eemaen

Hello everyone,

I just purchased Shimano R501 wheels (Shimano R501 Wheels | Merlin Cycles). They've got Shimano r-501 freehub. I tried to fit my Sram PR-1050 cassette on them. Cassette is just fine with my Bontrager wheels that came with my Trek XO-1 2011 cyclocross, but i can't get it tight on my new wheel. The problem is similar to this one: https://www.youtube.com/watch?v=poZk8UyB3AE though not as bad. Some of the commentators in that video said that I'd need a 1mm spacer. Is it correct? Where can I get one?

Do you think this could cause chain skipping or does the problem lie somewhere else? I replaced simultaneously chain and after replacing wheels and chain skipping started. It happens occasionally, and the problem seems to be worse on middle cogs but it's also present on small or large cogs.

HillRider

Shimano 10-speed cassettes come with a 1 mm spacer to be used when they are fitted to Shimano 8/9/10-speed freehub bodies. Usually SRAM 10-sppeed cassettes don't need that spacer but if your cassette is loose, get one. Any LBS should have a bunch of extras.

hueyhoolihan

the video shows, to me, an indication that the lockring is not tight, either because it has come loose, or never been tightened properly, or IS TIGHT and a requisite spacer is missing between cassette and freehub, that permits the lockring to tighten down, as it should, on the cassette body rather than the freehub itself.

BTW, it looks as though someone has responded before i could finish my final editing...

anyway, you could have both problems, loose cogs and skipping chain, in as much as the video shows a problem that i wouldn't think would create skipping, just a lot of excess noise and possibly shifting problems, but you never know.

eemaen

I acquired the spacer recommended. However, I still wasnt able to get the cassette tight enough. The problem seems smaller though. Any ideas what I should do next?

About chain skipping: most times it happens when I decrease pressure on cranks. Could it be because of bent deraileur? Hanger is OK for I just replaced it. There are bunch of photos attached. I can't surely tell if the der is bent of just somehow badly adjusted. Any help is appreciated.

Phil_gretz

Doesn't look obviously bent to my eye, but it's best to measure with a derailleur hanger straightening gauge. My guess is that you have the cable tension a little light (back the barrel adjuster out 1/4 turn). This is from judging the position of the play in the top pulley in photo #3 , which is a guess.

You changed the chain? Same number of links as in the chain that it replaced? Using the big-big method, do you have a link or two extra in length?

Bill Kapaun

IF cogs are still loose with the lock ring cinched down (around 30 ft.-lbs.) then you need "more spacer".

Chain skipping might be an issue simply because you have a different cassette and need to "tweak" the barrel adjuster a bit.
Even same brand cassettes aren't identical due to manufacturing tolerances.
Fix the KNOWN problem before proceeding to the secondary problem.

Also, you said you replaced the chain?
Your cassette may be worn enough that it doesn't match the new chain.
Try the old chain again and see what happens. IF the problem disappears, you have a worn cassette.
In that case, I'd just use the old chain & cassette and run them into the ground.

Wilfred Laurier

if your drivetrain started skipping after replacing the chain but not the cassette
then the cassette is worn to match the old chain and will not work with a new chain
this is a very common and well known problem

eemaen

My cassette shouldn't be too worn. However, I think I'll get new cassette anyway. That will hopefully help with loose cog problem also. Can anyone recommend some budget 10-speed cassette? I use my cyclocross bike for touring and large sprockets come handy. I'll be needing 30-32 teeth sprocket,

eemaen

Can anyone tell from the picture if the cassette is worn? It's a sram pg-1050 cassette.

Wilfred Laurier

it is difficult or impossible to determine visually if a cassette is worn

generally you can tell by installing a new chain
and if the new chain skips then the cassette is worn
and you have done this test already

another indicator is the condition of the old chain
as wear in the cassette is actually the cassette wearing to match the elongated pitch of the worn chain

Chain Maintenance

scroll down to the section on chain wear
the article has information on how to measure and whatnot