Giant40

I have a real mystery that I’m hoping to get some help with. It’s regarding a problem I’ve asked about before. My chain is “skipping” when I pedal with hardly any pressure at all. I have to pedal very, very lightly and gain speed very gradually, or it “skips”. If I pedal any harder while looking down at the chain and rear cassette, I can see that the chain is not skipping from one gear to another, but is staying on the same gear, so I concluded that it was a problem in the freewheel or freehub, depending on what’s in there. Someone suggested that I spray lube into the hub, which I did, but it didn’t help. The bike is a 7 year old Specialized Hardrock mountain bike which I’ve ridden in the rain and snow, which I figure contributed to this problem.

Today, I did something that I thought for sure would give me a temporary fix. I have another Specialized HR which is in much better condition and has no skipping problems. I thought an obvious “fix” would be to temporarily use my newer bike’s rear wheel on my older bike’s frame, thus replacing the skipping freewheel with one that has no problems. The result? The exact same problem! It’s a total mystery and I’m at a total loss to explain it! If the chain is staying on the same gear and is not slipping off, then what else could be causing this to happen? It can’t be the freewheel since it happens on 2 different ones. Can someone help me out here?

bikeman715

you need to replace the chain . there may be frozen links in the chain from winter riding and/or the chain is just worn out . another possible would be the rear derailer hanger is bent . if the chain is worn so can be the freewheel / cassette .

prathmann

Have you replaced the chain? Usually skipping is the result of using a new chain in combination with an older cassette (or freewheel). The old cogs have worn so they allow for slightly longer than normal spacing between the chain links so they work fine with the old chain. But when a new chain is installed it has the proper link spacing and hangs up on top of the teeth of the cogs and results in skipping. It's entirely possible that both of the wheels you tried have somewhat worn cogs on them that are skipping with the chain you're using on that bike. Happened just recently to a friend of mine and he was sure it couldn't be the cassette since it acted the same on two different ones - but it turned out that both were worn.

If you haven't replaced the chain then I agree with the post above that it could be some links in the chain that are sticky and not meshing properly with the teeth on the cogs.

cny-bikeman

It is common to isolate a problem by substituting a known good part to see if the problem remains or if it goes away. If it goes away you know that the part you replaced was the problem (or at least part of it). But if the problem remains, and the substitution was functionally not different than the original, then you still don't know for sure what the problem is. In this case either the chain is worn and neither cassette is worn or the chain is new and both cassettes are worn. We don't know if the chain is old or new, but skipping under low pressure is usually a new chain on worn cogs...unless the chain is REALLY worn - just found this from an earlier post of yours:

"I just measured the chain like you said and it was 1/4" past in 12". I guess that means it needs replacement. Would that mean I need to replace the gear cassette too? The teeth on the gears are pointy in some places."

FBinNY 

Either you chain is well worn compared to the freewheels (or the opposite), or there's a stiff or damaged link. Since you describe it as being sensitive to load instead of occuring every three turns of the crank or so, I lean to the classic new chain/old freewheel, or old chain/new freewheel issue and you need to replace on or the other.

You can also measure the chain for stretch (wear), and if you don't know , you can search chain stretch on the net. Note chain stretch is only an indicator of condition, chains can also wear in other ways leading to the same effect. The definitive test is to replace the chain (save the old one for the moment) and see if a new chain runs well on your freewheel.

hueyhoolihan

i would put the rear wheel that is questionable on the new bike (i.e. the one that works) just to satisfy my curiosity...

and like others, it sounds to me like a chain issue.

superfred

How old is the chain? (in miles)
How old is the casette?
If you keep using a worn chain, you will begin to eat up the teeth of your casette and possibly crankrings, resulting in a costly replacement.

Giant40

I guess it could be the chain. This morning, I gave it a very thorough cleaning and relubing, and I just rode it again and got the same results. The chain I'm using is the same one that came with the bike, so it's the same age as the cassette.

ThermionicScott 

1/4" of stretch in 12" of chain is really bad -- you should allow for up to 1/8" at the most. Is it in the trash yet?

Bill Kapaun

Apparently you choose to totally ignore post#4.
IF the chain is THAT worn and it came with the same cassette, they are probably both way beyond their useful life.
Probably damaged the chain rings too??

ultraman6970

He needs to change chain, cassette and chainrings. Oil wont do anything at this point. Stubborn people

Giant40

I'm not ignoring anyone, but just trying to see if there are any alternatives. I figured if a chain is dirty enough, maybe it would keep the links from pivoting the way they should. I guess that wasn't the problem.

I don't even know how to change a chain. I've heard special tools are needed. My bikeshop wanted to charge me quite a bit for purchase and install, plus wants to change my cassette as well for even more money after I've already spent quite a bit lately on this bike, so it makes me hesitant to spend much more.

FBinNY 

People often thing bike shops are just trying to sell more when they suggest (strongly) a new cassette or freewheel with a new chain. It's a sore point, but the simple fact is that a new chain won't run on a well worn sprocket, and an old chain won't run on a new sprocket.

If your original chain and sprocket are worn to where they're slipping, it's 100% sure that replacing either alone won't solve it, and will likely make it worse. You need both, and as someone else pointed out, you might need a new chainring or two, but these are more forgiving, so you might skate on that.

Most shops, only charge nominal labor to install a chain and cassette if you buy both from them (when I was in retain, we'd do the install free if both were bought new). Or you might search locally for a bike co-op where you can do it yourself, using their tools, learning in the process.

If you had listed your city of residence in your profile, someone could likely have steered you to a decent shop or co-op in your area.

I assume this is an older bike and understand that you don't want to spend any more than you absolutely have to. Look for a "blue collar" bike shop, where they specialize in more basic family family and entry level bikes and repairs, than a "pro shop" which caters to a more monied crowd.

