Belt drive/Nexus slipping - which is the likely culprit?

scrumpydave Posts: 143
edited March 2017 in The workshop
Before I get told off I've been searching the forum which has thrown up some results (notably viewtopic.php?t=12927073) but I'm still not sure about this.

I've been given a Trek Soho with a Gates Carbon belt drive and Nexus 8 speed hub. I've found it slips under heavy load. So is it more likely to be due to the hub or the belt drive?
- the belt is showing signs of wear and it feels a little loose (but I don't know what the correct tension should be)
- the hub shifts nicely and the yellow marks at the back are lined up

I suspect it is the belt, but a new one is expensive and hard to fit.

Any thoughts?
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  • Does it slip in all gears? The Nexus hub is basically a 4 speed with and overdrive so if there was a problem they may be a pattern, e.g. 1st & 5, 2nd & 6th etc?

    I don't know about belt drives but it does seem possible that's the culprit from your description.
  • scrumpydave
    scrumpydave Posts: 143
    I haven't investigated which gears it slips in - I'll check.

    I agree I think it is most likely the belt, but I thought I'd see if people had ever experienced a slipping hub drive.
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  • The Rookie
    The Rookie Posts: 27,812
    One of the biggest causes of slipping with a belt drive is the rear wheel not being mounted precisely square in the frame, a small amount out and it can slip, check that the front of the rear wheel is centred in between the chain stays.
    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.