Are bicycle rear racks and panniers suitable for cross-country riding? Later this summer, I intend to make a ten-day travel. It is going to be mainly road touring with one-two-tree days of sloped dirt roads or forest trails possible.

I usually pack heavily, carrying a 60 litre pack, that I will probably fill up for this journey (tent, sleeping bag, beer will be restocked continuously). Both the backpack and bags have rain covers. However, my concern is that putting around 10 kg(22 lb), maybe 15kg(33 lb) directly over my rear wheel will ruin the rim at the first hole I bump.  Which should I choose : the backpack or the system of rear rack mounted bags system?

Related: Why do cyclists prefer messenger bags over backpacks?
Gary Fisher Kaitai suffers from handlebar wobble at moderate speed with 10lbs on rear rack

I'm a member of Warm Showers, and regularly host cross-country bike tourists and get to check out their gear. Except for the occasional monk with orange robes and a small backpack, what bike tourists choose has been surprisingly uniform.

It's usefully Ortlieb panniers on front and rear racks, and sometimes a handlebar bag. The details and presence of the handlebar bags vary some, but the choice and use of Ortlieb panniers has been a near constant. I don't own any yet, but I suspect they are chosen because they are waterproof and durable-- two key qualities for a long distance trip!

Here are a couple sample photos of bike tourists I've hosted (both with Ortlieb panniers)

I would add: don't worry about the weight-- with a proper rack, bike tourists sometimes carry 50 to 80 pounds of gear, much of it on the rear wheel.


Gap between internal cartridge headset and fork so I've replaced the bottom headset on my 2016 Kona Jake the Snake as the old one was rough and rusted. The replacement is the same size in all dimensions however doesn't seem to fit in properly - between the fork and the bottom of the frame there's a sizeable gap. There's no movement in the headset, it's just got about 5mm of space.

The headset purchased is the following: https://www.evanscycles.com/pro-headset-replacement-bearing-outer-52-inner-40-height-7-mm-EV204261

This photo shows that gap, I estimate it to be around 5mm.

this photo shows how it was before tightened the compression screw on the top. I noticed it wasn't quite right so tried to remove it - but it's now jammed into the frame. Comparing the old headset's fit onto the fork, it sits in a very similar way, albeit with a very slightly smaller gap.

This image shows the factory photos of the bike - the gap is visible, which makes me think it's always been like this. There's no crown race on the bottom of the fork, only the taper.

I guess my question is threefold - firstly is there anything that can be done to fix this? the second is, is this safe to ride like this? It seems it's been close to this from factory and the replacement headset is identical to the old one (both are cartridges btw!) The final question is - if it isn't sad for fixable - how does one go about removing a wedged headset cartridge from the frame without mangling it?

Many thanks!

Some forks have an integrated crown race, and yours is one of them.

When you get a new headset for use with such a fork, you leave the crown race out.

Some sources imply the existence of 36° integrated crown races, but all the ones I've ever seen are the common IS 45°. As long as you've chosen a non-weird headset, it should just work.

Do not ride it like you have it pictured. The crown race that's jammed against your fork could damage it. (It probably wouldn't, but don't risk it.)


Trainers & Mountain Bikes Can I use a trainer with a mountain bike?

I want to the same bike off road at weekends so I don't really want to change the setup of the bike.

You can use a trainer on a mountain bike, but a big issue that you will run into if you don't want to change set-up between the trainer and your rides on the weekend is that running knobbly tyres on a trainer is just plain noisy. If you are determined to run the same tyre on the trainer as off-road, I'd recommend looking into the tyres that have a raised, slick low rolling resistance portion in the middle, with knobs on the sides to help with cornering.


GPS mount resistant to vibration? I like to ride with a bike-specific GPS device mounted on my handlebar or stem, so I can look at it whenever I want. I use Garmin eTrex 30 with a mount like this:

The problem is, the GPS device falls off the mount under strong vibrations, and the mount wears out pretty quickly (a few days of heavy riding), which leads to the device falling off even easier.
Which options do I have? Should I replace my GPS device (I like it very much, so I prefer not to) or is there some more sturdy mount, or maybe one with shock absorption?

I have exactly the same type of mount and the same type of GPS with it, and after a few years of use the contact interface has become worn out, just as you describe.
The problem was exacerbated by the fact that it was both the mount guides and the GPS unit's backplate grooves that got widened, so replacing just the mount part would not be very effective.
What I did was to use molding plastic that hardens over 24 hours. There are brands such as Sugru, Kintsu glue etc. that sell it.
Spread a very tiny amount of the substance along the rails of the mount, as well as inside the grooves of the device's backplate.
When hardened, the resulting silicon creates quite extra friction when sliding the device onto the mount. This makes the rattling go away, and secures the device.
Additionally I put some of the stuff onto the "tooth" that latches into the backplate (left side of your picture) and also the square "hole" in the middle of the mount so that it will take up some slack created by the wearing process.
The restoration has worked for me so far. I do not expect it to last forever however, but the procedure can be repeated later when the surfaces are worn again.
Even before I've encountered the problem with the worn-out mount plate, I've always used a piece of a thin cord to tie the GPS device to the handlebars. When I crash, zip ties that hold the mounting plate can snap if something strikes the handlebars (it did happen several times). The GPS can then fly away into an unknown direction if not for the cord.
The same cord is used to bear the GPS on the neck when I am off the bike (I once lost my GPS in the water when crossing/swimming across a wide smelly ditch in the middle of the night. I won't ever dare to hold a GPS device not secured by a cord).


Interesting frame, not sure what I got I just bought this nifty looking bike, but alas I don't know the manufacturer or model it is. There's a logo with a silver looking "Z" and a made in Taiwan sticker. Any help you can provide would be greatly appreciated.
P.S. There was also a sticker that said the bike was "Manufactured Exclusively for S.B.S. Inc., Seattle". Seattle Bike Supply closed about 5 years ago.

It looks a lot like this 1998 Zephyr Boardwalk 6

BikePedia
The Boardwalk also came in a single speed. Both bikes came in men's and ladies models.
Sorry about the bad picture, I looked for better ones.
The "Zephyr" brand was also used to on BMX bicycles.
On the linked BMX bike the logo is similar and there is a "MANUFACTURED EXCLUSIVELY FOR S.B.S INC. SEATTLE WA" sticker.
If the BMX Museum is accurate the BMX bikes were made between 1985 and 1999
Interestingly there is also a "Torker Boardwalk 6" cruiser which looks a lot like the Zephyr. It turns out that:

In 1984, the Torker Bicycle Company went bankrupt, and Seattle Bike Supply purchased the name.
Wikipedia


Why are derailleur jockey wheels commonly made of nylon? Almost all derailleurs seem to come from the factory with nylon jockey wheels . What is the rationale for the use of nylon (rather than alloy or aluminum)?  Is it merely weight savings (which would seem to be trivial given the size) or is there a functional advantage to  nylon/plastic?

Caveat: I've only seen two or three sets of metal pulleys in my life. There are several reasons:

cost: plastic parts are cheaper to make than metal ones
weight: it's easier to make a lightweight plastic part than a metal one (this is also related to cost, "easier" usually means "cheaper")
durability/resilience: somewhat counter-intuitively, plastic cogs are less likely to fail completely. When the plain bearing locks up the plastic wheel is likely to slip on the metal bearing (and many people don't even notice that this has happened), or the teeth with abrade off to form a smooth surface that the chain will run on (it's very hard not to notice this). A metal pulley does not do this, if they stick for some reason generally the bike isn't rideable, and it's unlikely that the aluminium pulley will slip nicely on the steel bearing.

The latter is somewhat hard to get experience with, since metal pulleys are sufficiently rare and expensive that few people use them. Also, people who pay extra for them tend to maintain them so I haven't seen them fail other than via "full of mud, not going round". In that case, though, the chain will not go through the rear derailleur at all, so the bike needs to be converted to single speed before you can ride it. Which is an ugly thing to have to do when you're out on a bike ride.

Note that recumbent idler pulleys have the same concerns but often they're on the drive side of the chain so the forces are larger. So are the pulleys to reduce chain bend angles and thus losses. In that case metal cogs are usually also lighter and quieter but significantly more expensive (more than double the cost). Derailleur pulleys would also benefit from being larger, but that's relatively rare, I suspect because weight and air resistance also increase with size (and a larger cog would mean extra chain, further increasing weight)


Loose cassette on road bike I recently bought a new wheel for my racing bike. The first few rides were in rainy weather so I took the cassette off to clean it. When I put it back on I noticed that there was a gap of several millimetres between the outer sprocket and the lock ring. As a result the two outer sprockets (the ones separate from the rest of the cassette) wobble quite noticeably when I rotate the wheel. The cassette was fitted by the LBS where I bought the wheel. It is 8 speed (Shimano) and has 12 teeth on the smallest sprocket and 25/26 on the largest.

I have another 8 speed cassette on my bybrid bike. That had 32 teeth on the large sprocket and fitted just fine when I put it onto the racing bike. Likewise both cassettes fit ok on the wheel of the hybrid bike.

Having looked at other answers on this site, it seems like the most likely explanation is that I mislaid a spacer when I removed the cassette. Does that seem right, or is there another possible explanation which I have missed.

Seems like I'm a Necromancer again...

Most likely a spacer. No, I take that back; Almost certainly a spacer. With the Hybrid cassette fitting correctly, it's quite often that they are slightly thicker, even by a couple of millimeters. An easy way to check is to check the limiter screws on the deraileur if you haven't adjusted them. If there's too far away from the wheel for where the jockey wheels line up, it's probably missing a spacer. If not, it needs a thicker spacer or more, assuming the gears were properly set up before you took it to pieces.

Also, good call, taking the cassette off to clean it. Too many times, people leave it on their wheel using a degreaser to clean it, and it breaks down the grease inside the hub and freehub body! Annoying because I usually get asked to replace them when it happens, then I lecture them about all the problems from doing so..... Boring!


Advice on buying a SCOTT SUB Sport 10 2014 I have been looking at the Scott SUB 2014 as a potential candidate for my cycle to Paris (approx 90 miles) and a cycle across the South Downs this summer.

Having such different terrains, I was wondering if anyone has any insight as to the quality of Scott bikes (never owned one before) and suggestions as to if you think this bike would be fit for purpose.

