Singlespeed & Fixed Gear - Trek 1000 Magic Gear
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11-13-08, 05:47 PM
I have an '89 Trek 1000 frame that I'd like to do a SS/FG conversion with, but it's got vertical dropouts. Don't have enough money for an ENO Eccentric, so I'd like to find the "magic gear," if at all possible.
Now, I found a bike exactly like what I'm planning on Velospace, and the owner says he found the magic gear of 48/16.
So should this ratio work for me too? Chainstay length, chainring size, and sprocket size should really be the only factors affecting chain length and thus whether or not the magic gear will work, correct?
Or should I just save up for that White Industries?
11-13-08, 05:54 PM
You could figure it out if you could find the diameter of the front and rear cogs.
the math formula to give you a pretty close idea would be
.5(2Pi(radius of front cog))+(.52Pi(radius of rear cog)+2(distance between centerlines of cogs) and then divide that number by 1/2. Once you got a whole number, you would have your magic ratio.
11-13-08, 07:36 PM
leave it be and convert another bike.
11-13-08, 07:56 PM
Don't got no other bikes that fit me.
Anyway I don't mind a challenge, and I got most of the parts already. :D
Thanks clink, that math tells me what the ratio I need to run is? Or the gain ratio or something else?
11-14-08, 12:07 PM
There was an early 90's Trek 1400 (same frameset as 1000) on fixedgeargallery.com a while back that was converted with a 49x16. I used the ENO on mine. The frame does make for a nice conversion.
More than one way to skin a cat (http://sheldonbrown.com/harris/images/half-link.jpg).
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