# Shifting woes: Felt Z & Shimano 7900, anyone have this setup that works well?



## 4bikes (Sep 9, 2011)

I upgraded my 2010 Z4 to all 7900 during the holidays. Haven't been able to get the rear shifting right ever since. 2 bike shops have given up and it is currently at a 3rd. Basically can't get it dialed in where it won't slow shift or hang in one direction or the other depending on adjustment. Don't remember this problem with the original 6700 setup, nor with other bikes I've owned with 7800.

The bike has the original bars and stem. Also has Ksyrium SL Premium rims, but I've tried 4 other wheels including the original Fulcrum 7s with next to no miles.

Here's a list of things that have been tried:

Replaced the new rear shifter under warranty (thanks shimano)
Replaced the new rear derailleur with a new one (thanks amazon)
New 7901 chain
New 6700 cassette
Shift cable routed on the outside (tried inside for grins, but no help)
Shimano SP41 pregreased housing with DA7900 cable (no help)
Jagwire PTFE cable / housing (maybe worse)
Yokozuna housing and cable (small improvement)
Different lengths on rear cable housing
Housings routed with very wide radius taped down to hold still but no bar wrap.
Wheel dished
Hanger straightened
Tried new bontrager RXL scandium wheel
Tried SRAM red cassette
Tried SRAM chain
Tried 6700 rear derailleur

I'm begining to worry that the Felt housing stop distance to the axle or hanger to axle distance may be affecting it. The frame is about the only thing I haven't replaced.

Anyone had better luck or the same problem? 

Oh yeah, I built a Cronus Ultimate with SRAM Red and that doesn't have the problem.  That's the only thing keeping me sain while I wait for the Felt to get sorted out.


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## Camilo (Jun 23, 2007)

Is the derailleur hanger straight? Maybe have the LBS check it with their gauge.


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## 4bikes (Sep 9, 2011)

Camilo said:


> Is the derailleur hanger straight? Maybe have the LBS check it with their gauge.


Yep. That was in the list above. Just got back from the latest LBS, and they said it was slightly off. Funny that a different mechanic from the same shop last week said he straightened it. Anyway, it did not help the problem and I left it with them.


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## easyridernyc (Jan 10, 2008)

that sucks...sounds expensive too


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## Camilo (Jun 23, 2007)

4bikes said:


> Yep. That was in the list above. Just got back from the latest LBS, and they said it was slightly off. Funny that a different mechanic from the same shop last week said he straightened it. Anyway, it did not help the problem and I left it with them.


oops, sorry. I'm a scanner, not a careful reader, obviously.

I have tricks I use to dial in shifting, but can't begin to second guess pros who actually have the bike in front of them.

That said, rigging up derailleurs, cables and shifters is not rocket science. The only tricky part is housing lengths, and even that, within reason, isn't critical within 1/2 - 1 inch for most lengths. It's more of a tweaking thing.

The things that make big differences are error in connecting the cable to the shifters or derailleurs, hang ups in the cables or cable guides, gross misadjustment of the derailleurs, bent stuff.

If it were my bike, since I have set up a few, I'd just start from scratch. I can't personally make any other suggestions.

The only thing I can't do myself is check hanger alignment, which you've done.

PS: you might want to ask this question in the components and wrenching section or the Shimano section since it most likely is related to the mechanical part of your bike, not the frame.


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## Superdave3T (May 11, 2009)

4bikes said:


> I upgraded my 2010 Z4 to all 7900 during the holidays. Haven't been able to get the rear shifting right ever since. 2 bike shops have given up and it is currently at a 3rd. Basically can't get it dialed in where it won't slow shift or hang in one direction or the other depending on adjustment. Don't remember this problem with the original 6700 setup, nor with other bikes I've owned with 7800.
> 
> The bike has the original bars and stem. Also has Ksyrium SL Premium rims, but I've tried 4 other wheels including the original Fulcrum 7s with next to no miles.
> 
> ...



I've never heard of a serial problem with Shimano shifting before on any frame. Felt makes two derailleur hangers, both within the Shimano tolerances and derailleur/axle placement. The 7075 CNC machined hanger uses the shortest distance in the range Shimano provides, and the 6061 forged hanger uses a longer distance.

The 7075 and 6061 will both shift. We use the 7075 hanger on bikes with Di2 that can only run cogs up to 27t in size.

In any case, all FELT road bikes use the same derailleur hanger (AR, F, Z, ZW, CX,) and the Z series model's longer chainstays make it a quiet forgiving base for any drivetrain.

Prettty tough for me to diagnose a shifting issue over the internet, but the likelyhood of the frame being the culprit seem low, especially if the original 6700 worked well.

-SD


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## 4bikes (Sep 9, 2011)

SuperdaveFelt said:


> I've never heard of a serial problem with Shimano shifting before on any frame. Felt makes two derailleur hangers, both within the Shimano tolerances and derailleur/axle placement. The 7075 CNC machined hanger uses the shortest distance in the range Shimano provides, and the 6061 forged hanger uses a longer distance.
> 
> The 7075 and 6061 will both shift. We use the 7075 hanger on bikes with Di2 that can only run cogs up to 27t in size.
> 
> ...


Thanks for the input. I started with the 6061, switched to the 7075 to see if it helped. Both showed the issue. Doubted it had anything to do with the frame, but wanted to hear of someone else with the 7900 and Z frame to see if they have any better experience.
Thanks,
Mark


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## 4bikes (Sep 9, 2011)

Well, I've now exhausted the third shop in Austin (and fourth mechanic) that can't fix the problem. Sure does stink that I can't get a 7900 setup working right on my z4 since I love the way the z4 handles.