Would love to hear your thoughts, full spec can be found here.

Scott is a fine brand. The most important thing is how it rides and fits for you (this is a highly personal decision on your end).

For a 90 mile ride though, you may want something with drops (with a relaxed geometry - something like a Trek 520 wouldn't be bad for this purpose, for example) or a flat bar with bar ends or a trekking bar or something for multiple hand positions if you're taking the 90 miles in essentially 1 or 2 shots. However, I'm not familiar with the particular European terrain, so I'll defer to the Europeans.


Bike difficult to pedal I added a new rear wheel to my bike, and set the chain and spun it by hand so it spins properly. However it is very very difficult to pedal, requiring a lot of force. Also when I pedal, I hear a light grinding sound that I can't identify. Does anyone know how I can fix this?

This could be a number of things. Any of the chainset components, hubs, brakes.

To narrow it down,

Take the chain off the front chainring and pedal by hand, do you feel any resistance here? If so this could indicate a problem with the bottom bracket
Spin the wheel off the ground by hand in a forward direction. Does it spin freely and continue spinning when you let go? If not this could indicate brakes or hub bearings
If neither of the above are the problem then it's likely your gearing, and its probably best to take it to your local bike shop for repair.


Friction Shifter Rear Derailleur, Not Holding Low Gear My 86' Raleigh 10 speed with friction shifters insists on not holding the lowest gear. If I hold it in the low gear, it will stay but the moment I remove my hand, it goes back up. I'm assuming it is a bent derailleur because it theoretically shouldn't resist a gear that much... I have fiddled with all the adjustors, but nothing is changing the problem.

It may not be a bent derailleur, but a bent derailleur hanger. You can buy the park tool derailleur alignment gauge and bend it back to shape or have a shop do it for you.

After that I would check the cable tension, disconnect the rear derailleur cable and make sure that the chain stays on the smallest cog to start and then slowly the tension appropriately to make sure it shifts in to all gears properly.

Also, check to make sure you don't have a loose bolt on your friction shifter that is allowing too much play in the lever, which may let it slide out of the desired position.


why would my chain slip on the road, but not when the bike is on a stand? The chain on my bike has started to slip a lot -- every couple of seconds when riding. It happens, as far as I can tell, in every gear, and is unrelated to shifting.

The precise nature of the problem is hard to diagnose because I can not make it happen when the bike is on a stand, it happens only on the road.

What kind of chain/derailleur problem would manifest only on the road and never when the bike is on a stand?

You likely have a problem with worn drivetrain components. You only really notice the jumping under load is my experience.

It's either a worn chain or a worn cassette in most cases. If you replace the cassette, replace the chain too.

Surprisingly enough, a worn chain and a worn cassette may work well together till one of the two parts are replaced.


What type of bike is appropiate for my situation? First off, sorry for being unable to phrase my question more precisely. Currently, I ride a 26" hardtail mountain/trail bike to and from work/university (around 7km each way). Surely, this is not the ideal bike, but I do love the ruggedness (occasionally jumping a flight of stairs etc.) and maneuverability. So I‘m not going to replace it entirely, but rather extend my fleet.

Also, I’m considering doing a bike tour through Europe once I finish my degree (another two years until thats the case). In the meantime I’d naturally like to train, i.e. riding more than 50km at once, which isn’t nice on a trail bike.

Also, I plan on building it myself, if that makes a difference?!

So here are my concerns:

Should I just buy a touring bike now? Seems they are too heavy for what I need now.
Should I buy a fixie? I’m surely not interested in being fashionable, but I read here that it helps develop a smoother pedaling style; that can’t be bad?!
Should I get clipless pedals? There are some which you can still use with normal shoes, is there a major drawback?

But mainly, what type of bike?

Edit: Based on the answers so far (thanks guys) I noticed that I wasn’t really clear. I don’t want to use this bike for touring, I want to get around town quickly and do a longer day tour with it, no need for carrying stuff.

If it were me I would buy a comfortable steel road bike with fenders and racks. This will give you a bike you can comfortable go distances on as well as practicality for the commute. You aren't racing so you don't really need an extremely expensive, high end road bike and a steel frame will be comfortable and durable assuming you store it properly. When you feel the need to romp around you can take your MTB out. If the road bikes are out of your price range then consider a similar setup with a single speed/fixed gear. Fixed gear bikes will make you pedal smoother but a disciplined rider of any bike can get the same benefits using cadence drills without the added danger of getting bucked by pedals moving faster than you can.


wide rims/narrow tyres danger? I've got a set of fairly wide road tyres (32c) on my charge plug. I'm looking to move to 23c. My current rim (inside) width is 22mm I've heard of some dangers of narrow tyres on wide rims, but no one has been specific or had any hard evidence of problems. Has anyone heard of any problems or had any troubles? As far as I can think, logically there shouldn't be any?

If you at the Sheldon Brown tire width chart,  you can see that there's only 1 width listed where 23 and 32 are recommended. On that page, he says using too narrow a tire can result in pinch flats and rim damage. If you think about the extreme case, where the width of the rim is almost as wide as the tire flattened out, then you wouldn't have much cushion between the rim and the road.

What is your reason for wanting to go with such a narrow tire? Wider tires are more comfortable and offend have less rolling resistance. the advantages of narrow tires are lighter weight, and more aerodynamic. however, the aerodynamics only matter at very high speeds, and a good quality 32 mm tire won't be that much heavier than a 23mm one. If you want to go a little narrower, you should probably try 28 or 25 at a minimum. A lot of racers are using 25 mm tires now.


How to lock up a bike with a rear wheel lock? Really did try searching for this but couldn't find an answer. I'm getting a bike with a rear wheel lock like this:

Since the rear wheel is locked to the frame then would securing the front wheel and frame to a solid object with a ulock/chain be enough? Bike is around $1500 in the US, higher than average larceny in my city but not known for bike theft. Here are my options

1) Rear wheel lock + ulock or chain around the front wheel, frame, and bike rack = 2 locks in total

2) Rear wheel lock + chain around rear wheel, frame, and bike rack + pitlock skewer for the front wheel = 2 locks + skewer

3) Rear wheel lock + chain around rear wheel, frame, and bike rack + ulock around the front wheel and frame = 3 locks in total

4) Rear wheel lock + chain around rear wheel, frame, and bike rack + ulock around the front wheel and frame + pitlock skewers on the front wheel, saddle, everything

Living in a country where this is the standard bike lock I have learned to work with it.

For a short stop where the bike is at little risk or while getting your second lock out, always lock this lock as soon as stopped.
Then you get a second lock out, U-lock, a cable or chain as per your choice or your insurance requirements or a combination of those.

As the rear wheel is locked to the frame, you can now select to use your second lock for the front wheel to the frame and both to a fixed point.
Or you can get a cable to be locked into your ring lock, either as a separate entrance to the lock for which the lock has its special hole, or one with a loop to go round the locking pin. And use that to fix the bike to a fixed point when you chose to lock the front wheel to just the frame.

I have always chosen a separate cable lock (when insurance allowed) or a chain to connect the frame to a fixed point, but my bike is not as valuable and always one of many where parked.
For a valuable bike I would likely use a good quality U-lock, a good quality fixed point and use that to lock the front wheel and frame.
If no good quality fixed point is available, I would not leave the bike there.


RevoShift Friction: shifting to the largest gear takes a lot of force? My wife's bicycle has Shimano Revoshift shifters, and while the right (rear) one works fine, the left (front, Friction) has been problematic for a while. Originally, when we bought the bicycle, the left shifter made a clicking sound when it was turned. After a while, it stopped clicking, and since last summer, it has required tons of force to shift from the middle gear to the biggest gear.

I've tried to adjust the front derailleur (orientation, height) and the low and high limits, as well as the cable tightness, but nothing seems to remedy the force. This morning, I took the shifter apart, suspecting that something would be broken inside it, but everything seemed OK. I put it back together, but it still doesn't click and I have to use both hands to turn the lever to get it to the biggest gear.

I suspect that there's still something wrong going on in the shifter, though. If I gently pull the cable underneath the body, the shifter rotates. It shouldn't do that, should it?

The exact model is Shimano SL-RS35. Thanks for any help in advance!

Some of the revoshifts are actually friction and just don't click period, while others are pseudo-friction (they click in small increments so you can trim your shifts) - I suspect you have the latter. They are also the bargain bin parts (less than 20 dollars for a set), and thus are built with low quality and things often go wrong. Pretty much all you can do is check that the cable tension is OK, the cable isn't caught on anything and the derailleur is set up properly (If the shifter is gunked up, sometimes flushing it with WD40 helps, but thats just a temporary fix).

As suggested in this question, I recommend throwing out the RevoShift shifters if they start to cause problems and then replacing them with some other cheap shifters (maybe switch the left on a cheap thumb friction shifter, or a Shimano trigger shifter with the same number of speeds, or a SRAM Attack front shifter if you want to stick with twist).


Surly Trucker Disc Compatibility with Ryde Taurus Rims Is it possible to put these Rims (Ryde Taurus 21 Disc: 26', 21-559) on this frame (Surly Trucker Disc)? I just cannot find any hint at the Surly Trucker description, but since I am not a native and new to bikes I might have missed something.

By the way, I want to use a Shutter Precision PD-8 hub but I think if the Ryde Taurus fits and I know the Shutter fits into the Ryde I can use it as long as the Ryde Taurus can be used.

EDIT the wheel size for this bike model depends on the frame size!

26˝ wheels for frames 42, 46, 50–62 cm
700c (a.k.a. 28") wheels for frames 56–64 cm

So you need first to make sure that your bike runs wheel size 26", as Ryde Taurus rims are 26".

Having smaller wheels on a frame designed for bigger wheels is possible for disk brake systems, but it is not recommended unless you are certain (i.e. you have already tried it) you will be fine with changed (worsened) bike handling.

The same web page, "Complete bike parts kit" tab lists both 29" and 26" wheels as options, depending on frame size:

Tires (26˝) Continental Tour Ride, 26 x 1.75"
Tires (700c) Continental Contact, 700c x 37mm

The rims you mention have 19 mm inner width:

These rims should be compatible with the original 26" × 1.75" tires.

