Some things to try to make your bike  less susceptible to wind gusts.

Maintenance - check your headset is not loose and has no discernible play.  Ensure your bike frame is true so that the front wheel leads the back wheel precisely and that the fork is not bent at all.  Check your wheels are true and that your wheel bearings are smooth with no wobble.   All these things minimise the bike's reaction to a sudden gust.
Get more aero in your body.  Sitting up will catch more air than getting bent over.
Get less aero on your wheels.  Deep section aerodynamic wheels are getting better, but classic old box-section wheels are best at coping with side winds and gusts.  Good for the training bike
Geometry changes to your bike - longer wheelbase is more stable at speed but corners worse.  Fiddling with Rake and Trail in the fork can change the feel too.
Be more visible - gusts are worse as the vehicle gets closer.  So at the very least wear a high vis top (not black!) and run a blinking Daytime Running Light on the rear of the bike.   This helps vehicles to see you and take avoiding action.
Be less on the road.  Consider moving a small amount to the kerb.  That's not the same as ducking way-over into the road detritus and rocks.
Likewise if you are forced to take the lane (and your location legally allows this) then clearly take the entire lane.  Don't half-it and let a driver think they can squeeze through.  Of course if you do take the lane then get up and go - its good road manners to minimise the delay.
(michael) Wider handlebars help with adding leverage.  You can control a swerve faster as your hands are further apart.  HOWEVER this makes you less aero and more likely to catch-22 wind.
(andyp) More tight fitting clothing, lower volume tyres (big sidewalls catch more wind), and removing mudguards
Finally, be NOT on the road.  If you have an isolated/protected cycle lane, then use it.   If you have a side street that isn't quite as tight as the main road then consider it.   Going 10% further is a good trade for a safer road.

Longer term, look into supporting local bike advocacy to get those protected cycle lanes and shared roads.


Pedal thread gone SRAM 150/100 chainset - what can be done?

You can try to helicoil the crankset. This is an insert which can be used to repair threading, though you need some special tools to do it. Your bike shop may or may not have this as an option. They may charge you as much as dropping in a new SRAM S100 crankset for this.

The crankset uses a Powerspline BB (which means if you to keep the BB, you're going to have to use a SRAM crankset and it seems like your only option is the SRAM S100).

You can replace the bottom bracket (BB) with any conventional threaded type and use correspondingly compatible crank. For Shimano, you'll get a Hollowtech II bottom bracket for most mid range or higher cranks and a square taper or octalink for the lower end. Note there are other companies which you might want to look for cranks as well (e.g. FSA).

Your bike shop will be able to guide you on this depending on what they have in stock and your price range. It's an easy job to replace the crank or put in a new bottom bracket, but you need the right BB tool, a large crescent wrench and a crank puller.


Does anyone have any special notes on buying pannier racks?

Bang for buck would suggest an aluminum rack, but these typically don't support high loads.  Once you start heading into the 20-30+ kg range steel performs better in terms of total load capacity and behavior under load (I.e., less flex which reduces the chance of a shimmy).  In terms of steel I have had good luck with Tubus and hear good things about Surly racks.  However neither of these racks are cheap.

About fenders

In terms of frame eyelets and fenders, some racks (usually the higher end ones) have additional mount points for fender struts.  If you are handy you can often create your own mounting points.

About pulling building supplies

If your intent is to be in the transport building supplies such as plywood, you should really think about alternatives to racks such as a trailer. There are lots of different types of trailers. I've seen some flat bed like trailers for putting large awkward objects.


I can't find a fat tire inner tube, any help would be appreciated

You don't reveal where on the planet you are looking Bernard!

For example in Australia the main bicycle wholesalers have both 20x3 and 20x4 readily available. I'd imagine if you are in Europe or North America it would be similar, so you just need to ask your lbs to order it in for you. It's unlikely to be a stocked item as it's a slow mover.

A motorbike shop may also have them but they won't call it 20"!  To them it will be about 14" or 15". Just show them your old one or the tyre.

Not a lot of people know that bike tyre sizes in inches are given by the approximate outer diameter, whereas motorbikes and vehicles go by the tyre inner diameter or wheel OD, hence yours is called approx 14" to them. HTH.


Size of Pedal Threading on old German Glockenlager?

Just try chasing the threads with the normal taps (remember the left side is reverse threaded) then try the pedals. Sometimes just chasing and cleaning will be enough, and what have you got to lose if the threads are already damaged. Some pedals have a longer section of thread than others, certain pedals may work better or contact the intact threads better.

Otherwise there are insert kits that cut a larger diameter hole then insert a brass threaded part that has normal pitch threads on the inside. These kits are expensive and may only be made for aluminium cranks so check that out first.


Replacing my bottom bracket. I need help IDing a replacement

You have done your homework correctly. You need a square drive bottom bracket with a shaft length as close to 125mm as you can get to fit a 68mm frame. I have taken out quite a few of the plastic cup units with no issues, but I prefer the metal one. But that is just personal choice. Take a look at the area of the chain stay (the tube from the rear axle to the bottom bracket) for crank clearance. Some frames run the big ring very close and bringing the crank closer may cause an issue. You can use a shim behind the crank- side cup to move it out to the same location as original. It is doubtful you will notice the difference if the nondrive side is a mm closer to the centerline. you will likely have to fine adjust the front derailleur when your done.


The Deore M4100 cassette is a 10-speed cassette. It goes to any Shimano splined freehub body but you need an additional 1.85mm spacer if the freehub body is intended for road 11-speed cassettes (MTB 11-speed does not require the spacer). You choose the type of hub based on the frame, for example:

130mm over locknut diameter quick release hub
135mm over locknut diameter quick release hub
142mm M12 thru-axle

Shimano makes many good hubs for all attachments, for both rim and disc brakes. Select the spoke hole count to match your rims. Since you already have the STI shifters, you no longer have the choice of selecting either rim or disc brakes, you must use what you already have. For the front, you have a choice between hub dynamo or no hub dynamo; as a user of a hub dynamo I can heavily recommend it.
Are your shifters R7000 (meaning they'd be 105) or Tiagra (meaning they'd probably be 4700)? R7000 shifters are 11 speeds so not compatible with a 10-speed cassette so you have to change either the cassette or the shifters; changing the cassette is cheaper. 4700 is compatible with a 10-speed cassette but requires a rear derailleur intended for the standard 11-speed cable pull ratio. So I suspect the rear derailleur should use the Shimano road 11-speed pull ratio.


What type of shoes should I get with regular pedals

I like downhill larger platform pedals with what is commonly referred to as street shoes.
I don' like advertising a brand but an example is the best answer.
All Mountain Flats

You have people advising clipless (spd) and I don't agree.  Ironically clipless means the ski boot type clip in.  But I don't agree with spd.  I would do a 500 mile multi day ride on some big platform downhill pedals with the little spike and some and some nice street shoes.  There is enough traction to hold your foot in position.  You can move your foot around a little bit to change how you hit muscles.  I will ride an uphill is a little different foot position.  When you get off you can walk around and loosen up you legs.  You don't have to carry another pair of shoes or sandals.  Now a one day 100 mile ride - then I would ride spd.


Yes, my friend just bought that bike new and ended up taking it back and getting a similar priced Cannondale, mainly because it came with a Shimano 105 group set. I would look at that as a major upgrade especially if you are experiencing poor shifting. If you have 500 to spend you could probably get an Ultegra group as an even better upgrade and have a really nice performing bike on your hands, as well as lighter. I'm not partial to Shimano so I'd probably check out Sram as well, Rival will be in your price range.

A new wheel set would be the other major upgrade you could make for 500. There are a ton out there at that price but if shifting is what's bothering you I'd get that taken care of first.


What do you do if you find your stolen bike's frame on ebay?

To determine if the bike is indeed yours, you could contact the seller and ask for more information about the bike and for more pictures in the hope that you'll get one with a visible identifying mark.

You'll need to be careful. If the seller know's it's stolen asking for more information and pictures could tip them off that you are the rightful owner with the intention of retrieving your property.

You should read the Ebay Stolen Property Policy for what to do if you are convinced the bike is in fact yours.


Are there any downsides to using a mountain bike as a commuter bike?

are there any real downsides to this?

The one thing about a typical MTB that really doesn't work well on the road are soft-compound, deep-thread tyres: they have lots of rolling resistance and wear out quickly. But this is easily fixed because even the burliest enduro bike can be fitted with more road-suitable tyres without problems.
Smaller disadvantages include the higher mass and suspension bobbing. IMO neither of that is really an issue for commuting, though it definitely does mean you get not the best performance. If it's a long commute then maybe you're better off with a more performant bike but for a short commute (< 5 km) honestly just about any bike will do; I'd recommend making longievety / low maintenance more of a deciding factor than performance. Also, a fancy bike is no good if it's stolen.
In summary: an inexpensive hartail MTB makes for a perfectly adequate commuter bike, as well as for “light exercise”. Only if you want to get a bit more adventurous about the MTB part, then I'd recommend rather getting two separate bikes, with a cheap, used, road-only one for the commute job.


What are the long-term effect of riding with a chain that's too short?

The main problem with a chain that is too short, is when you're in a combination of gears where the chain is too short to go around both chainring and cog.
You'd have to be moving the chain from a lower to a higher-tooth count gear, so at some point in that first half-revolution, the chain will bind, the cranks will resist you, and any more force on the pedal will start to snap and bend components.
Since you've already ridden so far on the chain, it might be more a case of possibly a little short for optimal vs the catastrophic "too short" described above.  Or you've never ever put the chain into big-big.
Frankly I wouldn't worry, but when the new chain is fitted make it one link longer and see how that rides.    Remember to count links, not measured length when comparing it to the current chain.


Best posture to ride a road-bike down hill?

This answer will be for riding down hills fast, but a lot of the advice applies to slower speed descents.

When riding downhill you should have your hands in the drops, the pedals at level (i.e., one foot forward, one back) and depending on your flexibility you want to get your butt back and bring your head down close to the stem so you don't present your chest to the wind. You also want to avoid a "death grip" as this can make the bike unstable.

