joe@vwvortex

I run the Campy 10 with a 11-29 rear Campy 10sp cassette, Campy Long Cage Record and a 26/39/53 front chain rings and have no problem with chain wrap at all. My low gears with the 39/29 and 26/29 are near identical to when I was running a 28/32 and 42/32.

If anyone wants it - I have a Sram X9 modified by DiVinci to work with Campy 10's and 11-32 Sram cassette - both with less than 500 miles on em. Shoot me an offer - the worked great - but I wanted a 10 speed.

Krenovian

Using the formula for calculating chain wrap (largest chain ring-smallest chain ring)+(largest cog-smallest cog), your setup would indicate a 45 tooth capacity rear derailleur, something like the Shimano long cage MTB derailleurs. With the SRAM XX long cage rd (which has a claimed 40 tooth chain wrap capacity and is the calculated chain wrap capacity needed for my setup) my chain goes slack on the 13t cog (3rd up) when the chain is on the 30t inner chain ring. I can cross chain 53/28 with no problem. With your Campy Record long cage derailleur (39t rated chain wrap capacity), where does your chain go slack as you shift down the cassette when you are in the 26t inner chain ring? Can you cross chain 53/29?

Curtis

joe@vwvortex

No slack anywhere even 26/11 and yes I can cross chain the 53/29 with no problem at all. I never run it in the 26/11 - in fact it rarely goes past midway in the 26 because there is no reason to do it. I've also never paid attention to chain wrap capacity - I figured I'd give it a shot and see if it works messing with chain length. It did.

Krenovian

Thanks for the info Joe. I appreciate it

Krenovian

I just couldn't get even close to satisfactory shifting with or without the Shiftmate #5S. Satisfactory for me being no missed shifts. I pulled the Shimano XTR Shadow long cage derailleur (9spd) off my wife's old mountain bike and gave that a try. I routed the cable on the opposite side of the clamping bolt from normal (inside vs. outside of the bolt for this particular derailleur). This is a trick I've read about through the years to get Campy 10 spd. shifters to work with Shimano derailleurs. It works great. I'd rate it an 8 out of 10. I'd give it a 9 out of 10 except sometimes it is a little slow to drop down off of the largest cog. Here's a link to an explanation of how to do this: https://www.highpath.net/highpath/cycles/info/rear.html. My setup looks like Figure #4 Narrow pitch.

The shifting is great. With a 11-28 or 12-27 Shimano/SRAM cassette all gear combinations including big-big, little-little are attainable with no danger of damaging the derailleur and no chain slack. I pulled the 11-36 SRAM 10 speed cassette off my wife's new mountain bike to see if it works. Can't cross chain big-big without adding some length to the chain but it shifts onto the 36 cog from the 39t middle or 30t inner chainring just fine. I'd did have to adjust the B screw for the two largest cogs to run right.

Some other bits I've gleaned from the different combinations of derailleurs, cassettes and chains I've tried include: the SRAM Red 12-28 cassette was the poorest shifting regardless of derailleur, The SRAM 11-36 shifted as well as the Shimano cassettes (12-28 and 12-34), the SRAM 10 speed chain shifted better than the KMC 10 speed chain, Campy Record derailleur (short cage) shifted well with the Shimano 12-27 and the SRAM 11-28 cassettes, even without the appropriate Shiftmate installed. I haven't tried a Shimano 10 speed chain yet. I run those on most of my bikes regardless of whose derailleurs I'm using and tend to prefer them though in the past I've felt that the KMCs were equivalent in performance (Not sure, but I think KMC makes Shimano's chains?).

So why wouldn't the Campy shifters and the SRAM RDs work for me? I don't know. Issues that might be contributing could be friciton in the system, cable stretching and rebounding, type of cable being used (Jagwire Ripcord teflon coated stainless steel). The Campy derailleur cable spare I have for my single bike seems more supple than the Jagwire cable I used. I didn't have a Campy cable long enough for our tandem to check that out. Ryan from Jtek thought the cable might be moving on the Shiftmate, but I couldn't document this. I marked the cable and regardless of the number of shifts I did, it always seemed to be in the same spot on the flat of the Shiftmate pulley. Originally I thought the problem might be with the XX derailleur as it is desinged for a 2x setup though couldn't see how this would make a differnce other than how much chain the derailleur could take up. I tried an X0 derailleur which are listed for 2x and 3x setups to check this out and found equally poor performance with the Campy shifters. YMMV.

Curtis