Note that you asked about frame vs wheel rims compatibility. You also mention hubs that you want to use; frame/hub, fork/hub and hub/rim compatibility issues are different question. In particular, the chosen rim should have the same number of spoke holes as the hub has, and that hub comes with hole counts varying from 28 to 36.


Shimano 105 v Tiagra I have a new Giant Fastroad, with 10 speed Tiagra, my old bike (7-8 years old) has 9 speed 105.
I think that the 105 was smoother even on the old bike, would the 105 be compatible to fit to the new bike and be able to cope with the extra gear?

Shimano 9 speed has a different pull ratio to 10 speed.
So this wouldn't be possible.
If your Tiagra is the newer 4700 series - the cabling is routed under the tape - which gives a cleaner line but I found on my Shimano 5700 105 (vs the older 5600 external routing) gave a stiffer shift.

I have found on servicing my cables with lubed and sealed Jagwire - the shifting has improved greatly though.


Internal gear hub maintenance I have a Muji utility bicycle with a 3-speed internal gear hub which I got second hand around 5 years ago. The LBS which I bought the bike from has since closed down and I haven't managed to find another bike shop which does maintenance on this kind of bike (the last one I visited just told me if my bike broke down I should get a new one). I was wondering how complicated it would be to do maintenance by myself and if anyone has experience with internal gear hubs?

My experience as a bicycle mechanic in the Netherlands: don't mess with it.

If it is an Shimano, it will probably run >100.000 km. If it is a Sturmey Archer, SRAM or any other well known brand, it will mostly do >50.000 km as well.

If there is a small hole for lubricant, only do this once a year or so, with some thin grease, but not oil. Oil is to thin.

If it doesn't shift well, first look at the cable. You probably only need to adjust the tightness of the cable. If this doesn't work, de-attach the cable. Every hub must work correct in the smalles or biggest gear without a cable attached. If this still doesn't work, the hub is broken. (Happens almost never.) If a 3-gear hub is broken, it is easy to take apart and build together again. And finding which gear or bearing is broken isn't difficult either. Finding a bearing balls is easy to, but finding a spare gear is probably not so easy.

Main point: leave it as it is.


Why do disc brakes stop faster in dry conditions? I have heard that bikes with disc brakes have shorter stopping distances even in dry conditions, such as the comparison in this video:
GCN - How Much Faster Can You Stop With Disc Brakes?
At about 1:30, on a dry gravel road, the bike with disc brakes stops 2 meters sooner:

My understanding based on car tires is that stopping distance is a function of the tires' traction with the ground and whether the driver/ABS can avoid locking up the wheels (source). While there are higher end cars with fancier braking (e.g. disc brakes on all wheels, or bigger brakes), the main benefit is dissipating heat faster under repeated braking.
Is it because disc brakes allow wider tires which have a bigger contact patch? Or do I have an incorrect assumption - maybe stopping distance is not traction limited in bikes? Thank you.

No, the stopping distance is not just traction limited - or at least not just by the wheel/road surface combination. Even if you can block your wheel with your rim brakes and get the wheel slipped, you might be able to stop faster with better modulation when you actually avoid the slip. The consistency in breaking in the disc brakes helps to predict the exact force necessary.
Also, the raw power is definitely bigger, there is no question about it..


What parts do I have to change if I want to change my derailleur to higher speed? I want to change my derailleur from a Tourney TY-300 to an Altus M2000. What bike parts do I need to change? I want to change my derailleur because i mostly ride forest trails and I have heard the new m2000,3000,4000 are for mtb bike.i have a big buck bike
And I wanted to upgrade the derailleur because my derailleur got bent a little bit because of an accident and after sometime it got more bent because of me riding trails so that why I want to change it and because the derailleur doesn’t shift good and the bike mechanic shop near me said there is no fix for this derailleur and that he Could only adjust it and that fix would only be temporary.so I have to choose between getting a new ty-300 derailleur or upgrading to an actual mtb derailleur

Assuming you want to upgrade from a Tourney 7 speed group component to an Altus M2000 is 9 speed.

You'd obviously have to change the rear derailleur, shifters, rear sprocket cluster and chain.  Presumably you have 3 chainring crank, Altus M2000 comes in a 3x9 option. You'd have to swap the front derailleur but you might be able to keep the crankset.

However, you need to look at your rear wheel. If you have an old style freewheel (sprockets and pawls mechanism in a single unit) you can't upgrade it to 9 speed. If you have a freehub and sprocket cassette (ratchet mechanism is part of the hub), you may be able to upgrade to 9 speeds. The freehub body for 7 speeds and below is narrower than those for 8 and above. If you have a 7 speed freehub, you can't upgrade to 9 speeds. If you happen to have an 8+ freehub with a 7 speed cassette and spacer you will be able to. If your rear wheel isn't compatible, you'd need a new one that is.

If you have to swap out the whole drivetrain, crank and rear wheel it's probably just not worth doing the upgrade, especially when you factori in the cost of having a bike repair shop do it for you, or the cost of special tools you'd need to do it yourself.


Can I approximate how much air pressure is lost from disconnecting the hose? I have a floor pump intended for mainly rather low pressure tires.

It lets out quite a bit of air from the hose when disconnected.

Can I calculate (approximately) how much air pressure is lost by measuring the hose length and diameter?

I need to get it up to 100psi, so should I pump it to 110psi, 120psi, 130psi?

Can I calculate (approximately) how much air pressure is lost by measuring the hose length and diameter?

No, you cannot tell how much pressure is lost based on the size of the hose. This is not because there is not enough information to tell but because the hose is irrelevant.

You seem to be under the impression that there is some total amount of pressure in the hose and in the inner tube, and when you disconnect the pump and release the pressure in the hose, some of it is lost.

This is an incorrect understanding of what pressure means. Pressure is an intensive property — it is something that is the same for of all the air no matter how you divide it up within the connected system. The pressure in the hose equals the pressure in the inner tube, which equals the pressure in the whole pump-and-hose-and-inner-tube system.

In the tradition of physics education, let's consider the ideal case with a separately controllable valve on the tube. This is what would happen:

With the pump attached to the inner tube, you open the valve. This causes the pressure in the hose and tube to equalize: this is when the gauge on your pump jumps upward. At this point, the pressure in the tube has reduced, because some of the mass of air in it moved into the hose to pressurize it.
You use the pump to increase the pressure as desired, according to the gauge.
You close the valve on the tube. The pressures on each side of the valve remain equal to each other and to that read by the pump's gauge.
You disconnect the hose. The extra air in the hose escapes to the atmosphere.

As soon as you closed the valve, the inner tube became a closed system: the pressure in it is no longer affected by anything about the pump. It will stay where the gauge said it was while you were pumping.

Now, in a real valve and pump chuck, there isn't a separate control to close the valve (pumps may have moving center pins to push the valve open as part of the “lock” but they aren't always exactly the right length — but I've never used a Presta valve so I may not have this right for those), and it is instead closed as you pull the chuck off the valve. This may release some air from the tube, due to the valve not being fully closed before the connection starts being open to the atmosphere. However, the amount of air released from the tube depends on the valve and how fast you let it close. It does not depend on the volume of air in the hose (except insofar as the pressure in the hose opposes the pressure of the tube even though both are also flowing out to the atmosphere, which is probably a minor effect).


Looking for components needed to route 3 cables on top of toptube for cyclocross bike My bike is setup for cable routing under the downtube. I would like to route my rear brake, front derailleur, and rear derailleur cables along the top tube of a bike I plan to use for cyclocross to prevent the exposed cables from getting gunked up frequently with mud or snagged on things when I'm riding through brush in the woods (really bad in the spring / early summer). Reduced maintinance is my goal, I'm willing to take the weight penalty for that since I'm ultimately not ever standing on a podium.

I'd prefer not to use complete housing over the whole top tube, but I'll accept that I'll need to do that and use 6 cable clips (3 in front, and 3 in rear) if there are no better options.

So, I figure I need two things.
1) Something to keep cables on the top tube.
2) A clamp on cable stop to help terminate the brake cable on the seat tube for the front shifter (I've got a mountain derailleur which goes top or bottom pull)

I've seen a 2 cable clamp on solution for 2 cables, the problem solvers backstop, but that doesn't work for 3 cables. What are my options here?

If you are going for less maintenance, you may just want to go with full housing. My exposed cables (on my top tube) get water, mud, grime and need to be replaced at the end of each season of cross racing. Extra maintenance during to keep them lubed up.

I would go full housing and use six of these: http://problemsolversbike.com/products/clamp_on_cable_guides

Other things to think about once past the top tube...

Front derailleur routing:

While not the best image (but best I could find of my older CX bike) you can see the routing of the front derailleur will need a cable stop near the top of the seat tube. Mine uses a pulley below the derailleur. You can use the backstop you put in the question.

Clamp on pulley: http://problemsolversbike.com/products/cross_clamps_pulleys

Rear derailleur routing:

Does your frame have stops for the rear derailleur on the seat stay or the chain stay? As the rear derailleur cable comes down the seat stay from the top tube, my cross bike goes to open cable and then back to housed cable for the curl to the derailleur. You'll need something here as well to either route the full cable down the seat stay or more clamp on cable stops.

Rear Brake routing:

If you are using Cantilever brakes (center pull), you will also need a cable stop for the brakes. You can get a seat post mounted clamp or even a seat tube clamp that has the center pull cable stop. Found one here.


Problem with cassette and derailleur I am a newbie and this is probably a simple question. I have a new Trek Domane 2. It is the 2020 model. From what I can tell on the Trek website, it has a Shimano Claris R2000, 8 speed shifter. Based on the back tire (where there are 8 gears) I think that is correct. In the winter I want to be able to ride the bike on my wahoo kicker. When I went to the bike store the only cassette they had was the Shimano CS5700 11-25T which is has 10 gears. I've adjusted the tension on the derailleur, but that doesn't seem to do anything. The 4 big gears and the small one seem to work, but not the other ones. What do I need to do to fix this?

You can't use an 8 speed shifter with a 10 speed cassette. The space between individual cogs is smaller than on an 8 speed cassette. The shifter moves the derailleur a fixed distance per shift, so it can't reach the position of the cogs if they are not spaced as intended.
The fact that you can use the 4 biggest and the smallest gear is pure luck, because the derailleur seems to match those positions good enough to make it work.
In conclusion, try to find an 8 speed cassette that fits on your trainer.