This position isn't entirely about aero (for that you can do the death tucks like lying on the top tub your getting your head and upper shoulder ahead of the handle bars forming a wedge). You want a weight distribution that makes the bike stable, but responsive enough that you can avoid obstacles and navigate turns.  Getting into the drops shifts weight forward which slows down the responsiveness of the steering to light input but lets you carve harder turns.  Conversely if you put all your weight on the back the steering becomes lighter which can be unstable at higher speeds.  The drops is also the strongest position on the bike in terms of physical leverage.

I also like to hover above the saddle, that way if I hit a pot hole or dip the bike doesn't become unsettled.


While I have no practical experience trying to do this, I doubt that what you propose is easy, and it may not be possible.
Rubber seals require a lip machined into the inner and outer races. This retains the seal. I suppose you could check for a lip. If the bearing were designed specifically as an open (i.e. un-sealed) bearing, which is sensible for a low-contamination environment, then it likely wouldn't have a lip. If it did, you would then have to source a seal with the correct dimensions to fit the lip. There are probably a number of different geometries of seal lips. I don't know the descriptive terminology or important measurements for seal lips and grooves. If you found these out, I expect you'd then have the problem of buying just two pairs of seals - the entities selling those seals probably aren't set up for retail transactions, since really what consumer does this? So, it might be several hundred seals.*
It should be difficult, and it may be impossible, to extract the balls from the cartridge. The balls fit tightly in the races, and in many cases, I suspect they sit in grooves in each race. For example, see the second picture at this link. If you can’t pry the bearings out, you would need to disassemble the cartridge to get at the balls. Furthermore, cartridges aren't designed to be disassembled, so I think this process would be destructive, i.e. you'd need something like a hacksaw. Getting the balls into a new cartridge could require industrial machinery like a hydraulic press. And finally, remember that a bearing series number like 689 just describes the outer diameter, the inner diameter, and the depth. The race thickness can vary - so, thinner race means larger balls and vice versa. You'd need to find two pairs (again, consumer vs industrial scale problem) with all the important dimensions matching your ceramic balls.
Finally, ceramic is relatively hard. I believe that best practice might need you to specify an appropriate race hardness as well (it may be more important in wheel bearings, since as you go over bumps the balls might indent softer steel races). I am not sure how this quantity is parameterized in the industry (i.e. maybe it's Rockwell hardness or something like that, and you need to specify a minimum hardness, and I don't know the appropriate minimum). On another tangent, be aware that the quality of ceramic balls does vary, and I suspect cheap ones are low quality. Plus the quality of the steel used in races also varies, with cheaper races probably having poorer material qualities (probably stemming from more impurities, poorer manufacturing processes) and probably looser tolerances.
This answer is written with no practical knowledge of manufacturing or remanufacturing cartridge bearings. Basically, I learned from a podcast. I could be wrong! And if I am, you should free to let us know. However, hopefully this post has given you some idea of the possible pitfalls you would face.
*I am aware of one company that sells replacement seals for its own bearings: Kogel, which coincidentally makes jockey wheels and bottom brackets with ceramic bearings. Kogel's instructions suggest annual regreasing, which is why they sell replacement seals (although they have communicated to me that if you carefully remove the seal, it's usually reusable). I haven't asked, but I would suspect Chris King sells replacement seals for its bearings, although they have seals that are designed to be repeatedly removed for regreasing. The issue is not that no seals for cartridge bearings can be bought in consumer quantities, it's that you will probably only find seals matched to specific bearings that are designed to be serviced, and this seems like the minority of sealed cartridge bearings.


How can a recumbent tadpole trike brake three wheels with only two levers?

Most are set up with one lever that works two brakes at the same time. There are lots of different styles, such as this one for example.

You can see that it has 2 ferrules instead of 1, most commonly used on dual disc brakes. There are other models that differ somewhat visually but the idea is the same. Many Trike levers also have a push button locking mechanism that functions like a parking brake so that it cant roll while engaged.


32 teeth should be enough to clear the frame.  Even using a 30 Tooth (pictured below) there is still plenty of frame clearance. That's a different frame, but still, it looks like there would be plenty of room on any frame.

The following picture shows a 2010 Big Hit with a 32 tooth chainring, and you can see there is ample frame clearance. The chain device actually has to bring the chain closer to the frame. Perhaps your chain device what's causing the problem and it is bringing the chain too close to the frame. You should be able to use the bike without the chain guide as the narrow wide chainring should be enough to keep the chain on there by itself. or perhaps use a different chain guide that mounts on the top.


Is there a way to completely deflate an inner tube?

According to Yehuda Moon (google it), you can take a properly-sized ball bearing (or even a pebble) and put it inside the valve cap, then screw the cap halfway so that the ball/pebble will keep the valve open.

Then, you roll the tube like toothpaste, and when you finish you remove the cap and the pebble to avoid the natural elasticity of the tube to suck back some air.

Hope this helps


Are "V" brake rims safe to use with discs

Not only is it safe it is fairly common. When disc brake became more affordable many after market manufacturers sold dual brake wheels. Disc hubs and "V" brake rims. Just don't use "V" brakes on a disc only specific rim. The dual use wheel may have been a way to limit new inventory to one type of wheelset.


It's really easy to do but it's not very reliable either.

Since you got some good old 550 chrome wheels and it's french maybe they come from Rigida. Thing is, Rigida wheels where, at the time, stamped with their fabrication year which you will find inside a little losange.

Other way is to go for the hub. Some manufacturers like Normandy also dated their production by engraving the year (you got two numbers and have to look at the second one which is the two last digits of the year).

So assuming that the wheels are the original ones, that's your best bet to date your bike.

From instinct I would say that it's a late 70's bike and from the tubing it could be italian more than french but here I can be wrong.


Neither system is better than the other. In some situations, 1x is better, in others, 2x is better. As cassette range expands, effectively because the largest cog is getting bigger, the advantageous of 2x (or 3x) are decreasing. (SRAM just released a 1x12 with a 10-50 cassette, which is probably the nail in the coffin of 2x in the top end gear sets on MTBs).

As a  rough starting point, if you are regularly using you lowest gears, and other times your highest gears, a 1x is probably not for you. if you ride flattish terrain, or are a strong rider who climbs well, 1x is a candidate. The NX and XT cassettes are 11-42 giving a gear range of just 380% vs a typical 2x of 11/36 and 24/36 giving 470%  (although 11-46 are available giving 420%)

A large reason for popularity of 1x in Mountain bikes comes from full suspension frame builders. By loosing the front shift, they free up space around the already crowded bottom bracket area. This is a very high stress area of the bike, throw in pivots for full suspension and life gets difficult. Removing the derailleur and it goes from 'impossible' to 'nearly impossible' to make a better frame.

Manufacturers love 1x as it lowers the total cost and complexity of an installed drive train, and marketing love it because is something thats clearly 'new' and therefore must be 'better' Meaning there is cost saving to be had, that does not need to be passed on to the consumer as it can be sold as an improvement.

If we put those two aside and consider just an upgrade of an existing frame

2x Advantages

Bigger overall gear range
Closer spacing between gears (if same number of gears)

1x Advantages

Lower weight
Linear gears
Less cluttered handle bars
Fewer mechanicals - less things to go wrong, less adjustment

Keep a very close eye on costs - upgrading from Tourney means the bike was not really high spec to start with. Its likely a 1x11 gear set will cost more than the bike is worth, and provide no significant advantage over upgrading just the rear derailleur and shifter (Cassette, chain, shifter cables are really consumables).


Converting a mountain bike to a urban commuter

Feelings are definitely very important, but a dual suspension bike with a two-crown fork is a difficult start for a commuter bike. Especially if your budget is limited.

I would think that you should inflate the tires well and take a ride to school to see what it's like in its current condition. If you can block suspension, that might help.  I guess if you love or hate your first ride, it'd be a part of an answer to your question.

If it's neither a bliss nor a hell of a ride, you could ask a more specific question, e.g., for advice on particular problems you experience. A possible way out is to sell certain components (such as the fork) and buy new ones that would fit your purpose better.

But yeah, after all, it's a beautiful machine, personally I'd try hard to keep it. Good luck!


The reason why the RD has that bend in it is because it is what tension the chain in every single cog in the cassete. Also if it does somehow work. The length of your chain will increase, because it will have 2 cages to go through.


Turning the preloaded dial towards the negative symbol will decrease the preload on the spring. Therefore if you find the forks are too stiff, backing off the preload will soften the fork. Alternatively if you wish to firm up the fork, turn the preload dial towards the positive symbol. This will compress the spring and stiffen up the suspension.

I would adjust the preload with the lock out off, though I don't believe it would make any difference beside allowing you to compress the fork as you dial preload on/off to see what affect it has on the fork.

Hope that helps!


It's hard to tell from the photo ( is that large vertical streak said crack? ), but if your frame is cracked, don't use it. Riding on a cracked frame is risky as it could result in a catastrophic failure / injury / death.

It looks like that's probably a steel frame, so find a local frame builder ( not your buddy who's handy with a welder ), and depending on the damage they may be able to repair it for you.


Frozen cables happen because you've got moisture in the cable and housings. This can happen fairly often if you bring your bike inside after they've been wet and then have it back out long enough for that moisture to freeze. Two things can help.

First, make sure your housing covers as much of the cables as possible. Second, use a cable lubricant, which will help keep moisture out.

WD-40 should not be used on brake systems, and should only really be used on your bike as a temporary lubricant (to remove seized parts, for example). It's primarily a solvent and a de-greaser. You actually want grease on your cables.

EDIT: I was having trouble adding a comment below to answer your questions:

I use TriFlow, which is a light synthetic. You'll only need a few drops at a time, so don't worry about buying in bulk.

The other lubricant you could try, and I've seen some people in bike shops do this, is a waterproof grease, the same stuff people use on their bearings and threads.

Generally, I look for light oils for my cables, as others tend to gum up in the housing, but they should be good in a pinch.


