1. ## gear ratio thoughts

read today that due to wheel size a 29" in the 24x36 position (granny) is equivalent to a 26" in 24x28 (roughly 3rd from highest in back). the article also stated that the 29er in other equivalent gears is 15 % faster than a 26" at the same rpm. this would explain alot when it comes to my riding vs my friends on 26ers e.g. equal to slower on +15% grade climbs and much faster than most as the grade decreases.

input?

2. Originally Posted by LB412
read today that due to wheel size a 29" in the 24x36 position (granny) is equivalent to a 26" in 24x28 (roughly 3rd from highest in back). the article also stated that the 29er in other equivalent gears is 15 % faster than a 26" at the same rpm. this would explain alot when it comes to my riding vs my friends on 26ers e.g. equal to slower on +15% grade climbs and much faster than most as the grade decreases.

No they just push a higher gear & go the same speed.

input?
No they just push a higher gear & go the same speed.

3. Nominally, it is a 12% difference in diameter. So a 36 tooth rear cog is the same relative diameter as a 32 on 26". I think somebody got screwed up between the area of the wheel and the diameter. Area is exponential but diameter is just a ratio.

4. Originally Posted by bulerias
Nominally, it is a 12% difference in diameter. So a 36 tooth rear cog is the same relative diameter as a 32 on 26". I think somebody got screwed up between the area of the wheel and the diameter. Area is exponential but diameter is just a ratio.
That's right but a 33t on the 26 wheel is actually the closest match to the the 29'ers 36t. A gear inch chart is the easiest way to compare gearing between different wheel sizes.

Originally Posted by muzzanic
No they just push a higher gear & go the same speed.
I know what you mean but actually they push the exact same gear to go the same speed. One rider on a 26 wheel bike and another on a 29er riding side by side at identical speed and identical cadences will be using different cog/chainring combos but will be riding in the same gear because wheel size is one of the three factors in determining gearing.

5. Originally Posted by J.B. Weld
That's right but a 33t on the 26 wheel is actually the closest match to the the 29'ers 36t. A gear inch chart is the easiest way to compare gearing between different wheel sizes.

I know what you mean but actually they push the exact same gear to go the same speed. One rider on a 26 wheel bike and another on a 29er riding side by side at identical speed and identical cadences will be using different cog/chainring combos but will be riding in the same gear because wheel size is one of the three factors in determining gearing.
You don't see a lot of 33 tooth cassette cogs tho. Nominally it would be 32.3 teeth but a 29" wheel is really only about 28.5 which makes 32.85 so you're right. The point was that it was nowhere near 28 teeth.

6. Originally Posted by J.B. Weld
I know what you mean but actually they push the exact same gear to go the same speed. One rider on a 26 wheel bike and another on a 29er riding side by side at identical speed and identical cadences will be using different cog/chainring combos but will be riding in the same gear because wheel size is one of the three factors in determining gearing.
You are right but I was trying to make it easyer for the OP to understand.

Because they ahe using a higher gear on the cassette.

7. Originally Posted by LB412
read today that due to wheel size a 29" in the 24x36 position (granny) is equivalent to a 26" in 24x28 (roughly 3rd from highest in back). the article also stated that the 29er in other equivalent gears is 15 % faster than a 26" at the same rpm. this would explain alot when it comes to my riding vs my friends on 26ers e.g. equal to slower on +15% grade climbs and much faster than most as the grade decreases.

input?
The power of the engine is what determines the speed.

29ers are typically geared a little lower so that the gear inches fall into the same range as a 26er.

If you ride a 29er with 26er gearing, though, you will either just get stronger or you will end up downshifting a lot.

-F

8. It's really only the Granny gear I question as it is the difference maker on the steepest of climbs (for this engine)... Sounds like you confirmed that it is more difficult but not to the level I first thought.... 24x33 vs. 24x28.

9. 32x18 29er = 32x16 26er

10. Originally Posted by bsieb
32x18 29er = 32x16 26er
Makes sense as the difference should flow through all gear combos.

11. Sounds like Shimano feels there is a need:

2014 Shimano: 29"er Friendly- 27.5"er Intros, New Deore Group

12. 22-36 27.5" is almost exactly 22-34 26" EWD. 22-36 on a 29er is still a full 1" bigger EWD than 22-34 26" so they're still ignoring 29er climbing capability.

13. ## gear ratio thoughts

great link for easy gear ratio calcs:

Mountain Bike Gear Ratio Calculator V4.0

"I ride my bike to ride my bike"- Zen proverb

Posted via iPhone

14. ## gear ratio thoughts

Originally Posted by LB412
Sounds like Shimano feels there is a need:

2014 Shimano: 29"er Friendly- 27.5"er Intros, New Deore Group
I predict the crankset will be standard equipment on 29'ers sold in 2014, just as compact chainrings (50-34T)are now standard on road bikes. More bike consumers of average ability than hammerheads out there.

"I ride my bike to ride my bike"- Zen proverb

Posted via iPhone

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