Fixitman

So I picked up a cervelo RS. As I do a lot of climbing and it came with a compact crank I opted for an 11-28 cassete. The bike came with ultegra (all I can afford right now ) The salesman sugested changing the rear derailure to a durace long cage to work better with the 28 tooth cog. The cassete he recomended was the sram PG1070. The bike shifted fine when I test rode it before the changes were made. Now it hangs up very badly when up shifting to the last 3-4 cogs . The other thing I noticed is that when coasting the normal clicking is much louder than it was with the same wheels diferant cassete on my other bike.
The bike shifts fine upshifting in the lower gear range and downshifts fine. Any thoughts on the sram cassette, the louder hub noise. Think adjustments are going to take care of the shifting or is it an equipment issue.

bt

yes

daxr

Is the chain long enough? The long-cage derailleur and 28 tooth cassette both add to the length of chain you need.

chadteck

Hopefully you didn't have to pay for the DA RD. I'm pretty sure I've read that an Ultegra short cage RD should work fine with a 28t. Shimano lists 27t as the max for both long and short cage, but larger works according to posts here. Its not Shimano, but I've got a friend with a 32t in the back and uses a short cage Centaur RD.

As for the noise, it could be related to the RD not being adjusted properly, chain being too short as stated above, or change in cassette.

CollectiveInk

I have always read that Shimano short cages are good up to 29 teeth difference (compact 50/34 = 16t + 11/28 = 17t [16+17 = 33t difference) ie... the long cage is needed. But as was suggested above, if they just stuck on the new cassette, new RD and the OLD chain - it might be too short and thus limiting the movement up the cassette. Have them verify the chain length and adjust as necessary.

If it's a brand new bike from them, I'd be in there every single day until it's purring like a kitten (Free adjustments FWIW).

Chuckie

I'm running the exact same setup you are on my RS, except my cassette is an 11-26 SRAM Red 1070. I haven't had any problems with mine. Yours may need adjustment, and (as others have stated) your chain might be too short.

The noise could be from the hollow inside of the SRAM cassette, maybe it's amplifying the sound.

KevinF

Where did you ever hear that the derailleur cage length affects the chain length?

Fixitman

It's nice to know I did not waste my money on the rear derailleur. I am taking the bike in today and indeed I do expect it to be purring like a kitten. Right now the last four gears are just about useless and I end up up shifting until I coax it into the top gear and then down shifting to get to the gear I actualy wanted to be in

NRRider

I'm not an expert, but I wouldn't think this has anything to do with the new cassette or the chain. This clicking is produced by the pawls inside the hub. I suppose the road vibration could be rattling the cassette if the cassette is not on tight enough. Have you checked the cassette to make sure there's no play and that it's nice and tight?

Fixitman

That was kind of my thought as well and found it very odd. The damned thing sounds like I have playing cards on the bike! You can actualy feel it pulsing in the frame as well. Every thing is plenty tight. I am going to the LBS a little latter today to see if I can get this sorted out. It cant be good for the hub whatever it is.

daxr

Look at the distance between the derailleur gears - the spacing on a long cage takes about one more link of chain to span.

af2nr

Not doubting what you've read but the 08 Specialized Tarmac Expert Compact comes with a Shimano short cage derailleur and a SRAM 11-28 cassette? The one I had never had any of the issues the OP is describing BTW. My 09 Pro doesn't have any of those issues either, compact as well, but it's got SRAM instead of Shimano?

Fixitman

I am officialy getting frustrated now. Took the bike in and they messed around adjusting it for about 20 minutes. Took it home test rode it and it is only margianly better than it was before!
Just for the record when I test rode the bike before the new cassette was installed the bike shifted fine. I am thinking about spending my Sunday at the bike shop getting this damned thing right.

NRRider

Wonder if something is stuck in the derailleur causing it to not be positioned properly. Have you removed the RD to inspect for debris? Is the chain new or could it be stretched? Is there a master link? If so, you sure it's connected properly? Sometimes the Wipperman Connex in particular causes shifting issues. Possibly bent RD hanger? Wheel in the dropouts tight? B screw adjusted properly? Sure the cogs aren't loose (I know you said above everything is tight, but just checking). If it's none of the above and adjustments don't work I'm at a loss.

Beaker

I had an all Shimano setup 50/34 Ultegra SL cranks + Ult chain + 105 12-27 cassette with DA FD and DA short cage RD. I just switched my cassette chain to SRAM PG1070 11-26 and PC1030 (el cheapo) chain.

To your questions, the short cage RD has worked just fine for me and the 12-27 shifted great. The new PG1070 is shifting well too - there's perhaps a slightly different noise, but frankly nothing that grabs my attention. Has your derailleur hanger become bent perhaps? If the indexing has been readjusted and you still have problems in the lower gears, maybe that's worth a look.

I'm not sure what to say about your comments on the freehub noise though. It sounds as though you've used the same wheel/cassette on another bike and find that you have a louder noise on your Cervelo. I'm wondering if that's just the way that sound is being amplified/transmitted through your frame and nothing to do with your other concerns.

Fixitman

The only things that are not brand new on this bike are the wheels and me!
I don't know wtf is going on. Nothing should be bent unless they bent it putting it on. Can't be road debris as it has done this from the first shift after they changed the deraileur and the cassete. and surley when I had it in they would have seen anything like that. I still have the original new cassette & derailure. I think I am going to put that cassete on another set of wheels that I have and try that on the bike. I guess either the deraileur or the cassette could have some sort of defect. If the cassette does not do it then I am going to make them change the deraileur. Hell I will even throw a tripple on there if that what it takes to make this thing shift right.

Bicycle dad

I am not sure this is your problem but on my Specialized non-compact crank but 12-27 cassette I used to get clicking when it was in the 53-12 and it was very rough to pedal while on a stand. When I switched out the chain I took one link out and then the problem went away.

Before changing the chain and while it was clicking the rear derailleur was pressed against the cassette. The slightly shorter chain solved the issue. Worth looking at if the derailleur is hitting up against the cassette.

dsmyers

You should probably be using the b-screw adjustment to handle this case.

Fixitman

Well tomorow the old deraileur will go back on along with a 11-28 dura Ace casstte and we will see how that works. Becouse whats on there now just ain't doing it.

Bicycle dad

It would adjust it out far enough to cure the problem. WHen I took one link out problem was completely gone.

Also talked to a friend the other day and he was having shifting issues like you mention and he did everything but replace the cassette and when he lastly changed the cassette all problems disappeared.

Hope you find a solution soon.