Trying to identify vintage English bike maker

I think this answers your question.
Your headbadge is slightly different, probably older.

See also https://en.m.wikipedia.org/wiki/Sunbeam_Cycles
Also http://historywebsite.co.uk/Museum/Transport/bicycles/Sunbeam.htm


Shimano front derailleur - tensioning, can't move shifter

Best approach is to start from scratch following a procedure so you know you are not making things worse.

There are a few youtube videos that walk you through the procedure. My favorite is Park Tool Company’s as it’s the easiest to follow and includes checking height and yaw. (Link at bottom.)

Before attempting the adjustment, make sure the cable and housing is properly inserted into the shifter body and and the guides on the frame.

Another thing to do is check the shifter is pulling the cable properly, and the cable is running freely independent of the derailleur. Disconnect the cable from the derailleur, grab the cable and put some tension on it (a set of pliers can be helpful), then turn the front shifter through it's clicks. You should feel the cable retracted and released.

Front derailleur and shifting adjustment is pretty tricky, so don’t feel bad that this has got the better of you.


Yes, the piece in the lower left is the crown race. Split types (with the slit) should gently pinch onto the crown race seat of the fork. What's important with that type is that there's zero play (slop or free movement) between the race and the fork. It will be able to turn but shouldn't be able to just spin freely.

If there is play or free spinning, you could go a couple different directions. You could measure carefully (with a caliper) and determine whether the race internal diameter is oversized and/or if the fork's crown race seat is undersized. Then you could get a different one of whichever is causing the problem.

Alternatively, if you just want to make the parts you have work, a good approach here may be finding a shop that has a Stein knurling tool, which is a very fast way of slightly raising the surface of the material, for round parts that are supposed to fit just a little bit snugger than they are.

The other piece is the compression ring, which goes between the upper bearing and the top plate.


Proper fit in an aerobar posture is designed to allow you to race well. In order to race well you will need to be comfortable enough to produce power, to reduce aerodynamic drag, and to handle the bike well and safely for the duration of your race. If your fit otherwise meets all your needs, you shouldn't be concerned about where your knee is positioned relative to the pedal. Under UCI regulations (see section 2 of chapter 3 here), the nose of the saddle should be a minimum of 5 cm behind a vertical line through the bottom bracket; morphological exemptions can be made to bring the nose of the saddle up to the bottom bracket. Some riders do not compete under UCI rules and the saddle can be forward of that; and many time triallists will sit only on the front half of their saddles, effectively bringing them even farther forward. The forwardmost position of the pedal will be determined by the bottom bracket and the crank length. Some riders use "short" cranks to improve their aerodynamic position, and that will also change the position of the knee relative to the pedal. The location of the cleat and the length of your foot will also determine where your knee is positioned relative to your toes.

Optimize your fit to achieve your other goals. Don't focus solely on where your knee is positioned.


Yes you did something wrong. You are supposed to put the tube in the tire and mount it on the rim.

If you inflate a balloon you will see similar behavior.  After you have stretched a tube IN the tire the behavior outside the tire will change slightly.


Tire size compatibility, 700x35c or 700x38c for original size 700x37c

Both of those tires are quite close to the tires that you already have. There is a really good chance that they will fit. Because of the extra material in the SmartGuard layer these tires are taller than they are wide, but only by a couple of millimeters. So all you need to be concerned about is to look at the clearance on your bike with your current tires. Do you have decent clearance between the red of the tire and the crown of your fork and the bridges in the rear (or the fenders if you have the fenders installed)? 10-15 mm would be very comfortable, on my old Trek I've got like 5 mm. I don't have enough room to comfortably run fenders with my Marathons, but I'll be OK until the rain returns :-)

If you have enough room at the top, you probably also have room at the sides, but it is worth looking there too. The more generous the clearance the fewer hassles you'll run into with bits of junk on the road (it can get caught between the tire and the frame) or an out of true wheel – like if you break a spoke. From the look of the bike in the photos you should have plenty of room – the lower edges of the fenders appear to be aligned with the full diameter of the tires and the specs say that the bike comes with 37 mm tires.


Will a hollowtech shimano BB fit a bike which currently has an octalink bracket?

The bikes themselves - in this case, the frame - are pretty much standard on all the modern mountain bikes.

The Hollowtech and Octalink systems are different because you need to match the crankset to the bottom bracket, that is, you cannot use the BB from one system with the crankset from other system.

But any of the bottom brackets can be installed in the same type of frame (the "default"/ISO 68mm wide, 1.37in diameter, 24 TPI).

Hope it helps


Should I prioritise reach over stack (in choosing a new bike)?

Endurance geo tends to be shorter reach with a higher stack, but variation on the recipe between brands.

Cyclocross bikes are race bikes (although years back they were often marketed as do all bikes, which gravel/all road have now taken over). Race bikes tend to have a lower longer cockpit for a given size, with variation between brands.

So it isn’t far comparing a Grand Fondo bike to a bunch of race bikes.

In terms of what to prioritize most bikes have a fit window, which is a range of final realized stack/reach coordinates after you adjust spacers, stem length and stem angle. Even handle bars have different reaches, which can further tune fit.

You have a lot of latitude with a simple stem swap. The 51 BMC CX Reach is 10 mm longer, which could mean running a 10 mm shorter stem. If you are planning to race you may find you prefer a slightly longer position.

The size down 48 BMC CX could be harder, it has 40 mm less stack, moving all the spacers will only typically give you 30mm of stack on most mainstream bikes, which means you will have to flip the stem. Also note that spacers or flipping the stem up will reduce the reach (the head tube is on an angle).

Typically I will crunch the numbers in a spreadsheet to determine what stem, spacer combo is needed for a particular fit.

  but too low means an awful lot of spacers which is a no-no.

Why is this a no-no? Are you riding a bike or worrying about style? People have different proportions. If for example you have a long inseam you lose stack height and will likely need spacers. A larger frame won’t handle as well due to weight  distribution differences.


Check your tire pressure regularly.  Different tires (tubes, actually) have different "leak down" rates, but at a very minimum check once a week, and probably every 3 days (or before every ride).
Clean/lube your chain.  Depends a lot on riding conditions, but in "average" conditions you should clean/lube every 200 miles or so.  More often in wet, sloppy conditions or in extremely dusty conditions.
Inspect your wheels.  Hold the end of the bike up and spin the wheel.  Check for any wobble (watch right next to the brake blocks for rim brakes) and check that there are no serious bulges in the tires.
Check your chain for stretch.  Get an inexpensive chain stretch gauge and check after you clean the chain.  Replace the chain when it's too far stretched (about every 2000 miles).
Check your sprockets for wear when you replace the chain.  How to do this is a bit involved for a short answer.
Check your brake blocks for wear maybe every 500 miles.  The blocks should be mating nicely with the rim and not worn to the point that the metal holder is close to scraping the rim.

There are others I'm not thinking of at the moment.  And this question is likely a dupe and there are other threads with more info.


mountain bike switching tyres I get a puncture, why, am i doing something wrong?

A theory:  There is some damage or debris on the inside of your tire.  A second theory is slightly out of position rim tape.  A third theory is your technique may be leading to a pinch flat.

Questions to help diagnose:
When you switch between tire sets, does the flat happen only going to one set of tires?  Or does it happen no matter which tire?  If it's just one tire set, then inspect the inside carefully for debris or other issues.

Next time the tire is off, look at the rim tape carefully and run a finger along it. It should be smooth and sturdy. You may also want to check that it's secure all the way around. If it is moving around during tire changes it could be exposing a spoke nipple.

The third theory would be that if the tire it tight or tough to get on then perhaps you are pinch flatting during the tire change. Advise here is to go carefully...


There are several things (such as fit) to consider when buying any bike.  However aero bikes have some special considerations to be made.

Comfort

Has the design compromised the comfort by making the ride overly harsh.

Weight

Are you going to be doing a lot of climbing on the bike?  Aero bikes are heavier than normal bikes due to the tube shapes, however some aero bikes are particularly heavy.

Maintenance

Are you going to be looking after the bike yourself?  If so, maybe you don't want the nifty hidden brake calipers integrated into the fork.

Travel

Are you going to be travelling with the bike?  Is any integrated bar/stem and magical cable routing going to cause problems?

Wheels

Do you already have your own deep section wheels?  If not, does the bike have a good set?  Wheels will give bigger aero gains than the frame itself

Tyre Clearance

Given the increasing popularity of larger tyres and wider rims, does the frame have clearance for larger (28c) tyres?

Aero Bars

Are you potentially going to want to use the bike for  triathlon or time trials?  If so can the shape of the handle bars accommodate clip on aero bars, or does the manufacturer produce their own special version?


Are 32mm tires ideal for a fast commuter bike?

I commute on two bicycles:
— a road bike, with 25mm tire up front and a 28mm back.
— a custom commuter bike, with 32mm up front, 35mm back.

I'd recommend you go with the 32mm tires.

The 28mm tires I've used are good for commuting (I think the 25mm I have is too small — I have to give it too much attention when crossing curb lines and such).

That said, 32mm tires offer a lot more protection in urban environments. I ride suburban roads (25mm is fine for those) into an urban environment, and then I go into a college campus.

It is on campus where the 25mm tires get dicey. There are many different surfaces on campus, and each change creates an edge — It is those edges that will get you, either trip you up or cause a pinch flat.

A 28mm tire does OK, but a 32mm tire handles these conditions much better.

Some 32mm tires are heavy, some are lighter weight. For what you hope to do — go fast — search around for lighter weight tires (Panaracer might be a good place to start).

Enjoy the fatties!


My rear bike wheel is wobbling back and forth when I ride

If it's wobbling side to side, there are two problems that are possible; Your cup-and-cone bearings could be loose or your wheel could be out of true (slightly buckled.) Take your wheel off and hold the axle. Wobble it up and down a few times. There should be absolutely no movement besides the spinning it's meant to be doing. If this is wobbling, just tighten the hub cones slightly until there is no play. The rule is No play, No binding. This means having it borderline between perfect no play and perfect no sticking, otherwise it'll make your ride unpleasantly harder.

