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Bike problems
August 4, 2012 10:53 AM   Subscribe

BicycleFilter: So I don't know anything about bikes. Help me fix these problems with mine!

So, I bought a very, very low-end used bike and it's got problems.

- The problem that came up today that didn't happen yesterday: when moving forward, a grinding/scraping happens somewhere in the front. It's a heavy vibration and it keeps the bike from moving forward. I think the wheel is scraping against something - but what? And how do I fix this?

- The recurring problem: Often, when on the first gear, pedalling is inconsistent and a clicking noise is audible. This doesn't happen on the second gear. (It's a three-gear bike; I haven't yet needed to go above second gear.)

I hope these descriptions are clear - I have nearly no vocabulary for bicycles.
posted by LSK to Sports, Hobbies, & Recreation (29 answers total) 1 user marked this as a favorite
 
I've been using this bike for two months, by the way. I'm not sure if that helps, but it worked for riding up until today's problem.
posted by LSK at 10:54 AM on August 4, 2012


Problem #1:

Does the wheel scrap on the brake pads? If so, you can try to realign the wheel yourself, if it's just loose. If the wheel is bent then I'm afraid it's time to buy a new wheel. (You really, really don't want to ride on a bent wheel. I put off replacing mine and ended up face-planting on concrete.)

Problem #2:

This is probably an issue with your derailleur. That's the little metal thing that guides the chain to another gear when you switch gears. See if it's loose. If it is, try tightening it. It might also be a chain problem. Can you tell exactly what piece is causing the clicking sound?

Sorry, I can't give better advice without knowing more details.
posted by deathpanels at 11:06 AM on August 4, 2012


problem 1: So the grinding/ scraping - is it coming from your front wheel, or from the gear area by your pedals (the crankset)? If it's the front wheel, you should be able to visibly tell if it is hitting something.

Lift up the front of the bike and give it a spin, does it go freely? Is it hitting something? Check the upper part of the fork that holds the wheel, and also check your front brake. If it's hitting one of those, the first thing I would do is to remove the front wheel completely from your bike and hold it in front of you so you are facing the tire. Grab each side of the axel with your hands and spin the wheel freely. Check to see if the tire/rim stays straight, or if there is some wobble to it. If there is wobble, you need to take it in to the bike shop and ask them to "true" your wheel. If not, it could mean that the tire just wasn't sitting in the fork at a neat angle. Reattach it to your bike and try to get the rim so that it stays in the center of the fork as it spins for an entire revolution.

If it stays centered, but still hits the front brakes, it sounds like your front brake got pushed out of place a little bit. The brake is just bolted to your bike, you may be able to adjust it just by pressing it with your palms and straightening it out a bit. If not, don't be afraid to loosen the nut on the back of the fork a bit to give your brake some looseness, adjust it so that it allows the tire to spin all around freely, and then re tighten that bolt.

If the wheel is straight and you can't see it visibly hitting anything, it could be a problem with your hub (the part that the axel spins through), and that's a major thing that you need to take to the shop.

problem 2: When you say "first gear", do you mean that you have three gears on your back wheel, and the chain is on the littlest gear? If the clicking only happens when you are pedaling, then it means that your derailleur (the thing that moves the chain up and down the gears when you hit your shifter) is a little out of alignment. The clicking noise is that contraption pulling on the chain because it is just a little too loose or tight, and that basically is the sound of your chain trying and failing to go up to the next gear repeatedly. That or the derailleur is so loose that it is trying to shift "down" another gear, which you don't have, so eventually it may pull your entire chain off of the gear.

There's a couple ways to work on that issue at home, but I would say it depends completely on the type of shifter you have. Does your shifter have three positions that *click* each time you shift? If so, then you have "index" shifters, which take a bit of extra calibration and I would just take it to the shop as they are a bit of a pain to adjust on your own. If not, let us know and maybe we can help out. You may have to adjust something called "limit screws" on your rear derailleur, but generally that's a pain in the butt and I would still tell you just to take it into the shop for a quick tune up.