Fixed gear wheel NOT stopping when feet stop. Any ideas why? I have a Pure Fix fixed gear bike. I've been riding it in single speed mode for a while but recently decided to flip the wheel and make it a fixed gear.

My problem is that when I try to stop moving my feet on the pedals, the bike wants to keep moving forward. Like the momentum of the movement is causing it to be extremely hard to stop. The wheel doesn't just stop, and the pedals push back against my feet. That means I'm having to put a great deal of force on the pedals in order for it to just slow down!

Aren't fixed gears supposed to do exactly what your feet do? I used to have an old bike a long time ago and it was really easy to stop the tires from turning, making skidding or braking a breeze.

That bicycle you had long time ago had rear brake (actuated by pedals turning backwards), the one you have now has no rear brake and you have to fight force of inertia with your feet to stop it. One might be tempted to add that this is the exact reason why brakes were invented and added as standard equipment to bicycles.


DIY wooden bike rack -- looking for plans I'm planning to build a bike rack to store several bikes on the floor of my garage. Does anyone have plans for such a rack? We have a circular saw and a drill and the usual hand tools, but no router, so nothing too fancy, please! Something that can be made inexpensively from 2x4's and 1x3's would be ideal.

Edit: Hanging bikes on the walls isn't an option for me, I'm looking for floor rack designs only.

Edit2: After Gary.Ray's answer below, I came up with this:

If you don't mind punching some holes into the wall, the style my roomy and I have in our living room is very space efficient, and quite cheap.

It is basically a 2x4 screwed to the wall, with hooks placed into it at a 45 degree angle.  Because we both ride year-round, we put plastic don to save the walls, but being in the garage this may not be necessary.  The plastic does make a good white-board, however (garage decorations!).  Basically the wheel at the top is in contact with both the hook and the wall, and the bottom wheel is touching the wall.  Alternating hanging the bikes by the front and rear wheel means you can put the hooks closer together, and put more in the same space.  It is a very strong design, with ~8 drywall screws holding it to the wall.  Strong enough to hold a Big Dummy (though the rear end of the Big Dummy does sit on the carpet), a Pugsley, and 3 other bikes.

The size of hooks may vary.  For example, I have a large one for my Pugsley:

The plastic we used is also very cheap.  I think it was ~15$ for 100 feet of the stuff.  We plan to replace the plastic once it gets dirty, and I estimate the sheet we have will last 4-5 years.  We also used patches of duck-tape where the tires hit the plastic in order to prevent the tires from wearing through too quickly (especially important for the bikes with studded tires).

The most expensive part of the build was the hooks, the most expensive of which were ~15$ (going from memory).


In need of guides to maintain the bike that I'm about to get I'm about to get myself a cheap hybrid (costing ~200 USD) and I'd like to be able to learn how to maintain it on my own without having to go to a bike shop every now and then (and also because I'm a student who can't really afford to do that). If there are any books that could be suggested, that'd be really helpful!
It'd have alloy (6061) frame and rims (double walled). Shimano tourney groupset (3×7), adjustable handlebar stem, quick release seat post as well as both wheels.

Link-only answers are frowned upon here but I'm going to provide one anyway
https://www.parktool.com/blog/repair-help
Park Tool Company's Repair Help web site is the most comprehensive, professional and understandable set of articles and videos on bike repair and maintenance that is out there.
If you run into specific problems, Bicycles Stack Exchange is of course a great resource.


Cleaning Carbon Black off a Bicycle Brake pads for a rim brake are usually treated with Carbon Black (powered carbon) to make them last longer. This is what makes them black.

When I ride a road bike in hilly areas, the carbon black accumulates on the rim and on areas surrounding the brake pads. Later, if I ride the bike in the rain (without fenders), this powder mixes with dirty water kicked up by the wheels, and spreads around on the frame of the bike, and into gaps on the headset and bottom bracket. If allowed to dry, it becomes extremely difficult to remove.

Right now I remove as much as I can with elbow grease, and then make an abrasive paste out of water and baking soda. The paste works pretty well, but leaves a residue. Further, on some of the really bad stains, it seems to spread out the carbon as much as clean it off. It still needs a lot of rubbing.

Is there a standard cleaner in which carbon black is soluble? Is there a better way to remove it?

Since no answers I will post my comment as an answer

Car wheel cleaner. It is made to deal with brake dust.

But I would not user car wheel cleaner on paint.
For hard to clean on paint I use a cleaner wax.


Rims with replaceable braking surface? Despite the movement to disc brakes in these days (even in the road cycling world), many still use rim brakes. Heck, even I still see rim brakes on our fellow MTB riders here at my place.

What I'm wondering is, why hasn't the industry produced rims with a replaceable braking surface? Especially with roadies drooling over deep-section carbon rims (which would be a waste if they get dissolved with every descent), I guess they could've made it for those who can't afford replacement rims.

Have they been already made? I've searched for them online but nothing's popped up so hit me up if there are any made.

Replaceable brake surfaces would add weight and complexity to the rim, plus make them more expensive. If they have been considered in history these factors would probably stop them taking off.

Someone correct me if I’m wrong, but there would likely have been a frame builder and a wheel builder in most major towns historically. Wheels weren’t typically sold as factory built sets, rather you would choose a hub and rim and have your local artisan lace them up. Or do it yourself, bikes would need more regular maintenance and so more people had these skills.

That is almost to say, braking surfaces were replaceable, if the braking surface wore down you would have replaced the rim. Nowadays that’s less common because wheels are cheaper and hubs aren’t considered so serviceable, we’re now likely to wear out both at the same time.

Rims used to be made of steel, something else to factor in.

Bringing it forwards, these carbon wheels (at risk of dissolving) have been the preserve of racing cyclists who care more about results than their wallet, and follow the example of the pro teams who are sponsored.

Disc brakes came along and offer a replaceable braking surface along with other benefits, starting in the off-road world with harsh conditions.

Meanwhile, the demographic of people who honestly can’t afford to replace their rims, either with the same one or a cheaper one, is small and small enough that the market hasn’t included them in the way you suggest. It’s cheaper to offer a thick, heavy, durable rim, than it is to develop a rim with replaceable parts; there isn’t an economic benefit.

Just some rambling thoughts!


Pros and cons of using 20-25mm inner tube in a 32mm tire? I'm using 700x32mm Maxxis Detonator tires on my hybrid road bike. Although it is possible to find wider inner tubes that could fit better that tire, the 20-25mm ones are popular and available to buy more often.

I would like to know what are the pros and cons of using a 700 inner tube 20-25mm on this tire.

I use a 700x23 butyl inner tubes (I've tested Michelin, Pirelli and Kenda) in a 700x28 tyre and I've had no problems so far. But 700x20 one is 'too thin' in this set, so it can explode. It depends on the brand and you can't rely on the assumption that every inner tube will work in every tyre.


Is it possible to perform tricks with 100% safety during commuting? When commuting in the city, i encounter many transitions between road and sidewalk. It's easy to jump from the sidewalk down to the road (~20 cm vertical) if you have enough speed, but to get back onto the sidewalk, i always brake, losing energy.

I tried doing a bunny-hop or the like to jump from the road to the sidewalk (seems easiest when approaching perpendicularly to the curb), but i never got proficient enough to attempt that at high speed (had a crash, breaking an unimportant part of my bike, so decided to stop trying).

Is it possible/worthwhile to learn the jumping technique and become good enough to do it all the time, without having to slow down, without the fear of a crash?

You can't bend over and tie your shoes with 100% safety -- you might throw your back out, you might lose your balance, etc.

As to "tricks", one man's "trick" is another man's "ho-umm" -- it depends on your level of skill and physical conditioning.  Certainly, hopping a moderate height curb is within the realm of possible (I used to do it on occasion, before I became old and crotchety), but doing so at relatively high speed is non-trivial.

But "tricks during commuting" is concerning -- while you're welcome to be as daring (or foolish) as you want to be when you're safely by yourself and not a hazard to others, when any bicycle, pedestrian, or vehicle traffic is nearby (or potentially nearby but unseen) it's incumbent on you to behave in a manner that does not put others at risk (or serious inconvenience).


Topography aware route planning I'm in San Francisco and hills are crazy (think ~40° slope) and I would like to avoid taking many such hills (both when going down and up).

Are there Google Maps-like apps that can take this into account? I don't mind biking for 30% more distance if it means avoiding crazy slopes.

Google maps tries to do this in biking mode to begin with: http://googleblog.blogspot.com/2010/03/biking-directions-added-to-google-maps.html

Mapquest is also hill aware to some extent: http://blog.mapquest.com/2011/04/21/cycle-route-planner-aerial-languages/ (I have tried this, but I don't think its particularly great. But I haven't tried it in SF).

Specific to SF, but http://amarpai.com/bikemap/ exists. http://bikesy.com/ is another SF specific one.

http://veloroutes.org/bikemaps/ isn't directions, but gives you topographical information.


Which footwear is the safest for summer cycling? This morning I could not find my training shoes. So, I used my sandals. I found that the sandals not only kept my feet cool but there was no pedal slippage as I had expected. The more I think about it, having no laces is probably another advantage. So, which footwear is best for summer cycling?

When summer comes around, I love riding around in my Chaco sandals.  When using any non-cycling shoe on a bike, you'll want to have proper pedals with a good grippy platform, I particularly like the MKS Grip King.  The biggest danger is probably getting the tops of your feet sunburned.

I wouldn't recommend flip-flops or non-sport sandals, but sport sandals are perfectly fine on a bike.  If you want to get seriously dorky, you can even get SPD-cleat ready sandals from Shimano or Keen.


Which grease is for what? I used to think as simple as lubcirants and grease, now that I'm off to buy grease to assemble a bike I'm confronted with dozens of different types of greases.

Does it matter what grease I buy? If absolutely not what grease do I use for what?

The only question I would have is if the bike is Carbon Fiber or not. I'm guessing it's not and is an alloy (metal) bike. Just like cars, there are tons of stuff people will try to sell with magical properties. Ignore them.