If it's wobbling at 0' and 180' points of the wheels to make it slightly oval, that is also to do with wheel being untrue and buckled, or trued incorrectly.
This job is a totally different ballgame. This usually happens when the spokes have been tightened more on one side than the other, and is a pain to fix, even for me, after repairing bikes for over three years now.

Worst case scenario, you could be looking at missing spokes or a bent axle. Maybe even some trashed bearings, but are usually rather cheap. A good thing to do if you're wanting to learn to do hubs is look at RJTheBikeGuy on YouTube or Global Cycling Network on YouTube. Both are extremely helpful with their guides.

I really, really apologise if this doesn't help, and I hope you get back to riding again!


Convert SRAM Force 11 to single chainring

I'd find a new local bike guy. Although the "evil of cross chaining" is a very persistent myth in the bike world, you might not be able to find any shop guy that doesn't preach this nonsense.

All you really need is a new chain and cassette and a chain wear checking tool so you can replace your chain before it gets worn enough to destroy the cassette. If you replace the chain often and keep it clean, your cassette will last many thousands of kilometers.

Switch to a single ring if you want, but doing so to "avoid cross-chaining wear" is complete nonsense. Seriously, do the math. Switching to a single ring crankset is going to move the chainring in about 3mm at best. The change in the widest chain angle is going to be 0.43 degrees assuming a 40cm chainstay.


I'm not sure of the exact size of your rims, as it doesn't appear that a 28.5 inch tire is mentioned anywhere in Sheldon Brown's rim sizing chart. However, there is mention of a 28 inch wheel which is used on "Indian Rod-brake roadsters". The actual measurement for this rim is 635 mm. 700c wheels have a 622mm BSD.  This means that 700c road bike tires are smaller (assuming your bike has 700b tires mentioned on Sheldon's site).  Which means you may be able to fit the 700c rims on your bike, provided your brakes have enough reach.  Check the rim size by reading the numbers off the tires. There should be a number there like 635 or 700b if they do use the 28" tires.

As to the question installing drops and a new drive train and brakes, that might present other problems. If this is the type of roadster you are referring to, there's a couple things you'll have to look out for. Dropbars could be easily installed, but there's a lot of other stuff to consider. Is the rear hub spacing the right size to accommodate a wheel with a standard road cogset.  Are there proper mounts for caliper brakes.  The bike in the provided link has "rod brakes" that use rods instead of cables.  Can the bottom bracket be replaced with one that is compatible with a crankset you like.  It might just be easier to keep your eye out for a used road bike rather than try to convert a roadster into a road bike.  You'll have to buy quite a few new parts, and often the price of the parts far exceeds the price of a bike.


There is asthma due to exercise. (Exercise-induced asthma). So one can have lung problem simply due to huge exercise. (not very likely in this case, but possible).

Waiver for meds in my view is "permission" to take a medication. E.g., epilepsy drug to prevent you from having seizure during the race.


66 yo female road bike rider needs advice on THE BEST CLIMBING components/groupsets available!

Also consider some help from an ebike motor.  It may not be fully to your preference, but the small push on the steepest bits will help save your knees and your heart.

This may go against the "purity" ethos that some cyclists value, but at the end of the day its all about riding.

There are retrofit wheel kits for existing bikes, or a bolt-on mid drive, or a much more subtle bottom bracket booster like that woman used in the CX competition (apparently by mistake)

A higher end solution would be to get an electric road bike where the motor is integrated into the frame at the bottom bracket, and batteries are stored in the downtube rather than bolted onto your water bottle mounts or out the back on a parcel rack.  But that's much more cost.


Looks like the TRP Parabox Hydraulic Disc Brake is what you're referring to.  Basically it allows you to use your existing mechanical brake levers to control the hydraulic pistons.  So you can use your old brifters, and still have hydraulic braking.  Here's a review that explains how they work, as well as provide and idea of the performance characteristics.


How can you remove logos from a bike frame?

It's almost certainly stickered if it's a cheap bike, plus laser etching is usually reserved for bare metal frames - Titanium in particular. Cheap or not, it's still probably got a clear coat over it, and that sticker is almost certainly underneath the clear coat. Unless you're prepared to strip it down to raw metal, prime it, and paint it, you're probably better of just leaving it as it is - especially if it's a cheapie.


Found out those "clamps" are called conduit hangers:

https://www.homedepot.com/p/2-ACC-Conduit-Hanger-67820/202077114


Converting Mountain Bike for Road to complete in 33 mile mini triathalon

Even if you do not go as far as different rims, consider different tires.

Slicks (1.25") vs the regular tires (2+ inches) will make a huge difference, and usually can be found for $30 a tire or so in the US or Canada.

Beyond that, remove unnecessary hardware.

Front shocks are probably the worst thing you might have on the bike.  I do not know if it is worth considering a hard fork just for this race or not.


What is the effect on battery life of enabling glonass support on garmin edge 25?

You're only going to experience roughly a 10%, (maybe 20% max) loss of battery life. Unless you're planning on frequent century or all-day rides, the difference is relatively negligible. The average use case, a commute to and from work, or the average 4 hour group ride, won't see any difference because the battery life will go from about 8 hours on a full charge to 7 hours.

If you do plan to take it on century rides or night rides, you might want to upgrade to a medium tier unit, 510/520/etc, as the medium sized units have nearly twice the battery life. Using the GPS+GLONASS mode doesn't have a significant effect on battery life at all in this case because we're looking at about 16 hours of battery life in GPS-only mode vs 15 hours of battery life with GLONASS. Unless you're living on the edge (no pun intended), the GLONASS mode isn't going to make it or break it.


Front derailleur cable keeps snapping, change of riding habits perhaps?

Excessive force or frequency in front shifting habits may be able to play a role in a cable breaking, but it's very likely that it was primarily caused by factors beyond your control.

Front derailleurs vary in how much bending in the cable at the anchor bolt is created as they move through their range of motion. Some recent mountain front derailleurs push this to extremes, which is unfortunate because in doing so they add to the risk of breaking cables.

Mechanics are at times faced with a decision in setting up cables whether to accept there being a previously anchored section between the final anchor point and the lever, or of clamping partway over a previously anchored spot. This can happen as a result of anchoring the cable and then the derailleur's mounting position needing adjustment or by needing to have less starting tension or a more inbound low limit screw adjustment. The problem with allowing this is that it creates some degree of a weak point, and whether it's enough to lead to breakage is impossible to say conclusively. Typically the more skilled a mechanic is, the better they are at sticking to an order of operations that negates this, while newer mechanics may not even realize it's something they should care about.

At some point, the scrupulous decision becomes to put a new cable in and start over, but it doesn't always happen when it should. When cables break at the anchor bolt, I think this is the most common primary reason.

As for shifting habits, most people on multiple-chainringed modern bikes (as opposed to 10 or 12-speeds, say) stick to choosing a chainring that matches the current terrain and then adjusting their rear gear as needed. So in other words you're shifting in back far more frequently than in front. Because the jumps between gears in back on modern bikes are relatively small, not much is lost with this approach in terms of pedaling efficiency, and the inefficiency and hassle of doing all that front shifting is saved. Older bike drivetrains with smaller numbers of gears in back and larger jumps pushed one more in the direction of making constant front shifts in order to find a reasonable gear to be in.

There are stylistic and strategic elements to shifting too. Some people just like using muscle to get through spots where a lower gear could also be appropriate, or conversely might choose to force themselves to operate at a higher cadence when a higher gear would also work. From an efficiency standpoint, these things have to be weighed against the lost efficiency of bothering to shift, especially in front.


List of essential tools to maintain an Ortler Mainau bicycle

Lennard Zinn has written books on maintaining road and mountain bikes (a trekking bike probably falls under the "road bike" category in terms of maintenance). He lists four levels of tool kits based on how ambitious you want to get with servicing your bike. I think this is a reasonable approach, especially since we don't know how ambitious you want to get servicing your bikes in particular.

Also, to some extent, a tool's necessity will be determined by what kind of bike you have, for instance, my road bike has no torx bolts; with a carbon bike, a torque wrench is probably more important. So any advice also needs to be tempered by the bike you're servicing.


How to silence a creaking cassette/freehub body

There should be no significant movement between the hub body and the cassette. Because of that, lubricant choice should not make any difference. The very fact that applying lubricant temporarily makes the noise go away means that there is too much relative movement between parts which are not supposed to move. Not only it sounds annoying, it may well shorten life of the freehub body by gouging its splines.

The only real use a lubricant should have there is to prevent corrosion. What I can suggest:

Make sure you tighten the cassette to a torque specified by the manufacturer. It is typically a high value (40 Newton-meter or so), and it really makes difference.
Check tolerances of the hub's and the cassette's splines. Are splines wide/high enough to fully engage with their counterparts? It might not be easy to do without high-precision tools. But if you have a component with poor interface tolerances, it will be hard to alleviate this without swapping the components. You might be able to compensate the gap between them by filling it with thin metallic shims (people have used sewing nails, paper clips etc.), but there are no guarantees that it will be possible or even work.


Is it difficult to do a post-break-in wheel tune-up?

As has been mentioned in the comments, you should take it to a shop. You're likely to do more harm than good if you're not already experienced in at least truing and preferably building wheels.

It also might not even take a couple hundred miles. I'd probably check on it once a week or even every couple days. Feel the spokes. Once it gets to a point where there are notable differences in tension, go ahead and take it in.


How to Reattach Cable End for Road Drop Bar Brake Lever

Going out on a guess for anyone who might stumble on this. it sounds like he grabbed the brake lever and pulled tight, perhaps checking for brake pad alignment, spacing, etc. The cable pulled loose from the brake caliper (not lever) and disappeared into the cable housing. If so, grab a zip tie (or a shoe lace) and pull said lever all the way back to the handebar. Secure it to the handlebar by zip tie, shoe lace, whatever. Grab a flashlight and shine it into the innards. You'll see the cable end coming out of the internal guts of the lever. Take a flathead screwdriver or needle nose pliers and push the head slowly back into the lever until it stops. Check the end of the cable housing by the brake caliper and you should see the cut end sticking out. hold on to it and release the brake lever from the handlebar. That should do it.