All in all, bicycle mechanics are totally visual and you shouldn't be afraid to look at it and try to diagnose the problems on your own. Your body can sense where the issues are through your seat post and handlebars, and you can almost always see where a problem is coming from. Fixing those issues takes some research, but there are a ton of great video tutorials on the web to help you out.
posted by Think_Long at 11:12 AM on August 4, 2012 [1 favorite]


I just went back out to the bike. The front wheel spins fine when it's lifted or when the bike is leaning to the right. It's when the bike is leaning forward or to the left that it scrapes against something. I think it might be scraping against the round cover?

My shifters are apparently index shifters. I'm going to have to take the bike to the shop for that one. I should resolve the first problem first, so I don't destroy my wheels on the way.
posted by LSK at 11:28 AM on August 4, 2012


The problem that came up today that didn't happen yesterday: when moving forward, a grinding/scraping happens somewhere in the front. It's a heavy vibration and it keeps the bike from moving forward. I think the wheel is scraping against something - but what? And how do I fix this?

Pick up the front end of the bike and spin the front wheel. (It may help to have an assistant do this.) Do you hear the grinding/scraping? Look carefully everywhere that the wheel gets close to other parts of the bike. You should be able to see some other part coming in contact with the tire or the rim. If it is rubbing against one of the brake pads, you may be able to fix it by re-aligning the brake. If you have caliper brakes bolted to the front of the bike, you can probably just nudge them back to a centered position if they seem to have rotated to one side. (Wikipedia says: "Low-quality varieties [of side-pull caliper brakes] also tend to rotate to one side during actuation and to stay there, so that one brake pad continually rubs the rim. These brakes are now used on inexpensive bikes . . .".) If the brake pad is not the problem, see if you can figure out where else the grinding/scraping is coming from and assess whether it's something you can nudge out of the way. If the grinding/scraping doesn't happen when you spin the front wheel in the air, then pick up the rear wheel, turn the pedals, and see if you can zero in on the source of the noise in the area of the front chainring (the cog on the front that you turn directly with the pedals).

The recurring problem: Often, when on the first gear, pedalling is inconsistent and a clicking noise is audible. This doesn't happen on the second gear. (It's a three-gear bike; I haven't yet needed to go above second gear.)

As Think_Long suggests, this is probably a matter of derailleur adjustment. However, I wonder if you could elaborate on what you mean by "pedalling is inconsistent." If you mean that the pedaling is normally smooth but there are intermittent "pops" or "jumps" where the pedal seems to jump forward a notch before meeting resistance again, then you may have a stretched chain and/or there may be damage to the cog in the rear. The stretched chain will be cheap to fix; a damaged cog will cost more. If you take the bike to a bike shop they should have a chain measuring tool that they can use to tell you in a matter of seconds whether the chain needs to be replaced. Any decent bike shop will measure the chain for free and give you a quote for the chain replacement before you commit to the cost. If they say the chain needs replacing, I recommend that you do it; over time, pedaling with a stretched-out chain will damage the cogs and then you have a more expensive problem to fix.
posted by Orinda at 11:28 AM on August 4, 2012


Orinda: There are indeed said "pops" and "jumps".
posted by LSK at 11:29 AM on August 4, 2012


When you say "the round cover", do you mean the fender? (The curved guard over the tire that keeps you from getting splashed when you ride through a puddle.) If so, you should be able to adjust it or remove it completely using basic hand tools or maybe even your bare hands to undo the screws/nuts/bolts holding it on (I'm not sure what the standard attachment is for these things). Just make sure that if you loosen a bolt that's also attaching a critical part, like the wheel axle or the brake, you tighten it up again with the part properly aligned before you try to ride to a bike shop.