Giant40

The shops I've been going to, which are small, charge the same for the install as for the item--they simply double the price. If a chain was $20, it would be $40 installed. Same for the cassette.

The bike is a Specialized Hardrock about 7 years old. I've been using it for rain/snow rides so I can save my newer bikes for better conditions. I'm not anxious to press one of them into rain/snow riding, but also not anxious to spend even more money.

FWIW, I don't see the chain actually slipping over the gears when the skipping happens, which is why I originally thought it was the freewheel. The chain appears to stay firmly on the gear, which is another reason I questioned whether or not the problem is with the chain. I'd just hate to replace the chain only to find that it's not the problem. I've done that sort of thing before (with this bike) and it was frustrating.

FBinNY 

The best indicator of the situation is the 1/4" in 12' stretch you measured (I think that's what you said). With a chain that work it's just abiut certain that you'll need both. I always buy both, then try to skate replacing only the chain. If the chain wasn't too badly worn this usually works, and I can keep the cassette for the next time, but if you measured correctly, the odds of not needing both are 100:1 or worse.

Another way to measure chain and sprocket wear is to shift to the slipping combination, and use a small screwdriver to lift the chain away from the sprocket at the back (the 1/2 way wrapped point). You can always lift a little bit, but if you can lift the chain away so there's 1/4" of daylight under it at the bottom of the teeth, you know one or both re toast (usually both).

Look for a co-op, or at least a more reasonable shop, since the install prices you're getting are very high, especially if you replace both together.

BTW- where do you live, someone can refer you to the good guy in town?

ultraman6970

If you tells us where you are maybe somebody close by can help you?

bikeman715

The shop shouldn't double the price when you buy the items , that doesn't make good business sense . I'm not saying they can't charge you for the service . In many shops the service be free or little at the time of the sale , that way the shop know you will return in the future . For the chain I would go for the cheapest you can find knowing this is a winter / bad weather bike . And replace the freewheel too . The cost for both should be around $ 30 .00 and with the right shop 10 more for labor .

davidad

The cassette will wear with the chain. Usually the skip occurs with a new chain on a worn out cog.
A chain should be replaced when it measures 1/16" of wear. After that everything begins to be worn out.
At this point you may need to look into the cable and cable housing to see if that is causing a problem.

Airburst

Wow, 1/4" stretch over 12"? I'd imagine you've done some damage to the chainrings at that point, never mind the cassette.

billnuke1 

It almost sounds like the chain is riding between two sprockets! You cannot see this exactly this from the seat! Get on your bike shift into the gears that are giving you the trouble. When it starts to happen, get off your bike and take a close look at the chain and where it is laying. I think that you will see your chain laying on top of two sprockets. If so, check your derailleur for adjustment. Good luck!

joetheun

I am guessing frozen links in the chain. While off the bike turn the peddles and watch the chain as it goes through the Jockey pulleys of the derailleur. If you notice that part of the chain does not conform to the pulley but stays straight, that would be the culprit. you may need to force the links to flex using pliers and a good penetrating lube. I've seen this a few times on older bikes with poor maintenance.

cny-bikeman

Making an initial guess is fine, but you need to abandon anything that cannot be reconciled with the results of a diagnostic procedure liike switching wheels. There is exactly zero possibility that it is the cassette pawls if putting on a different wheels elicits essentially the same symptom. Likewise, tight links or any problem limited to a section or sections of chain will show themselves in a rhythmic manner that is a multiple of crank revolutions (links in chain)/(chainwheel teeth).

Bike troubleshooting is not a guessing game or a matter of choosing the solution that suits you, but a logical process based on known mechanical relationships, which in turn are based on the laws of physics and mathematics. You asked for assistance, and have been provided (free of charge) opinions from two of us who have decades of professional experience. In addition I doubt anyone on this forum has more knowledge about chains than FB, and few have as much drive train experience. But aside from that the only logical conclusion one can reach from the information you have presented is that the chain is indeed the problem. It does not matter who comes up with the solution to a problem - if they reached it in the proper way it is likely true.

ultraman6970

I think the problem is that the guy doesnt want to spend any money and he is looking at other possibilities, sadly it is a bike and not a car, you have 3 parts that could be the problem IMO the 3 all together, for other guys is just 2 parts. Cleaning the chain really well and adding a lot of cooking oil wont work and did not work, maybe putting more air to the wheels, adjusting the saddle height and painting the bike with a brush will make the trick this time, you should try all of those.

Sorry for the sarcasm but you are not the 1st one neither the last one looking for a solution to fix apparently a bike with zillions of miles of use, using prayers because is cheaper than what people w/o any interest in getting your money is telling could be the problem.

Good luck with your bike man...

cny-bikeman

Thank you for making me look kind. I don't tend to couch my posts, simply because it's not personal but rather the result of objective diagnosis. I see no benefit in my giving encouragement to the exclusion of accurate information, but some consider doing so to be harsh.

FBinNY 

I understand that, and am sympathetic, but in looking at his options he won't find relief by not replacing RIP parts. Since not replacing some hardware isn't an option, the OP should consider what the bike is worth to him, find out what else it may need, then decide what he's willing to spend to keep it on the road.

Then knowing what it needs he can go about looking for the most cost efficient ways to meet them, and trying to stay within the budget. He can consider less expensive chains or freewheels, decide if he is willing to learn to DIY, get pricing for the tools needed (freewheel or cassette lockring tool, and chain tool), and see if that makes more sense for him.

Also, if he's serious about saving money, he can say where he lives and try to cash in on two offers to help him find a co-op, or better dealer, or possibly get some buddy help.

Here on the forum, we can lead him to water, but it's up to him to drink.