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Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

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Old 01-04-13, 02:13 PM   #1
HoraceLai
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Chainline & Sturmey Archer

Hello,

I am working a bike which is a fixed gear bike, but I am building a rear wheel that I can swap with it so that it can have gears. Therefore I have built up a wheel with a 5 speed Sturmey Archer hub.

However, I have a problem with the chain line. The rear sprocket is too far from the centerline, too close to the chain stays. The cog is already flipped in the direction that puts the teeth closest to the middle. Currently the misalignment is approximately 6.8mm.

I measured the amount of threads on the drive side of the axle and it seems to be just enough for all the bolts and spacers and my frame with no extra room. I was thinking that I could just swap some of those spacer nuts around but it doesn't seem like I have room for it. The only way this would be possible is if I can shift the axle to make more threads. Is this possible? Something tells me it isn't.

The other option is to use chain ring spacers, which I would like to avoid if possible because it wouldn't look very good.

Is 6.8mm chainline misalignment too much for a internal gear hub? I guess it is for a fixed but on a fixed the chain is tighter as well.

Thanks.
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Old 01-05-13, 02:06 AM   #2
europa
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Don't use a 1/8 chain, they're designed to run straight, use a 3/32 chain because they are designed to bend. Your 7mm offset is nothing like the offsets a chain on a geared bike faces so it'll be fine

Of course, with fixed gear, all bets are off and the chainline must be straight but as soon as you introduce a freewheel, the only issue is increased wear on the chain and cogs.
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Old 01-05-13, 09:40 AM   #3
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Depending on what crankset you're using, you could easily make up the difference and straighten your chainline by using a bottom bracket with a slightly longer spindle.
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Old 01-05-13, 01:53 PM   #4
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can you post a pic of the Sturmey Archer? I've been tinkering with the idea of having multiple gears on my fixed steamroller, was thinking of going the cheap way with a Dingle Cog or the White Industries version.. but thats just for two gears... but five?!?!? got me curious haha
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Old 01-05-13, 05:24 PM   #5
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Dude, Sturmy Archer hubs have one cog and are internally geared.

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Last edited by Scrodzilla; 01-05-13 at 05:52 PM.
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