Some accessories like racks and fenders attach to braze-ons and are safe to completely remove, including the bolts or screws. Other accessories piggyback on the brake and wheel attachments. You need to be more careful in removing or adjusting those, for obvious reasons.
posted by Orinda at 11:39 AM on August 4, 2012


Additional question/comment to problem 1.:
If you turn the bike around and settle it on saddle and steer, and spin the wheel, it spins freely? It's only when the bike leans to the right and you're actually biking that it scrapes against something? Okay, try to see if your wheel bearing has any loose play, by rickety-racketing the wheel sideways while holding the fork still, to test whether it moves sideways at all, or not. If yes, it's likely also shop work, unless you want to learn how to pick the bearing apart.
posted by Namlit at 11:44 AM on August 4, 2012


On my bike pops-and-jumps usually means the shifter and/or derailleur are a bit out of adjustment so that it's on the edge of trying to shift up or down a gear— if that's the problem it's a relatively quick bit of adjustment at a bike shop (it's not hard to do at home either but it sounds like you'd be more comfortable taking it to a shop and that's ok).

The front wheel spins fine when it's lifted or when the bike is leaning to the right. It's when the bike is leaning forward or to the left that it scrapes against something. I think it might be scraping against the round cover?

You mean the front fender/mudguard? (TBH I don't know the proper name for that thing either.) Maybe the fender is just bent so that it's rubbing against the wheel; if that's the case try gently bending it back. But I wouldn't expect the wheel's position to change much when you're leaning— it's supposed to be pretty solidly in place. Is the front wheel loose? It should spin freely, but if you lift up the bike (or turn it over) and grab the rim of the wheel and try to move it side-to-side you shouldn't be able to do anything but spin it. The axle shouldn't shift in the forks, for example.
posted by hattifattener at 11:48 AM on August 4, 2012


I think it might be scraping against the round cover?

I bet your fender is bent or loose. They're supported by really thin wire-struts that can get pretty bent or rickety. If you put your hand on it, can you jiggle your fender pretty easily? If so, take a look at the wires that hold it up and see if they have detached themselves from the fender itself, or down closer to the hub/axel where they attach to the bike. These things can often just snap if they're cheap, or sometimes a bolt comes loose.

I would do as Orinda suggests and just remove the fender. You should be able to do it after you pull the front wheel off. You don't even need to replace it if you don't want to, it's totally up to you whether or not you want to keep that fender.
posted by Think_Long at 11:48 AM on August 4, 2012


p.s. The co-ops mentioned in response to your previous question may be a good resource for low-cost bike repair help, if you're still in Chicago.
posted by Orinda at 11:51 AM on August 4, 2012


I think it is the fender. I'm going to try removing it. Thanks!
posted by LSK at 11:51 AM on August 4, 2012


You know, I was actually reading Sheldon Brown's article about creaks, clicks, and clunks the other day. I will say that you haven't quite given us enough information to accurately diagnose your bike, but this article may be of immense help to you in figuring it out yourself. Some of your possible problems are easily corrected at home, others might better be dealt with by a professional. The following advice is going to be necessarily pretty broad-strokes because you don't give a lot of information about your bike or its symptoms (which is understandable -- I get the impression that you don't yet really know what to look for) but might provide some guidance. If you want to get down to the nitty-gritty I'd be glad to hammer things out here or over MeMail. You'd want to start by describing the make, model, and at least approximate age of your bike and ideally by posting some pictures of the bike itself, its gears, and the front brake assembly (ideally showing the gaps between the brake pads and the rim). We could start from there and I bet we could sort you out proper.

Anyway, general advice:

There are a few things that came to mind for me when you mentioned that your front wheel is rubbing -- the first was that your rim might be out of true. You say you bought a very cheap bike (you don't say what age it is, which will affect your options some) and when you're shopping down at the bottom end of the market the bikes that you buy aren't always in good condition even if they're brand new. Your front wheel may have a wobble or a bow in it that causes it to rub on the brakes or the fender once per revolution. You can check this by spinning the wheel and looking next to the brakes to see if there's a part of the revolution cycle where the rim gets noticeably closer to the brake pad. It's a bit hard to describe in words but it's pretty obvious when you see it. This is something that at best will significantly degrade the performance of the bike and at worse may eventually destroy your rim. It's easily corrected at a bike shop, and can even be corrected at home bit it's a bit fiddly and I think you should just take it in and have it looked at.

