Jump to content


29er Gearing Mindf*ck


  • Please log in to reply
42 replies to this topic Post Order

#33 Azonic

Azonic

    Admim

  • Members
  • 5,951 posts
  • Province:Eastern Cape
  • Cycling Interests:MTB, Road, Triathlon / Multisport
  • LocationEarf

Posted 04 July 2012 - 02:37

View Postsometime, on 04 July 2012 - 02:34 , said:

Yes

@100rpm

26er 42/11 47.5 km/h
29er 39/11 49.2 km/h

Cool...

Flip, Ideally I'd love to get a 40x27 in a 180mm crankset. Seems impossible to get though.

#34 philip.maree

philip.maree

    Ultimate Hubber

  • Members
  • 739 posts
  • LocationCenturion

Posted 04 July 2012 - 02:40

View PostAzonic, on 04 July 2012 - 02:37 , said:

Cool...

Flip, Ideally I'd love to get a 40x27 in a 180mm crankset. Seems impossible to get though.

Think Rotor and FSA do 40/27
Lam 3:22  The steadfast love of the LORD never ceases; his mercies never come to an end;

Lam 3:23  they are new every morning; great is your faithfulness.

#35 fabes

fabes

    COFBA HQ

  • Members
  • 6,743 posts
  • LocationPE

Posted 04 July 2012 - 02:44

View PostAzonic, on 04 July 2012 - 11:36 , said:

Indeed. I think I might have eventually faded into the mindset that different bikes suite different courses. I'm building the 29'er for Trans Baviaans and courses where a 29e'r might be better. My 26'er won't be retired and will probably be used most of the time still. My 'Rida eats 29'ers for breakfast. But, like on Last year's Trans Baviaans - when I'm spinning my moer out on slight downhills, the bloody 29'ers just roll past you and you can do nothing but watch in awe.
If you that fast on your 26 inch don't you think you waisting money by buying a 29er? Just a question...
I love Forrest Gump

#36 Azonic

Azonic

    Admim

  • Members
  • 5,951 posts
  • Province:Eastern Cape
  • Cycling Interests:MTB, Road, Triathlon / Multisport
  • LocationEarf

Posted 04 July 2012 - 02:48

View Postfabes, on 04 July 2012 - 02:44 , said:

If you that fast on your 26 inch don't you think you waisting money by buying a 29er? Just a question...

50/50 I guess. For marathons I'm sure a 29'er must be better. On very tight XC races I usually gap 29'ers, but when the course opens up a bit they pull away again. But that's besides the point. For Trans, which is a road race on gravel it must be better...

...and when the pace is on, I'm gatvol of spinning my 26er out :eek:

Edited by Azonic, 04 July 2012 - 02:49 .


#37 fabes

fabes

    COFBA HQ

  • Members
  • 6,743 posts
  • LocationPE

Posted 04 July 2012 - 02:54

View PostAzonic, on 04 July 2012 - 02:48 , said:

50/50 I guess. For marathons I'm sure a 29'er must be better. On very tight XC races I usually gap 29'ers, but when the course opens up a bit they pull away again. But that's besides the point. For Trans, which is a road race on gravel it must be better...

...and when the pace is on, I'm gatvol of spinning my 26er out :eek:
I agree with why you would want to get a 29er but for 1 or 2 races a year it might just be a waist if you see yourself riding the 26er mostly...

BTW I also had this mindset 2 months ago when i bought my 29er thinking i would use the 26inch more....i sold the 26er 3 days after purchasing my 29er
I love Forrest Gump

#38 Iron

Iron

    COFBA

  • Members
  • 7,522 posts
  • LocationGreenstone

Posted 04 July 2012 - 02:57

26" ( 2.0 tire ) 42/11 with 180 cranks = 3.82 ratio @ 100 rpm = 47.9km/h
26" ( 2.0 tire ) 42/11 with 175 cranks = 3.82 ratio @ 100 rpm = 47.9km/h ( same as 180 cranks )

29" ( 2.0 tire ) 39/11 with 180 cranks = 3.55 ratio @ 100 rpm = 48.2km/h
29" ( 2.0 tire ) 39/11 with 175 cranks = 3.55 ratio @ 100 rpm = 48.2km/h ( same as 180 cranks )

But you will be able to spin up a 175 crank easier than the 180 from a power perspective . my point, dont stress with 180 .

But its your call.

Edited by Iron, 04 July 2012 - 02:58 .


#39 Dubber88

Dubber88

    Ultimate Hubber

  • Members
  • 935 posts
  • LocationPretoria East

Posted 04 July 2012 - 03:13

I went from a 28-40 ; 11-36 ( Finding the top end burning me wishing for that little bit of a lighter gear).

As an experiment I installed a 24 blade, running a 24-40 currently (Not recommended by manufacturer) and am as happy as can be.

This setup is on a 2012 XT groupset.
Please visit : www.blindpilot.co.za



#40 Azonic

Azonic

    Admim

  • Members
  • 5,951 posts
  • Province:Eastern Cape
  • Cycling Interests:MTB, Road, Triathlon / Multisport
  • LocationEarf

Posted 04 July 2012 - 03:26

View PostIron, on 04 July 2012 - 02:57 , said:

26" ( 2.0 tire ) 42/11 with 180 cranks = 3.82 ratio @ 100 rpm = 47.9km/h
26" ( 2.0 tire ) 42/11 with 175 cranks = 3.82 ratio @ 100 rpm = 47.9km/h ( same as 180 cranks )

29" ( 2.0 tire ) 39/11 with 180 cranks = 3.55 ratio @ 100 rpm = 48.2km/h
29" ( 2.0 tire ) 39/11 with 175 cranks = 3.55 ratio @ 100 rpm = 48.2km/h ( same as 180 cranks )

But you will be able to spin up a 175 crank easier than the 180 from a power perspective . my point, dont stress with 180 .

But its your call.

I know crank length has nothing to do with it in terms of speed and RPM's etc. Its a case of leverage. When I got my first real MTB in 1998 it came with 180mm cranks, and I've been using them ever since. I did have 175's before that one bike came with 180's, but I'm not going to risk going back now.

#41 Tankman

Tankman

    Ultimate Hubber

  • Members
  • 6,838 posts
  • Province:Western Cape
  • LocationD'Urbanvale

Posted 04 July 2012 - 06:17

View PostAzonic, on 04 July 2012 - 02:35 , said:



Shot, but I asked the opposite... 10 speed everything... on a 9s crank.

That works!

In short 10 works with 9, 9 woks with 10, 11 works with 10 and 10 works with 11 ... see?
The difference between winning and losing is most often ... not quitting!

#42 Azonic

Azonic

    Admim

  • Members
  • 5,951 posts
  • Province:Eastern Cape
  • Cycling Interests:MTB, Road, Triathlon / Multisport
  • LocationEarf

Posted 11 July 2012 - 10:02

I went for a 11-36 cassette, and a good old 44/32/22 crankset. Oldschool, its what I know. I'm guessing that the 44x11 on a 29'er is going to be one serious gear...

#43 Dustbug

Dustbug

    Advanced Member

  • Members
  • PipPipPip
  • 43 posts
  • LocationDurban SA

Posted 11 July 2012 - 10:04

Quick question guys with the 2x10 you can buy just about anycombo of front chainrings and fit as you want as long as they are within specs but with the inside chainring if you fit a smaller ring ie: 24 in place of a 26 will you need to reset the derailleur or will it drop down and pickup as for the 26 bearing in mind it is not a huge diameter difference? I know the outer ring will need a reset.