[FoShizzle]

Just curious.....

Is there any tangible reason to go with say a 32:18 over a 34:19? They are virtually the same gearing and given the range of teeth that ENO freewheels allows for, both chainring sizes can easily work for me. Just wondering if there is something subtle or otherwise that would steer somebody towards a 32t vs a 34t or vice versa.

thanks in advance,
FoShizzle

 

[2farfwd]

Just curious.....

Is there any tangible reason to go with say a 32:18 over a 34:19? They are virtually the same gearing and given the range of teeth that ENO freewheels allows for, both chainring sizes can easily work for me. Just wondering if there is something subtle or otherwise that would steer somebody towards a 32t vs a 34t or vice versa.

thanks in advance,
FoShizzle

Generally more teeth engaged = smoother drivetrain feel = slower wear. Not much of a difference between those two sizes though.

 

[FoShizzle]

Generally more teeth engaged = smoother drivetrain feel = slower wear. Not much of a difference between those two sizes though.

as usual, thanks for answering my question.

i have a 32t on order but was just curious what prompted folks to go with a 32 over a 34 when in general, I would imagine either could work for "most" people given the range of freewheels available.

cheers

 

[Guital2]

it also gives you more ratio selections for your cog....for instance going from a 32-16(2:1) to a 32-17(2:1.8) is a larger ratio jump than say a 42-21(2:0) to a 42-22(2:1.9)

 

[trial-sin]

not too mention the two gear inches you gain with the 32/18 over the 34/20

 

[pacman]

Just curious.....

Is there any tangible reason to go with say a 32:18 over a 34:19? They are virtually the same gearing and given the range of teeth that ENO freewheels allows for, both chainring sizes can easily work for me. Just wondering if there is something subtle or otherwise that would steer somebody towards a 32t vs a 34t or vice versa.

thanks in advance,
FoShizzle

Consider what other ratios you will be using. An EBB or sliding drops should allow a 4 tooth range of cogs without changing the chain length. It could be 32:18,19,20,21. A 34T chainring might have 34:16,17,18,19. If you want the ease of slipping on a different cog without changing the chain and you know what ratios you will be using - plan ahead

Subtle enough?

 

[Cygnus]

prime numbers

Do the math. in some combinations, prime numbers (e.g., your 19 tooth freewheel) will achieve a much longer cycle between the time when the chain ring, freewheel, and chain are in exactly the same position. does it matter? i don't know. but singlespeeds raise interesting mathmatical questions.

 

[FoShizzle]

not too mention the two gear inches you gain with the 32/18 over the 34/20

forgive my ignorance.....what does that actually mean?

 

[pacman]

Do the math. in some combinations, prime numbers (e.g., your 19 tooth freewheel) will achieve a much longer cycle between the time when the chain ring, freewheel, and chain are in exactly the same position. does it matter? i don't know. but singlespeeds raise interesting mathmatical questions.

Yeah, right! That's why I use a 48" chain with a half-link.

 

[Cygnus]

Gear inches

forgive my ignorance.....what does that actually mean?

'Gear inches' uses the wheel diameter, because this factor will influence how high or low your gear feels once you have settle on a gear ratio. Among other things, calculating gear inches allows you to compare gearing between mountain and road bikes....or tires with different 'heights' (diameters).

(Chainring / Freewheel) * Wheel diameter = Gear inches

(32/18) * 26 = 46.2 gear inches
(34/20) * 26 = 44.2 gear inches
...or two more gear inches in the 32/18 combo

 

[FoShizzle]

'Gear inches' uses the wheel diameter, because this factor will influence how high or low your gear feels once you have settle on a gear ratio. Among other things, calculating gear inches allows you to compare gearing between mountain and road bikes....or tires with different 'heights' (diameters).

(Chainring / Freewheel) * Wheel diameter = Gear inches

(32/18) * 26 = 46.2 gear inches
(34/20) * 26 = 44.2 gear inches
...or two more gear inches in the 32/18 combo

Thanks Cygnus, I gotcha....so it is a helpful relative comparison. I was thinking that an apples to apple comparison would be the 32/19 vs the 34/20 since they have about the same gear ratio. In that case, the Gear inches are about the same of course since wheel size in my case is a constant yielding the 34/20 a tad higher than the 32/19.

I kept my order for the 32t figuring with my bad feet (major reconstructive surgery), friends that will laugh at me if I ever walk a hill, and relatively steep terrain, a 32/20 is great. I will order an extra 34t chainring since that is cheaper that another ENO freewheel so I will have the best of both worlds.

cheers

 

[BCBlur]

I believe that an odd number of total teeth will result in less drivetrain wear over time. I'm not sure that the difference will be significant, but it's something to consider.

 

[shiggy]

41 x 23
Do it.

 

[FoShizzle]

41 x 23
Do it.

Shiggy, did those come out of your random number generator or is that combination blessed by Shiggy

 

[pacman]

Shiggy, did those come out of your random number generator or is that combination blessed by Shiggy

It's the prime number selection criteria. What they forgot to tell you was to mark the chain and cog every time you remove the rear wheel (flat?) or else the wear will be uneven. If you accidentally derail and lose track of the positions you are up the creek ...

To even out the wear rotate the chainring on the cranks 90 degrees (72 degrees - 5 holes). The teeth closer to the crank arms wear faster than those 90 degrees from the crank arms due to the torque being maxed when the cranks are horizontal.

 

[FoShizzle]

It's the prime number selection criteria. What they forgot to tell you was to mark the chain and cog every time you remove the rear wheel (flat?) or else the wear will be uneven. If you accidentally derail and lose track of the positions you are up the creek ...

To even out the wear rotate the chainring on the cranks 90 degrees (72 degrees - 5 holes). The teeth closer to the crank arms wear faster than those 90 degrees from the crank arms due to the torque being maxed when the cranks are horizontal.

as usual, thanks for the clarification pacman.

in terms of "marking", what is a robust way to mark it.

and does this really translate into a "tangible" difference on the trail? I guess it just surprises me that it is that sensitive to putting the chain back on in a different "position", but I seem to be learning that my logic is often flawed.

cheers

 

[pacman]

as usual, thanks for the clarification pacman.

in terms of "marking", what is a robust way to mark it.

and does this really translate into a "tangible" difference on the trail? I guess it just surprises me that it is that sensitive to putting the chain back on in a different "position", but I seem to be learning that my logic is often flawed.

cheers

The first paragraph was marked with (sarcastic).
The second paragraph is for real, I have a unevenly worn chainring.

 

[shiggy]

Same ratio as you are wanting to run. The ENO FW is available in a 23t. More teeth = smoother feel IMO.

The prime thing was a happy bonus!

I currently use a 35 x 21. Switching to 38 x 23 (because I can).

 

[FoShizzle]

The first paragraph was marked with (sarcastic).
The second paragraph is for real, I have a unevenly worn chainring.

ahhhh...good. i am glad it was just me being a dumb gullible blonde. i felt like i was just dumber than dirt for a minute.

 

[FoShizzle]

Same ratio as you are wanting to run. The ENO FW is available in a 23t. More teeth = smoother feel IMO.

The prime thing was a happy bonus!

I currently use a 35 x 21. Switching to 38 x 23 (because I can).

gotcha. thanks.

I really want to go with ENO cranks and I dont think they make odd numbered teeth rangs (at least not ENO) so I am just going to keep the 20t ENO freewheel and buy an extra 34t ENO chainring since that is cheaper than buying an extra ENO freewheel.

cheers