Can I put a Tortec Epic rear rack on a 27" frame?

Do you mean this rack? On the linked page it says that the rack will fit a 700c bike. Also I see that there are two holes at the bottom (dropout) mount, that would make it easy to use something like a repair strap to raise the rack if that proves necessary. Use a bolt through both holes so that the repair strap and rack can't move under load.

If you're handy with tools you might find it just as easy to get a short piece of stainless flat bar (or aluminum) and cut and drill it yourself.


Could you please identify this wtb cantilever/roller cam brake

Those brake boosters are definetely by WTB, you can see a logo on third photo. I'd gues that whole assembly is by WTB too, at least google images return very similar results (this post especially, scroll down a bit for a picture).


Which shifters are compatible with dura ace 740x?

The 740x rear derailleurs are unicorns that only index with 7400 shifters. I believe there is an SL-7402 downtube shifter.
7400 shifters have a cable anchor routing trick that allows them to work with latter generation RDs, but there is no such trick that works the other direction for RD-7400 et al.


Yes - one or two torque arms will help.   Otherwise all the impulse is being send through your dropouts, which will be steel and will flex.   This undoes the wheel nuts over time.   This also fretts out the dropouts whih will cost you a new fork.

Do you have anti-rotation washers in the fork dropouts too?  Even my 250W motor needed them.

More info:

From http://www.ebikeschool.com/torque-arm-need-one/


The word is "repacking" where you swap out the rechargable batteries inside a pack.   Generally speaking the pack's design does not make this easy, but its not impossible.  Its normally done at the end of life for the batteries, so after 500-4000 charge cycles.

Note this is quite different to fitting primary cells (ie disposable batteries) that you can throw away once they are discharged

First budget for a replacement battery, in case you stuff up the original one.  Can you afford $40 for the new one?

Then closely examine the pack.  There will be a seam somewhere, either at the end or down the side where the original battery was inserted.  If you're positive its an 18650 then the hole will need to allow that size through.  18mm in diameter and 65mm long.

Crunch up the seam in a bench vise, they're normally built with an inside and an outside clip.  You want to compress the "inside" part of the shell.  Then use a wood chisel directly on the seam.  A light but sharp tap with a hammer should pop the seam without damaging the old battery.

Figure out how to get the cell out, and eyeball it.  Its probably unlabelled.

The battery on the left has protection, the cell on the right probably doesn't. The rim you see is a small circuit board that does the voltage sensing.  You need the same kind as you removed.  Its possible the voltage protection circuit is built into the plastic housing already, and two of them in series is bad.

The vent holes around the positive end are NOT a sign of electric protection.  Instead they're vents for any gas buildup.

Reconnect your new battery to the wires, reinsert in the housing, and test.  Then use superglue to close and seal the housing.  This will be a one-time repack, it should give you another couple years of usage.


Where to get replacement bike frame cable entry grommets?

I discover your post because I have a Dengfu frame (recognized it on the photo!) with the same problem. I had a contact with Dengfu (Jame Yang). They can send me a pair for free but I have to pay $10 for the shipping. I found this too expensive and besides, i presme I'll have the same problem after a while. So I just put a nice black strap around the downtube of the frame holding both clips. It's very discreet and cheap!  ;)
Hope this helps and does not come too late!
Rudy


Quest was sold by Oshmans sporting goods in the 90s with mid range
 cro-moly frames and Shimano components.


Ride on rightmost lane that goes straight or right yield to drivers?

I do this regularly biking in the US. Taking the lane at an intersection reduces many dangers at intersections. If there was a car in the lane that was going straight the cars behind would also not be able to turn right on red. At the light, you are moving at exactly the same speed as a stopped car going straight and so there is really no reason for you to not use the same amount of space.
I am not a lawyer and the exact laws around biking vary between states in the US so this is not legal advice. Though for reference my state would require me to ride "as far to the right as is safe/reasonable" so I believe that my suggestions follow this.
Also as an aside, cars turning right on red is really dangerous and shouldn't be a normal thing.


My child seems to have difficulties riding bike - would different tires help?

Not a helpful answer, but I would definitely find a lighter bike. In the UK, Frog and Isla are popular makes for light bikes. I would say a 20" wheel is OK for a 5-6 year old.
A single-speed Frog 52 (20" wheels, 10" frame) weighs under 8kg.  Make sure the saddle is high enough, and raise it if he looks uncomfortable.
Both my children had Frog bikes and did fine. We bought ours second hand. They are very expensive, but maintain their value, and we sold both of ours for a profit when both children had outgrown them.
I doubt tyres will make any difference.


I commute on 28 km/day at 22-25 km/h average. I normally use a city bike, where I am not exactly leaning forward but neither sitting at 90 degrees.

However, I had to use for an entire week a different model, where I was more "seated":

though at the beginning I was feeling more relaxed, on the long run it was not that comfortable: keeping a decent pace was a struggle (drag and head wind, feet slipping on pedals), and also the steering was far less precise than I wanted, resulting in slower rides.

Maybe see if you can borrow such a (or similar) bike and use it for a week or so, before switching to it.


Problem with caliper brakes of Pure Fix Original Series

Tiny metal fragments from the rims embedded in the brake pads is fairly common, although the amount you have in yours looks excessive to me.

The rims may have not been machined very well and had poor surface finish which lead to the high level of contamination of the pads. As the rims wear in this should decrease. You don't want to leave all those bits of metal in the pads, you can pick them out with the corner of a razor blade or replace the blocks.

You could try smoothing the rim braking surface with something like Scotchbrite to remove any loose particles. I would not use anything much more abrasive than that.

Don't worry about circumferential scratches on the rims, they will be smoothed out by wear in time.


Saddle or frame shape for painful Coccyx?

A good seat should put most of the pressure sitz bones rather than the tail bone. You'll probably want to look for something like the Rido Saddle which has the back cut out and would probably minimize pressure on your coccyx. I can't say whether this type of saddle would work well for you, but in my mind it seems like it might do a good job.


After conversion, Paramount OS is super squirrely

If the headset is good then you need look at tire balance

The tire itself could be out of balance and also it could not be seated evenly.

Examine how tires are seated.

Put it on a stand or upside down and see if the wheels hold in position. Rotate 1/8 turn and check all 8 positions.

For the rear you can spin the pedals - at high speed does it wobble?

If not balance then pull the tire and remount it.


Should I consider buying a velomobile as my daily commute vehicle instead of a bike?

By velomobile you mean something like this, a fully enclosed/faired bicycle, tricycle, or quadricycle:

Unless your commute is in the heavy rain/snow and you have a fully enclosed velo; or you're commuting more than 100 km on salt flats each way and need the air-resistance efficiency, there are very few advantages to a velomobile and very many disadvantages:

Velomobiles:

Are very heavy/slow going up hills, or starting up from stop lights for that matter
Are terrible to park (take too much space)
Are terrible to secure (no easy place to put a U-lock)
Are terrible at maneuvering (around your workplace's parking lot, for example) because you can't really walk most velos by yourself
You're too large to split lanes but also too slow to keep up with traffic so that cars will honk at you when you take up an entire lane.
Can't easily be carried up stairs
Won't fit on a bike rack, back of a car, or in an elevator. This has implications for mixed mode commuting (bike+bus or train) as well as makes it difficult if you have a major problem at the side of the road and need to transport the velo back home, to work, or to a repair shop.
Many enclosed ones can be very hot in the summer
Are expensive to buy, fragile, and expensive to fix/maintain (thx Rider_X)
And ... are just the right height to get squished by a truck or bus

Now, electric-assist velomobiles do have some advantages, but (as the podride homepage you initially linked to itself notes,) the four wheel version is in a legal gray zone as in some jurisdictions it might be considered an automobile rather than a bike or motorcycle. And if you are in a jurisdiction where the motor is limited to 250 watts, be prepared for a lot of hard work pedaling.

Tl;dr If you want a small electric car, get a small electric car like a neighborhood electric vehicle (USA) or motorized quadricycle (EU) These have license plates and can be driven and parked on local roads without any concerns about legality. They also have headlights, tail lights, turn signals, and other safety equipment.


I want to change the tyres on Voodoo Marasa

Changing tires will help - but probably not as much as you want. The annoying truth is likely simply that the people passing you have lighter, more efficient bikes and are fitter and stronger.

That said, you can definitely decrease your rolling resistance with narrower tires, with less tread, running at a higher pressure. The narrowest you can go is limited by your rim width. There are many rim with vs tire width charts out there you can consult. Manufactures also specify minimum and maximum rim widths for their tire models.

A 28mm road tire is probably as narrow as you want to go on your bike, even if your rims allow narrower. Be aware that narrower tire affect ride comfort significantly.

Other things you can do are: make sure you are not running pressures that are too low for road use in your current tires; make sure you drivetrain is clean, lubed properly and not worn out.


What is the biggest component difference between a cheap road bike and an expensive road bike?

As with any other equipment, it depends on how much you would like to spend...

The main difference between a cheap and a better bike is the quality of the materials and the comfort/performance they provide!

I have several cheap bikes and two "better" bikes, the differences between these are:

better derailleur system, both the front and back, it makes a lot of difference!
better shifter (the cheap one has a thumb-type shifter, and the better has a shimano trigger-type shifter), for me having trigger-type shifter is a huge difference in comfort
better brakes (you could go for the v-brakes, but there are some flavors to choose from; you could also go for a disc-brake; also the brake levers can make a lot of difference also!)
tyres, normally the cheap bikes have sub-par tyres and tubes.
obviously the wheel (good rims, good spokes, I have noticed that indeed!)
the frame, weight, strength, shape (cheap frames can affect a lot on the way you ride, but honestly I've had cheap frames and loved them!)
seat, a good seat and seat post are important.
overall, good materials, that don't disintegrate after some time and resist (as possible) to the corrosion.

I may have forgotten something but this gives you an idea.


