Bicycle Needs Repair, Badly

June 7, 2007 4:01 PM

After riding today, a couple things started going wrong with my bike, and I'd like to fix the problems myself, if possible.

I ride a somewhat old Trek mountain bike and use it as my main form of transportation. Today I took it on an relatively long ride and started running into some problems.
When I pedal, there is a very loud creaking noise; it can be felt throughout the entire bike. I usually pedal standing up, so I'm thinking this is probably a result of me putting too much pressure on it. However, sometimes the creaking noise comes up even if I am just coasting. Can anyone diagnose exactly what is wrong with it? Could I fix this problem myself, and if so, how?
The second problem is that the back wheel has started to become wobbly. If I lift up the bike, I can shake it back and forth a bit. How do I go about tightening the wheel (or doing whatever needs to be done)?
If possible, please direct me to some online repository of bike repair information so I know where to start in the future.

posted by god particle to sports, hobbies, & recreation (19 comments total)

Something is probably loose. Check the bolts that hold the cranks (the arms the pedals are attached to) to the bottom bracket, the nuts and bolts that hold the gears to the cranks, and how tight the pedals are attached to the cranks.

It might help if you can isolate the sound by pedaling one foot at a time, on different gears (if you have them), etc.

Creaking when you are coasting seems a bit odd, though. That may be common the problem with the rear wheel. If I'm reading you correctly, maybe the hub needs to be repacked or have its cones tightened? The wheel is loose in terms of axle-to-hub, right? If it's axle-to-frame, try tightening the nuts or quick release.

Bonus plug: While there are a couple really good bike repair books, I personally like _Zinn and the Art of of (Road / Mountain) Bike Maintenance_ most.
posted by trouserbat at 4:08 PM on June 7, 2007

Creaking can be very hard to diagnose. When my bike starts creaking I break it down to it's tiniest little bits, clean them, lube them, and then build it back up. It's a zen experience for me. I geek out on this shit.

If it creaks when you pedal hard it could be your bottom bracket (the bearing around which your cranks rotate). If you have the tools and knowledge, remove it, clean it, lube it, and put it back in. It can also be your pedals.

Sometimes it happens when you're coasting? That could be any number of things. Start with washing your bike and then going over every fastener to make sure it's appropriately tight.

Wobbly rear wheel? I'm guessing you mean that the wheel can be moved side to side when you grab it, and not that it's just out of true (meaning it looks a little "warped" when you spin it). It could be that the cones need adjusting, or you might just not have your quick release tight enough (if you use a quick release, it's the thing you have to undo to remove your wheel).

If you could take pictures of these parts and post a link it might help.

Resources:

• Zinn and the Art of Mountain Bike Maintenance
  
• Park Tool Service Instructions

Good luck! It's not rocket surgery. With the proper tools it's pretty easy once you know what needs to be done, and it's really satisfying to know that you can do whatever needs to be done for the bike.
posted by spikeleemajortomdickandharryconnickjrmints at 4:15 PM on June 7, 2007

You could have a problem with your rear wheel axel. Mine snapped (jaggedly in half) a while ago, but still would lock together well enough most of the time to function. It would creak like none other though, and when I really torqued it it would sometimes freeze up.
posted by devilsbrigade at 4:23 PM on June 7, 2007

And by axel I of course mean axle.
posted by devilsbrigade at 4:25 PM on June 7, 2007

Seconding that it could also be the bottom bracket (missed that, spike).

Chasing creaks is a great way to learn bike repair, btw.
posted by trouserbat at 4:26 PM on June 7, 2007

If that is the case, this is the assembly you should be looking at. There's a lot of stuff in there, and it can be a pain to take apart, but it gets apparent pretty fast if something's seriously screwed up.
posted by devilsbrigade at 4:27 PM on June 7, 2007

A wobbly back wheel might be a broken axle, or (more benignly) loose cones. You'll need a set of cone spanners to tighten them down. They should be just tight enough to touch the bearings without really impeding the wheel's spin. Check the front wheel while you're at it.

Or it could be that your spokes are all so loose that the rim is wobbling, but not the hub. That would be pretty serious.

Squeaks and groans are hard to diagnose. I spent a long time tracking down a squeak that was in my derailleur pulleys, so now I lube them. You'd only be experiencing this if you were soft-pedaling while coasting though: if the chain is still, they make no noise.
posted by adamrice at 4:31 PM on June 7, 2007

If the problem with your rear wheel is the cones, adjusting them requires some special tools and a fine touch (see step 7). If you're looking for the cheapest solution for right now, take it to a shop. (Although buying the tools and learning to wrench will be cheaper in the long run.)

Here's a page on squeeks and creaks.

Until you get the creak figured out, I'd recommend that you sit down to pedal. It's much safer, in case you suddenly lose a crank arm or whatnot.
posted by hydrophonic at 4:31 PM on June 7, 2007

This guy is a regular old bike genius...

posted by Carnage Asada at 4:43 PM on June 7, 2007

...and here's the link!

sheldonbrown.com
posted by Carnage Asada at 4:44 PM on June 7, 2007

The creaking sound plus the problem with the rear wheel could mean anything from broken spokes, to a hub or axel related problem. It could also mean a cracked seat or chain stay. (Or some other frame problem.)

