Building a Rohloff Hardtail

Discussion in 'Mountain Bikes' started by Stretch-4x4, Nov 7, 2007.

  1. Stretch-4x4

    Stretch-4x4 New Member

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    Hi all,

    I am looking at building a new light weight bike, incorporating a Rohloff hub. I have been getting into 6 hour cross country races but also want it to be good on road. I am looking to build a hardtail and have been suggested to use the Voodoo wanga frame, which has horizontal dropouts for the adjusting chain tension.

    My questions are would it be worth getting a carbon fibre frame manufactured for better performance?

    Also considering the hub and fame are going to cost a bit what other components should I fit for best value/performance ratio.

    Cheers Andrew
     
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  2. cruisin

    cruisin New Member

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    A custom built carbon frame sounds bloody expensive.
    Google up Thorn cycles as they have some nice steel frames and bikes Rohloff specific with eccentric bottom brackets and a deeper left side vertical dropout which eliminates the torque arm.
     
  3. Stretch-4x4

    Stretch-4x4 New Member

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    Yes I do remember seeing them now and looking again that does look very nice, similar to what I was wanting. The only reason I suggested the carbon fibre is because my cousins have carbonfibre Scotts and in comparison to my aluminium Trek they are ridiculous to pick up. It's a shame the hub is so expensive other wise I would think about the carbon fibre option more because it has to be of benefit both off and on the road.

    Any thoughts on the eccentric bottom bracket versus the horizontal dropouts? I think I prefer the simplicity of the later, like on the voodoo frame but not moving the rear end around is probably stronger.
     
  4. scuppy

    scuppy New Member

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    The problem is if the frame is carbon and flexy, then the chain tension may be a problem. Maybe ask some single speed riders.
     
  5. Stretch-4x4

    Stretch-4x4 New Member

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    Good point, the other thing suggested to me is that a carbon fibre frame would not have the same shelf life a steel frame would. So because its probably to expensive and probably doesn't have many benefits I am planning on a steel frame. I think I have found a guy in America who can make the frame for me, with special dropouts and ship it, hopefully without too much expense.

    Now I have started looking at forks, more confusion, so far I am beginning to think a Rock Shox Dart 2 would go ok, Fox seems very expensive.

    Cheers
     
  6. threaded

    threaded New Member

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    Been there done that. Doesn't matter if it is a hard tail, doesn't matter what material, with a Rohloff hub you will need a tensioner on a MTB or the chain will drop off. Unless of course the MTB is never seeing any rough ground.

    Anyways, suggest a titanium frame, otherwise your hub will outlast the frame. ;)
     
  7. Stretch-4x4

    Stretch-4x4 New Member

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    You sound prettty sure of this, why will sliding dropouts or an ebb not tension the chain enough to stop it coming off? And yes I am probably not going to ge going fast enough to cause the chain to come off. :p

    Any frames in particular? Titanium sounds expensive, if a steel one broke, there is always fixing it yourself. :eek:
     
  8. scuppy

    scuppy New Member

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    It isn't different to single speed really. I am not a racer but it is my understanding downhill single speeders use chain tensioners because of the beating they take. Trail riders don't seem to need them. If you asked in a single speed forum, you might get a more enlightened answer.

    I'm yet to have my chain come off and have done around 1000km of riding, 50% of that on dirt tracks. I don't deliberately do jumps or other crazy things but some of the trails I've done are pretty rough. My bike is a Kona Unit 29er (steel) single speed.

    Note single speed chain rings are in just the right position so the chain is in line with the rear cog, which could have been the other posters problem, unless he's just a hard core rider. Sheldon Brown talks about it on his web pages.
     
  9. Stretch-4x4

    Stretch-4x4 New Member

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    Yeah I thought this was one of the benefits of singlespeeds, the fact that the chain could hardly ever come off. My riding style is pretty tame so I doubt I am ever going to have a problem with the chain coming off a single speed or rohloff.

    Cheers
     
  10. threaded

    threaded New Member

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    Well, if you rarely drop chains on a single speeder, you'll be OK I guess.

    Another issue that comes to mind is getting the chain line straight. The cog on the Rohloff sits at 54 mm (but at 58mm if you use a 13 tooth cog) and it can be a pain to get the front ring to line up nicely, but you can fit some seriously fat tyres. :D
     
  11. Stretch-4x4

    Stretch-4x4 New Member

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    Why does the distance change depending on the size cog at the rear? shouldn't they be the same. I must admit I haven't ridden single speed but I know my riding style is very tame. Plus the chain should be fairly taught by using sliding dropouts so I am still not exactly seeing why it should come off bar getting something like a stick in it. But as I say tame riding I am sure there are plenty of other people who ride hard enough to get the to come off, though I wouldn't have thought frequently. But just my small bit of understanding.
     
  12. alfeng

    alfeng Well-Known Member

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    You do know that the hub, alone, is fairly hefty (over 1.7kg) ...

    Regardless, if you want to save some weight, go with V-brakes (at least, in the rear) instead of disc brakes rather than buying a carbon fibre frame to try to save weight.

    Consider "green"/(latex) inner tubes to save weight for your races.
     
  13. Stretch-4x4

    Stretch-4x4 New Member

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    Yes the hub does way a bit, which is the reason I was hoping to make the rest of the bike lighter. I dont mind how much it weighs too much, I just thought that that could be one spot, where I could gain back a lot of weight and hopefully speed. Now I am basically looking at steel frames (given up on carbon fibre). Although I did take a rohloff equipped bike for a ride yesterday, it was very nice but not quite what I expected so the whole thing may not happen anymore. :(

    Cheers
     
  14. lick my boobies

    lick my boobies New Member

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    Make sure you get a coupler placed into the chainstay on the drive side. the new Spot belt drive system will have Rohloff-compatible cogs so you could run belt drive.
     
  15. Stretch-4x4

    Stretch-4x4 New Member

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    Sounds interesting, although I dont think I have enough money to buy any bikes let alone a rohloff anymore. Also I took a demo bike for a ride and wasn't quite as impressed, yes it was good but just wasn't sure about how it would be for racing.

    Cheers
     
  16. artemidorus

    artemidorus New Member

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    I think that you really need to think about this project a little more. Firstly, are you after a lightweight bike or not? A choice of a Rohloff hub suggests that you are after durability and low maintenance rather than light weight. There'd be little point getting an expensive, light composite frame to put a Rohloff on.
    Secondly, you've got to spend the money where it gives benefit. If you're going to lay down lots of bucks for a custom frame and a Rohloff hub, don't put a cheapo fork such as a dart 2 on it. That bike would deserve something like a Reba or a Fox, and you'd notice the difference.
    From the point of view of brakes, I used to be a v-brake purist, but a few wet rides taught me to hate the sound of my rims being chewed up by gritty pads. Go for disc - offroad, the benefits definitely outweigh the small weight penalty.
     
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