[Deyv]

Hi,

I just got a Kona Unit 2-9 and the ratio is 32/18. I used to run 34/18 on my SS 26, Is the ratio the same on a 29er compared to a 26?

Thanks

 

[Westy]

It is close but I think a 19 tooth cog on the back would be closer to what you are used to.

 

[douglas]

I agree w/Westy - a 19 or maybe even a 20 would be equiv. to your 34/18.

on my 29er I run 32/20 or 32/18 depending on how much climbing the trails have. I plan to buy a 19 and just leave that on.

 

[MMcG]

I'd say 32:20 would be closer deyv

 

[MMcG]

I agree w/Westy - a 19 or maybe even a 20 would be equiv. to your 34/18.

on my 29er I run 32/20 or 32/18 depending on how much climbing the trails have. I plan to buy a 19 and just leave that on.

Shoot! Too bad you didn't tell me about this sooner. I had one sitting around. It has since been sent off to bogey though.

 

[Westy]

My math says an 18.8959 tooth cog would give him the exact same ratio so let's all stop this 20 tooth nonsense

 

[peter6061]

Somewhere between 18 and 19.

Use the gear calculator on Sheldon Brown's page...

http://www.sheldonbrown.com/gears/index.html

I'm showing a gear inch of 49.9 for 26" 34/18
The closest matches for 29" using a 32T cog are... 19 (48.7) and 18 (51.4). You can probably get closer by changing the 32 to something else, but the 19 will probably be fine.

 

[Biscuit]

http://www.pvdwiki.com/index.php?title=Single_Speed_Gearing

Tables and formulas for everything you wanted.. and so much more...


A 32/19 (153.4)or a 34/20 (154.9) would be really close to your 34/18 26er (156.7).

 

[Nowheels]

I was at the LBS yesterday and asked the same question as I am getting a new set of SS wheels built. They said that a 34 / 20 was the way to go for a 29er. I'll probaly do a 36 / 21 to start as I have a 36 chain ring already.

 

[Ralph Furley]

Going from a 26 to 29 wheel you add 2 cog teeth, so... 32x20