As I have said in other articles , I am trying to get a retro look to this bike using the best modern components I can find and afford. The first set I considered was the new SRAM 2 x10 setup. Using only a double front crank set it promises the full gear range of a triple. That package was the most obvious choice but I had some problems with it. The range was pretty good but not what I was looking for in a long distance road bike. On those rare occasions, seems like once every 10 years, that you have a tailwind or a sustained slight downgrade, I really want to be able to get on those 100+ gear inch rings and take advantage of it. The other issue was purly cosmetic, it was only available in black, yuck.
The next choice is Shimano, yes they are a quality brand, yes they make some less than high end stuff too. The up side to Shimano is if you bust a part, just about every shop in the world (outside Italy of course) has parts and can fix it.
I decided to investigate Campagnolo, the parts are beautiful to look at certainly, but their absolute focus is on lightweight speed machines. They do however make a Triple front crank set with a 30-42-52 chaining set. OK then, I can have Campagnolo quality and looks on my touring bike, great. The back end of this set up is where my heart sank. The long rear derailleur can only accommodate up to a 12 -30 rear cassette (typing this from memory so I may be off), the important point is, it’s not enough. There is no way I can grunt out a 27 inch gear on a 7+ percent grade at a rolling weight of 350 lbs+. Ain’t gonna happen.
Back to the drawing board. I really like that Campy front set, as a gear geek it rises to the highest level of bicycle porn. How can I make it work? Too bad I can’t mix the Campy front with a SRAM rear derailleur, that would give me a 47 tooth differential to work with. If I change out the fronts by shelling out another $225 for smaller Campy rings, that would be awesome. Too bad you cant mix Campy and SRAM components without some witchcraft.
Enter Lennard Zinn.
Somehow I found an obscure article he wrote a ways back. It described the problem of mixing the two systems, it is more than the distance between the cogs it has to do with the amount of cable that is pulled or released during shifting. There are adapters (called shiftmate), essentially a hybrid of a cam and a pully that changes the pull length mechanically. The absolute beauty in all of this is it is almost entirely related to the 8 and 9 speed groups or mixing parts designed for one with the other. What Lennard discovered is that in 10 speed systems the pull length is very very close, so close in fact that if you keep with all 10 speed parts and keep them adjusted properly they will keep a tenuous level of peace and harmony. Hmmmm.. If Lennard says it will work, that’s good enough for me, it’s worth a try.
So the final build went on using a Campagnolo Comp Triple in the front with two new Campagnolo rings at 40t – 50t and a Salsa 28t on the low side. The outers had to be campy since it is a non-standard 130mm ? bolt pattern instead of 110. The inner is a 74mm so I was good to go with the Salsa, campy dosen’t make anything smaller than a 30t anyway. In the back, this meant that I had to make a concession to style and get a black rear derailleur, oh well. The lower gears are WAY more important than the aesthetics after all I’m building this for the road , not a bike show. SRAM X7 rear has a 47 tooth differential capacity meaning with my front choices I still have 25 teeth to play with. I’ll have one of those 11-36 SRAM cassettes, please. A Campagnolo bottom bracket keeps things spinning nicely.
One problem with going big is SRAM never envisioned their equipment being used in a mixed enviroment this way. The stock chain was too short! Normally you remove links from a new chain. At $70.00 a piece it was not a happy surprise but I did make the most of it however, and carry a short piece of the leftovers in my tool & spare kit along with some powerlinks.
This whole excercise was well worth it. It gives me an enormous range of gears the low is about 21 gear inches and the top end is almost 105 gear inches.
This setup now has about 8,000 miles on it and I have only had to adjust the rear derailleur once at the back. I think that was because new cables, even Campagnolo, stretch when breaking in. All other adjustments to keep the shifting working have been done at the shift cable downtube bosses. I have had to do that a couple times. Here is a photo of the NOS (new old stock) Campagnolo bosses that I got from GearWorks Cyclery’s private stash in Leominster MA. Just another $20.00 worth of gratuitous bike porn. Your welcome.