There are two greases I use: The first is because it is everywhere, cheap and easy to apply thanks to the tube:

If you want more grease for your money, you can't beat Lucas Marine Grease:

In the end either will do the job very well. The marine grease is longer lasting and theoretically more rust resistant. But I use it because it does the job well, a tube lasts forever (use a plastic spoon to dig some out when needed) and it's thicker than Park's stuff.

I carry the Park stuff with me on a mobile job because it is easy to apply and customers like names they recognize.  The cost is the same for either. I'd vote for Park due to convenience.


I nicked the tip of the taper on a bottom bracket spindle. Is it still safe? I had to cut the crank arms off of a bike I'm working on. Used an angle grinder. Despite my efforts to avoid damaging the bottom bracket spindle, I nicked it in three places, all at the tip.

The bearings and surfaces are all dandy. Is it safe to use this with new crank arms?

  This is the worst of the three.

I'd reuse that spindle. The tips bear the smallest load. A nick near the center of the spindle would be more significant


Adding suspension forks to rigid bicycle I'm thinking of adding suspension forks to a rigid mtb. I realized that the geometry will change with the front higher and so the chain will be slanted up. Does this affect how hard and tiring is it to pedal and the steering. If I were to do it, how much travel of suspension do I need, or should I just stick to the rigid.

You can most likely switch to suspension forks without much trouble at all. The shouldn't be any real difference in how hard it is to pedal as you're still putting in the same amount of energy with the same number of turns of the cranks. The only thing i would suggest is to Stick with the Smaller Travel Forks as that will minimize the amount of difference that you notice in how the bike handles.


Is it possible to remove a coaster brake from a preschooler's bike? My boss bought her 4 and 3 year old a bicycle for Christmas, but she didn't notice that one had double hand brakes and the other has only a front hand brake and a coaster brake in the back.

The 4 year old is the one who has the bike with coaster brake and he can't get the hang of riding the bike because every time he goes to push he just engages the coaster brake instead.

We've been looking for bikes that have no coaster brakes but all of the ones his size have them or they very expensive. We found some with double hand brakes but they still have the coaster brake.

Would it be possible to get one that has double hand brake and coaster and remove the coaster brake completely from it?

Short answer - no, not easily.

Kids don't have the hand strength to use handbrakes properly, so a coaster brake is going to function better, once he gets the hang of it.

He's activating the brake by pedalling backwards.  So don't do that.  Instead encourage him to push off with pedals level instead of optimal angle.  That will discourage the rear brake from kicking in.

If you do want to remove it, you're better off finding another rear wheel that fits and lacks the coaster hub.  The local recycling shop here has plenty of bikes for $10, great parts donors.

Can Mister Four ride a 2 wheeler or is he on training wheels?  Has he had time on a balance bike?  He might benefit from "scootering about" on a two wheeler with no pedals first.


Which type of frame is better for a touring bike, steel or aluminium? I hear that a steel frame is more comfortable to ride for a long tour but that it is heavier and easier to rust than aluminum.
Which material is better for a touring frame?

Steel is still very common for relatively expensive "touring" bikes (bikes intended for long distances carrying panniers).  The slight additional weight of a steel frame over aluminum (well less than 10 pounds in most cases) is inconsequential when you have 40-100 pounds of gear on the bike, the bike is more durable, and the flexibility of a steel bike is preferred by many on a long ride.

Aluminum is more rigid because the tubes must be made fatter and thicker to achieve the same yield strength as steel.  In some contexts this additional stiffness may be appreciated, but generally not when riding long distances.

Stainless is hardly ever (never?) used for bikes because it's too hard to work with and the metallurgy doesn't allow the characteristics of the material to be  controlled nearly as well as steel or aluminum.  And its heavy.

Carbon fiber is carbon fiber.  Great for lightweight frames (saves another 2-5 pounds, maybe), great for bragging rights, but fragile and often excessively rigid.

One important consideration on a cross-country ride is that a steel frame is very unlikely to suffer fatigue failure, while the other materials are considerably more likely to do this.  (And, in a pinch, a steel frame can be repaired by a welder at a local auto or tractor shop, while a broken aluminum or carbon frame is likely toast.)  (Of course, any good quality frame that isn't overloaded should hold up to a 3000 mile journey, but sometimes things happen.)

The tendency of a steel bike to rust is of little consequence.  A steel bike would need to be exposed to the weather constantly for 20 years before rust would cause a failure, and at that point all of the components would have already disintegrated.  And I don't know about carbon, but aluminum and stainless steel tend to suffer crystallization of the metal at the welds as they corrode, and this can lead to sudden joint failure.


What can be used to replace a Shimano 105 5600 long-cage derailleur? I have a Fuji CCR3 with a triple in front, 9-speed casette in back.  It came with a Shimano 105 5600 derailleur, but no local shops stock those.  I've also been told that the 5600/5700 are 10-speed derailleurs and shouldn't be used on 9-speeds (though they can, they just don't work very smoothly).

So, what should I replace my (broken) derailleur with?

Depending on your gearing you might be able to use the fairly widely available RD-4500-GS.  I personally haven't seen a ton of difference between 105 and Tiagra components.  The sora derailleur is also available in a 9 speed configuration.


A pin punctured my tyre. Should I only replace the inner tube, or patch the outer, rubber tyre? Today I managed to run over a flat heat board pin, and my tyre got punctured.

I will change my inner tube tomorrow, because it's not that expensive and I find it easier than patching it up.

My question is: Should I be concerned that the outer rubber tyre was damaged? If so, would applying a tyre patch on the interior of the outer rubber tyre do any good? Or would it make things even worse for the new tube? My fear is that the hole means a weak spot in my tyre, and that the tube would break.

Thanks for your help!

The size of the puncture really dictates whether a new tire is in order... that being said, if you patch your tube and inflate the tire (the one with the puncture) you want to make sure the tube is not exposed through the puncture hole.

If you need to ride and the tyre is questionable... an old trick is to put a dollar bill or power bar wrapper on the inside of the tire over the puncture hole... then install the tube and inflate.  The pressure from the inflated tube will be distributed across the wrapper resulting in an extra barrier keeping the tube from protruding.

Good Luck.


Rear wheel won't move or keeps falling off This question is in regards to my X-treme trailmaker bike. I removed the rear wheel in order to replace the inner tube. However, I cannot seem to reinstall it properly. When I tighten the two nuts on each side of the rear wheel (pictures at http://imgur.com/a/cPNNE), the wheel no longer moves.

However, if the nuts are not completely tightened, the wheel falls out.

I thought the resistance may be from the disk brakes, but loosening that didn't resolve the issue. Any help would be much appreciated.

I'm going to say that you have the axle washer on the wrong side, should be inside the dropout rather than on the outside, doing so can stress the disc brake as it was aligned with it (the washer) on the other side, or your simply pushing the frame into the rotational surface so much that it can't move due to the pressure on the entire surface rather than just the axle.
Basing my answer on experience and reading through this

When it's in the wrong spot ( on the outside ) you are also pushing the frame against the surface of the hub which when tightened enough will prevent it from being able to turn. Washers prevent this by adding both space and reducing friction between a moving object and a static one. Essentially a bearing turns fine on an axle but if you sandwich something up against the entire surface of the bearing it wont move due to the friction present on the entire surface area rather than just the axle sleeve.


Snow and Ice tires for road bike? I have a road bike that have just enough clearance for 700x28c (continental pro4 endurance 28c). Obviously, this is not the best bike for winter conditions, but what are my best options for tackling ice and snow with that bike?

There is one thing you can try, if you have disc brakes. It works a lot better than one might think. You can put zip ties around your tire and rim if there is enough clearance. The more zip ties the better the traction. Also the heavier duty zip ties the better. When placing them alternate the heads so that they are on both shoulders of the tire.

I have ridden on ice and snow several times with this method and have yet to go down. I wouldn't get to crazy on them and it helps to keep a pocket of ties, but this method works and does not break the bank like a $100+ studded tire will.

If you can lower your tire pressure slightly that will help as well. I have run this method on a 26" MTB tubeless, running 15psi and it never slipped on a parking lot covered in 1" of solid ice, that i had trouble walking on.


What is the trick to riding on sand? I have been trying to ride on some trials that have very soft sand and especially agitated by ATVs.  When I hit a soft patch my front tire pulls in one direction and I freak out a little.  I cannot seem to plow through it and ultimately just end up moving slower and slower, which than leads to a full stop.

Is there some trick or style to riding on these trails?

Yes there is one main trick, and some regular skills.

The trick is: if you LOWER THE TIRE PRESSURE, any tire will float over sand like magic. It should not be so underinflated as to allow easy pinch flats, but the lower the pressure, the more marked the floating effect. There are just two limitations:

If the tire is skinny (low volume) it might not be possible to have a pressure level that allows flotation AND safe riding over rough terrain on other trail sections;
It's not possible to adjust tire pressure "on the fly" ;o)  But if you know you're having a long stretch of soft terrain, it's possible to have a good trade-off.

Anyway, huge tires (2.3 +) are perfect for that (watch this Surly Pugsley video). Also, knobby doesn't help that much, sometimes slicks are better; they cause less shearing of the sand and rob you of less kinetic energy.

Now the skills are mostly help maintain speed and direction.

Speed: not so fast as to suddenly throw you over the bars in case of loss of control, not so slow that your rear wheel loses traction in order to maintain or recover speed.

Direction: plan ahead the smoothest possible trajectory, and point your front wheel firmly along that trajectory. Avoid wobbling on the pedals, major gear changes, and specially avoid sharp turns, because there is a critical steering angle above which the front tire skids sideways and the bike becomes unstable, making it almost impossible to regain control in some cases (of course the more skill one has, the more one can recover from).

Hope that helps and... PRACTICE! Few things can be more fun than that!


Is my dream of finding a light/commuter/hauling bike a pipe dream? For a while now I have been trying to find the perfect bike. One that is fast and allows me to ride 20 mph for 50 mi. One that I can load stuff on and has braze-ons for racks, fenders, etc. A bike that does not punish you for riding more then 40 mi.

So my question is does this bike exist? Is there a bike out there that will suit all of my needs or will I need multiple bikes for every occasion?

I think that it is generally true that any "all-purpose" tool is less-than-ideal for most purposes.  There are trade-offs for everything.

