Mountain Bike Reviews Forum banner

NRS frame flex = shift problems

1059 Views 5 Replies 6 Participants Last post by  mtbcyclist
Does any one else have chronic ghost shift problems on their NRS?

When I torque under heavy load up a rough hill in race mode the bike will not stay in gear. THis is my second year racing this bike and it is begining to really grind me. I am on my 3rd xt derailleur 3rd chain and 2nd set of cables. Myself nor anyone I know can seem to fix this problem. I am convinced it is caused by frame flex or worn bushings. All the pivot points are tight though. The bike is an 03' with about 1500mi. The shifting has been a problem since about 400 mi.

Any one else?
1 - 6 of 6 Posts
Remove the rear pivot bolts, and inspect the spacer sleeve bushing for wear. Since it's a dark gray anodized surface, if any has significantly worn off, you will see bare aluminum, this can create play.

I never had shifting problems when my frame was new. I converted the cable stops on the frame by using a Dremel tool and carbide deburr bit to open the cable stops to accept full length cable from the shifter to the rear derailleur. Never had a ghosting problem, and the cable stayed much cleaner too. I used zip-ties to hold the cable to the frame and seatstay, so it wouldn't slide around under suspension motion.
**Does any one else have chronic ghost shift problems on their NRS?**

Yup, been there.

Here are some things I have learned:
- cable don't stretch. myth. what happens is that the cable housing and cable ends/ferrules seat, gives the impression of stretching cable...
- if the housing ferrules/ends are not the correct size the slop can induce cable flex -- size them correctly. housing is sold in 4 and 5mm sizes. make certain to get the correct size ferrules. sells a good selection of ferrules. (no affilitation, blah blah...)
- if the ends of the housing are not trimmed cleanly the little inner wires that run throughout the length of the housing are going to be flexing around inside the ferrules -- trim those ends clean.
- housing length is critical. all derailleur housing should have two bends in it. one smooth arc is not enough. leaving housing too short, especially on a frame such as the nrs where some seat-stay flex is *normal* will cause ghost shifting in itself. this is especially true on the piece that terminates on the derailleur. it may look/seem a little strange at first, but it'll cure what ails you (or yer bike...)

Ride it like it's rented!
See less See more
Just drill out the cable stops on the seatstay and run full housing through them so it won't ghost shift when you are trying to crank and the suspension is in motion fighting your power input.
What bikesatori said works. I did not drill out my holes as I did not have the right equipment. You can get hydraulic brake cable mounts and put them on. They screw into the existing brake cable holder and provide a larger diameter "clamp" to run your cable though.
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.