What’s your preferred chainring size?

PB Forum :: All Mountain, Enduro & Cross-Country
What’s your preferred chainring size?
| Next Page
Author Message
Posted: Jan 14, 2020 at 7:02 Quote
or..try an oval 34 or 36. best of both.

Posted: Jan 14, 2020 at 7:24 Quote
gmoss wrote:
or..try an oval 34 or 36. best of both.
I need to try an oval one day. Do you know if they cause any issues with clutch derailleurs due to the oval constantly chaining the effective chainring diameter?

Posted: Jan 14, 2020 at 7:36 Quote
Pick a chain ring size and be a dick about it.

Posted: Jan 14, 2020 at 7:50 Quote
DonLopez wrote:
Switching from 32t to 34t is equivalent to a half gear higher. Try a 36t on the XC bike if it will fit, you will gain an extra high speed gear but loose a granny gear.

@ DonLopez Thanks for the tip will try that. Just switched to the Oneup Switch so changing over rings should be easy.

Posted: Jan 14, 2020 at 11:34 Quote
DonLopez wrote:
I need to try an oval one day. Do you know if they cause any issues with clutch derailleurs due to the oval constantly chaining the effective chainring diameter?

It's doesn't - and can't - change the chain length, only the instantaneous effective ratio. i.e. It has zero interaction with a clutch.

Posted: Jan 14, 2020 at 12:57 Quote
R-M-R wrote:
DonLopez wrote:
I need to try an oval one day. Do you know if they cause any issues with clutch derailleurs due to the oval constantly chaining the effective chainring diameter?

It's doesn't - and can't - change the chain length, only the instantaneous effective ratio. i.e. It has zero interaction with a clutch.

As the chainring turns from low ratio to high ratio, the chain length in contact with the chainring increases and decreases which in turn creates back and forth movement of the derailleur cage to compensate. My SLX clutch handles the movement without issue.

Posted: Jan 14, 2020 at 14:31 Quote
undescended wrote:
R-M-R wrote:
DonLopez wrote:
I need to try an oval one day. Do you know if they cause any issues with clutch derailleurs due to the oval constantly chaining the effective chainring diameter?

It's doesn't - and can't - change the chain length, only the instantaneous effective ratio. i.e. It has zero interaction with a clutch.

As the chainring turns from low ratio to high ratio, the chain length in contact with the chainring increases and decreases which in turn creates back and forth movement of the derailleur cage to compensate. My SLX clutch handles the movement without issue.

That’s what I thought would happen, but it mustn’t be much of a problem because many people use oval chainrings. I imagine my XTR clutch would be fine.

Posted: Jan 14, 2020 at 15:48 Quote
der movement is almost nill. maybe a 1/8" on my bike. this was back pedaling and forward pedaling. really no affect.

Posted: Jan 14, 2020 at 16:07 Quote
DonLopez wrote:
undescended wrote:
R-M-R wrote:


It's doesn't - and can't - change the chain length, only the instantaneous effective ratio. i.e. It has zero interaction with a clutch.

As the chainring turns from low ratio to high ratio, the chain length in contact with the chainring increases and decreases which in turn creates back and forth movement of the derailleur cage to compensate. My SLX clutch handles the movement without issue.

That’s what I thought would happen, but it mustn’t be much of a problem because many people use oval chainrings. I imagine my XTR clutch would be fine.

i heard it causes accelerated clutch wear/premature failure. which makes sense. but there's only one way to find out ... for me i don't notice any difference so back to round. sorry didn;t look at my own clutch movement but I did watch youtube videos which appear to show some movement.

also don't forget the clutch tension is acting against the rear suspension compression. so i imagine having an oval is like some nasty gremlin rhythmically jerking on your rear suspension twice per pedal revolution, however small that jerk may be.

Posted: Jan 14, 2020 at 16:10 Quote
Jonofthejungle wrote:
I have been riding with a 32t for a year now and I always found climbing way harder than it appeared for my riding buddies on smaller chainrings but I was concerned that if I dropped to a 30t or 28t I would lose a lot of the top end peddling speed.
So I got a 28t ring, threw it on and it was so much easier on climbs plus i matched my fastest speed on the downhill fire road section.
So if anyone else is pondering the same thing, go for the smaller chainring unless you have legs like a velodrome cyclist.

same. i'm on a 28T (42-10 cassette), perfect for my needs. if anything i would like another gear at the top. 50-10 would be better but don't need any more speed where i ride. got skinny chicken legs too.

Posted: Jan 14, 2020 at 16:23 Quote
chickenrunz wrote:
DonLopez wrote:
undescended wrote:


As the chainring turns from low ratio to high ratio, the chain length in contact with the chainring increases and decreases which in turn creates back and forth movement of the derailleur cage to compensate. My SLX clutch handles the movement without issue.

That’s what I thought would happen, but it mustn’t be much of a problem because many people use oval chainrings. I imagine my XTR clutch would be fine.

i heard it causes accelerated clutch wear/premature failure. which makes sense. but there's only one way to find out ... for me i don't notice any difference so back to round. sorry didn;t look at my own clutch movement but I did watch youtube videos which appear to show some movement.

also don't forget the clutch tension is acting against the rear suspension compression. so i imagine having an oval is like some nasty gremlin rhythmically jerking on your rear suspension twice per pedal revolution, however small that jerk may be.

no, it is actually a more natural pedal stroke for your legs. Oval only makes sense to me. Need to spend time on one before dismissing it. : )

I can say that the minimal amount of movement is nothing compared to the movement the der sees during any ride, otherwise.

I will never go back to round.

Posted: Jan 14, 2020 at 17:22 Quote
chickenrunz wrote:
Jonofthejungle wrote:
go for the smaller chainring unless you have legs like a velodrome cyclist.
got skinny chicken legs too.

For anyone worried that a small chainring will make your legs small or who believes in a correlation between leg size and appropriate ratios:

It's not a matter of leg strength. Our ability to turn a "big gear" is limited by our aerobic and anaerobic capacities, not our strength. If strong legs were required to turn a big gear (at a sensible cadence), bodybuilders would be great cyclists. Instead, top cyclists have tiny legs and look like they're starving.

Examples:

Every male* pro XC and road racer: Emaciated.

Stéphane Tempier: Turns the biggest ratios of any World Cup athlete, yet particularly thin.

Me: Last season was one of my fastest in the past decade and I was turning big ratios, but my legs were visibly smaller and would cramp and collapse when I switched back to my main winter activity of trail running / fast hiking. Didn't do any strength training all summer ... oops.


* More variability is seen in female physiology. Some women at the top levels of XC and road cycling have endomorph body types, which is essentially nonexistent among their male counterparts.

Posted: Jan 15, 2020 at 10:38 Quote
Lol looked up body types. The ectomorph describes me perfectly. That explains why in college I was the skinniest guy in the gym but yet beat all my mates at bench press, leg raise and arm wrestling. Unfortunately that cannot be said now as gym retirement was nearly 20 years ago.

| Next Page

 
Copyright © 2000 - 2020. Pinkbike.com. All rights reserved.
dv65 0.012653
Mobile Version of Website