Fitting a Shimano 130mm 39t on a Sakae 250 biopace?
07-29-08, 08:33 AM
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Fitting a Shimano 130mm 39t on a Sakae 250 biopace?
I have an old Sakae FX crankset, with 42t and 52t Sakae 250 biopace chainrings.
Lately I've started climbing some hills, and pushing the 42t (with a 28 in the back) can be painful (for me). The easiest solution would be to find a chainring <42t; but there doesn't seem to be anything like a Sakae 250 <42t around. You can see the Sakae 250 130mm 42t here on ebay: https://cgi.ebay.com/SR-SAKAE-250-5-a...742.m153.l1262
So, I was wondering if it would be possible for me to fit a "normal" 39t 130mm chainring, like this Shimano one: https://cgi.ebay.com/SHIMANO-SG-5-arm...742.m153.l1262
Has anyone experience doing anything like that? Any suggestions/hints?
Thanks.
Lately I've started climbing some hills, and pushing the 42t (with a 28 in the back) can be painful (for me). The easiest solution would be to find a chainring <42t; but there doesn't seem to be anything like a Sakae 250 <42t around. You can see the Sakae 250 130mm 42t here on ebay: https://cgi.ebay.com/SR-SAKAE-250-5-a...742.m153.l1262
So, I was wondering if it would be possible for me to fit a "normal" 39t 130mm chainring, like this Shimano one: https://cgi.ebay.com/SHIMANO-SG-5-arm...742.m153.l1262
Has anyone experience doing anything like that? Any suggestions/hints?
Thanks.
07-29-08, 01:19 PM
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Seems to me you'd spend nearly as much for a chainring as you would for a whole crankset, and biopace cranksets command decent prices on eBay. Why not replace the whole thing and sell the Sakai?
While you're at it consider a triple.
While you're at it consider a triple.
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07-29-08, 01:27 PM
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Yes, a regular round 130mm 39T ring will fit. However, I doubt that you'll really see much of a difference riding up the steeps hills for two reasons...
1) A 39T gives a low gear only ~7% smaller than a 42T.
2) Biopace rings give a slightly lower effective gear during the "power" phase of the pedal stroke. A 42T Biopace is probably more like a 40T round.
I actually use a Biopace inner ring for climbing.
1) A 39T gives a low gear only ~7% smaller than a 42T.
2) Biopace rings give a slightly lower effective gear during the "power" phase of the pedal stroke. A 42T Biopace is probably more like a 40T round.
I actually use a Biopace inner ring for climbing.
07-29-08, 02:24 PM
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Thanks, this is good feedback.
I don't think I need more than that 7% of help; but I guess I'll know only after I try.
About changing the whole crankset: I thought about that, but I'd rather keep this simple, and I like my 52t biopace big ring, which is what I use 95% of the time. Also, I don't think that going much smaller than 39t or even 3 chain rings would be an option without chaning the deiralleur(s)...
I don't think I need more than that 7% of help; but I guess I'll know only after I try.
About changing the whole crankset: I thought about that, but I'd rather keep this simple, and I like my 52t biopace big ring, which is what I use 95% of the time. Also, I don't think that going much smaller than 39t or even 3 chain rings would be an option without chaning the deiralleur(s)...
07-29-08, 02:28 PM
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Go for a 38t, which is the smallest that'll fit on 130mm BCD.
ebay-38t SRAM chainring
ebay-38t FSA chainring
Do one day per week of short hill-intervals to max-HR and those hills won't hurt you so much after a month.
ebay-38t SRAM chainring
ebay-38t FSA chainring
Do one day per week of short hill-intervals to max-HR and those hills won't hurt you so much after a month.
07-29-08, 03:08 PM
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38t might be an even better idea.
And maybe I used the term "hill" in a "conservative" way... what I'm talking about are little mountains in the 2,000' range; this one is next.
And maybe I used the term "hill" in a "conservative" way... what I'm talking about are little mountains in the 2,000' range; this one is next.
