Rear Cassette wobble

[Ratchet]

First of I'd like to say hello! I'm come to this forum quite often but have only just signed up and am happy to be here. Wonderful site.

My rear cassette wobbles when my rear wheel turns. The wobble speed and the rotation speed of the wheel are synced - one revolution per wobble.

It's pretty bad. When I'm peddling hard it jumps gears back and forth quite quickly which no doubt is very unpleasant.

What is the actual issue here? The cassette? The rear hub?

Any help on a solution or what I should be looking at replacing would be great.

Thanks a bunch!

- Ratchet

[Painkiller]

Welcome to biketutor, first I would like to know what bike you have, I have seen many a department store bikes like the ones by Pacific cycle do the same thing. Caused by not so perfect axles, bearings, cups and cones.If this is the case not much to be done. So more info and we can go from there

[Ratchet]

(03-09-2012, 09:11 PM)painkiller Wrote:  Welcome to biketutor, first I would like to know what bike you have, I have seen many a department store bikes like the ones by Pacific cycle do the same thing. Caused by not so perfect axles, bearings, cups and cones.If this is the case not much to be done. So more info and we can go from there

Hey Painkiller. Short answer is: I don't know. It's a 10 speed road bike - frame looks like a simple Peugeot road style. I have no idea what brand as it looks like it's been Frankensteined from several different bikes. It's not a new bike by the looks of it.
I just got it off a random on Craigslist so I don't really know anymore.

What you described sounds like it could be the issue as the wobble does a circular, off axis motion. To be more exact the space between the hub axle and the cassette body is larger on one side and as the wheel goes around the "larger" space moves around respectively.
aka The cassette does not appear to be parallel to the tire/chain.

Not sure if that helps at all.

- Ratchet

[ghost]

(03-09-2012, 11:44 PM)Ratchet Wrote:  

(03-09-2012, 09:11 PM)painkiller Wrote:  Welcome to biketutor, first I would like to know what bike you have, I have seen many a department store bikes like the ones by Pacific cycle do the same thing. Caused by not so perfect axles, bearings, cups and cones.If this is the case not much to be done. So more info and we can go from there

Hey Painkiller. Short answer is: I don't know. It's a 10 speed road bike - frame looks like a simple Peugeot road style. I have no idea what brand as it looks like it's been Frankensteined from several different bikes. It's not a new bike by the looks of it.
I just got it off a random on Craigslist so I don't really know anymore.

What you described sounds like it could be the issue as the wobble does a circular, off axis motion. To be more exact the space between the hub axle and the cassette body is larger on one side and as the wheel goes around the "larger" space moves around respectively.
aka The cassette does not appear to be parallel to the tire/chain.

Not sure if that helps at all.

- Ratchet

PK is dead on and seems to be a problem with low end bikes. A lot of the time, if the wheel is spun an up and down motion of the cassette usually shows a bent or out of round axle. Hope all this helps.

[Ratchet]

Quote:PK is dead on and seems to be a problem with low end bikes. A lot of the time, if the wheel is spun an up and down motion of the cassette usually shows a bent or out of round axle. Hope all this helps.

Yeah it does, thanks gang!
I guess I'll need to replace my whole rear end then.

[Joe_W]

Go to a LBS that has been around for a while. Get a used rear wheel there. I got a set (not matching, but hey) for... 20 EUR (about 25 USD?). Had to overhaul the bearings but that's not much work. Just a bit messy.

[Ratchet]

(03-10-2012, 01:22 PM)Joe_W Wrote:  Go to a LBS that has been around for a while. Get a used rear wheel there. I got a set (not matching, but hey) for... 20 EUR (about 25 USD?). Had to overhaul the bearings but that's not much work. Just a bit messy.

That's a good idea. Thanks Joe_W! To be clear will I need just a "new" rear wheel or the wheel and cassette?

[Painkiller]

you have a freewheel, not a cassette most likely.
if you could somehow swap another freewheel to see how it acts that would help cross-check the problem to be sure if it is the hub or the freewheel....good luck sir and let us know what you come up with

[Ratchet]

(03-10-2012, 02:27 PM)painkiller Wrote:  you have a freewheel, not a cassette most likely.
if you could somehow swap another freewheel to see how it acts that would help cross-check the problem to be sure if it is the hub or the freewheel....good luck sir and let us know what you come up with

(I just Googled a grammar lesson on "to" vs "too"... I think I have it right now.... I hope)

I'm not too sure on the difference between a freewheel and the cassette but I assume you're right!
I got a line on a free rear wheel with tackle I should be able to pick up over the next few days so I figure between the two I should be able to make a working version.

I'll keep this up to date as things progress and I'm assuming I'll have some questions along the way.

Thank you all for being so helpful! Brings me great joy to know there are still people out there into helping just for the sake of helping and teaching something they love. (end of heart felt spiel)

[Joe_W]

You want to read this on cassette vs. freewheel:
http://www.sheldonbrown.com/free-k7.html

One problem that might / will crop up next is the frame spacing: your old Peugeot is built with a distance between the dropouts of (I guess) 124mm. A new-ish roadbike rear wheel has 130mm. It is possible to cold set a steel frame (if it is that old it most likely is steel, don't try this with carbon or aluminum). Then, you'll have to readjust the dérailleur hanger. I did this with my old Peugeot, it has now a 9 speed setup (today you refer to the # of speeds in the rear), with microshift integrated shifters/brake levers (I think some call them brifters). Works ok (except for my old brakes...). If you update things, beware: it is a money sink. (I love riding it, so it was money well spent). Now I just need a new fork (because of the brakes: Mafac Competition brake mounts are only compatible to centre-pull brakes of that time, those are not compatible to modern brake levers).

[Ratchet]

Hey all. Finally got a replacement rear wheel setup and it fit perfectly and solved my issue!!
No more gear skipping or noise.

Thanks for all the help.

- Ratchet