Can I put a road bike tyre on a mountain bike?

They make slick tires for mountain bikes used as commuters (and fat slick tires which the air provides a lot of cushioning). Some examples are Schwalbe's fat franks or big apple's (these are more baloonbike) or Marathons . Thinner doesn't necessarily mean more comfortable - in fact, the smaller the tire, the less comfortable it will typically be (this is a function of the bike's geometry and setup as well as the terrain and tires and tire pressures though). Go to your LBS and ask them for tires for road use or commuting and they will probably point you towards something similar to the Schwalbe big apples. Currently on my mountain bike which i use for commuting, I use Geax Evolution tires since I got them very very very cheap (though something like their street runner or some of the Kenda Kwick tires are probably something better for just road use if you're cheap).

You can't just take a mountain bike wheel and put it on a road bike and vice versa - the brake mounts and what not have to match up (this has been discussed a few times on these forums, whcih you can find with search) which is difficult if they're running different sizes.


I want to start riding a road Bike. Is it a big difference if I buy a generic one?

Both bicycles have similar components (the Gravity slightly nicer drivetrain, but with a cheapo looking seatpost, etc) and are manufactured in similar facilities in China or Taiwan. The Trek will be set up and fitted by your local bike shop, which will be very helpful if your local bike shop is competent (some aren't).

The Gravity will be set up & fitted by you unless you can find a bike shop to pay $50-$150 to do that work for you-- many won't want to do that work on a bike they haven't sold.

My girlfriend has a Gravity that she's used as a commuter for the past two years in addition to some touring & road rides, and it's done well— it's a perfectly competent cheap bike.

If you yourself were skilled at working on bikes, or have a friend who's willing to help you fit & assemble your bike in exchange for some beers, you'll get a much better value out of the Gravity. But since it sounds like you're not in that situation, and it's fall when bikes go on sale, you'll probably do better buying a Trek/Giant/whatever from a good bike shop on clearance.


Yeah, that bike is more than adequate for that type of riding.  The only thing you might consider tailoring for your riding styles would be the tires.  The trail you posted looks pretty smooth.  If you got into some trails that were looser or rocky then you could go with something more knobby and/or higher volume.

I say just ride the bike and enjoy the trails.  If you haven't already, figure out how to dial in your suspension and you should get tons of great riding out of that bike.


Does riding high gear up a hill damage a recumbent bike?

The bike will be fine -- the riding conditions are within the specifications of the bike components.

The bigger issue is you -- you don't want to end up damaging joints and what not by overexerting yourself.


How to stop air leak when disconnecting inflator from Schrader valve?

I do two things - I overinflate the tyre by about one stroke of the track pump, and if the pump has a lever I flick it off pretty smartly.    However my pump at home is a thread-on track pump and doesn't have any issues with pressure loss when slowly unscrewing the hose from the valve.
Also, try another pump.  Borrow one from another cyclist, or check the LBS for an air line.  Some bike fixup workstations have a pump built in too.  Last resort is to try a car air pump at the local service station, though they can be quite brutal.
If you use a track pump, leave the handle in the up position while disconnecting the hose head from the valve, and you'll see the handle fall under its own weight.  I bet the HISSSS of air moving stops at the same time the handle bottoms out, suggesting that the released air is coming from the pump not the tyre.
Lastly for self-reassurance, check your tyre pressure by hand before removing the pump hose, and again immediately after.  You'll have a good-enough muscle memory for the pressure needed by your thumb to dent the tyre's tread.  I expect it to have exactly the same perception of resistance to your thumb before and after hose disconnect.

Minor clarification - the pin does NOT need to be pressed down in a schrader valve to add air.  If the air in the hose is high-enough pressure to overcome the internal tyre pressure plus the spring pressure, then air will go into the tube (barring no leaks or sticky valves)


What is the sliding bar on the bottom of my road shoe for?

Seems that is the Look Memory Eyelet, where you can attach some kind of tab to help get replacement cleats in the same position.

This Keo page seems to have a video on the subject, but I can't view it immediately ...


GRX Di2 front derailleur compatibility with Ultegra 2x crankset

Is there any particular reason you want to mix FC-R8000 cranks with a GRX Di2 FD-RX815-F front derailleur? the Ultegra Di2 FD-R8050 will get along just fine with GRX Di2 rear derailleur as Di2 sees it all as part of the road family.
the GRX front derailleur, including the Di2 FD, is shifted +2.5mm outboard to match the GRX cranks. I would not count on it working with your Ultegra crankset. that being said, depending on where the frame manufacturer's actual braze-ons lie relative to Shimano spec, the chainline issue may or may not work. unless you've bought smaller chainrings for your FC-R8000, however, your large chainring is too large for the FD-RX815-f, which is designed for a 48T max. if you have purchased the Ultegra 46-36 chainrings for cyclocross, you'll be even further from the 17T capacity of the GRX front derailleur, so I'd treat the front drivetrain as a package deal, and if you must buy one before the other, maybe buy the crankset first.
There was a post on the S-Tec (Shimano bike shop employee site) community forum where a user said that on his Di2 equipped Trek Boone, he was able to get the GRX crankset to work with his old (non-GRX) front derailleur. I wouldn't expect it to work as well in the opposite direction, but the location of the FD braze-on on the Checkpoint might be slightly different one way or the other.
According to a post from 9 months ago on the S-Tec forum, you could even use the RD-RX-817 with a front derailleur, albeit with some limitations, and no official word on "whether or not that will be 'fixed' in a later patch."


New chain, new cassette, new trainer...new noises

I got the same with my new COVID-Kickr, in my case it was simply the alignment of the cassette/trainer with respect to the frame/rear-derailleur/chainline.

For whatever reason the usual stops in the frame that ensured same/similar alignment when mounting the wheel just wasn't quite right for the trainer (skewer QR system here).

It's hard to notice as without the wheel you can't check the placement with respect to the front of the chainstay (or brakes in terms of 'roll' misalignment) as you would with a wheel (assuming it's correctly dished).

If you're grinding in the bottom 3 then I'd suggest your first tweak would be rotating the trainer slightly counterclockwise (looking down) with respect to the frame, this amounts to relatively more rearward in the left dropout, and/or more forward on the drive-side. If it's better then that's a win, if it's worse then go the other way.

Either way it's helpful to get someone else to ride while you investigate (wish it were so easy on an actual bike huh!)


Is rubber cement in stationery stores the same as in tire patch kits?

The "cement" used in tire tube patch kits (de)vulcanizes the rubber in the patch and of the tube. Which is a chemical process, usually using sulfur, where the rubbers bond and form a stronger bond than just an adhesive would do.

Rubber cement is just a gooey adhesive. Usually latex with acetone and other chemicals to make it more pliant. You wouldn't want to use it to patch a tube since it is not very strong, will degrade the integrity of the surrounding rubber and patch, and in general make a mess.


Yes, you can use 120mm hub. In my opinion the frame is well within tolerance for 70s steel bike. If the difference bothers you, you can add an 1mm spacer to each side between cone and locknut.


How many chains before the cassette is replaced?

This is really going to be different for each person. If you replace your chain early enough, there should be very little wear on your cassette and you can go more chains between cassettes. If you let the chain go for a long time, you pretty much have to replace the cassette with the chain.  Each one should be replaced as they are needed depending on wear.  The amount of wear on the cassette is going to depend a lot on your riding style. If you spend a lot of time in one gear, that sprocket is going to wear out. If you use all the gears evenly, the cassette as a whole will last more miles.


Can you use bicycle boulevards for effective interval training?

In principle yes, but keep in mind that, while you will be using public places you will be likely meet other cyclists who are not there to train and will act, to your eyes, just like moving obstacles: kids riding and suddenly stopping or turning, flocks of teens looking at their phones while riding one hand and then suddenly stopping their bike across the lane, elderly people just taking a ride to enjoy the sun, etc.

You, while busy in training, might even call them like CSO (Cyclist Shaped Object), but in reality they are as legitimate users as you are. And I know fellow amateur cyclists who prefer to practice peloton techniques on the highway rather than on a cycling lane (dumb, isn't it?).

With that in mind, how heavily will that affect your training schedule? If you are really chasing the numbers and the performance I assume the impact will be heavy, and maybe it is better if you look for a better place (either less used or dedicated to training). If you just want to put some more effort, go for it and take it as a good chance to also improve your reflexes.


14" tires are actually quite common on department store bikes (Wal Mart, etc), but they are not found on "bike shop" brands. I think this is where some of the confusion on this issue has come in.

You will almost certainly be fine with the slightly wider tire. For one thing, there is no true standardization on tire widths. I.e., every company uses its own gauge for what it means to be 1.95", etc (I once had a 2.55" tire from brand X that was narrower than a 2.2" tire from brand Y).

To be on the safe side, make sure you have a little clearance wherever the tires pass the frame or fork; but I would bet money that the 2.125" tires will fit, and on top of that you probably won't be able to tell any difference between the old and new tires.

EDIT:
Apparently I don't have enough points or something to comment on the answer that links to the Schwalbe website. I was going to say, "Those tires with fractional widths on the Schwalbe website will be entirely different from the tire with a decimal width mentioned by the O.P. If the O.P. gets a 14" tire with a decimal width he will be fine. In the USA I doubt there is anything else to be had."

Finally, if Wal Mart does not sell replacement tires for its own bikes (regardless of the marked width), any bike shop can order the correct tires for you and offer you a guarantee that they will fit.


Why are frame pads no longer readily available?

From my perspective (normally a road bike user, and fairly good at falling of an MTB on rapid downhills) when I fall I always try to leave the bike, as pedals, cranks and sprockets hurt legs.

So to me the most important things to protect are head, elbows, knees/shins and back. Frame pads aren't going to do anything for me, but protective clothing will.


How is bicycle fit affected by switching from a riser bar to a flat bar?

Looks to me like the difference is as much in the stem as in the bar.  (It may be that for the Dr. Dew the bar has simply been rotated to a flatter position.)  And both bikes appear to use a threadless headset, so the stem can be replaced without touching the headset proper.  In some cases the stem is designed to allow it to be removed from the bar without having to "strip" the bar, in other cases not.  Can't tell from the pictures.

