chain ring question
11-15-16, 12:15 PM
#1
Old guy on a Bike
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chain ring question
We've got some serious hills here in San Antonio (I know-hard to believe) would I benefit from changing to a 38T front chain ring from my current 42T? I believe my spacing is 130mm.
11-15-16, 12:23 PM
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There is about a 10.5% difference between a 38T front chain ring and 42T front chain ring. Courtesy of Sheldon Brown's gear calculator.
11-15-16, 12:27 PM
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The Torpado's BCD looks to be 144mm. Smallest inner which can be fitted is 41T. Options are to make a change on the back or use a different chainset.
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The Torpado's BCD looks to be 144mm. Smallest inner which can be fitted is 41T. Options are to make a change on the back or use a different chainset.
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11-15-16, 12:40 PM
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Or add a triplizer ring
(Red Clover Components - Red Clover Components - Bicycle Triplizers and Chainrings)
although that might be a more elaborate solution than you want.
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11-15-16, 12:43 PM
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Or add a triplizer ring
(Red Clover Components - Red Clover Components - Bicycle Triplizers and Chainrings)
although that might be a more elaborate solution than you want.
(Red Clover Components - Red Clover Components - Bicycle Triplizers and Chainrings)
although that might be a more elaborate solution than you want.
11-15-16, 01:45 PM
#6
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Sounds like I just need to suck it up and live with it! Ha--story of my life.
Thanks guys
Thanks guys
I don't use my small chainring or front derailleur unless I go to San Antonio!
11-15-16, 02:43 PM
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If gearing not to your needs do not hesitate to make a change.
A bike which is not geared correctly for you is a disincentive to ride.
BTW Sig. Torresini's front mech looks to be one of the seldom seen Nuovo Valentinos. Is that correct?
11-15-16, 02:54 PM
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I live in Buvlerde, to get home from Cibolo Creek is a 400' climb including 14% grade, and here's what I did - a cyclotouriste triple with half-steps and a granny ring (26T)
This also required changing the bottom bracket to 121mm asymmetric, which I did with SKF and 2.5mm spacer (if you try this, get a 4mm spacer, too, and use which one works best - tightest clearance is the chainring stack bolt heads against the chainstay).
here's the chainline on the little ring (and 18t middle rear cog)
A cyclotouriste is so narrow, it works best with road double FD
I did this originally on my '77 Grand Prix, which I rode this way for about 5 years, and I'm moving the whole drivetrain over to an International frame.
I have another cyclotouriste stack and arms around here, but I think a friend has already claimed it.
and yes, if all else fails, take the 10%.
This also required changing the bottom bracket to 121mm asymmetric, which I did with SKF and 2.5mm spacer (if you try this, get a 4mm spacer, too, and use which one works best - tightest clearance is the chainring stack bolt heads against the chainstay).
here's the chainline on the little ring (and 18t middle rear cog)
A cyclotouriste is so narrow, it works best with road double FD
I did this originally on my '77 Grand Prix, which I rode this way for about 5 years, and I'm moving the whole drivetrain over to an International frame.
I have another cyclotouriste stack and arms around here, but I think a friend has already claimed it.
and yes, if all else fails, take the 10%.
Last edited by bulldog1935; 11-15-16 at 03:25 PM.
11-15-16, 03:03 PM
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Now that's getting it sorted!
Thanks for this fine post.
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Now that's getting it sorted!
Thanks for this fine post.
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11-15-16, 03:27 PM
#11
Old guy on a Bike
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So I'm assuming they dont (and never have) made a 38t ring with a BCD of 144mm. That sure sounds like an easy fix. Wouldnt want to loose the pantographed big ring. Damn, I might just have to move to Houston.....
11-15-16, 03:31 PM
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smallest chainring for 144 BCD is 41t, which TA makes (I may have one here). SJS and most UK/EU vendors sell it - search Campagnolo Strada chainrings to find it.
https://www.sjscycles.co.uk/chainrin...nring/?geoc=US
I ran half-steps with 46/41T and 13-28t rear for a few years before I sprung for the cyclotouriste.
never mind, i checked - I have the 46T - the 41T went with the Strada-clone crank to my daughter's go-fast.
https://www.sjscycles.co.uk/chainrin...nring/?geoc=US
I ran half-steps with 46/41T and 13-28t rear for a few years before I sprung for the cyclotouriste.
never mind, i checked - I have the 46T - the 41T went with the Strada-clone crank to my daughter's go-fast.
Last edited by bulldog1935; 11-15-16 at 03:37 PM.
11-15-16, 03:41 PM
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Ironically, the maker of your chainset, OFMEGA, was the first manufacturer to offer a 41T c/w for the 144BCD. Prior to that 42T was the smallest. Also well known in the U.S. as Avocet brand.
Last edited by juvela; 11-15-16 at 04:05 PM. Reason: addition
11-15-16, 03:42 PM
#14
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Here's a closer shot of the front DR. From what I've read Valentino's are not highly thought of, though it works fine for me.
Last edited by LouB; 11-15-16 at 03:51 PM. Reason: spelling
11-15-16, 03:56 PM
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Can see the winged wheel logo on the cage in this new photo. It was not discernable due glare/reflection in the earlier picture.
Have one of these on a Bianchi model 980 from ~1979-80.
There is the Valentino (pushrod) and the Nuovo Valentino (parallelogram).
VeloBase.com - Component: Campagnolo 2050, Valentino
VeloBase.com - Component: Campagnolo Nuovo Valentino
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11-15-16, 03:59 PM
#16
What??? Only 2 wheels?
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If you put some pedals on that bike you'd get more power to the ground. Then you might not need the triple.
FWIW, a 47T-42T ring pair makes a nice half-step crossover with a 14-34T 6-spd FW.
FWIW, a 47T-42T ring pair makes a nice half-step crossover with a 14-34T 6-spd FW.
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11-15-16, 04:00 PM
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Still waiting on my seatpost - if I stand the whole time, I don't need the triple.
and yes, those are nice half-steps
47T TA Pro5Vis outer rings are hen's teeth - they haven't made them since the 80s - I actually have one on the other ring stack,
47/42/26T.
and yes, those are nice half-steps
47T TA Pro5Vis outer rings are hen's teeth - they haven't made them since the 80s - I actually have one on the other ring stack,
47/42/26T.
Last edited by bulldog1935; 11-15-16 at 04:04 PM.
11-15-16, 04:07 PM
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Pedaling without a seat post is a WHOLE lot more comfortable than pedaling with a seat post and without a seat.
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Pedaling without a seat post is a WHOLE lot more comfortable than pedaling with a seat post and without a seat.
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11-15-16, 04:25 PM
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It's not possible. A 144 mm BCD is simply too big for a chainring that size. The chainring bolts of a 144 mm BCD crankset would be sitting in the teeth of a 38-tooth chainring and getting in the way of the chain.
11-15-16, 04:38 PM
#20
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11-15-16, 04:48 PM
#21
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so another option would be to keep the 52/42t front and swap out the free wheel for one with a larger big ring.
11-15-16, 04:54 PM
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A 28 was about as large as derailleurs of that day could handle, but if you have something smaller, a 14-28 was a very common cog range. You could get more going to a long cage RD though.
11-15-16, 04:55 PM
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I know, shameless of me--couldn't help myself.
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11-15-16, 05:07 PM
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11-15-16, 05:15 PM
#25
What??? Only 2 wheels?
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