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  1. #1
    Sir Fallalot wroomwroomoops's Avatar
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    How would/does a Nexus 8 fare on a tandem?

    If I built a rear wheel with a Shimano Nexus 8 gear hub, could I expect it to last, on a tandem, or is it too sensitive?

    I'm asking because I just happened to have one laying around, and I want to replace the front+rear derailleur setup on a tandem.

    The Nexus 8 has a rollerbrake.

    Maybe I should ask this in the mechanics' forum?

  2. #2
    hors category TandemGeek's Avatar
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    I'm not positive, but as best as I can recall I believe the Nexus hubs have max RIDER weight limitations that fall somewhere between 190lbs - 250lbs (a quick check yielded a range of weights for the 3, 7 & 8 speed models). I'm not sure if the weight limitation pertains to the hub brakes or the hub itself.

    Edit: Added "Rider" to answer next question.
    Last edited by TandemGeek; 07-14-07 at 06:45 AM.

  3. #3
    Sir Fallalot wroomwroomoops's Avatar
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    Quote Originally Posted by TandemGeek
    I'm not positive, but as best as I can recall I believe the Nexus hubs have max weight limitations that fall somewhere between 190lbs - 250lbs (a quick check yielded a range of weights for the 3, 7 & 8 speed models). I'm not sure if the weight limitation pertains to the hub brakes or the hub itself.
    What does that weight limitation even mean? And this is a general question, even with tires: say a tire has a weight limit of 110 Kg. Is that the weight of the rider? The weight on a single tire? Total weight of bike + rider?


    EDIT: if the weight limit pertains to the brake, then the "weight" thing is clear: it's about the total weight of bike+rider(s).

  4. #4
    hors category TandemGeek's Avatar
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    The the only hard and fast reference I could find in about 5 minutes pertains to the Inter-M roller brake. It's not so much a limit as it is a warning that the brake was only designed to meet a specification for a total weight of 100kg, after which the brake may not perform as designed (extract below). It would probably be a good idea to contact Shimano's tech support folks and ask them flat out: Is there a max torque / weight limit on the Nexus 8?

    Like the Rohloff, the constraints seem to be spoke count and drop-out spacing. The Redline uses improved bearings designed to support off-road use of the hub so that's a plus. The drop-out spacing is something of a "tweener" in that at 132.5mm it falls 1/2 way between the road spec of 130mm and off-road spec of 135mm to seemingly fit both. Trying to put one on a tandem with 145mm spacing would obviously be something that would require technical direction/advise from Shimano. The 36h spoke count isn't as big of a concern because the hub's flanges are tall enough to yield a wheel that's probably as strong as any 40h tandem wheel.

    Here's a link to a fairly detailed review of the Nexus 8 Redline used on a single bike: http://forums.mtbr.com/showpost.php?...3&postcount=78

    As for weight limits in general, I can't recall seeing any bicycle tires with weight limits, but with respect to rims and wheelsets the often times cited limits of 180lbs - 200lbs always assume a bicycle with two wheels and tied the weight to the rider. This may vary from manufacturer to manufacturer but they usually specify, such as American Classic does in their tables: http://www.amclassic.com/pdfs/WheelWeights.pdf
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    Last edited by TandemGeek; 07-14-07 at 11:05 AM.

  5. #5
    Sir Fallalot wroomwroomoops's Avatar
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    Quote Originally Posted by TandemGeek
    The 36h spoke count isn't as big of a concern because the hub's flanges are tall enough to yield a wheel that's probably as strong as any 40h tandem wheel.
    I thought the exact same thing! Thanks for helping me make up my mind... about this detail of the implementation.

    Quote Originally Posted by TandemGeek
    Here's a link to a fairly detailed review of the Nexus 8 Redline used on a single bike: http://forums.mtbr.com/showpost.php?...3&postcount=78
    Sadly, I don't have the redline version of it. Now, I'm thinking of canning the whole project.

    Quote Originally Posted by TandemGeek
    As for weight limits in general, I can't recall seeing any bicycle tires with weight limits, but with respect to rims and wheelsets the often times cited limits of 180lbs - 200lbs always assume a bicycle with two wheels and tied the weight to the rider. This may vary from manufacturer to manufacturer but they usually specify, such as American Classic does in their tables: http://www.amclassic.com/pdfs/WheelWeights.pdf
    It's written in all manu catalogues I've seen so far - and never seen it defined. So, what you're saying is, they don't mean the weight on one tire, but the weight of the rider when both tires are that tire.

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    If you fancy trying one for rides round the park and gentle road trips I would just go for it, since this sort of riding isn't going to stress it as highly as a fit MTBer giving it grief. However the application would be experimental and if you're heading far from home say doing a touring trip, it's probably worth ponying up for a Rohloff.

  7. #7
    Sir Fallalot wroomwroomoops's Avatar
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    Okay, I know the Rohloff Speedhub is teh bestest, but I just don't have the money for it.

    Is there any other hub gear, apart from Rohloff, that is sturdy? I don't need the huge span in gear ratios that the Rohloff offers. Heck, not even the 300%+change of the Nexus 8 is necessary. I just need it to be strong, and cheap. I also have a wheel with a SRAM S7. How does that fare, in the robustness department?

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