Forum home Mountain biking forum MTB buying advice

Asymetric rims

veronese68veronese68 Posts: 24,665 Lives Here
edited January 2017 in MTB buying advice
Thinking about building up a new set of wheels and the WTB Asym i35 caught my eye. Does anyone have any experience of these? My understanding is that they build a stronger wheel as the spoke tensions are closer between each side. I guess the front would be offset towards the disc and the rear toward the cassette. Would that just look weird? Should I just stick to normal rims? Also head says Novatec hubs for value, quite fancy a set of Hopes though.

Posts

  • cooldadcooldad Posts: 32,601
    I have asymetric rims on my 29er, but no idea if they are stronger. The spokes look the same as if they were standard rims though and the rims are the same way round (if that makes sense) front and back.

    I also have some Fulcrum wheels on a 26er, which are laced 8 one side and 16 on the other. Those have the patterns reversed, 16 on the drive side rear, 16 on the braking side front.

    Both sets have been pretty much bulletproof, but I'm not a Rampage type rider.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • The RookieThe Rookie Posts: 27,748
    I have asymmetric on my commuting bike, Alex rims, and previously had some Ritchety branded ones on my MTB, you don't even notice it, but make sure you allow for the offset in the spoke calcs!

    In theory it creates a stronger wheel as you say, first the spoke at a lower angle is at a slightly better one, secondly it has to distort much further before it can buckle over the spokes, like CD I am far to skilled (or old is perhaps more likely) for this to be an issue, my 3 year old 75Kg weight limit wheels are still true despite me being a (tiny obviously) but over that before I even get knitted up.
  • veronese68veronese68 Posts: 24,665 Lives Here
    Thanks both, I think I might give them a go. I had a bit of a read up on them. Apparently the Roger Musson spoke calculator has a way of putting offset into it. What I read about building them said they should be offset in opposite directions front and back as the hubs are offset in opposite directions. I'm not exactly the bravest rider either, also too old and I know how much it hurts when I get it wrong. I was going to stick the wheels currently on my 29er onto the CX bike as the plan was always to have a spare set of wheels that would fit both bikes and build some fatter rimmed wheels for the 29er. Think I'll stick with Novatecs as the credit card bill came in.
  • The RookieThe Rookie Posts: 27,748
    Use an online spoke call of repute like the DTswiss one, if it doesn't have rim offset in it, then just add/deduct from the flange distance.

    Yes the offset is different front to back, away from the disc at the front and away from the cassette at the rear.
  • RockmonkeySCRockmonkeySC Posts: 15,247
    I would go for the Hope hubs. They're bombproof plus they're dead easy to service and parts are easy to get next day.
    If you buy Hope Hoops or Hope Tech wheel sets then they actually work out cheaper than the cost of the parts.
  • cyclecliniccycleclinic Posts: 6,865
    Asymmetric rims are better rims full stop. The onlh disc brake wheels that should be build with symmetric rims are wheels with symmetric or near symmetric dynamo hubs. Not only is low side spoke tension improved whicn helps spoke life and pringle resistance lateral wheel stiffness is also improved wjich again helps spoke life and pringle resistance.

    The stiffness increase is easily quantified. Take my velocity blunt35 rims on shimano m965 hubs. Tension balance is 65% but if the rim has a 3mm offset then the wheel would be 3.8% stiffer and tension balance would 81%.

    I do have another set of mtb wheels and these use asymmetric rims.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • veronese68veronese68 Posts: 24,665 Lives Here
    Thanks all, confirms what I suspected looks like I'll definitely go for asymmetric.
Sign In or Register to comment.