If you are just looking for a bike that allows you to ride fast and long while carrying a load, though, I think you are looking for a light touring bike.  Get something with drop-bars and road-y geometry.  Get a comfortable saddle for it--maybe  Brooks B17.  It will go reasonably fast (not racing-bike fast, but certainly faster than my Globe Vienna).

Personally, I am not following my own advice--I am doing what you suggest on a mid-80's Schwinn steel road bike.  I have racks and fenders on it.  It goes not-as-fast as my racing bike but fast enough for sure.  When I routinely carry lots of heavy loads on it, I start breaking spokes but that's the wheel's fault and not the frame.  The old steel Schwinns really do never break--if you put the right components on them, they will haul anything you want.

At some point I may replace the Schwinn with something more modern.  After all, I'm running it with old 105 gear and down-tube shifters.  Generally fine, but when I can afford it I'll upgrade.  My Vienna has started to spoil me, with its IGH and shiny paint.

In your position, I might consider a Civia Bryant.  Go with the belt-drive option.  It can haul a load, go fast, seems comfortable (having only looked at the geometry), and is low-maintenance.


Hydraulic Disc Brake (how to choose correct model) I recently broke off the lever of my front brake and am looking for a replacement lever or front brake. Need some input/suggestions from more experiences riders.

Some of my questions:

What are the (dis)advantages of multiple pistons (for example a 4 piston caliper) better than less pistons?
Would cooling fins be recommended? (I don't ride downhill but do brake hard and often)
Is there a way to find the piston size/lever 'leverage ratio' without having to ask each manufacturer?

I originally had a Magura MT4 which I was very happy with but I fell and the lever (more specifically the fluid reservoir) broke in half (due to it being made of plastic). If I could get something similar in terms of braking power which is a bit more robust (not made of plastic) that would be great. Alternatively I could install something similar to this to prevent the lever from breaking/snapping (I believe they're called "lever guards"):

The bike is very heavy (e-bike), approx 45kg and fast (70kph) so I need very good braking power. With the MT4's I could do a stoppie (riding on front wheel only) with 2 fingers on the lever.

I replaced the broken off lever on my MT4 with a Shimano lever (not exactly sure which one, will add photo below) but for some reason I have to press the lever way way harder (on MT4 I needed 1-2 fingers with very little force to block front wheel (dry tarmac) and with the Shimano lever I need to press as hard as I can with 3-4 fingers and still can barely block the front wheel) to get the same stopping power (same caliper/hose, different brake lever).

Shimano lever:

I have tried looking for replacements online but could not find the 'leverage ratio' (leverage of the brake lever itself and the size of the piston in the brake handle) anywhere in the spec sheets for the models I've looked at. I am using a 180mm Magura brake rotor.

I think a downhill type brake would be the best option.

Brake Requirements:

a lot of braking power (block front brake with 1-2 fingers without much force)
Weight is no issue (they can be heavy)
price under 120usd/100eu if possible (if there is a big difference in quality/performance when going a bit higher budget please don't refrain from suggesting a bit more expensive models as well)
adjustable bite point/reach for bonus points
they do NOT need to be e-bike specific (no brake sensor needed)

Any suggestions are welcome/greatly appreciated. Thank you!

Original (broken) MT4 lever:

As Argenti said in comments - mixing levers and calipers is not recommended.

Magura's website is very informative on what Magura parts go with what Magura brakes and how to select parts. I did not find any Magura / Shimano cross reference.

There is a very nice explanation of the pros and cons for different hydraulic brake configurations to aid in decision making. Here is a chart describing 2 vs 4 pistions:

Two Piston vs 4 Piston vs Trail Combination (4 Piston Front / 2 Piston rear)

The page also has information on Magura specific rotors and brake pad performance and an interactive guide for setting up brakes.

Magura also makes a one finger aluminum MT4 compatible lever.


Spending up to 200 dollars now on a bike for slow rides on gravel roads I'm a dad with a kid just getting old enough that we can bike around together. I've been using a 10 dollar bike I got from a garage sale but it's just rusty junk at this point. Our other kid is still going to need to be in a back mounted seat for another year or two so I don't want to bother investing in a nice bike for me that is going to get busted up just from the mounting of the child seat.

So if I only have 200 dollars at most to put into a bike, what type of bike is least bad when it's cheap? I've picked up that the "full suspension" bikes are just horrible on the cheap bikes (and that's all that my Walmart seems to have), but what about the full body solid road type bikes? I'll be spending 95% of the time just piddling around on gravel roads and maybe light gravel trails. Nothing on mountains but also no need for real speed.

I'd recommend another used bike.  It might take some time to find a suitable one that fits your budget, but garage sales, thrift stores, and maybe even Craig's list are good places to find good used bikes that would fit in your budget.

A couple of recommendations:

Don't buy a bike without seeing it.
Bring a set of decent tools to do a good inspection (Don't use cheap tools on someone else's bike...)
Loosen and remove the seat post, look inside for bad rust/corrosion
Do ALL the parts that are supposed to rotate/move smoothly? (A rusty chain is no big deal - it can be replaced, but count that in your budget)
See if you can loosen the pedals from the crankset
Remove and replace the wheels - you're going to have to replace tires and tubes eventually...
Check cables and brake pads (no big deal, they might well need to be replaced, but count that in your budget)
Loosen the handlebars and headset

Obviously, you'll have to be able to return the bike to its original condition.

If you can't do any of that without damaging the bike, it's not a good bike to buy.  For example, if you can't get the seat post, pedals, or headset loose, there's probably way too much corrosion or rust.

If the seller doesn't want you to check out the bike like that, don't buy it.


Quick release wheel is either too tight or not tight enough My front inner tube popped yesterday so I changed it, but when I put the wheel back on the bike I couldn't seem to tighten it properly without it being too tight, or not tight enough.

If it was too tight, the disc brake would be rubbing and I couldn't pedal without extreme resistance. If it was too loose, I run the risk of it falling off.

I know theres a way to put the bike back together obviously cause I've been riding it for a while now. Any advice?

Your problem is more likely to be wheel alignment than anything being too tight. The tops of the dropout (with the bike upright) should be sitting on the axle, but it's easy to get a little gap there if you're not careful. When that happens the wheel doesn't sit quite stright in the fork and it will rub on the disk rotor if you have disks. Plus if you're finding that you have to wind the quick release in and out it may be riding up on the wheel retention tabs (lawyer lips). Front dropouts are shown in the lawyer lips link.

The system I use is this:

put the front wheel in loosely, or leave it in if it's in
stand over the bike and reach down to the quick release, holding the bike upright with your body (belly on the handlebars)
release the quick release
wiggle the fork or wheel a little to make sure the wheel is properly seated
do up the quick release

The idea is that because the bike is pushing down on the wheel it will seat properly in the dropouts. Trying to do that while the bike is upside down or you're trying to hold it upright often means one side of the axle is not properly in the dropout, so the wheel sits at an angle when you do up the quick release.


How can I tilt up a stem of my bike's handlebar which is held by two bolts? I bought a second hand hybrid bike and would like to adjust the stem of the handlebars such that I can ride it in a more upright position.

The following photo shows a side view of the stem with an arrow pointing in the direction I want to tilt it.

As you can see there is a hex bolt; a similar bolt is on the other side of the stem. I managed to loosen them on both sides (the bolt seen in the photo was very tough to turn), but could not get the stem to move.

What am I missing here?

Adjustable stems follow a couple different design schemes, all of which involve some interlocking toothy bits that hold the angle in place. If the angle isn't changing, the toothy bits are still locked together.

There's probably a bolt on the underside of the stem extension. If so, that's what locks the angle adjustment in place. So you loosen the side bolts, loosen and adjust the underside one, re-tighten underside, re-tighten sides, in that order.

There's another type of adjustable stem without the underside bolt, where the side bolts are tightening down a pair of toothed plates that hold it all together. That doesn't appear to be what you have, but in the case of a recalcitrant one of those, you would just need to gently pry the plates free.


Can I switch a single speed mag rim into a six speed? I’m interested in getting mag rims for a hybrid bike that I own. Only problem is that mag rims come in single speeds not six. Is it possible to have mag rims modified to mount a six speed cassette?

The mag rims that I have are Skyway Tuff II single speed cassette.

Going from single speed to multi speed is akin to re-building the whole wheel, since you'll usually need to swap the hub and consequently need to put in new spokes and stuff.

However, a cursory google search shows several mag wheels for bicycles which take cassettes. I can't vouch for their quality or safety, but they exist.

A 6 speed "cassette" is almost surely a freewheel (i.e. the mechanism that allows you to coast without pedaling is in the thing that holds the sprockets, not in the hub of the wheel) and not a cassette, and this is a fairly outdated design. You'll likely end up upgrading to a 7/8 speed cassette if you make this switch (which may also involve spreading your frame to get the new wheel in, if possible (i.e. it is a steel frame)).


Do brake pads designed for both carbon and Alloy rims exist? I had in interesting question today that got me thinking. Are there any brake pads that are marketed specifically to be able to switch between alloy training rims and carbon race rims? As in switch wheelsets but using the same pads.

Generally i would think this is a bad idea as an alloy material that made it's way into the pad could then utterly destroy a carbon brake track.

Then i saw this on competitivecyclist.com

  SwissStop makes it clear that there's no need to swap out pads from carbon-specific to non if you switch wheels from your carbon race-day gems to your aluminum training set. However, we'd recommend always checking your pads and removing aluminum debris before installing your carbon race-day wheels.

However after checking Swissstop's site for their yellow carbon compound pads, there was no mention anywhere of them also being compatible with alloy rims.

I would also tend to think the specific compounds like differ quite a bit and something that stops quick and quiet on carbon or basalt brake tracks would not have the same attributes when used on alloy.

Has anyone ever heard or seen such a thing?

Unfortunately not. Carbon pads would work on alloy rims but not effectively so you might end up in a pickle if having to stop quickly. If you tried to use alloy pads on a carbon rim then you'd have the same performance issues with the added effect of squealing like hell and leaving serious scores on your rims due to the material hardness.

Since its so easy to change out pads, i'd just keep some spares and swap out at the same time as your wheels.