The second was that your brakes might be out of alignment. You don't describe what style of brakes you have, but I know that for example on older bikes with side-pull cantilever brakes, it's possible for them to get off-center so that one pad rubs a bit against the rim. Newer brakes are less prone to this but have their own issues of course, and again if you bought a cheap newer bike it's possible that the brakes were simply set up wrong at the factory. The places that pre-assemble department store bikes are not really concerned with whether things are properly adjusted or indeed even facing the right way -- their goal is to just slap things together and get them out the door as rapidly as possible.

It could definitely also be your fender. If it's an old bike then it might be dinged up and out of alignment, or if it's a new bike it might've been installed crooked or backwards or have been damaged in shipping. Take a look at how the wheel moves through the fender and see if it's rubbing anywhere. If it is, take the fender off and bend the arms a bit so that it leans away from that spot when you put it back on the bike. Also make sure that your wheel's axle is properly centered in the fork and isn't leaning off to one side -- that's another bit of assembly that's easy to screw up if you are going more for speed than for quality.

You don't mention if your bike has derailleur gears or hub gears, but you say it's a three-speed so I kind of am guessing it has hub gears. (All that indexed shifting really means, by the way, is that your shifter has specific spots that it clicks into which correspond to specific gears. Older bikes had friction shifters that allow for continuous movement between gears and would therefore permit the rider to set the chain in a spot *between* gears where it won't ride properly. Nobody makes bikes like that anymore except for specialty shops that specifically cater to the retro market.) Does your bike have a bunch of gears on the back wheel with a thing that guides the chain from gear to gear when you move the shifter, or does it only have one gear in the back and kind of a fat hub inside the wheel (which conceals a complicated but very reliable planetary gear arrangement that you don't really need to worry about right now)?

If the former (lots of gears), then your derailleur probably needs adjusting so that your shifters will slot the chain into the right spots. That's doable at home but a bit fiddly and if you aren't into fiddling with that sort of thing then there's absolutely no shame in having someone who knows what they're doing take care of it. If it's the latter, then it's a little harder to diagnose. Is it just a sort of soft, constant *click-click-click* that happens as you ride along in certain gears? Then that's just your freewheel and you don't need to worry about it. If (as you seem to say above) it's a popping and clunking that you can actually seriously feel through the pedals, then you need to get that looked at by a pro. It may be a simple adjustment, or it may indicate a need for a whole new hub -- there's too much variety in the world of hub gears for me to be able to say one way or the other over the internet.

The good news is that whatever your problem is it can be fixed, probably cheaply, possibly at home. I for one would absolutely love to help you diagnose the issue either here or over MeMail and provide instructions for fixing things if your problem is a simple one, but doing so properly would probably involve taking pictures of the bike and engaging in some back-and-forth about what kind of bike it is and what's going on with it. If you are game for that then so am I, but I bet if you take it to a shop they'll have you sorted in a jiffy.
posted by Scientist at 12:30 PM on August 4, 2012


Okay. I'm trying to remove the fender, but it's secured to the bike by an L-shaped piece of metal going through a screw-type object (which also holds the front brake). That piece of metal has two small hex-shaped objects that aren't big enough to grab with a screwdriver holding it to the fender. I hope this makes sense.
posted by LSK at 1:19 PM on August 4, 2012


Hex-shaped objects are either nuts (you'll need a spanner) or bolts with a hex (aka allen) head, which means you'll need a set of hex (allen) keys.

If you're sure it is the fender, you should ideally be able to adjust it rather than remove it completely... although that too may require basic tools.

