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Old 03-21-10, 05:26 AM   #1
daredevil
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How small a chain ring can an IGH handle?

2008 Trek Soho with 8 speed Alfine. The 44t chain ring is too big. How small can I go on it, as far as I want?

The other issue is the second gear. It seems to give a little when standing. I can feel soft spots in the pedal stroke if I stop pedaling mid hill for instance then start again. Is that normal? It only happens in 2nd gear. Thanks all. Haven't been able to get an to this in mechanics.
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Old 03-21-10, 09:55 AM   #2
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OK as I start to answer my own questions....after a little more time on the bike, and IGH has a little different feel in general to a regular geared bike, right? The pedal stroke sometimes isn't quite as firm in more than one gear. It happens when putting some torque on the cranks from stationary. Does this sound normal? If not, I have a faulty hub.
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Old 03-25-10, 11:18 AM   #3
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As for the gearing,you have many options,but it would be much cheaper/easier to swap the rear cog. You can use Sheldon's gear calculator to see what effect the changes would have.

http://sheldonbrown.com/gears/internal.html

I'm not sure what to say about your other issue. Are the cranks tight? Chain properly tensioned? I'd ask this over in the Mechanics Forum.
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Old 03-30-10, 01:43 PM   #4
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Originally Posted by daredevil View Post
2008 Trek Soho with 8 speed Alfine. The 44t chain ring is too big. How small can I go on it, as far as I want?

The other issue is the second gear. It seems to give a little when standing. I can feel soft spots in the pedal stroke if I stop pedaling mid hill for instance then start again. Is that normal? It only happens in 2nd gear. Thanks all. Haven't been able to get an to this in mechanics.
What is your current rear sprocket size?

As noted a lot cheaper to change it than the chainring. The old rule of thumb for IGH bikes was to not go lower than 2:1 input ratio and that was the Sturmey Archer recommendation. The Shimano 8 speed hubs are apparently strong enough so you can go a bit lower if desired.
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Old 03-30-10, 04:23 PM   #5
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What is your current rear sprocket size?

As noted a lot cheaper to change it than the chainring. The old rule of thumb for IGH bikes was to not go lower than 2:1 input ratio and that was the Sturmey Archer recommendation. The Shimano 8 speed hubs are apparently strong enough so you can go a bit lower if desired.
Just brought it home from the shop and am now running 39 X 22. That gives me a low gear of about 25 inches and a high near 90. That should fit my terrain fairly well. Had never heard about the 2:1 thing.
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