29er and gearing

[agallant]

Just a point of curiosity... would a 29er require different gearing or crank-arm length? On my "normal" 26er, I use 175mm cranks and 44-34-22 rings matched with a 12-32 cassette. Would any of this change on a 29er?
Thanks.

[Bytesiz]

Just a point of curiosity... would a 29er require different gearing or crank-arm length? On my "normal" 26er, I use 175mm cranks and 44-34-22 rings matched with a 12-32 cassette. Would any of this change on a 29er?
Thanks.

Different gearing? Not required, but your wheel diameter impacts your final gear ratio (inch gears). So those same gears on a 29er willl be taller. See http://www.sheldonbrown.com/gears/ to get more info about this.

Longer crank arms for a gear 29er? I would say no. Many SS MTB folk like a longer crank arm for more leverage for climbing, but on a geared bike, crank length should be same regardless of wheel size (within reason).

[gdw]

Most folks run stock gearing but some chuck their large ring and run a 32-22 or 20 double paired with a cassette with a 34 or 36t big cog. The large ring is good for pavement and fireroads but rarely used off road and can get trashed in rough rocky terrain.

[palincss]

Just a point of curiosity... would a 29er require different gearing or crank-arm length? On my "normal" 26er, I use 175mm cranks and 44-34-22 rings matched with a 12-32 cassette. Would any of this change on a 29er?
Thanks.

The wheels are larger in diameter, so any given chainring/sprocket combination would represent a higher gear. I don't imagine the fact that larger wheels roll over small obstacles better than smaller ones would help you on the steepest hills, so I think you'd want a larger large sprocket. Shimano now has a 12-36 9spd developed, so it's said, just for 29'ers.

[agallant]

Thanks all for the comments.
AG

[gearguywb]

You loose about 9% on the easiest gears and gain it on the top end. Don't know anyone that really needs a 44/11 combo on a 29er though. If you live in climbing country throw a 11-34 cassette on there and you will be fine.

I ran a 2x9 setup for a couple of years and loved it! 22/34 up front with a 11-34 in back.

[dogdriver]

I ran a 2x9 setup for a couple of years and loved it! 22/34 up front with a 11-34 in back.

This sounds sweet. I do use the big ring on the road, but could live without it...

To answer your question, I went the 29er way a couple years ago and initially noticed that I had to go to the granny ring on a few spots that I had been able to climb in the middle ring with the 26er (same 11-34 rear cassette). All this really demonstrated was that I had probably been in the 34-34 on the 26er and should have used the granny anyways.

FWIW, the local single speed mtb crowd generally considers 32-18 to be "nominal" for 26" wheels, and 32-20 for 29ers, ie-- the larger wheel diameter equates to about a two tooth difference in the back to get an equal gear for climbing. The big boys go a little taller gear, slugs like me go easier (34-22).

Bottom line, you probably won't notice a difference (just shift until it feels right) unless you spend a lot of time in the big ring in back.

My $.02, Chris

[mbusa]

I have a SRAM XX 39-26 paired with a 9spd 11-34 and it's awesome. I had been running a 32 single before. The 39/11 is a little small when going hard on pavement but fine in the dirt

[Cantdog]

34 front and 11-34 rear. So nice not having to deal with a front derailleur. Been running this setup since November and love it.

[gearguywb]

34 front and 11-34 rear. So nice not having to deal with a front derailleur. Been running this setup since November and love it.

All depends on where you live! 34/34 on a 29er in Pisgah=lots of walking :)

[Cantdog]

It didn't stop me last time ;)

[PaMtbRider]

I think 29ers work best if you can keep a little momentum. Standard gearing i.e. 44-32-22, 11-34 works fine for most people in most situations. Lower gearing than 22-34 and you might as well get off and walk. I like a 1x9 setup like Cantdog mentioned, with the only difference being a 32 instead of 34 front chain ring.

[that guy]

Mine is set up 32/18 :banana:

[Jack Brunk]

Spent this weekend on my new 29er. XX 39/26 up front and 11/36 rear.
Got in almost 5 hours and I couldn't tell you what gears I used. Bike is bitchin and too me it really doesn't matter what the gearing is. if it gets too steep I'll get off and power walk/run up the climb. Don't over think it.

[gearguywb]

Mine is set up 32/18 :banana:

On a SS 29er I was running a 32/20.....but it was really a 3 speed

1. sit down and pedal
2. stand up and pedal
3. get off and push