If you don't have tools beyond a screwdriver, it may be worth investing in a very basic (and cheap) cycle multi-tool.
posted by pipeski at 1:25 PM on August 4, 2012


The fender's bent and I don't think I'll be able to adjust it in a way that'll put the bike in working condition. I'd rather remove it - I don't ride in the rain anyways.
posted by LSK at 1:31 PM on August 4, 2012


Yup, you're going to have to disassemble the brake to get your fender off. This will require a wrench (aka spanner for British folks) or at the very least some kind of pliers though a wrench is preferable. Make sure when you take it apart that you remember how everything goes back together -- I recommend laying out any washers and such that you remove in order of how they go back onto the brake assembly, kind of like an exploded diagram.

Take off only as much as you need to remove the fender bracket, then put everything back on. Make sure that none of your nuts are wiggly, but don't make it tight, either -- a bit more than finger tight is about right. If you overtighten things then your brakes will bind up and will tend to rub against the rim. You want to remove any play from the system but allow things to sill open and close easily. This would also be a good time to maybe take a clean rag and get rid of any dirt or grease in the brake mechanism, and maybe add a drop of light oil or a bit of graphite powder (being careful of course not to get any lubricant on your brake pads or your rims).

Take your time and be careful. It's a simple job that is completely within your ability, but as with anything in bikes if you rush it you're bound to foul it up. As a bonus, you are going to learn how your brakes go together and a bit about how they work, so that in the future you will have an easier time dealing with any brake-related problems that might come up.

Welcome to the world of home bike repair!
posted by Scientist at 1:39 PM on August 4, 2012


Fenders are useful even if you don't ride in the rain. If you come across a puddle, it will splash not only onto your shoes and pantlegs, but also onto your bike drivetrain (chain, pedals, and chainwheel) unless you have a fender. You're in a city, so that puddle will contain not only water but motor oil, street dirt, and God knows what other substances. Unless you're completely hopeless with mechanical things, you should be able to figure out why it's rubbing and adjust it so that it is no longer rubbing.

You need to find a good bike shop that can help you with basic mechanical problems, and maybe also help you gain more confidence in diagnosing problems. Sheldon Brown's website (mentioned above) is a great learning resource and part of his legacy. But having a shop where you can go and have your problems fixed is also important. Bikes are simpler than cars, but they're both mechanical vehicles. Just as a car owner needs a good mechanic, so too does a bike owner. I use bikes for much of my transportation, and I do most of my own basic bicycle maintenance, but I have a couple shops I go to when things are too complicated for me or I just don't have the time.
posted by brianogilvie at 1:41 PM on August 4, 2012


Is this a three speed with internal gears? Those are really hard to adjust, I'd definitely take it in to a pro for that. And while you're there I bet they'll take that fender of for you.
posted by fshgrl at 1:52 PM on August 4, 2012


I agree that it's worth remounting the fender if you can manage it. Fenders protect your bike even if you don't ride in the rain, and on that one day when you just have to ride in the rain or immediately afterward, you will be glad to have fenders. Chances are good that it's not so bent that you can't unbend it with a pair of pliers or even just your hands. Once you get it off you should fiddle with it for a minute and see if you can't get it straightened out.

I would take slight issue with the "internal hubs are hard to adjust" thing. If there's something wrong with them then they're hard to fix, but if it's just a matter of proper cable tension then that's usually easily adjustable without even requiring any tools. As usual, Sheldon is your guide here.

Someone remind me to find out where he's buried so that I can visit his grave when I'm up in Massachusetts next week. The man is the Patron Saint of old bikes.
posted by Scientist at 2:00 PM on August 4, 2012


Okay, so I removed my brake and now I'm trying to put it back on. However, when I removed it, a part flew out - it's a piece of wire that looks vaguely like a pair of eyeglasses, or an bridge with two circular loops in the middle. I can't figure out how to get this back on, and all the brake assembly guides I can find don't even mention a part like this. I think it's the device that pushes the brakes back when they're not in use.

