29 er and gearing

[trevorhough40]

Hi all 29er fans

 

 

 

Been riding my 29er gf hifi deluxe for about a month and loving it. Riding a sram 12 34t on the back, found i am at least 2 gears difference when compared to my merida hard tail. My only concern is that raced yesterday in elgin and checked my hr profile and was shocked to realise that 50 % of race was over 75 % of max.

 

 

 

Does anyone have any thoughts or experience on effort expended and gearing choice on a 29 er. Or am i just unfit.

 

 

 

Thanks all.

[evolve]

Hey there. I have been on my 29ers for more than a year now and dont find any differant from 26 ridiing in terms of HR etc, all i find is that its more efficient than a 26.

Maybe you trying to push to hard to keep your assmed pace, dont try with the 29er it comes when when you dont expect it.

[Johan Bornman]

Gearing on a bicyle is measured in inches if you live in the US or as Gear Advancement in the metric world.

 

You don't say what you mean by "two gears difference" but I'll assume that it is two gears harder.

 

You can calculate the gearing on your 26er and 29er and compare. This is best done in a spreadsheet.

 

What you want to find out is how far the bike travels per pedal revolution.

 

The formula is: Number of chainring teeth divided by number of teeth on the rear sprocket, times wheel circumference.

 

Wheel circumference is of course Pi R Squared. You may want to simply measure it by rolling the bike on the floor and measuring one revolution. You would have done this for the computer.

 

Do this calculation for every gear combination for every bike. You'll soon see that there are duplicates within one bike and, whether or not your 29er has a higher gear than your 26er.

 

 

[Eldron]

Gearing on a bicyle is measured in inches if you live in the US or as Gear Advancement in the metric world.

 

You don't say what you mean by "two gears difference" but I'll assume that it is two gears harder.

 

You can calculate the gearing on your 26er and 29er and compare. This is best done in a spreadsheet.

 

What you want to find out is how far the bike travels per pedal revolution.

 

The formula is: Number of chainring teeth divided by number of teeth on the rear sprocket' date=' times wheel circumference.

 

Wheel circumference is of course Pi R Squared. You may want to simply measure it by rolling the bike on the floor and measuring one revolution. You would have done this for the computer.

 

Do this calculation for every gear combination for every bike. You'll soon see that there are duplicates within one bike and, whether or not your 29er has a higher gear than your 26er.

 

 

[/quote']

 

The science is that if you use the same gearing from a 26er on a 29er - the gears will be longer (at the same speed in the same gear you'll pedal slower on the 29er because the 29er has larger wheels - ie: you ride further per pedal stroke).

 

The nonscience (nonsense??) is that it's just a learning curve - when I moved to a 29er I found I kept getting bogged down in a bigger gear and having to stand up and power over ramps/steep uphills. Within a month or two I was back to my old RPM.

 

The gearing is so wide on an MTB (27 gears!) that you shouldn't need to put different gearing on for the 29er...

 

 

[SteveS]

Hi trevor

 

In single speed terms there is definately a difference. Based on an excel chart that I got from Steel Niner, if for instance you are riding a 32 front and 17 rear on a 26" inch bike which would give a gearing of 48.94 you would need to ride with a 32 front and 19 rear to get the same gearing on a 29" bike. I think Eldron is correct. In theory it should only affect you in your easiest or most difficult gears. 

 

[Tumbleweed]

The science is that if you use the same gearing from a 26er on a 29er - the gears will be longer (at the same speed in the same gear you'll pedal slower on the 29er because the 29er has larger wheels - ie: you ride further per pedal stroke).

 

?

 

The nonscience (nonsense??) is that it's just a learning curve - when I moved to a 29er I found I kept getting bogged down in a bigger gear and having to stand up and power over ramps/steep uphills. Within a month or two I was back to my old RPM.

 

?

 

The gearing is so wide on an MTB (27 gears!) that you shouldn't need to put different gearing on for the 29er...

 

?

 

?

 

yeah, i played on one on saturday morning, and struggled to find a gear to wheelie on it at first. although i'm too short for these bikes, ngala's chumba may push me in that direction