When replacing wheel bearings, is there a standard or are they different for each type of bike I have a claudebutler CapeWrath D24 (around 3 years old). My front (not sure about rear at this point) wheel bearings need replacing.  The wheel it has is a Rigida Zac2000.  I realize that some bikes now have hubs that have a case for the bearings that click on and the like, but mine seems to be more old fashioned / simpler.  Take the cone off and the bearings are greased underneath it.

Can I get a standard type of bearing or are there particular ones I have to use?

Is there a particular type of grease needed?  I have some White / creamy Teflon grease from wiggle, but not sure if this is the right sort of grease.

Should there be bearings all the way around?  On one side of the wheel there is a gap big enough for another bearing, the other side has bearings all around.  Can you buy single bearings or do they come in packs?

First of all, good on you for having a go at proper bike maintenance.

Unless you have an expensive American Classic or other 'pro' hub you will be needing 10 3/16 inch balls on either side of that front hub of yours.

Typically these are available from your Local Bike Shop in a pack that will have a few spares for the ones that run away whilst you put them in. The cost of replacement ball bearings is low and, unless you are fiscally challenged, you should always put a new set in when you pack your hub.

The grease that you have is fine, just do not over pack it as this will attract dirt. Cleanliness is crucial, pop off the press-fit washers on the hub body and give everything a thorough clean - GT85 comes in use as does WD40 or even petrol for this application - you want a solvent that will dry off completely and not water down your grease. When you put the press-fit washers back in you will need to use a soft-end hammer or wooden mallet to gently tap them in properly.

The cup and cone flat spanners are needed to put the hub back together again and get pre-load correct. These are affordable tools and not to be used as regular spanners. Normally these are sold with 14/15/16/17mm ends to suit front and rear hubs on most bicycles.

Spindle bearings vary by hub brand so even if the ball count is the same the cone outer diameters can differ. Check the cones and cups are not too pitted - black rough spots - and decide for yourself whether you will be able to live with whatever damage is present.

There should be a gap - as you describe, the gap should be less than a ball's width. Depending on your hub you may need more or less than the expected 10.

Preload is important on the hub. Once upon a time, before this was understood, hubs would be setup so the unloaded wheel would spin 'forever' and stop with the valve at the bottom. However, when you place weight on the wheel there needs to be a bit of extra tightness on the hub to accommodate for that. For me it is a matter of feel although I am sure there are more scientific ways of getting this right. I tighten up the hub so there is no 'play' in it when it is in the fork/frame. Then I give the lock-nuts a proper tighten, in the process introducing extra tightness that makes the spindle feel slightly rough when turning it in your fingers.

When you go on your first ride there might be some grease popping out - wipe this off as soon as you can.

Should you go for adjusting/cleaning the back hub you will need 1/4 inch balls, typically nine per side.

A final note, the hub is usually made by someone other than the rim (and spokes) with affordable-style bicycles. The label on the rim does not identify what the hub is except for with Campagnolo and other posh pre-built wheelsets.


Maintaining an old bike properly I have a 6 years old bike, I got it when I was 9. It's a great bike, however I've always had the problem of maintaining it properly. I have a few questions which I hope to get answered here. Before everything.
1. How can I maintain my bike during winters?
I live in a small house in the city, and during winters I often am at a loss when it comes to maintaining my bike because I can't put it in the house (It's a big bike, and the hallway is tiny). After winter the bike often has terrible problems which take me at least a month to fix. They are: Rust, dust, completely useless tires, sometimes even a loose chain, and it makes terrible noise until I oil it. How can I maintain it during winter? I should note I have a tiny tool shed I keep it into. It's not helping by much but it's better than being outside.
2.How long should a bike tire stay pumped?
I very often find my tires loose after 3-4 weeks from the last pump. I'm wondering if this is normal.
3. What are the basic things that you have to do when maintaining your bike?
All these years I have been oiling specific areas of my bike and pumping my tires occasionally but that's pretty much it. Can you tell me other things you can do to maintain your bike at top performance?

If you must leave a bike outside during winter, the best thing to do is to shelter it as best you can (eg, under an eave, but not in the "dripline") and cover it with a sturdy plastic tarp.  The tarp should be tied down well to keep it from blowing off, but should be open at the bottom to allow air in.

Before storing the bike, squirt some chain oil on the chain and sprockets, and squirt some aerosol lube (not WD40 but maybe something like LPS or SuperLube) down the brake and shift cable housings.  Dab off excess but leave a good coating.

Ideally, hang the bike or store it upside down, so that the weight is not on the tires.  (Standard quality tires and tubes will hold enough air to support a bike without going flat for anywhere from about a month to 6 months, but will only hold enough air to support the rider for 2 days to two weeks.)

Otherwise, maintenance is based on wear.  Clean and relube the chain once a season or (ideally) every 500 miles, replace the chain after maybe 2000 (get yourself a chain stretch gauge to check this).  Have a bike shop check the sprockets for wear after maybe 5000 miles and then every 1000.  Have the wheel and headset bearings relubed every 10,000 miles or so.  Replace tires when the tread wears through or when the sidewalls develop cracks.  Replace tubes when you replace tires.


Does this bike count as antique? I found this bike.

The front wheel is ruined. Back is normal, but I can replace it if it worth.
It have 5 gears.
It have no serial number under BB.

So here my questions:
1. Can anyone tell when this bike was manufactured?
2. How much can a bike like this cost if fully repaired?
3. I can get any parts (good quality), so, if it worth to repair, what parts should NOT be changed (as antique), and what HAVE to be changed to modern parts?

Just estimating from the picture it could be late seventies early eighties
I see similar bikes for sale at around 150 €
With a bit of effort it coud be turned into a robust, efficient commuter, but it is not worth too much as antique. The frame is the best part, but equipping everything else new might get expensive. But the front wheel doesn't look that ruined, you could put new spokes. A thorough cleansing and lubing and new cables and that and the bike could go as it is. I'd put wider tires but that could be a problem with the fenders. Also old brakes like those can be weak, so that could prove a necessary change.


Dahon Speed Uno. Main frame hard to fold Is there a way to lubricate or adjust the tension on the main frame hinge on a Dahon Speed Uno? New bike, and it is extremely difficult to fold in half.

The main frame hinge is made to have adjustable tension. A little lubrication on moving parts is a good thing.
The manual Dahon publishes is a one-size-fits-all manual with instructions for adjusting a variety of frame hinges starting on page 14.
Here is a review of the Dahon Speed Uno that goes into great detail on how to operate the bicycle along with videos of folding and unfolding.


Would like to know if the following Crankset is compatible? I have a Decathlon Rockrider 5.2 and I'm planning to replace my current crankset with a Shimano TOURNEY FC-TY501 6/7/8-speed Square Crank 48/38/28.
Would like to know if this compatible with my bike. Currently here's what I know about the specs:
Rear Cog: 32/11 (8 speed)
Rear Derailleur: Shimano Altus Rd- ct95 8 Speed
Front Derailleur: Shimano C050 Top Swing Sis
Crankset: SR Suntour PFF 42/32/22

FD-C050 is profiled for a 42. This degree of mismatch is usually not enough to keep it from working at all, but it's not necessarily negligible either. The tighter curve may force the FD to need to be mounted higher than ideal, which can result in inferior contact with the chain and/or gaps that allow derailment. An FD is a cheap enough part that I recommend just getting one that you know will play nice with your 48 and be done with it.
As pointed out in the comments, it's possible to run into frame clearance limitations with the bigger rings.
Total capacity is 43 on RD-CT95 so that's fine.
If the chain is sized right for your current crank, it will be too short for the new one.


Can anyone help me identify this touring bike? I found this LL Bean Touring Bike on Facebook marketplace, the price looks pretty good and the owner said it was around 15 years old. I know that at some point, but not very recently, LL Bean Bikes were made by canondale. Can anyone give me any information on this bike?

I have a bike just like this one, same color - if you look on the back sprocket protector, (the black plastic piece), it will have Cannondale in raised letters. I bought the bike, along with a Cannondale LL Bean mountain bike in 1983 (I believe) from the catalog, and I'm pretty sure I still have the owners manual.  The rear rack is not original to the bike.  It has twelve speeds, which was pretty cool at the time when everyone else was still riding bikes with ten. Cheers!


What is the difference between Time-Trial and Triathlon bikes? Time-Trial and Triathlon bikes differ from normal road bikes in that they are designed for maximum efficiency when riding alone (not in a group).

What, then, is the difference between them? Would there be something wrong with using a TT bike in a triathlon, or vice-versa?

There doesn't seem to be an objective difference between the two, and I often see them lumped together as a category. Is there a significant (if any) difference between them?

They are very similar but have to follow different certification rules. For example, under UCI regulations the saddle of a TT bike must be at least 5 cm behind a vertical line drawn through the bottom bracket (cf. Rules 1.3.011 to 1.3.025), there are constraints on the size, shape, and orientation of frame members, and so on. Triathlon bikes are certified under a different set of rules depending on the race being run and allow a greater degree of integration of components (such as water bottles that are designed to fit within the frame in a way that enhances aerodynamics). Currently, any UCI-certified TT bike can be used in a triathlon but not all triathlon bikes are allowable in UCI-sanctioned races.


Why are roadies concerned about weight? I have never ridden a road bicycle, so this question is probably silly (and a duplicate). Still:

Assumptions:

Road bike
Riding fast, 30km/h nominal
Few and gradual corners
No abrupt stops (i.e. no traffic lights)

In the face of those assumptions, why are road cyclists concerned about the bicycle mass at all? The large inertia of a heavy bike should be no problem and should even be providing stability and comfort. The only conceivable drawback would be higher friction in the bearings, which should be negligible.

There are two main reasons:

Hills: Pushing a light bike up a hill is obviously easier than a heavier bike.  Everyone likes to brag about that HC climb he did the other day.  Without resorting to lying about actually climbing the hill, the easiest way for a cyclist to make his life easier is to carry less mass up the hill.  Nobody will say, "That didn't count because you rode a 3kg bike," and you get no extra points for lugging a 40 kg dutch commuter bike to the summit.
Technical Competence: Bicycle manufacturer have tried over the years to reduce bicycle weight, to the extent that weight (or lightness) has become a proxy measurement of the manufacturer's technical competence.  Anyone can build a heavy bike, but it takes real engineering skill to build one that is light.


