Thursday, July 22, 2010

The gears of D2R2


D2R2 is now less than a month away. I'm scrambling to figure out what bike to ride. I had a long haul trucker, the ideal bike, but I don't anymore. I have lots of suitable bikes, but none with the drive train and gearing needed for such a long weird ride. In fact, it's as if I've purposefully surrounded myself with bikes that all have some kind of short coming.

What I thought was a brilliant plan was to put compact cranks (50t & 34t) on my road bike with one of those megarange freewheels (14t-34t). I still think it's a brilliant plan, but I can seem to put a 34 inner ring on the bike without the chainring rubbing the chainstay. I could probably do something with the bottom bracket, but I'm not entirely sure what to do.


It took considerable work to get to this point, because my plan was to swap out the 34t from my diamond back with a 35t from an unused set of kludgey xtr cranks with an improperly install spider (not my fault, this is how I got them). After doing some things you're not supposed to do to bike parts, I finally got everything put back together, only to learn about the chainring rubbing problem.

My solution is to run the 34t chain by itself upfront in the outer position, but I'm concerned about cross chaining with a 7 speed freewheel. So, I've also bought a six speed megarange freewheel (13t-34t).



After all this stupid stuff, I'm probably going to end up riding my Stumpjumper again, because I'll want bigger tires.


PS. Sorry, the thunderstorm yesterday confined me to the basement, so I've got no bike ride to talk about.

6 comments:

Interstatement said...

Is an old school cup & ball bottom bracket? If so, check to see if the spindle was installed with the long end (if it is asymmetrical) on the non-drive side. Several bikes I saw at the Urban league were like that, and clearance issues would ensue.

I've run a single Biopace 38t chainring on the inside (middle) position on two bikes with room to spare. In one case I used a narrow bb spindle, in another I purposely installed the spindle backwards to improve the chainline using parts on hand (then spaced it further inward to boot). The Bio 38t is more like a 39t or 40t clearance-wise, and there was room to spare.

Brendan said...

It's a Suntour Sprint BB and it appears to be installed correctly. There's not even close to a clearance issue with any other cranks. This set of compact cranks (they're Sakae's) seem to require really long BB spindles. In fact, they're actually supposed to be triples, but I've been running them without an inner for awhile.

I think this gearing will actually be good because I've been forced to gear down, which'll save my legs.

Anonymous said...

1:1 at the very least. Patten Hill awaits us (Somewhere around mi. 100)!

-- Your fellow snail

Brendan said...

Patten Hill is the worst road in the world.


-- The Failed Snail

jwanerman said...

Please check my bike blog at www.jwanermanbikeblog.blogspot.com for info on the bike I'm using for the 2010 d2r2 100k. See you there.
Jeffrey Wanerman

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