Minor differences in bar position -- height and "reach" -- can have a major effect on riding comfort.  Lowering the bar and/or moving it forward will significantly increase the pressure on the hands and add strain to the back.  It does improve aerodynamics significantly, but, unlike with a "drop" bar, you tend to be stuck with that lower position, even when you'd like to relax a bit.  (But there are various add-ons for straight bars that allow one to switch back and forth between a relatively upright position and a more aero one.)

(In fact, it's a pet peeve of mine that many bikes are designed to look "mean" on the showroom floor, with bar positioned low, but the bars are positioned too low for the comfort of most riders, and the threadless scheme makes it harder to raise the bar very much.  As a result, many bikes are purchased, ridden for a few weeks, found to be uncomfortable, and then forgotten.)


Bottecchia are an Italian brand who sell everything from BMX bikes to professional racing bikes. Here in the US the brand is probably best known for being ridden by Greg LeMond in his historic 1989 Tour de France win.

It's hard to say the exact model of this bike. It's a low end model from the 1970s "bike boom". The crankset appears to be a Nervar cottered steel unit. The shifters and derailleurs look like low end Huret models. Both are typical of early 70s bikes.

Depending on your budget you could almost certainly do better than this. Bikes have made tremendous gains since the late 80s. Not only have they gotten lighter but they've also become more reliable. I would look for something more recent.


The new Copenhagen wheel - a worthwhile investment?

Some of your questions are not answerable, so I will only focus on what can be answered.

  Does anyone have any experience with it?

No one has any real experience yet as the wheels are still on pre-order.  A friend pre-ordered nearly 2 years ago and is still waiting.  That said, you live near their headquarters (Cambridge, Mass) apparently you can demo a unit.

  Is it more practical to buy a complete electric bike or to use a
  conversion kit?

This depends on what you mean by "practical" and what your use case is.  If you are planning on long distance commutes (e.g., 40+ km) with a high assist level, then it will not be practical as the battery housed within the wheel may not provide enough range.

If by "practical" you mean easy to convert an existing bike, the answer could be yes if your bike matches their required specs.

For geared bikes your will need rim brakes on the rear wheel (no disc brakes) and a rear hub spacing of 135 mm (road bikes are 130mm and will not work unless you spread the frame - difficult and requires steel frames).  If you are fixed or single speed your rear spacing will need to have a standard track hub spacing (120mm).

You will also need a smart phone in order to interact and change the settings on the wheel.

If any of these are a deal breaker then it is not practical for you.

In terms of pricing it is very competitive relative to existing electric bike or existing conversion kits.  Assuming it actually ships and works as advertised.

NOTE: For those unfamiliar the Copenhagen wheel is self contained (battery and motor are housed within a large hub)  rear wheel which you swap out on an existing bike.  Assuming your bike (or bikes) is compatible, this makes turning an existing bike into an electric bike a relatively quick and straight forward conversion. All controls are done via a smart phone application and bluetooth


Rockshox Quadra 21R -- Removal tips for old brittle elastomer

The replacement elastomers I ordered from suspensionforkparts.net arrived and I replaced them this past weekend. Easy job, and the front suspension works like new!


What is the difference in procedures for bleeding different disc brakes?

It's necessary to understand the design of the systems to understand why Avid requires a separate bleed kit.

There is a significant difference in the design of the brake system between Avid and other manufacturers such as Shimano and this is the main reason on why Avid have a proprietary bleed kit.

Although an 'open' hydraulic system Avid's Taperbore resembles a 'closed' system, one that operates in a vacuum. The Avid system uses a small reservoir fixed amount of fluid in the system and a bladder around the master piston with air in it. Shimano and other brands use a larger reservoir with a bladder separating the brake fluid (in this case mineral oil) and air. In both cases air is used to compensate for the fluid in the system expanding.

Because the Avid system operates in a vacuum it requires all air to be removed from the system and that is why you need the two syringe set, other designs simply require fluid to be topped up in the reservoir and air worked out.

All the different brake fluids have different characteristics (boiling points, freezing points, amount of expansion etc.). Avid specifies DOT 4 and 5.1, which is a pain. Like all solvents you don't want to get it on your hands but it isn't going to kill you unless you work with it everyday without protection. DOT fluid is hygroscopic, it attracts water so although you can buy it in larger quantities cheaper than through Avid it doesn't have a good shelf life once opened and probably shouldn't be opened again.

To bleed Elixirs you don't need a Avid bleed kit, just a hose barb that fits and some generic hose. I use the brass hose barb which is for my Rockshox x-loc and generic hose and syringes.

Also you can do a less complicated 'speed bleed' to remove air from the system, but a full bleed is better. I bleed the brakes on my hack/ commuter but leave it up to the wrench at my LBS to bleed the brakes on my XC bike (I just don't see the point in paying a few hundred for good brakes and then not getting them optimised by a professional).


The manual  says on page 24

THE SETTING MENU CANNOT BE LAUNCHED WHILE RIDING THE BICYCLE:  The product is designed in such a way that the settings menu cannot be launched if it detects that the bicycle is being ridden. This is not a sign of an abnormality.  Answer: Stop the bicycle to adjust the settings.

Resetting the trip meter is on page 27 of the manual.  Problem with this is its the bike's odometer, not a trip meter for each ride.  So by resetting this you have no idea how far your bike has gone in its life.  This is valuable information for servicing intervals.  It would be like clearing the odometer for a car.


How do i tighten the steering on this type of head?

Its a quill stem.

Remove the rubber/plastic cap from the top and you will see a bolt head, which needs tightening (probably hex). Don't over tighten it.


The parts that Blam refers to are known as the pawls and the ratchet inside the freehub. Slipping can happen for a number of reasons, including worn ratchet, worn pawls, weak springs, or excessive accumulation of grease & grime within the freehub.

http://dirtmountainbike.com/features/work-freehub-body.html has a thorough explanation of the different freehub types.

Depending on the hub you have, a repair consists of either cleaning, rebuilding or replacing the freehub. Some freehubs are rebuildable, others are not and must be replaced as a unit. That said, it's often possible to extend the life of a non-rebuildable freehub by flushing out the old grease & gunk and regreasing.

The mechanic at your local bike shop can almost certainly take care of this for you. If you're more of the do-it-yourself type, http://www.parktool.com/blog/repair-help/freehub-service has step-by-step instructions for several different freehub types.


Problems with Edge 510 Cadence/Speed Sensor

I also have an Edge 510 (since ~3 months) with the same sensor, but I have not experienced this. I have recently updated to the latest firmware, which often solves similar issues with power readings.

Since you were riding at quite low temperatures, the capacity of the battery does decrease, but since the speed reading is fine I would not suspect the battery if the sensor/battery is not old (?).

There is a line/groove on both the sensor and the magnet -- check that they still line up properly.

Check also that the sensor is installed in the correct orientation: the battery cover faces the wheel in my case.

You should also verify if the sensor also acts this way when used indoors at room temperature.


Shimano 105 front derailleur cage won't move at all

Myabe have a very careful look at your cable route.

That little pin can make the pull action go around the pivot on the wrong side, actuating the mech against the stop.


What bottom bracket would i need for my Specialized Allez Sprint 2020?

It's a BB30 frame with a normal BB30 bottom bracket in it. The adapters you picture are 24mm spindle adapters that plug in and reduce the ID to the 24mm that Shimano cranks want, and put the face to face spacing where they expect.
The other way to do it is use one of the press-in threaded inserts like the FSA one, into which you can then install a threaded bottom bracket, or use a thread-together adapter BB.
Since you already have these that's probably reason enough to do it that way. They're simple and work but have the drawbacks that they maintain the longevity and creak issues BB30 can have.
The 24mm BB30 adapters I usually use completely take the place of the BB30 bearing shields that the BB comes with. I can't tell if yours do or not, so you'll need to see what fits best and seems to provide correct spacing for the cranks.
Many BB30 frames have internal routing schemes that render the plug-in adapters the only practical choice due to access or interference considerations.


I don't think all Maxle's are the same, but I've had two different types and each could be tightened in a slightly different way.  With one (I believe an older design) there is a 2.5mm hex bolt on the lever end which you can tighten/loosen to affect how tight the lever is.

See an example of this here:

http://www.bike-manual.com/brands/trek/om/assets/pdfs/09sram_maxle_cengdfjnp.pdf

On the other, the lever could be tightened by pushing the end in and twisting.

Explained in this article about half way down:

http://www.bikemag.com/gear/news-rockshoxs-pike-is-back/


In road racing there are lots of way to try and gain an advantage (or not to give others an advantage).  Because this is a friendly race, I will break it down into friendly, indifferent and hostile tactics.

  Update 1:
  The OP updated their question to make it clear that they were a beginner and the other rider was a more experienced road rider. So I have added a paragraph at the bottom discussing the importance of how a tactic or strategy is executed.

  Update 2:
  A fun video:  How To Get Rid Of Wheelsuckers

1) Friendly tactics

These tactics are intended to keep the competition friendly by letting your friend draft, but with the intent of making a decisive move at some point to win, which will clearly demonstrate that you were the stronger rider on the day.

First over the line wins -  Simply put, keep the ride relaxed until near the end, then launch and maintain a strong attack that your friend cannot match.  This keeps them in the "competition" until the end, they save face by staying in until the end and you save face with your devastating tactic.  You can even let your friend take pulls to make it look fair.  The down side is that they may come away thinking the competition was closer than it really was.
Sustained Efforts: There are a couple situations where the advantage of drafting is reduced, you can then use these situations to launch a sustain effort in an attempt to ride them off your wheel, thereby gaining the advantage.

Climbs: As many others have pointed out, a significant climb is a good way to put distance on another ride.  Depending on how badly you want to rub it in you can control the distance.
False Flats: False flats are sections that appear to be flat but are actually have a slight incline.  If you do not have a computer that shows this (e.g., Garmin) the slight inclines can make you feel very slow.  Attacking with a sustained effort on a false flat is a great way to put a gap on someone, especially if you know it is a false flat, but they do not.

