|Cannondale SuperX Disc SSCX bikes|
Big statement I know, but dang, these things are wicked pissa. Thanks to the good folks at the Bikeway Source bike shop in Bedford, MA and Cannondale Bicycles we are now aboard a pair of Cannondale SuperX HiMod carbon fiber disc brake equipped SSCX bikes. We are also running full carbon tubular rimmed Carver C38 wheels thanks to the hookup from BigAl at Bikeman.com in Maine.
|Cathy's SSCX drivetrain|
|Rear guides for the cog = added reliability|
For wheels we use the Carver C38 carbon tubular disc brake wheels, the same wheels we run on the geared race bikes. They are mounted with Clement PDX 33c tubular tires, again the same setup as we run for geared racing.We both run Avid BB7 road disc brakes with 140mm Ashima Airotor rotors front and rear. We both run Thompson Elite 27.2mm layback posts and run SRAM brake levers on Cannondale 44cm C4 compact/shallow bars with ControlTech 110mm 99gm stem on my bike and Cannondale C2 42cm bars with C3 100mm stem on Cathy's bike.
The cranks on mine are Shimano Ultegra compact 172.5mm with a 110mm BCD x 40 tooth BMX ring and a BBG outside bash ring/guard. Cathy has very sweet 170mm DuraAce compact cranks with a 110mm BCD x 38 tooth BMX ring and BBG outside bash ring/guard.
In the rear we both run a Surly 17 tooth cog with individual spacers and guard rings both sides of the cog as an additional means of protection from chain drop. Regardless of chainline or chain tension I have found that when you are pedaling hard in really bumpy stuff, the chain somehow finds a way to pop off eventually. For Cathy I run a pair of vintage buffed titanium cogs as guards and on mine I have "Prototype" set of Lexan guards, both of which work flawlessly. Since I went to this setup I am able to run the chains with a bit more slack and have still never dropped a chain. For chains, I have a lightweight 10spd chain on Cathy's bike while I am trying a SRAM PC-1 nickel plated chain again on my bike (mostly because that was what was available at the shop last week). For pedals we run SPD's on all of our bikes and always have, well, at least since I went to them from the Onzo HO pedals that I started on back in the early 90's. They just work, period.
Regardless of the gear you choose, one important fact remains, you have to turn it. Over-geared makes this hard in places while under-geared may be easier in certain spots, it means that you are spinning fast and taxing your cardiovascular system the whole time. For racing, I always go a hair higher than what I think I would want. Yes, you have to push really hard up the steep stuff but the reality is, you are usually going faster as well. You have to in order to maintain momentum with the taller gear. For CX racing in New England, on most courses we see, you want to be well over a 2/1 ratio with a 700c wheel.
That's it, well, except of course for the thing that makes it all possible, the Eccentric Bottom Bracket (EBB), which is responsible for taking up the tension in the chain. The EBB unit replaces the BB30 bearings in the frame's bottom bracket shell and pushes the bearings outboard, to the Hollowtech II or MegaExo "standard" width and crank spindle diameter (24mm). That means you replace the BB30 crankset with a Shimano or FSA (24mm spindle) crankset, which in turn gives space for the eccentric lobe to pivot and fore or aft, tightening or loosening the chain. There are a number of these on the market now and I'm not certain that any one is better than another. I've always used the Beer Components for a BB30 application simply because they were the first available. They are very expensive though ($165) so would love to see some fair competition and alternative offerings bring the price down a bit.
I must admit, I'm not a fan of zip-ties especially when run with systems that a zip-tie doesn't actually lock out. I get it though, it is about participation and honestly, most of the regular cast and crew are running dedicated SSCX bikes. There are of course, numerous ways to fix a geared bike into singlespeed mode that assure that no shifting can inadvertently happen. It just takes a little bike of effort. That is part of it though, in my opinion, a big part; the fun of cobbling together a machine to race on the weekend.
Will chime back in as the season progresses. Hopefully all continues to go well. The big thing is simply how much fun it is to race SSCX. Pure and simple, you and the pedals, no silly gears to complicate your life.