Cables crossed in 695?
I bought a 695SR frame in Dec 2010. Love the bike, but one complaint I've had from the start is that it is impossible to properly adjust the shifting. I've had it looked at in 2 shops and neither could get the shifting perfect. It's functional, but not perfect.
Basically, I can have it shifting smoothly in either small or large chainrings, but not both. In other words, if I fine tune so that the rear der shifts smoothly in all gears when in the small chainring - if I then shift to the large ring up front, rear shifting gets poor (gears begin to make noise and even jump slightly). If I then re-adjust and get things shifting smooth while in the large chainring, when I shift back to the small ring, things go out of whack at the rear.
After discussions with my favourite wrench at LBS, I have decided that the cables for front and rear der are "interacting" somewhere . The only place that makes sense is inside the downtube - I strongly suspect that the "straws" (one for front der cable and one for rear der cable) that carry the cables internally through the downtube must be crossed or otherwise interacting abnormally. In fact, when I shift the front der into the large ring (ie introduce tension into the front der cable) I can feel the rear der cable increase in tension and then shifting performance decreases at the back.
I'm not sure how easy it will be to "re-route" the straws within the downtube. I actually have access to an xray machine and I'm going to try to take an xray of the downtube - if the cables are twisted over one another, I should be able to see it - steel cables should show up brightly on an xray - I'll see how that goes.
If they are crossed, I'm wondering if anyone has experience or suggestions for how I might re-route the internal cable routing straws - I'm concerned that once I pull the little straws into the downtube, I'll never get them back out - never mind getting them untangled.
Turns out they were crossed. Spoke w Look distributor here in Canada who offered to untangle for me. They suggested that in the past they have simply pulled out the guide straws and then fished them back through by trial and error. I figured I would give it a try myself rather than send in and wait - managed to get them untangled and now the shifting is perfect.
Mine are criss crossed too..
After reading your post and doing a little googling:
Weight Weenies • View topic - LOOK 695, Ride Report.
I got to thinking. I recently received my 695 built it up with campy record 11 and took it for a few spins. On the stand and on the road, the rear shifting was not "campy like". I knew exactly what it was....friction in the cable. I checked my cable/housing under the bar tape, at the rear derailleur loop. I tried a new RD cable and a new RD loop housing. Then tried a different RD...SR instead of Record, still wan't perfect.
Sure enough...I fished a spare piece of cable thru the straw in the down tube and bingo, shifting the FD caused the RD cable in the down tube to tense up. They were crossed. I pulled the straw out and cut a little point in the BB end to help it find its destination. I thought it would take forever, but within 10 minutes I had the straw properly installed
It was nice weather today so I rode instead of finish assembling it and I'm getting texts to ride tomorrow, so I hope to be on it Thursday or Saturday.
Hey vetboy....I think Justin @ Look owes us a a cool Look t-shirt for all our pain and suffering
2013 Cervelo P5
2015 Cervelo R5
2012 Specialized S-works Tarmac SL4
2013 BMC TM01
2013 BMC TMR01
Oooo - good idea - maybe one of those Look jackets I've seen Look staffers wearing in online pics - I'm sure Justin can send to Canada.
Originally Posted by eekase