Can a Shimano 38 teeth ring be used on a standard Shimano 52 -42 boltpattern crankarm?

On 4/7/2014 7:40 PM, Sir Ridesalot wrote:
On Monday, April 7, 2014 5:52:33 PM UTC-4, jbeattie wrote:
On Saturday, April 5, 2014 3:50:57 PM UTC-7, Sir Ridesalot wrote:

To get the gear I want a 38 teeth ring would be nearly perfect. That way I can use a screw on 14 teeth cog on my cassette hub. Is a 38 ring the same bolt center pattern as a standard 52 - 42 ring crankarm?







Thanks and cheers



By the way, is this a trick question? What is the significance of the 14t screw-on cog(presumably smallest cog on Uniglide cassette)? I thought you were looking for a lower low and assume you're not cross-chaining with the 14t cog.



-- Jay Beattie.

Not a trick question.

The 38 - 14 combo would give me almost the exact gear I want. The Uniglide 14 teeth cog screws onto the cassette and needs neither spacers or a lockring or extra cog to hold everything in position and together. The chainline is nearly perfect too.


38x14 is a 73.3, maybe 40x15 =72, 44x16 =74.3?
52x19, which wears better, is a 73.9

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Tuesday, April 8, 2014 8:12:51 AM UTC-4, AMuzi wrote:
On 4/7/2014 7:40 PM, Sir Ridesalot wrote:

On Monday, April 7, 2014 5:52:33 PM UTC-4, jbeattie wrote:

On Saturday, April 5, 2014 3:50:57 PM UTC-7, Sir Ridesalot wrote:



To get the gear I want a 38 teeth ring would be nearly perfect. That way I can use a screw on 14 teeth cog on my cassette hub. Is a 38 ring the same bolt center pattern as a standard 52 - 42 ring crankarm?















Thanks and cheers







By the way, is this a trick question? What is the significance of the 14t screw-on cog(presumably smallest cog on Uniglide cassette)? I thought you were looking for a lower low and assume you're not cross-chaining with the 14t cog.







-- Jay Beattie.



Not a trick question.



The 38 - 14 combo would give me almost the exact gear I want. The Uniglide 14 teeth cog screws onto the cassette and needs neither spacers or a lockring or extra cog to hold everything in position and together. The chainline is nearly perfect too.





38x14 is a 73.3, maybe 40x15 =72, 44x16 =74.3?

52x19, which wears better, is a 73.9



--

Andrew Muzi

www.yellowjersey.org/

Open every day since 1 April, 1971

Thanks Andrew.

I had calculated the different chainring and cog combos that's give me the gear I wanted. I was hoping to use the 14 teeth Uniglide screw on cog because with it I would not need spacers. I was hoping to use a used 38 ring on the crank. I have a nice drilled 50 teeth ring and a 20 teeth single cog freewheel I could use but then I have to use a different crankarm that isn't aero looking.

I'll see if I can get a used 38 ring to fit my aero crankarm. If not I'll use Plan B.

Thanks again and cheers

On 08/04/14 22:12, AMuzi wrote:
On 4/7/2014 7:40 PM, Sir Ridesalot wrote:
On Monday, April 7, 2014 5:52:33 PM UTC-4, jbeattie wrote:
On Saturday, April 5, 2014 3:50:57 PM UTC-7, Sir Ridesalot wrote:

To get the gear I want a 38 teeth ring would be nearly perfect. That
way I can use a screw on 14 teeth cog on my cassette hub. Is a 38
ring the same bolt center pattern as a standard 52 - 42 ring crankarm?







Thanks and cheers



By the way, is this a trick question? What is the significance of the
14t screw-on cog(presumably smallest cog on Uniglide cassette)? I
thought you were looking for a lower low and assume you're not
cross-chaining with the 14t cog.



-- Jay Beattie.

Not a trick question.

The 38 - 14 combo would give me almost the exact gear I want. The
Uniglide 14 teeth cog screws onto the cassette and needs neither
spacers or a lockring or extra cog to hold everything in position and
together. The chainline is nearly perfect too.


38x14 is a 73.3, maybe 40x15 =72, 44x16 =74.3?
52x19, which wears better, is a 73.9


The 19 is a favourite of mine, though with a 53. But that extra tooth
doesn't make much difference.

--
JS

On Tuesday, April 8, 2014 6:36:58 PM UTC-4, James wrote:
On 08/04/14 22:12, AMuzi wrote:

On 4/7/2014 7:40 PM, Sir Ridesalot wrote:

On Monday, April 7, 2014 5:52:33 PM UTC-4, jbeattie wrote:

On Saturday, April 5, 2014 3:50:57 PM UTC-7, Sir Ridesalot wrote:



To get the gear I want a 38 teeth ring would be nearly perfect. That

way I can use a screw on 14 teeth cog on my cassette hub. Is a 38

ring the same bolt center pattern as a standard 52 - 42 ring crankarm?