I have an old giant 9 speed, which I want to convert to an 11 speed, simpy to use on a smart trainer I've never done this before, so am wanting suggestions on what  parts I need to change. I have an 11 speed derailleur, but not sure what else I need to change, obviously not rear wheel or brakes, as it's going on smart trainer permanently.

You can convert it to 11 speed, but it involves changing a bunch of parts.

Obviously, an 11-speed cassette is required. For a road bike: you should check if your freehub body has a spacer, if it does then the hub can accept any Shimano/SRAM 11 speed cassette. If there's no spacer, you can get a Shimano CS-HG800 (works with narrow freehub bodies). If freehub is Campy-spec, then any Campy 11-speed cassette will fit. Another option is to source a wider, aftermarket freehub body if such an option is available. For MTB: get any 11-speed cassette compatible with your freehub (which is most likely a regular Shimano HG).
You will need 11-speed shifter(s), compatible with your new RD. A cheaper solution might be to get a friction shifter or only a rear shifter and leave the old front shifter as is. You did not say what RD you already have, but I hope it's a not an MTB-specific one, otherwise you'd have "fun" looking for a compatible shifter option (there are some).
Any 11 speed chain.
Make sure your new RD can clear the biggest cog on the new cassette. Usually, this info can be found in product manual.
Make sure the RD can handle the chain growth capacity. I'm not sure road 11 speed system work with a triple up front, you did not specify what the current groupset is.

As you can see, there's a lot of variables involved, a list of current parts would simplify the answer a great deal.


Where do stolen bikes go? I'm looking for, ideally, an academic study or authoritative source on what happens to stolen bikes, rather than just speculation. Is there anything I can do at this point to help track mine down?

My very dear two wheeled friend disappeared into the night yesterday, after its lock was cut through. Left in a bad spot for 'a few minutes' that turned into several hours.

I've filed a police report and the rest of it, but something that I keep wondering is where these bikes end up? Surely it would be too obvious to resell them on Kijiji or Craig's List, since people like me are now checking every couple of hours for their bike. Should I even bother looking around town, or do they get shipped off to a different city? Are they just scrapped for parts?

Bicycle Theft, Guide No. 52 (2008) gives details around bicycle theft in different variants, stages and from different perspectives, contains reference for theft data.
From the report:

Offenders
Not all bicycles are stolen for financial gain. Some offenders may take a bicycle simply to get from one place to another, and then abandon it. Research suggests that bicycle thieves can be categorized in the following way in terms of their motivation:
Joyriders-those who steal any type of bicycle for transportation and/or enjoyment. These offenders generally abandon the stolen bicycle after use. Younger offenders (16 and under) typically fit this group.
Acquisitive-those who exploit easy opportunities to steal any type of bicycle and trade it for cash or goods (such as drugs).
Volume-those who steal specific types of bicycles and/or numerous bicycles to order.

50 Denv. L.J. 177 (1973-1974) Marketing Theory and the Fencing of Stolen Goods; Roselius, Ted; Benton, Douglas (paywall!) -- goes down on marketing of stolen goods, and bikes are considered one of main prizes in this market (see previous link why)


stiff gears and chain coming off while pedalling forward (hub gear) So I recently replaced the back wheel's tyre on my bike. Got it all fitted back on again, and the chain and everything are in place as they should be. However, changing up gears has become very stiff indeed, and as soon as I get on the bike and start pedalling, the chain snaps off from the wheel and wedges itself in a gap.

No idea what the cause is - I slip the chain on by pedalling it a bit indoors (without sitting on it), but as soon as I get it outside and peddle for a second, it comes right off. The bike is about 10 years old, hasn't had much use until the last few months (when I've been riding it every day), and had never seen any reparations until I replaced the back tyre.

I'm fairly sure I've messed something up while putting the tyre on. I don't really know much of the terminology (wikipedia calls my gears 'internal hub gearing'). The gears seem to be attached to the wheel itself, rather than the bike frame (which seems different to the videos I saw on the internet), so I had to remove the chain and unhook the gear changing wire thing from the wheel to remove it.

Sorry for the vague information - anyone got any ideas?

There could be a few different issues:

It your Rear wheel is sliding around in the rear dropouts and you wind up loosing tension on the chain or screwing up the alignment of the rear wheel. It's really a common thing on bikes with horizontal dropouts, which I assume your bike has.  When you start to pedal, if the rear wheel bolts or quick releases are not tight, then the wheel can slide forward in the dropout, the chain comes loose and falls off. Try tightening bolts or quick release tighter or use a chain tensioner or tugnut to help prevent the axle from slipping.
Your chain is really worn and/or your cogs are very worn, this causes the chain to skip off the front chainring or rear cog. See Sheldon Brown's site about chain wear to diagnose this issue.
You have a bad chainline.  Instead of going from the rear cog on the wheel to the front chainring in a straight line, it bends the chain diagonally, causing it to hop off the cog or chainring easily.  This may be due to spacers incorrectly placed on either side of the rear axle. Credit @DanielRHicks
The chain could just have too much slack, try pulling the wheel back and resetting the tension tighter.
Bent chainring causes chain to jump.  Spin the chainring without the chain and see if it 'wobbles', if so this could be causing your chain jumps and the chainring should be replaced.


Why does my front mountain bike wheel sway left and right slightly? Went to a bicycle shop he said could be screw loose but after he tighten it still swaying to both side slightly once awhile

Two reasons why you may be seeing the wheel move from side to side, and each has a fix that involves tightening something.

The first is that the rim is out of true, so when you spin the wheel the rim and tire appear to move side-to-side relative to a fixed point such as the fork or rim brakes. What your mechanic would have done in this case is adjusted the tension in left and right hand spokes to make the rim true again. YOu may have had a single spoke that came loose and needed re-tensioning. If you are still seeing some apparent movement when you spin the wheel, or you have rim brakes and the rim hits the pad at some point the mechanic may simply have not done a particularly good job. You can ask for them to improve the wheel or go to a different mechanic.

The other possibility is that the hub bearings are loose and the whole wheel is wobbling on the axle. This is easy to diagnose: grab the tire and try to move the wheel side-to-side, if you can feel the wheel rocking slightly the bearings are possibly loose. Some hubs have adjustable bearings and you mechanic may have tightened them. Again you can return to your mechanic or use a different one.


Bottom bracket and crank confusion for dirt jumper I'm looking to build an NS Decade dirt jump bike. I'm super confused about purchasing the right bottom bracket and crankset.
The frame specs says 73mm threaded.
Ideally, I'd like to use 30mm Raceface cranks (because they're cheaper than BMX cranks it seems like).
Which one of these should I pick? Does any of these options work for this frame?

Also,
Would that work this these cranks?

It seems to suggest that I should buy this for 73mm shell?

A 'threaded' bottom bracket shell on modern frames means an ISO standard threaded shell aka 'BSA' or 'English'. Standard shell widths are 68mm, 73mm, 83mm or 100mm.
External threaded bottom brackets are usually used with 24mm diameter crank axles (Shimano Hollowtech or SRAM GXP), but 30mm axle cranks do exist - as you know because you found 30mm axle bottom brackets.
The crank you referenced has a 24mm axle so it won't work with any of the bottom brackets in the first set, however you correctly identified the bottom bracket it does need to fit in a threaded 73mm shell (RF-2925).
If you want a 30mm axle you need to identify the equivalent 30mm crank, the documentation should point you to the correct bottom bracket which should be RF-2881.


Why the wobbly/loose cassette? Why is my used Ultegra 10-sp cassette wobbly to the touch on a new Ambrosio hub? All spacers present/correct and 11-sprocket well-seated before torquing 40nM lockring. I tried another (used) 10-sp 11-21 cassette on the same hub and there is no wobble for that one. Puzzled!

Note: Different cassettes may need different spacers.

Unless there is a defect in the cassette or freewheel, it should not wobble (at all!) when properly installed.

Try removing and cleaning the cassette (a bit of dirt can cause it to get skewed a bit). When you put the cassette back on, make sure there is about 1 mm of cassette sticking past the freewheel hub before putting on the locking ring. If the cassette is not sticking past, then (just like a compression headset), you won't be able to tighten it properly and you will need to put additional spacers behind the cassette. Tightening a lock ring without the correct spacing can also easily strip the lock ring (which is better than stripping the threads in the freewheel, but will still ruin your afternoon).

If there is still ANY wobble, a visit to your LBS may be in order.


Options for fully lined bulk cable housing I perform maintenance on 3 personal bikes, and often friend's bikes (a few per year, usually).  One of the most common tasks is replacing shift/brake cables and housing.  I live in Boston, winter is brutal, and the bikes I maintain are used in terrible conditions as a means of transportation, so they must be reliable.

I'm interested in finding the cheapest, most effective way to have bulk housing that is fully lined or sealed.  It would be incredible if there was a type of housing that could be bought for cheap enough that could be used for both brake AND shifting, such as Jagwire's 5mm compressionless brake housing.  Right now I just use cheap bulk/shifting cable rolls, unlined, and I'm tired of having to replace the cables so much.

Any suggestions welcome!

EDIT:

Jagwire and some other companies make a 5mm compressionless brake housing.  Since it's compressionless, but strong, I was sort of hoping that there was a cheap alternative, and that it would work with both brake and shifter cables, even if the shifter cables have an internal extra 1mm to move around.

It seems that the best way to weatherproof the system is to just use full length housing.  I have seen cable setups before where the cable in between the housing stops has a liner as well, implying that the housing inner liner is separate and meant to be run through the housing like the cable.  I was basically wondering how those work, and if you can get that setup in bulk, but they seem to be pretty complicated and have a bunch of different cable housing ends for different.

I think I will buy some bulk lined cables to do full length housing runs.  I may try getting some jagwire 5mm compressionless brake housing and try to use it with shifters, and will report back with results.

Thanks for all the input!

You can buy 30 meter rolls of cable housing such as http://www.wiggle.co.uk/transfil-gear-casing-30m-box/ . I would opt for Shimano or Transfil, as have seen problems with the much cheaper Clarkes.

Brake  cable housings  have a completely different construction to shifters. The housing is a coiled sheath , compared to the axial strands in shifter housing. And brake housing is larger diameter. So different housing for different purposes.