suburbanbeat

Hi all. I'll do my best to explain a problem that I'm having with my Novara Randonee touring, 21-speed road bike.

The issue started a few weeks ago when my chain starting making a "creeking" noise. Nothing happened beyond that, so I figured I'd wait until I had to. Well, now I have to - because the creeking sound now leads to the gear "skipping". That is, when I'm pedaling, the bike will seemingly fall out of gear for a split second. It doesn't switch to another gear or anything, but it skips a LOT (every 5-20 pedal rotations, so it happens a lot more in lower gears).

To clarify, I have no problem shifting, so I don't think this is a derailleur issue.

A friend suggested a bad chain ring, but I'd like to get the opinion of people on here before I purchase any parts. Thanks in advance!

Sean

pierce

does it only do this in particular gear combination(s) ? 21 speed implies a 3 x 7 gearing... if your chain is worn and 'stretched' (they don't actually 'stretch' per say, but when the pins wear, its the same thing), it will be more likely to 'jump' a cog when using the smallest (high gear) cog in back. it has to be really bad to jump teeth in front on the larger chain rings.

if your chain is stretched, you shoudl replace it immediately, and have the cogs inspected for excess wear too, as a stretched chain wears out sprockets faster, then if you put a new chain on a worn out sprocket, it will damage the new chain faster too. any bike shop should be able to do this inspection quite simply, or check the stuff on sheldon brown's webpile, like https://www.sheldonbrown.com/chains.html#wear
(read the whole page, there's a lot of useful stuff there).

dsbrantjr

Have you lubricated the chain lately (or ever)?

suburbanbeat

Thanks much for the suggestions. So, even though I can't replicate the "jump" when the bike is upside-down and stationary, it sounds like this is an issue with the rear gears, but I can't be sure. Honestly, I've put a lot of miles on this bike training for a tour in June. It sounds like it might be best that I replace both the chain and the chain ring/freewheel. I'll look into these parts and check out that resource - thanks much!

And dsbrant - embarrassingly enough, I haven't. Oops.

joetheun

Before throwing money at it, be sure what the problem is. You may not need chain rings. I am guessing the chain is worn though. How good are you at maintenance i.e. lubing the chain weekly and after a wet ride? It may also be a miss adjustment in your derailleur. This may be from cable stretch or the derailleur having been hit. I also had this problem, the creaking noise and funky shifting. It turned out that the rear derailleur hanger was loose. So anyway, diagnose then repair.

suburbanbeat

Fair enough, thanks for the suggestion. Part of the reason I'm on the "replace everything" kick is because I currently have limited knowledge of basic maintenance and want to learn as much as possible by doing.

joetheun

learning by doing. That's how I learn also. How are you set for tools? If you are starting in this self taught Bike mechanic school, you wil find each project usually entails a new speciallized tool to do it or make it easier. good luck.

suburbanbeat

I am fortunate to have a few friends with plenty of tools between them to do whatever I need to do. I'll lean on them for now until I decide what I want to actually buy for myself.

pierce

to change the chain (or even remove it for a thorough cleaning), you'll need a chain punch, like https://www.parktool.com/product/mini...hain-tool-ct-5

to change the rear sprocket cluster, you'll need a freewheel or cassette tool, depending on what your wheel has, and a 'chain whip'. for a cassette: https://www.parktool.com/product/cass...ring-tool-fr-5 and https://www.parktool.com/product/spro...hain-whip-sr-1 for freewheels, well, depends on the freewheel.

to change the front chain rings, you just need the appropriate size metric allen wrench... but chain rings are the LEAST likely thing to be the problem here.


these speciality tools should last you pretty much forever, so they are a good investment. I still have the chain punch I bought in the late 1970s.

FBinNY 

The creaking usually means a dry chain, so start with the simple and oil it. The skipping might simply be because a dry chain isn't engaging smoothly and might resolve once you address the lubrication problem.

However, even well oiled chains will skip exactly as you describe when the chain and sprockets wear out. So if oiling doesn't solve he problem, use a 12" ruler to measure your chain for stretch (search chain stretch) and replace it if it's stretched more than 1/16" over 12". OTOH, if it's stretched beyond 1/8" over 12" there's a good chance your freewheel (or cassette) is toast also, and you'll need both.

oldbobcat

Chains need to be replaced every 2-3,000 miles or so, more often if you let them get really dry or dirty. Let it go long enough and you need to replace the cassette, too. With good chain hygiene, a cassette should last 2-4 chains. If you really let it go you can look at replacing some chain rings, and now we're talking about real money.

FBinNY 

+ 1/2

I agree that chains need checking and replacement when worn to preserve cassette life, but there's no fixed interval. Chain wear can vary by as much as 10:1 person to person, depending on a number of variables, including rider weight, strength, gear selection, hill climbing style, overall terrain, weather, and of course maintenance habits. A light rider in the plains states who doesn't pound the 53/11 combination can get vastly better chain life than a heavy rider in Pennsylvania, who attacks steep roller coaster hills on a regular basis.