Thanks and cheers







By the way, is this a trick question? What is the significance of the

14t screw-on cog(presumably smallest cog on Uniglide cassette)? I

thought you were looking for a lower low and assume you're not

cross-chaining with the 14t cog.







-- Jay Beattie.



Not a trick question.



The 38 - 14 combo would give me almost the exact gear I want. The

Uniglide 14 teeth cog screws onto the cassette and needs neither

spacers or a lockring or extra cog to hold everything in position and

together. The chainline is nearly perfect too.





38x14 is a 73.3, maybe 40x15 =72, 44x16 =74.3?

52x19, which wears better, is a 73.9





The 19 is a favourite of mine, though with a 53. But that extra tooth

doesn't make much difference.



--

JS

I've also read that you get better wear if the ring and cog are even number of teeth or if both have an odd number of teeth. Something about the same teeth meshing with each revolution of the crank rather than a new tooth.

I was just hoping to be able to use my screw on 14 teeth cog but it looks like, unless I can get a decent shape used 38 ring that I'll have to use a different cog and spacers. Ah well, I have lots of cogs to choose from.

Cheers

On Monday, April 7, 2014 12:22:43 PM UTC-7, wrote:
.... Stronglight also makes a 38 tooth chainring in 130mm bcd.

And a 55. I have a stronglight 55/44 pair that I bought and never used if anyone wants em.

Sir Ridesalot writes:

I've also read that you get better wear if the ring and cog are even
number of teeth or if both have an odd number of teeth. Something
about the same teeth meshing with each revolution of the crank rather
than a new tooth.

Ideally the number of teeth in the ring and cog are relatively prime,
that is, the greatest common divisor of the two is 1. Both even,
then, is less good. I doubt, however, that this is a significant
issue on a multigear bike.

--
Joe Riel

On Tuesday, April 8, 2014 11:56:18 PM UTC-4, JoeRiel wrote:
Sir Ridesalot writes:



I've also read that you get better wear if the ring and cog are even

number of teeth or if both have an odd number of teeth. Something

about the same teeth meshing with each revolution of the crank rather

than a new tooth.



Ideally the number of teeth in the ring and cog are relatively prime,

that is, the greatest common divisor of the two is 1. Both even,

then, is less good. I doubt, however, that this is a significant

issue on a multigear bike.



--

Joe Riel

Ah, but this thread is discussing a single speed not a multigear bike.

I find it very interesting how sometimes a seemingly very small thing can contribute greatly to either efficientcy or longevity of parts. Smaller chainring and cog mens shorter chain and all together means a lighter drivetrain but a bigger chainring and cog means better longevity.

Cheers

On Tuesday, April 8, 2014 11:56:18 PM UTC-4, JoeRiel wrote:
Sir Ridesalot writes:



I've also read that you get better wear if the ring and cog are even

number of teeth or if both have an odd number of teeth. Something

about the same teeth meshing with each revolution of the crank rather

than a new tooth.



Ideally the number of teeth in the ring and cog are relatively prime,

that is, the greatest common divisor of the two is 1. Both even,

then, is less good. I doubt, however, that this is a significant

issue on a multigear bike.



--

Joe Riel

We're discussing a single gear setup not multigears. LOL VBG

Interesting how a seemingly small thing can make for longer lasting parts. A small chainring and cog is lighter and uses less chain than a bigger chainring and cog does yet it's the bigger parts that will have the greater longevity.

Cheers

On 4/8/2014 11:10 PM, Sir Ridesalot wrote:
On Tuesday, April 8, 2014 11:56:18 PM UTC-4, JoeRiel wrote:
Sir Ridesalot writes:



I've also read that you get better wear if the ring and cog are even

number of teeth or if both have an odd number of teeth. Something

about the same teeth meshing with each revolution of the crank rather

than a new tooth.



Ideally the number of teeth in the ring and cog are relatively prime,

that is, the greatest common divisor of the two is 1. Both even,

then, is less good. I doubt, however, that this is a significant

issue on a multigear bike.



--

Joe Riel

Ah, but this thread is discussing a single speed not a multigear bike.

I find it very interesting how sometimes a seemingly very small thing can contribute greatly to either efficientcy or longevity of parts. Smaller chainring and cog mens shorter chain and all together means a lighter drivetrain but a bigger chainring and cog means better longevity.

Cheers


Correct.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Interesting how a seemingly small thing can make for longer lasting parts. A small chainring and cog is lighter and uses less chain than a bigger chainring and cog does yet it's the bigger parts that will have the greater longevity....


itsnot small. In facto, you can hear the difference tween small diameter and larger...scrape scrape scrape....

prob is, wear drops efficiency into a steep always increasing decline away from your computed theoretic max system.

if there's a choice, the larger diameter meets needs over time not on the drawing bored.

whatta you dong with a 14 ? move to the Alps ?