Or they could be unrelated. Creaking could come from the bottom bracket, the pedals, or suspension (if you bike has that.)

Regardless, your problem is beyond the "just tighten it", "just loosen it", or "just lube it" job that a non-mechanic can solve with simple household tools.

For your safety please have the bike inspected by a bike shop. They won't charge you anything just for glancing at the bike and if they can pin point the problem and tell you about it that will give you a lot more researchable information if you still want to attempt the repair yourself.

Working on bikes does require specialized tools and know how. As someone said its not rocket science, but like anything it requires experience and an attention to detail.
posted by wfrgms at 5:02 PM on June 7, 2007

If you can feel the creaks with each pedal, my guess would be lose bottom bracket.

I feel your pain though, my bike is my primary mode of transportation and everytime I pedal with the right leg forward I hear an annoying sound now (but without the shudder).
posted by drezdn at 5:07 PM on June 7, 2007

Spikleemajors... has it. "Zinn and the art..." is a great book, and a lot of the repair stuff is on the web. Although if riding is your major form of transportation, you should consider doing a bike repair class or session at a local shop--it demystifies, makes most jobs attainable, and more importantly helps you develop a feel for the various tightnesses you need.

And yes, get it looked over.
posted by Phred182 at 5:38 PM on June 7, 2007

Creaking is movement. How to spot it -- change it.

The fast way to modify a creak is lube. Note that this is almost always *not* the correct fix, but for diagnosis, it's a fast test.

You need a lube that's cheap, does little damage if misapplied, and is easy to clean. Surprisingly, such a lube is basically free -- we call it water. Water isn't a good lube because it doesn't last -- but for the few seconds we need, it'll do the job.

So. I suspect pedal creak or bottom bracket. Grab your water bottle, soak the pedal crank connection. Did the noise change? There's your creak. No? Next interface -- the bottom bracket.

Repeat until the creak changes. That interface needs work. Look at the lovely links above to repair the interface, and then ride again. Don't be surprised if you find other creaks.

Note that some interfaces require special tools to work with. They're often not expensive, but you must use the right tools to fix them. Cone wrenches and spoke wrenches leap to mind here -- get *decent* ones, and use them. Do not try to fake your way around the tools.

Bottom brackets have gotten cheap enough, and are so easy to replace, that the answer to a bottom bracket problem is "replace." Wheel hubs aren't easy to replace, you need to rebuild the wheel, so replacement costs more -- you're either paying to rebuild the wheel, or you're buying a new wheel.

The most common creaks -- pedal to crank and chain.
posted by eriko at 6:29 PM on June 7, 2007 [1 favorite]

Oh, yeah. There's one creak you can't fix, and that's a frame joint failure. Well, maybe you can -- maybe you have a lugged steel frame bike and the brazing chops to cut out the bad lug, cut the proper sized tubes, and remake the joint.

You probably don't -- 99.99% of humanity doesn't. In this case, you need a pro, or a new frame. Hint: Did you pay $1000 for the bike? If you paid $1000 for a steel bike, then the frame is worth fixing. Otherwise, it's either too cheap to be worth fixing, or it isn't fixable.
posted by eriko at 6:34 PM on June 7, 2007

Take it to a shop, have them true your wheels (cheap, might as well do them at the same time) and check the bottom bracket. That'll get you 90% there and if it squeaks when you coast they'll be able to diagnose that quickly on their own anyway.
posted by rhizome at 6:55 PM on June 7, 2007

However, sometimes the creaking noise comes up even if I am just coasting.

Are your brake pads rubbing? You mention a wobbly wheel, so lift up the back wheel and spin it to see if the breaks are touching the rims while aren't squeezing the break levers. It's more of a squeak that a creak, usually, but an easy fix if it's the cause of this issue.

Besides that, there's a lot of good advice here, and don't get intimidated by all the information.
posted by peeedro at 8:02 PM on June 7, 2007

get *decent* ones, and use them. Do not try to fake your way around the tools.

I'm constantly tempted to avoid purchasing the proper tools, and I'm constantly disappointed with my improvisations :)

However, one great trick I discovered.. Cables, and especially cable housing, are very hard to cut, but Dremel cutting discs do a pretty reasonable job.
posted by Chuckles at 11:01 AM on June 8, 2007

However, one great trick I discovered.. Cables, and especially cable housing, are very hard to cut, but Dremel cutting discs do a pretty reasonable job.

Grrr... I don't know about your dremel, but my $30 park tool cable and housing cutter (which I bought many years ago) is one of the most splendid and effective single purpose tools I own. The idea of plugging up (or charging) a dremel to snip a cable or some housing is pretty offensive IMHO to the human powered nature of bicycling. And a lot more inconvenient. If you're constantly cutting cables and housing as I do then get the park tool.
posted by wfrgms at 10:54 PM on June 8, 2007