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Post by brokenicarus on Jun 4, 2007 14:03:31 GMT -5
16 tooth? 17 tooth  forget that. I noticed today my bike's got a 13 tooth front sprocket, and a 630 chain!! It appears to have a 33 tooth rear sprocket  What the Hell? Why on earth would anyone do that? what kind of effect would you imagine it's having on my performance? I've never ridden another SR, so input would be appreciated. The only other non-stock bit was the winning pipe that came on my bike, odd stuff... Davey |
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Post by miker on Jun 5, 2007 9:08:20 GMT -5
Hmmm... I'm wondering what kind of rear wheel you have, any normal SR setup won't take a 33, right?
Mine came 17/44 and I've debated dropping to 17/42... I can't imagine it with a 16 front, that would be way too revved up.
miker
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Post by joneill4 on Jun 5, 2007 19:59:27 GMT -5
That's a pretty tall gear. If you ride strickly highway, it might be okay, but thats just not what the SR was built for. Does it even push 5th gear?
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Post by miker on Jun 6, 2007 10:21:48 GMT -5
13/33 is only slightly taller than 17/44. I just don't know how he got a 33 on there - XS650 back wheel?
miker
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Post by brokenicarus on Jun 6, 2007 14:43:22 GMT -5
we'll investigate... the reason I thought it was a 33 rear sprocket is this:  I thought it made sense because a 630 chain should be substantially larger than a stock sr chain, so the 33 teeth would be farther apart. My bike performs fine, It'll chug along fine at 70-80 in 5th gear and gets around 50 mpg if I'm just riding around. I just wonder if it's decreasing my throttle response or gas milage having such a huge chain on there. thoughts? what sprocket setup would optimize gas milage? switching to a stock 520 chain? |
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Post by wotavidone on Jun 6, 2007 17:44:40 GMT -5
A couple of points for you consideration.
My manual says stock gearing is 16/44, which is a reduction of 2.75 to one.
I run 17/42, a reduction of 2.47 to one.
13/33 is a reduction of 2.54 to one, i.e not as highgeared as 17/42.
Also for your consideration, the number on the side of your sprocket has nothing to do with how many teeth its got.
Honest!
My 42 tooth rear sprocket, and I've counted the teeth several times, has C45 stamped on it.
Only way to tell how many teeth you got is to count them.
Also, I sincerely doubt you have a 630 chain, given that the stock 530 only just fits.
XTs run 520.
Mick
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Post by miker on Jun 7, 2007 15:29:49 GMT -5
OTOH, I have a stock SR and XT rear on my desk, and they both say "44" on them. The XT one is thinner, of course.
miker
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Post by colinjay on Jun 7, 2007 17:31:35 GMT -5
Looking at the picture, and seeing how close the chain is to the mounting nut, I would say that the sprocket is 33T.
As to a 630 chain not fitting, the difference between 630 (which is 3/4" x 3/8") and 530 (which is 5/8" x 3/8") is only in the pitch (distance between roller pins) of the chain and the width of the chain is nominally the same. A 630 STD or HD chain will be no wider than a 530 STD or HD chain, however a HD O'Ring chain might be that little bit to wide.
CJ
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Post by wotavidone on Jun 7, 2007 17:46:18 GMT -5
I stand corrected on the 630 chain.
It does explain one thing though - 33 teeth of 3/4" pitch is probably pretty close to the same diameter sprocket as 42 teeth of 5/8" pitch. Which looks about right to me. There is not a lot of clearance between the nuts and the chain on my 42t sprocket either.
Looks like the number on the side thing depends whether you have a real sprocket or after market. Mine was probably made in outer mongolia. C45 probably stands for camel #45 in the train that brought the sprocket to market.
Mick
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Post by brokenicarus on Jun 7, 2007 22:18:44 GMT -5
It does explain one thing though - 33 teeth of 3/4 pitch is probably pretty close to the same diameter sprocket as 42 teeth of 5/8 yeah, that was my rationale about the teeth count being SO much lower. But why do you suppose someone would want larger links on there? does it give more complete power transfer at the expense of a heavier chain, or is there something fishy? If I switch back to our chain should I expect better gas milage, or is the rotating weight difference negligible? thanks for playing everyone. Davey |
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Post by colinjay on Jun 7, 2007 23:31:30 GMT -5
Don't quote me on this, but, I'm sure the diameter of the rollers on a 630 chain is greater than that on a 530 chain. Therefore there would be a greater contact area between the chain and the sprocket, which would then enable it to transmit more power with probably less wear on the chain and sprockets than a 530 chain. Just a theory.
Switching back to STD size chain and sprockets probably would not do much, aside from make it easier to replace parts as you don't have to work out what bike the 630 sprockets came from.
CJ
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