Originally Posted by Bill G

I posted the below info the other day, yes it will work fine as long as you have the 9spd long cage rear deraileur on back these deraileurs are 8,9,10 speed compadable. The brand new Dyna series shimmano 10spd MTB long cage rear deraileurs will not work as the cable rate is diffrent and will not match the 105 shifters but the rear cassette works great.

Ride Safe,
Bill G

For all out there that want more gearing with there 10spd tandems this set up works great. I have Ultegra 10spd shifters, FSA Triple cranks with a 26 tooth small ring instead of a 30 tooth along with a Shimmano XT long cage rear derailuer. I removed the 11-28 Ultegra rear cassette and replaced it with one of the newley released Shimmano Dyna SLX 11-34 10spd mountain bike cassettes and it works and shifts great ( I also have run a Sram XX10 11-32 with no problems) I now have realy good hill climbing gearing on our Co-Motion tandem. This set up works as well as the same set up in 9spd that we had on our last Co-Motion tandem.

Just thought I would pass this information on

Best Regards to all,
Bill G