Going from 26"...
 

[Closed] Going from 26" to 29er, currently 32T oval chain ring. Go for oval 30T or 32T?

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Cassette is a 9-42 with 32T oval chain ring at mo on my 26".

Going to a 29er from a 26" am I better off going for a 28T or 30T oval chainring to compensate for bigger wheels?

Oh, I like oval chain rings as better for my bad knee...

Im pretty unfit I should mention! However I mainly just ride the North and South downs... not mountains!lol

Thanks for the info guys.


 
Posted : 07/02/2017 3:05 pm
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Sorry guys, forgot about the online gear calc! Doh!


 
Posted : 07/02/2017 4:12 pm
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28t is closer on gearing, assuming similar tyre profiles, but will it fit?


 
Posted : 07/02/2017 4:18 pm
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Basically as you go up a tyre size drop 2 teeth on the chainring. So 32T on 26" is roughly the same as 28T on 29". But you might struggle to fit a 28T chainring if you've a standard 104BCD spider, I think 30T is the smallest you can fit in that case unless you go (or are already) direct mount.


 
Posted : 07/02/2017 4:32 pm
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To be honest I swapped from a 32t to a 30t on the same bike mainly for the chainline and I couldn't really tell the difference in top and bottom gears.


 
Posted : 07/02/2017 4:34 pm
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http://sheldonbrown.com/gear-calc.html

Hmmm... assuming I am using it right, going from a 26" with 32T to a 29er with 30T should give me same low gear for climbing but I will spin out a bit easier on the flat/ downs??

Calc done with 26x 2.35 and 10 to 42 cassette

Vs

29x 2.30 and 10 to 42 cassette.

Have I made a mistake?

Having same granny gear is fine, dont mind spinning out a bit sooner at speed.... need help on the ups though! ๐Ÿ˜€


 
Posted : 07/02/2017 6:36 pm
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I struggled to work this out recently. I was running 22/36 on the 26er. New 29er is 26/36. This made bottom gear much much higher. The net effect after a fortnight is I got much faster. I'm also a bit fat and slow. It'll be ok.


 
Posted : 07/02/2017 6:56 pm
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I have a 32t (round) on my Reign (650b) and 30t (round) on my Smuggler (29). Easiest gear feels approximately the same, would suggest you would need to be on the equivalent of a 28t round.


 
Posted : 07/02/2017 7:06 pm
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Right, decided to go with an oval 30T and see how it goes.

Thanks for the help guys!


 
Posted : 07/02/2017 8:27 pm