Either way, the kind of ghost shifting the OP describes is rarely caused by chain wear, and usually traces to lever slippage or an RD trim or alignment issue.

suburbanbeat

Just how costly does it get? So far, if I'm doing my research right, it looks like it wouldn't be more than $100 to replace my entire drive train with the exact parts that I have on right now (all Shimano). Seems very cheap, but then again I'm still new to this so I'm still using automobile repair costs as my point of reference.

Number400

Re-index the RD. Takes a few seconds and plenty of youtube videos on how to do it.

Check the distance between the RD top idler pulley and the smallest cog on your cassette. Distance should only be 6-8mm or so.

Also check that you don't have a failing RD cable. Once a few stands break in the shifter housing, it will work until it breaks but until then, all sorts of things can go crazy and almost work right.

Clean, inspect and lube everything involved.

Good luck and post the fix when you get it straightened out!

pierce

what year Novara is this?

wait, if you have friends with 'plenty of tools', are those bicycle-specific tools? automotive stuff is of little to no use here, except metric hex keys and a few small open end wrenches. if these friends have bike tools, presumably they know how to use them, and can diagnose your problem far easier than we can.

I would check rear derailleur alignment and adjustment, and chain stretch. if the chain is stretched, visual close inspection of the sprocket teeth.

suburbanbeat

I've had trouble pinpointing the exact year, but I believe it's a 2004.

Ah yes, I was referring to bicycle tools. I'm going over to a friend's house who has a well-stocked workshop. And it's certainly true that his know-how will come in handy, but I wanted to get a few different leads in case what he suggests doesn't work. I also don't want to go over without having any idea where to start! So this has been very helpful so far.

I'm looking at my chain now, and yeah, it looks and feels dry as hell. That's my fault. Lubing and possibly replacing is going to be my first line of attack, and I'll go through the rest of these ideas if that doesn't work.

FBinNY 

Why the rush to through dough at it?.


Start with what you know needs to be done, namely oil the chain, and see if that helps. Then measure the chain for wear and know where you stand. You might need a chain and cassette, or maybe just a chain, or maybe neither.

pierce

its not at all uncommon for a rear derailleur to get knocked or banged a bit and bent slightly inwards so the chain takeup wheels aren't exactly perpendicular to the axle and coplanar with the sprockets. This can cause sketchy shifting and skipping behavior like you're seeing. people will readjust things to try and compensate, which makes it almost work right.

If its only a slight bend, the solution is to bend it back til it looks as square/straight as you can tell, then readjust the limits and indexing as needed. if its overly bent, sometimes you need to replace the derailleur hanger, this is a separate little bit on most frames, but there's about 50 different designs, there are vendors who sell all of them, you look it up by year/model bike, then compare your own with the picture of the replacement part.

cny-bikeman

Replacing parts will not help you learn more and may have the opposite effect. Chain and cassette replacement is not done very often and is relatively expensive, so your time is best spent learning how to diagnose drive train problems, as well as how to avoid them.

In that regard, the first thing to do - because it's quick, simple and requires no specialized tools or knowledge - is to measure the chain wear.

1. Put your bike in a middle gear in the rear and middle or large chainwheel, and put the right crank level, pointing forward.
2. Take a steel ruler or tape measure and place it on the top run of your chain (top of cogs to top of chainwheel) so that you can see two marks 12" apart. I just use 1" and 13" to avoid problems with wear or tape measure clip ends.
3. Put hand pressure on the pedal with your right hand and then place one end of the measuring range on the center of a rivet (or on one edge). Look at the corresponding place 12" away to see how far the measuring point is beyond 12."

The previously cited page on Sheldon's site is an excellent resource regarding chain wear and replacement.

I'm not sure we have the info necessary to say for sure that the problem is wear. Even if the chain is worn it does not mean that is the cause of your problem, or that other problems do not exist. We need to know the following:

1. How old is the bike, and are the chain and cassette original?
2. Did any equipment changes or adjustments immediately precede the start of the problem?
3. In which chainwheel/cog combo's does the problem occur, and does it occur under pretty normal pressure or only when putting high pressure on the pedals?
4. Do the cranks jump only a small amount or is it sometimes larger?

Incidentally we don't even know that the creak led to the current problem. Creaks that occur regularly per pedal revolution almost always indicate a problem with the tightness or mating of pedals to crank, crank to spindle or bottom bracket to frame. I have a Randonee myself, and it's a great bike, but like all bikes it needs regular maintenance. If you have not had a tune-up done recently I would have a shop go over everything and then advise you as to care, so that you then have time to learn how to do the items you want to take care of yourself without pressure. Of course if you aren't riding in the winter you can take your time and learn on your own.

E.W.G.M.B

have u taken the bike back for the FREE tune-up?

suburbanbeat

Hi all - great suggestions from everyone. I really appreciate the hypotheses and ideas! For better or worse, it turns out Occam's razor proves correct here. The simplest solution was indeed the correct one. I just took my bicycle in for a quick lubing, and sure enough, my bike rides and shifts as if it were brand new. I feel silly that I went through this whole hoopla before trying something that took a total of 5 minutes, but hey, that's part of the learning curve I guess?

So, for any fellow cycling newbies who might be stumbling upon this thread in the future - just lube your damn chain before you panic and replace the drive chain. Oof.