(My brake is a calliper brake, the internet tells me.)
posted by LSK at 2:21 PM on August 4, 2012


OK, I know the piece you're talking about. There will be a metal bit with a groove in it that the top of the spring (the eyeglasses) fits into, and then the ends of it go on the pegs of the calipers such that the spring holds them apart. If it doesn't quite seem to fit together right, try flipping the spring over so the coils go the other way. The circle bits should be on top with the ends pointing down, but it also has a foreward and a backward -- use trial and error. When everything's right the spring should be under a fair bit of compression and it should be holding the brakes open quite firmly. Therefore you may have to use a little strength in reassembling that bit, but you oughtn't need any tools.
posted by Scientist at 2:53 PM on August 4, 2012


That probably is what it is (a spring). Your rear brake is probably very similar to your front brake— can you find the corresponding part on the rear brake to see how it fits together? Does this or this have a diagram of your style of brake?
posted by hattifattener at 2:57 PM on August 4, 2012


Yes, if your rear brake is also hand-operated it will go together almost exactly the same as the front, aside from the position of a washer or two perhaps. You can use it as a model.
posted by Scientist at 3:03 PM on August 4, 2012


The post is coming from inside the bike shop!.  Bike shop mechanic here.
 
It sounds like your bike might just be a hot mess.  It's hard to tell.  It's hard to tell.  At this point, since you might have flung your return spring out of your caliper, I suggest you call around to a couple of bike shops (or check for a bike collective where you can borrow tools and a shop stand), and get another pair of eyes on this bike.
 
That clicking that you hear in one gear but not in others?  My wild-ass guess would be that the derailleur cable is slightly too long, and it's hitting the crank arm as it passes by.  If that's the case, you can just bend it out of the way, or cut it so that it's shorter and doesn't hit the crank arm.  Before you cut it, make sure you have the little mouse condom that goes on the end of the cable.  Do not cut the cable before you procure one of those things (free from any bike shop worth their salt).
 
Like I said, it's hard to tell.  Working on your bike is pretty easy, once you have the right tools and you know what you're doing.  But when you're fishing in the dark, it's easy to make a bad problem worse.  If a customer asks me nicely to watch me do a repair, I'm usually ok with having them walk back into the shop and watch me explain what I'm doing.  Not always, because it can be a bit of a liability issue.  We do diagnostics for free, but shops around here that don't still don't charge that much just to tell you what you need to get your bike safely working again.
posted by spikeleemajortomdickandharryconnickjrmints at 3:21 PM on August 4, 2012 [2 favorites]


You said it's a 3 speed which implies you don't have a derailleur at all. 3 speeds are fairly easy to adjust but if they're busted, they just aren't fixable by normal people.

There's no way to tell what's wrong with your front wheel from the description. It could be the brake, or the fender, or your bearings could be wrecked.

At this point I'd suggest taking it to a shop. While you're there, see if they have a course on bicycle repair that you can take. It's well worth learning some basics.
posted by chairface at 4:05 PM on August 4, 2012


I've had this problem on my kids' bikes when they've turned the handlebars all the way around (360 degrees) and tried to ride that way. When they turn - only in one direction - it causes the brakes to deploy and stops the bike. Maybe?
posted by thatone at 4:43 PM on August 4, 2012


I don't know much about bikes, but bike collectives are amazing. When I had no idea what I was doing, the fine folks there supplied tools and helped teach me what I needed to know. Hopefully there's one you can visit!
posted by vasi at 8:06 PM on August 4, 2012


Nthing bike collectives or equivalent. Volunteers giving you free advice. Unlimited usage of their tools. Awesomeness.

In Chicago there is this West Town Bikes
which has open shop hours which may be what you need. If that shop isn't anywhere near you get a recommendation for one that is. Good luck, bikes are actually really fun to maintain.
posted by fieldtrip at 11:32 PM on August 4, 2012


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