[cal // sweden]

I bought an Ultegra rear derailleur because I didnt like my SRAM X7 with much longer cage.

The chaintension is just fine now with the Ultegra. But there is one major problem.

The derailleur is placed very near the rear pivot / chainstay on the SX Trail frame. Even when riding smooth trails it keeps slapping to the chainstay HARD with a loud "BONK!".

I've tried to put a lot of rubber between but it doesnt help much.

Is this frame / rear derailleur combo just useless or is there some way I can solve this problem?

 

[buildyourown]

Shimano derailluers + FSR bikes = Derailluer slap.
Try cranking up the B-tension screw. (the screw that contacts the tab on the frame)
Other wise your only option is SRAM. This is one reason SRAM is so popular

 

[sanjuro]

If it screwing in the B-screw does not work, totally unscrew the B-screw and put it on the other side. Screw it in so that end of the screw is flush with the hole, and you get another mm of adjustment because now the head is touching the hanger stop.

 

[Castle]

Shimano derailluers + FSR bikes = Derailluer slap.
Try cranking up the B-tension screw. (the screw that contacts the tab on the frame)
Other wise your only option is SRAM. This is one reason SRAM is so popular

 

[cal // sweden]

Thanks guys. I've turned the B-tension screw to the bottom. But it doesnt help. I guess another millimeter or two wouldnt make much difference.

It would be nice if the spring in the derailleur at the derailleur hanger, would work in the opposite direction. Pushing the derailleur downwards!

But I guess you cant modify them.

 

[cal // sweden]

It would be even nicer with a SRAM X0 micro cage! But I really cant afford it right now. And I would probably wear it out in a year.

SRAM! Please make the X7 and X9 in micro cage!

 

[atrokz]

If you look close, you'll see an OEM rubber pad on these. I'll try to find one if I were you. It wont help in ALL the gears (such as highest or lowest) but it + a small pad on the frame will aleviate the problem the majority of the time.

 

[cal // sweden]

Thanks atrokz.

I tried to wrap up both the deraileur and the rear frame pivot with rubber hose. Many layers. (looked crap)

But it still giva a loud "SLAP!!!" when riding over the smallest curb.

I guess I'll just have to give this Shi(t)mano-thing up.

 

[Dirty]

almost all of the specialized bikes come with a little rubber pad that is meant to be placed at that edge where they hit the chainstay. The rubber groove is sticky on one side and has a groove for a zip tie. They know about this problem and thats why they ship the special pad with their bikes. Go to a specialized shop, theres usually some laying around.

 

[_bp]

Be creative. If rubber doesn't help try a different material, such as foam.

 

[cal // sweden]

Dirty: Good point. I have one of those rubber-things that came with the frame.

But the reason I posted this thread was actually to see if there was some way to modify the derailleur so that it doesnt hit the frame. But that seems hard.

But I think I'll just glue this thing on there... (maybe cutting it down a little )

 

[monke880]

Specialized makes a little rubber knub that goes on the derailleur w/ 3M sticky tape and a zip tie. Your bike should have come with one of those. If it didn't you should check your LBS. Those things work just fine.