I just converted my bike to single speed. My 36/16 ratio was suppose to be my magic gear according to the Fixmeup calculator but I have a little chain sag. It doesn't slap the chainstays or anything though. I have a Forte tensioner but it seemed to make it TOO tight. Is this too much sag? Sorry for the crappy cell phone pics.
How's my tension?
Trek Willy
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I just converted my bike to single speed. My 36/16 ratio was suppose to be my magic gear according to the Fixmeup calculator but I have a little chain sag. It doesn't slap the chainstays or anything though. I have a Forte tensioner but it seemed to make it TOO tight. Is this too much sag? Sorry for the crappy cell phone pics.
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if that's a new chain, then yes, too much slack.
basically, if you can push the chain in with your thumb, and turn the crank away from where you are pushing in, and the chain comes off, it's too much.
basically, if you can push the chain in with your thumb, and turn the crank away from where you are pushing in, and the chain comes off, it's too much.
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That looks like way too much sag to me. I'd rather have the chain alittle too tight then way too loose. Throw a chain while riding and you may go over the bars! JMO
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Do you think it's alright to stick the tensioner (pushing down) on that chain like I had it or should I add some links? When I did have it on there it was pretty noisy. It looked like everything was aligned too.
I got identical results with the magic gear calculator. 34/20 was supposed to be 'it' with my 42.5cm chainstays. 'It' looked like what you got. In retrospect, I'm sorry I didn't try taking out a chainlink, and putting in a half link. I just put the Singleator back on, pushing UP. Why don't you try a half link, and report back to us? It's definitely too slack, as is
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I put the tensioner back on and with everything lined up it makes twice as much noise as my derailer. As cool as single speeds are I'm putting my gears back on tomorrow. It makes me mad that I bought a new crank and all the hours of work to have it turn out like it did.
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try adding a half link($2) or a half link chain ($20-40), but they only work if it is a BMX 1/8" chain KMC makes both replacement links and full chains, ask your shop to open the QBP book if they don't know what your talking about, and if you can't install it yourself take it to a shop that knows what a half link is
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It looks OK. When pedaling the slack will be on the bottom run. If the teeth on the cog can grab that chain, good.Trek Willy said:
As someone hinted above, wear on a chain makes a huge difference in slack. If you're using a worn chain a new chain may be too tight. That's a fundamental problem with magic gearing.
I hate tensioners too. The solution is a dedicated SS frame.
BTW That's a big gear ratio!
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Thanks for all the replies guys. I thought about it some more last night and I decided I didn't want to go back to geared. I put the Forte back on and played with the alignment a lot. My chainline looks straight and the Forte is as lined up as I can possibly get it. It runs pretty quiet now. My cheapo Dimension crank seems pretty good. My gears are so tall (2.25:1) because I do a lot of urban riding. It will probably be rough offroad but the land is pretty flat around here in south GA. I have a 18 and 20 tooth cog that I can stick on if trail riding seems impossible.
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I'd love one but they cost literally half as much as my bike did new. I'd like to convert to disc brakes eventually so maybe then I should build up a wheelset with those.LFASS said:
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Thanks man. I'll have to take some real pictures with my camera instead of my phone and put it in the "Post your singlespeed" thread.Doggity said:Ain't nothin' wrong with that bike...you got it lookin' good!
1: Take tensioner off and get chain back to your original pic showing it a bit slack.
2: Take off the little knob on the tensioner that causes the spring to be tight when the tensioner is put on the frame.
3: Put the tensioner on tight.
When you put the tensioner on this way you can adjust the amount of tension. Surly does the same thing.
2: Take off the little knob on the tensioner that causes the spring to be tight when the tensioner is put on the frame.
3: Put the tensioner on tight.
When you put the tensioner on this way you can adjust the amount of tension. Surly does the same thing.
You could try filing a flat spot in your axle. It may buy you enough adjustment to get the chain tension right.
go here and scroll down slightly
http://www.sheldonbrown.com/singlespeed.html#vertical
go here and scroll down slightly
http://www.sheldonbrown.com/singlespeed.html#vertical
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