2) Indifferent tactics

These tactics are a little more aggressive than (1) and may be fair game depending on your friendship and views on competitive behaviour.

Surge Attacks - If someone is drafting a good way to shake them time a short attack where you can put a bit of distance and break their draft, thereby negating their advantage.

Fast/Faster - For example you can ride at a strong tempo, wait to see if they are straining then do a short burst attack to gain a gap.  They will be tired from holding on earlier and now suddenly out in the full wind.  This will demoralize them greatly.
Slow/Fast - Similar to Fast/Faster you will be using changes in speed to break a draft.  In this case start to casually slow down, this will usually leave someone wondering what is going on... then attack to open a gap and break a draft.
Change direction and surge - If you change directions suddenly (e.g., zig or zag across the road, but no zig-zagging) while surging you can instantly remove the drafting advantage which can make it more difficult for the drafter to close the gap. (thank you @altomnr)
Catch them when they are sleeping  - Wait until there is a real lull in the "competition" to suddenly surge and break the draft.
Conversation to attack - At some point get into a friendly conversation, build a story and just as it starts to get really interesting (and your friend lets down their guard)... attack!  Catching someone off guard is a quick way to break a draft.

Using the wind:  If you live in a windy area and you know the route you can

Attacking into a headwind: this can be used in multiple ways.  One of the best ways is if you have an out and back course with a head wind on the way out, attacking a few km before the turn-around can be a decisive way to score a victory.
Guttering: If you get a cross wind (that requires an echelon in order to draft, you can ride next to the edge of the road to "gutter" the drafting rider.  Because draft position is effectively off the road-way and they cannot move off the road way into the draft they lose the ability to draft and have to do the same amount of work.  This is a good time to attack.

Repeat attacks: If you are in a lot better shape you can launch a series of repeat attacks in quick succession.  They may be able to hold on to one or two attacks, but stacking the attacks will eventually wear them out.

3) Hostile Tactics & Cheating

Depending on how much you value your friendship (e.g., frenemies), there are also some hostile techniques that I have come across in races over the years.  I document them for completeness sake to indicate what should generally not consider as a strategy.

  WARNING: In no way should the "forcing an error" tactics be used against your friend as these tactics can potentially send someone to the hospital.

Forcing an error:

Attacking on technical descents:  If you are a more skilled descender you can use this to your advantage by encouraging someone to try and keep pace, thereby taking them out of their skill level. People will often over shoot corners and otherwise get shaken forming a gap.  At worse you may cause someone to crash and have an injury.
Overcooking corners:  Another horrible way is to deliberately overcook a fast corners so that you can just hang on, but with the intent of forcing them to go off the road or crash.
Riding into hazards: Another way to shake a drafter is take them into hazards such as pot holes, or riding within less of an inch of the side of the road.  The idea is to fake them into letting off.
Brake checking:  There is a special place in hell for those that brake check, but it is effective way to shake someone.

Using a vehicles wake.  If you are a stronger sprinter jumping into a vehicles draft for a period of time allowing you to surge ahead
Lie: While your friend is drafting casually say: "You know I am just not feeling it today... do you want to call it quits?"  Then while they are thinking follow this with a decisive strike.
Change the goal posts:  Near the end if your friend is still drafting suddenly sprint for a arbitrary close finish line.  Claim victory!  As an extension, in the post finish confusion, attack again to actually win.

The Importance of Execution

The tactics and strategy outlined above will rely heavily on execution, which can be difficult for beginners.  Many new riders will only partially commit to a tactic, holding back for fear that it might not work out. The "secret" is that once you decide on a tactic you really have to commit everything to it (i.e., willingness lose and look like a fool). Otherwise it is only a half strength attack which is easier for the other rider to survive. The more experienced rider will be practiced in the determination needed to knuckle down and survive an attack (even though they may be less fit overall).  This mental strength and experience can make them a formidable opponent if you do not fully commit to a strategy or tactic.

It can take time and practice for beginners to develop the "killer" instinct needed for success, so don't get discouraged if a chosen strategy doesn't work first time out. Sometimes you just have to keep throwing mud at the wall to get some to stick.


1x10 drivetrain against 1x11 drivetrain on mountain bike

You get an extra gear ratio and closer spacing of ratios with 11 speeds. 10 speeds drivetrains weigh 1 sprocket less I guess, and 10 speeds chains and cassettes are cheaper too.


How long does an unused helmet keep for?

There is a common "fact" out there that you should replace a helmet after 5 years, regardless of use or crashes as there is concern that the crush properties of the foam may have changed (e.g., hardening) which could provide less protection.

However the data doesn't seem to bare this out.  A recent study did extensive testing of hundreds of used helmets  collected from the general public showed that there was no relevant impact performance change with age.  The helmets tested had been used but showed no signs of damage and were manufactured between 1987 and 2013.

These results show that if your helmet is not damaged there is no need to replace it simply because of aging.  Now likely at some point there is an upper limit whereafter a given age it will need to be replaced, however that limit appears to be well beyond  5 years (some of the tested helmets were over 25 years old - and they still passed crash testing).  The most important thing appears that they have been certified under a recent standard and the helmet is not recalled.


Abraham Olano won the 1998 Vuelta on an alloy frame. That might be the last Grand Tour win on alloy - as the Vuelta is the last Grand Tour of the year.


Crank Arm Compatibility - Shimano Ultegra 6800 and R8000

Yes

The website for the Stages Power Meter mounted to a Shimano Dura-Ace R9100 non-drive-side crank arm says:

  Crank Compatibility: All Shimano Hollowtech II road cranks

This also agrees with Rider_X’s comment and my own guess that they should all be compatible.


Torque of the rails or torque of the post?

If the max. torque on the rails is 6Nm then you shouldn't exceed that in no case. The 12-15Nm is the maximum when the clamp is used with metal rails.
In your case, start by taking the clamp apart and clean the bits that touch the rails of your saddle from any remains of grease with a solvent. Check the clamps for sharp edges and give them a sanding with fine paper if required. Then apply some carbon mounting paste, grease the bolts of the clamp and tighten to the recommended torque for the saddle.


Bicycle is harder to pedal when standing

Something is dragging as you pedal harder. The most likely thing is that your rear wheel is moving so that the tire drags against the chain stay when you apply power.

This is something that you'll probably need to troubleshoot when you're riding because it isn't likely to show up with the bike on a work stand. You might be able to make it happen by applying a standing load to the pedals while holding the front brake. To do this I'd want somebody holding the bars to stabilize the bike (and to help me look for what moves when I load the chain).

The interesting thing about what's happening is that you say the problem goes away when you ease up. If the problem is due to the tire rubbing on the chain stay then there must be some mechanism to return the wheel to its neutral location. The only thing that I can think of right now that might do this is a nutted rear axle where the nut on the right (drive) side is loose enough to allow the axle to move under load and then move back when the load eases up.


Front wheel getting misaligned while climbing hills

That's scary, you shouldn't be able to do that. It sounds as though you can straighten it easily too. If you straddle the front wheel facing backwards can you twist the bars in the fork easily?

If so, definitely tighten it up. Firmly. You should not be able to move that!

Who put the bike together? If it's new, take it back and talk to the owner of the shop - this is something they should be aware of so they can (re)train whoever assembled/serviced the bike. Of course, if it's a big box shop paying schoolchildren $2/bike to take them out of the box and assemble them they won't care, but you shouldn't be buying bikes from them for exactly that reason.

(edit: answer second part of the question) Over-tightening it could break things, yes. But that's normally quite hard to do. If it's a new bike get the shop to do this. If it's your bike it's easy enough to do.

For a modern threadless headset there will usually be two allen key bolts to tighten, and the best solution IMO is the Rolls-Royce one* - use a multi-tool with a short handle, so you don't have enough leverage to overtighten it. Do the bolts up firmly, test by trying to twist the handlebars. If you can, do it up a little more firmly. Then stop, because you don't want to strip the stem and there's probably something else wrong.

For a quill stem there will be a single hex head bolt going down into the headset (rather than across the top). But the procedure is the same, tighten it firmly and test.

In both cases, if that doesn't fix it you should open things up and find out why. But I'll leave that for another question.

Henry Royce made each spanner of such a length that when tightened firmly the relevant bolt was correctly torqued. There's a description here in the paragraph beginning "It is worth recounting that the ‘S’ series".


What is a better gearing combination for downhill?

I ride a hard tail over all sorts of terrain. Generally I ride on the middle chain ring in these situations. Its less to do with the mechanics, and more to do with whats possibly coming up, and fast + reliable gear selection. When on the large chain ring, you can get caught out by a short (or long), steep uphill, and not be able to get a low enough gear to climb it just changing the rear cluster.
I reserve the large one for easy predicable ground, or tracks I know really well - for instance sealed/gravel roads, manufactured fast tracks with sweeping / bermed corners where speed is all important, and you are unlikely / have no need to slow down below about 20km/h.

If the track is steep and rough, I am unlikely to run out of cadence before 'balls' - if you find you (like many others) have a "lower center of gravity" than me (i.e. smaller brain and/or bigger balls), and you run out of cadence, then go for the top chain ring. Also the chain can be dropped far more easily off the top chain ring - although on a well tuned bike this should not happen.

As far as chain slap and derailleur bounce - I ignore it. Its a mountain bike designed to be used and abused. If you want, you can get neoprene coves for the chain stay which will quieten it down, or wrap it in duck tape... I have never heard of derailleur damage caused by slap, but that is not to say it does not happen.


What is best for your brakes when stopping at the bottom of the hill?

In terms of wearing out the brakes, they will wear less when you brake at the bottom.
When you descend a hill you have a fixed amount of energy to lose, and when you descend at a higher speed, a larger proportion of that energy is lost to wind resistance.

Practically however, brake pads/blocks tend to last a long time and are cheap to replace, wear is not really something to consider too much.  It's better to descend safely at a speed you feel comfortable with.