29 er vs 26 er – where's the math?

Home Forum Bike Forum 29 er vs 26 er – where's the math?

Viewing 6 posts - 41 through 46 (of 46 total)
  • 29 er vs 26 er – where's the math?
  • CaptainMainwaring – Member

    I had a look at this recently. One quanitfiable difference is that 29″ wheels and tyres weigh around 15% more than their 26″ equivalents. The tyres and rims are also further away from the hub so I am guessing that makes them around 20% harder to accelerate but that they have 20% more “momentum”.

    This would suggest that a rider doing a lot of techy climbs and descents with constant variations in speed would be better off on 26″, but someone favouring smoother XC type trails would be better off on 29″

    Posted 13 minutes ago # Edit

    jameso – Member

    ^ True, but then consider roll-over and momentum benefit etc on those techy sections, and the ease of moving around a smaller wheel ..

    We get to the point of Rorschach’s gif very quickly )

    I agree that that there are lots of other factors, but they are difficult to quantify and in some cases could be +ve or -ve depending on circumstances.

    Yet another factor is that apart from weighing more, 29″ wheels are more prone to lateral distortion under load so again MAY be an issue for techy sections or cornering hard

    Premier Icon somafunk

    I’ve rode 24″, 26″, 650b, 29″ and 29″ front with 26″ rear – all good fun in their own way as they all ride and handle different over similar terrain, none were necessarily quantifiably better or worse than the other for the entirety of a given trail, they’re just bikes and if you’re a crap rider on one wheel size you’ll be an equally crap rider on any other wheel size so stop believing there is a holy grail of wheel size that’ll turn you into a riding god.

    If you’re tall n’ lanky like a big streak of piss then a 29″ wheeled bike may be the better bike for you, if your short n’ squat like a turd dropped from a height then a 26″ wheeled bike may be better for you, if you’re one of those “normal” folk in the middle then perhaps a 650b wheeled bike may be better for you.

    Personally i resemble a short n’ squat turd so i ride a 26″.

    Better at rolling over big rocks and more momentum. Sounds like they should be good for downhill to me… More so than XC even.


    Premier Icon kelvin

    If you’re comparing, would you use the same travel forks, or the same length/height?

    Premier Icon mattjg

    It’s not about the science.

    Big wheels are more fun.

    (I find).


    No maths required. The rolling resistance thing is a bit of a red herring as it is more related to tyre pressure. Simply put it is all about conservation of momentum. A larger wheel effectively flattens a bump, meaning less kinetic energy is wasted when the wheel rolls over a bump (i.e. less speed is lost), which in turn requires less energy the rider has to put in to maintain speed or in riding over bumps on a downhill. This is obviouly only of importance to those where speed over the ground is important – if you are into jumps, then suspension is far more important so you’re not going to be keen to compromise suspension travel for speed over the ground – so 26ers will still rule here. The reality is can you tell the difference? I have, but it is not that great – its not transformed me from an average rider into a superstar overnight. I wonder if they have these debates over on the tractor forum?

Viewing 6 posts - 41 through 46 (of 46 total)

The topic ‘29 er vs 26 er – where's the math?’ is closed to new replies.