Lefty hub not spinning freely

mtbrider123
mtbrider123 Posts: 102
edited May 2018 in MTB workshop & tech
Hi Guys,

My front wheel is not spinning freely for some reason. It’s not like there’s a lot of drag but there’s only a bit. Brakes are not rubbing. The rear wheel spins fine. Does anyone know what this might be?

I have a Cannondale F-Si (so a lefty suspension)

Thanks

Comments

  • 02gf74
    02gf74 Posts: 1,168
    If its not the brake disc dragging, it has to be bearings.

    If the fork should have one set of calliper lugs with gap, it is easy to undo calliper bolt to move the calliper clear of the disc, do that first.

    I can't think what else it can be as there is one bolt to hold the wheel on., no seals or anything else to get in the way.

    Remove the wheel and feel the bearing for stiffness and roughness. Bearing replacement is easy.

    As interim fix, prise off the seal, wash bearing with white spirit and pack with grease.
  • mtbrider123
    mtbrider123 Posts: 102
    Bearings are perfectly fine and they’re quite new too. When I removed the wheel, there was dry grease and a bit of dust/dirt. After cleaning and re-greasing, and going for a ride, the wheel was still not spinning freely. Maybe that’s normal with a lefty?
  • 02gf74
    02gf74 Posts: 1,168
    Bearings are perfectly fine and they’re quite new too. When I removed the wheel, there was dry grease and a bit of dust/dirt. After cleaning and re-greasing, and going for a ride, the wheel was still not spinning freely. Maybe that’s normal with a lefty?

    Definitely not. They spin freely as any other bike wheel.
    Was one or both bearing replaced recently, one may be fitted out of square, the misalignment may be the cause.
    Or maybe the bolt for the front wheel is done up too tightly - the cap states the lb/ft figure but since I am not near my bike, I don't see why that would make a difference - you could try loosening the bolt a tiny amount to see if it makes any difference.

    It is common for wheels with sealed bearing to have a tube with shoulders that the inner race fits up against - this prevents excessive bearing preload - can't remember if there is one in the lefty hub but something to look into.

    what hub is it?

    define "not spinning freely" If the wheel has tyre fitted, and you pull it as fast as you can, how many turns do you get?

    and you have done this with the brake calliper out of the way?
  • mtbrider123
    mtbrider123 Posts: 102
    02GF74 wrote:
    Bearings are perfectly fine and they’re quite new too. When I removed the wheel, there was dry grease and a bit of dust/dirt. After cleaning and re-greasing, and going for a ride, the wheel was still not spinning freely. Maybe that’s normal with a lefty?

    Definitely not. They spin freely as any other bike wheel.
    Was one or both bearing replaced recently, one may be fitted out of square, the misalignment may be the cause.
    Or maybe the bolt for the front wheel is done up too tightly - the cap states the lb/ft figure but since I am not near my bike, I don't see why that would make a difference - you could try loosening the bolt a tiny amount to see if it makes any difference.

    It is common for wheels with sealed bearing to have a tube with shoulders that the inner race fits up against - this prevents excessive bearing preload - can't remember if there is one in the lefty hub but something to look into.

    what hub is it?

    define "not spinning freely" If the wheel has tyre fitted, and you pull it as fast as you can, how many turns do you get?

    and you have done this with the brake calliper out of the way?

    If it’s not supposed to be like that, then I also think it’s the bearings. The bike is at the shop right now but I’ll do a video of how the wheels spins, if they won’t be able to solve it. I’ve tried with callipers on and off, same thing. Wheels are bike ahead biturbo RS. They have their own hub
  • The Rookie
    The Rookie Posts: 27,812
    It can only be brakes or bearings.

    Some bearings are quite 'gloopy' (e.g. Hope) the extra grease should make them more reliable but also adds drag, without some objective way of looking at the 'drag' you have its hard to say if its normal or not. Cup and cone (kept up on the TLC) spin more freely than cartridge as a rule.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • 02gf74
    02gf74 Posts: 1,168
    So was it the bearings?
  • michal.hosala
    michal.hosala Posts: 2
    edited December 2020
    I stumbled upon this thread when I was solving issue with lefty hub spin myself. While I haven't found any remedy here I was able to resolve the issue myself so I thought I might share what was the problem for me.

    Initially I thought my bearings are to blame so I changed them for high quality japanese NTN LLB bearings which are just perfect. However, mounting the wheel back on the bike made no difference. It still was looking like the bearings are "squeezed" little bit too much because I could literally see how the wheel is slowing down dramatically as I am fastening the screw into the axle. That made me think that probably hub is not manufactured properly and the smaller bearing is not touching the ring on the axle before fastening. I decided to buy metal shim washer with 15mm inner diameter 21mm outer diameter and 0.1mm thickness and put it on the axle just prior to fastening the screw and securing the wheel in place. Now everything works like a charm, wheel finally spins freely, on top of that my bearings will not get worn so fast.

  • steve_sordy
    steve_sordy Posts: 2,443
    Clever boy! :)
  • Thank you very much. What type of hub were you using that didn’t spin freely. Since the washer was added no stiction on the wheel or creaks?
  • It is a Sun Ringle Lefty hub, don't know the exact type. At first I used two washers (totaling 0.2mm) but that was a tiny bit too much as I couldwiggle the wheel from side to side very slightly when grabbed by the tire. Hence I reduced to just one which still allowed wheel to spin absolutely freely without any negative side effects. I've ridden just 50km since the fix on this particular bike though... Only thing to keep in mind is not to lose the washer when removing the front wheel :)
  • This worked for me, as well. I made a washer out of a Coke can. I’d like to find a professionally made washer like you did, but it’s near impossible to find one. Can I ask where you bought yours?
  • mully79
    mully79 Posts: 904
    Google "15 x 21mm diameter shim"