Anyone have this setup that can say they've had better luck?


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## Camilo (Jun 23, 2007)

Can't add anything productive exept has every shop done a full-on from scratch re-installation including inspecting everything, not taking it for granted, etc.?

It just seems weird to me; I can't imagine the frame, or any frame for that matter, not working with a very common high end group.

I'm really interested in what you eventually find out.


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## 4bikes (Sep 9, 2011)

Road the latest try today from the shop for the first longer ride (30 miles). Working pretty good with the cadence I normally pedal in the various gears. Only time I can get it to hang is if I pedal slow in a small cog and shift which is what I saw in the parking lot when I picked it up. Since I normally don't pedal that way, I'm calling it good enough and moving on.


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## 4bikes (Sep 9, 2011)

Well, 15 more miles on the way home from work and stuck shift once. Was from a stop light where I didn't get moved to the easy gears and took off hard shifting to harder gears. Maybe I'll be throwing a 6700 shifter set on after all.


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## 4bikes (Sep 9, 2011)

Latest update:

Picked up a really good deal on a 2010 F1 SL. It shifted fine. Swapped components until I isolated the problem. The F1 SL oddly enough had a SRAM 1070 11-28 cassette and an KMC x10SL chain. These two made the difference. Even though my 6700 11-28 cassette and 7901 chain were both new, the KMC and SRAM combo shift 100 times better. 

Also it was interesting that both had to be swapped. Either one alone did not help.


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## tallcaguy (Apr 6, 2012)

Have a Roubaix S-works w/ DA 7900 (first year, 2009). Rear shifting has never really been right. Currently ok with alternative routing out of STI and onger cable housing carefully arranged on the frame. It is not smooth and accurate like my 7800 was. Have another bike with 2011 Ultegra group. Rear derailleur shifts perfectly. It takes slightly more force at the STI. This works and feels like DA. I don't think Shimano got it right with the early 7900 group. Brakes on the other hand are just superb. Best in the business.


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## 4bikes (Sep 9, 2011)

tallcaguy said:


> Have a Roubaix S-works w/ DA 7900 (first year, 2009). Rear shifting has never really been right. Currently ok with alternative routing out of STI and onger cable housing carefully arranged on the frame. It is not smooth and accurate like my 7800 was. Have another bike with 2011 Ultegra group. Rear derailleur shifts perfectly. It takes slightly more force at the STI. This works and feels like DA. I don't think Shimano got it right with the early 7900 group. Brakes on the other hand are just superb. Best in the business.


7800 was my reference for good shifting. I'd say with the SRAM 1070 and the KMC x10sl, it is pretty darn close. I think you'd be amazed at the difference if you try it.

Mark


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## tallcaguy (Apr 6, 2012)

Agree the 7800 shifting is excellent. The 7900 front is flawless but the rear shifting isn't even close. Roubaix #1 (new Ultegra) gets ridden daily because it shifts right. Roubaix #2 (dream bike built with 7900 and the best of everything) has dust on it. I've been to several high end shops that have tried various fixes. It's ok now but my $25 town bike w/ bottom end Shimano shifts better (really). Crisp, quick and never misses! Talked to the local Specialized rep. He hears over and over about the 7900 rear shifting problems. 

Glad to hear you've found a good solution. Thanks for the suggests.


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## 4bikes (Sep 9, 2011)

tallcaguy said:


> Agree the 7800 shifting is excellent. The 7900 front is flawless but the rear shifting isn't even close. Roubaix #1 (new Ultegra) gets ridden daily because it shifts right. Roubaix #2 (dream bike built with 7900 and the best of everything) has dust on it. I've been to several high end shops that have tried various fixes. It's ok now but my $25 town bike w/ bottom end Shimano shifts better (really). Crisp, quick and never misses! Talked to the local Specialized rep. He hears over and over about the 7900 rear shifting problems.
> 
> Glad to hear you've found a good solution. Thanks for the suggests.


It is about $100 fix. If your chain and cassette need replacing anyway, then it is a cheap fix. Give it a shot and you may like 7900 after all.


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## OffRoadRoadie (May 15, 2006)

4bikes said:


> I upgraded my 2010 Z4 to all 7900 during the holidays. Haven't been able to get the rear shifting right ever since. 2 bike shops have given up and it is currently at a 3rd. Basically can't get it dialed in where it won't slow shift or hang in one direction or the other depending on adjustment. Don't remember this problem with the original 6700 setup, nor with other bikes I've owned with 7800.
> 
> The bike has the original bars and stem. Also has Ksyrium SL Premium rims, but I've tried 4 other wheels including the original Fulcrum 7s with next to no miles.
> 
> ...


Have you tried an after-market rear derailleur hanger. OEM hangers aren't the best, and you'll see lots of Pros using a stiffer after-market hanger on their bikes. Worth a try.


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## tallcaguy (Apr 6, 2012)

*7900*

Local Shimano rep (Northern CA) has heard about early 7900 rear shift problems over and over. Per recommend in here, did the Sram cassette/XL chain and it helped some. Early DA 7900 rear shift/STI just isn't very good. Mine is 2009. I've done the whole cable/routing/hanger/metal cable ends thing. Maybe Shimano's fixed the problem. 
My 2011 Ultegra group shifts perfectly. Crisp accurate and fast. DA 7900 rear shifts aren't even close. Good luck to everyone who's had the problem.


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