specific models are sometimes marks as such. When women's specific models started to appear they often had paint schemes based on pinks and purples, because these were thought to be 'women's colors'.


How to clean consumable metallic parts cheaply while touring?

The most frugal is not to intensively clean these parts except at the end of the tour when you overhaul your bike.

Simply brushing off the dirt with a cleaning brush, toothbrush, or rag and relubricating with a good dry lube will get you most of the benefits with little of the mess. And it’s a lighter kit.

You don’t need a spotless bike.


Broken rear axle. Why does it happen and is it worth trying to repair?

Most of times the axle is broken when not accurately jumping with bike (the same is with obstacles on road like holes and speed bumps). Wheels with freewheel are more exposed to this because their bearings (i.e. the place where wheel touching the axle) far from the place where the bike touch the wheel, therefor it have more moment to brake the axle.
To the question about worth repair. The only available repair of this - is to put a new axle, that means it will be like a new wheel (if you do not have other problems in your wheel). If you going to replace the axle, examine the bearings cup if it have any deformation. If it have, in most cases the wheel must be replaces. Examine also the cones.