Bicycle Mechanics - Shimano 8 speed hub
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When I was riding the Rosarita-Ensenada race last year I saw a guy with a Shimano 8-speed hub; I think it was 8-speed, maybe 9-speed?. Are these good hubs?
I was thinking about putting one on a Kilo TT. Would this be fairly simple?
(just don't tell anyone in Singlespeed)
02-18-09, 12:59 AM
Yeah, I have one on a Surly Crosscheck and another on a Bike Friday. They are 8 speed. It's generally recommended to get the premium red band version with better bearings or the newer Alfine line. When they first came out one needed to have a bike with horizontal dropouts, but now they can used on vertical dropouts with with a chain tensioner. Also there are shifters designed for drop handle bars. So it can be pretty much fitted to any bike now.
Check out Sheldon's gear calculator to determine what combination of sprockets and chain rings will work best for you. The smallest sprocket the Nexus 8 can use is 16 teeth. It think the hub comes with a 19 and 21 teeth sprocket as part of the standard set.
02-18-09, 11:49 AM
According to Sheldon Brown's site, the bearings and races etc. of the Nexus Red Band hub are supposedly Ultegra-level quality. The Alfine's are supposed to be even better! Where would that equate it? Dura-Ace?:p
You have to get anti-rotation washers specific to your frame's dropouts in order to prevent the axle wrecking your dropouts due to the natural torque stresses on the frame. If you have used an internal gear hub before, like those good old Sturmey-Archers, this should make sense.
As for chain tension, horizontal dropouts or track fork ends would be ideal, but if you have vertical dropouts, you can use a chain tensioner as stated above, or you could do as the fixed gear freaks do: calculate a "magic chainring to cog ratio" where the chain is tensioned properly in the absence of horizontal dropouts and a chain tensioner.
Straight chainlines are pretty :love:
02-18-09, 02:36 PM
I've been riding a Nexus-8 redband in an '80's road frame for 3 years and it's my favorite bike. Over 3500 miles and no problems.
Anti-rotation washers come with it and depending on whether you put them on the inside or the outside of the dropouts, the hub width can be 130 or 135mm. My frame had 126mm dropouts so I had to cold-set it to 130. Measure the Kilo TT -- that ought to work. And remember you can only spread steel frames, not aluminum or carbon! If you are really going to ride it for Time Trials I would consider the SRAM iMotion 9. That has much more even spacing between the gears.
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