Derailleur jockey wheel rubbing on cassette

Specialized Needs

Hi

Any ideas on this one? I have tried adjusting the B (?) screw and it is all the way in, but the upper jockey wheel on my rear derailleur rides on the cassette teeth when in the largest 2 rings at the back (when in the middle and small chainrings - I haven't tried the large chainring with it). This makes those two gears unusable (I know, I ought to MTFU and not use them, but I needed them uphill on Sunday with fully laden panniers in the heat :? )

This is a 2009 Sirrus Comp, with a new 11-32 cassette (but it did it on the old one, too) and a new chain (cut to length using the formula on Park Tools) and a new 52/42/30 set of chainrings (used to be 50/39/30).

What kind of gotchas should I be looking for here? Any ways to step through a diagnosis (or links to sites that do)?

Thanks

Stuart

nicklouse

so it had the same problem before?

what is the rear mech? sounds like the cassette is too big for the mech.

Specialized Needs

nicklouse wrote:

so it had the same problem before?

what is the rear mech? sounds like the cassette is too big for the mech.

Thanks for the response Nick.

Yep, same problem before, that was on a 28 tooth cassette (but only affecting the biggest ring), so a bit silly me trying a 32 I suppose :oops: . I am sure it was a 32 tooth cassette initially, but I'd have to look that up online somewhere.

I'll go and get some more info on this and the derailleur and post it up here in case it helps.

Thanks

Stuart

nicklouse

if the B screw is fully adjusted in and is correctly pressing on the drop out then the mech can not take cogs that big.

if it is a road mech then, lets take a Tiagra one, the max size for the big cassette cog is listed as 27T.

There is normally some leeway but that does depend on the exact position of the mounting hole.

Specialized Needs

nicklouse wrote:

if the B screw is fully adjusted in and is correctly pressing on the drop out then the mech can not take cogs that big.

It looks like I may be investing in a new cassette! After a bit of digging it seems the 2009 Sirrus Comp came with an 11-28 and a Tiagra long cage, so you must be right :oops: . I could have sworn it came with a 11 or 12-32. I blame my failing memory on age ...

Hmm, CRC here I come. Thankfully the chain is only a month old so should be OK. A shame that won't help me on the hills, though, as I think 28 was my lowest usable gear :roll: So it really is going to be MTFU time!

Ta for that Nick

Stuart

nicklouse

just get a mtb mech and keep the cassette.

The Rookie

Seconded, if you want to use the cogs then get an MTB mech!

Simon

Specialized Needs

OK. I would be happy to give that a go.

Can either of you recommend a suitable mech? I don't want to be silly again and get something unsuitable. Nothing too expensive!

Stuart

nicklouse

deore.

Specialized Needs

nicklouse wrote:

deore.

Bless you!


...I'll have a look at those...

Ta Stuart

Specialized Needs

nicklouse wrote:

deore.

Many thanks Nick.

1 x M592 long cage and a lot of fettling later and it all seems to be sorted (well, it worked over my 15+ mile commute this morning).

It felt silly going into the lower gears just to try them out. Need to find somewhere steeper just to test them, of course