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Potentially dumb question about rear hubs

Richrd2205Richrd2205 Posts: 1,267
edited November 2017 in Workshop
So, I am getting a Planet X Kaffenback 2 frameset to build into a winter commuter. I am fine with most of the build stuff, but have really confused with rear hubs. (I am needing to sort out getting wheels built because I am going to be using a dynamo hub on the front).
So the frame has a 135 OLD and is set up for disc brakes. So an MTB rear hub should work fine. Except the freehub needs to take a road cassette (I am wanting to build it up around 105). SJS website tells me that the Shimano MTB hubs don't take a road cassette.
So, a few questions. Apologies if these are really basic. I'm not very good with wheels stuff. (&, yes, I could simply ask my LBS to build up some suitable wheels, but the point of building up is to find out what I don't know and then to find the answers!)
1. How can I make a rear MTB hub work (does it just need a new freehub, or would I need an MTB cassette, and would this need a different rear mech)?
2. Outwith the Shimano options, are there any other reasonably priced hubs that might work? Much as I like the Hope hub on my best bike, I don't mind not spending £100+ on a rear hub!)

Thanks in advance

Posts

  • If I understand your question,(probably not) then the cassette bodies are the same and Shimano MTB cassettes and Road cassettes are interchangeable.
  • Richrd2205Richrd2205 Posts: 1,267
    Thanks for getting back so quickly. That was my original understanding, but when I looked at this page, it says explicitly that the Deore XT cassette won't take an 11 speed road cassette:
    https://www.sjscycles.co.uk/hubs-casset ... hub-black/
    Hence the confusion...
    (& you understood fine, esp given the inexact question... :-) )
  • Hmm, odd. I cannot think why. I would ask. Maybe they mean it won't fit in a road frame being a different axle length.
  • veronese68veronese68 Posts: 24,327 Lives Here
    MTB 11 speed fits like a road 10 speed cassette, so an MTB hub will only take up to 10 speed road. Most road disc hubs are 135mm with the exception of a few oddities, many MTB hubs other than Shimano will accept road 11 speed.
  • Richrd2205Richrd2205 Posts: 1,267
    OK, that makes sense, thank you.
    Are there are easy to find examples of a disc compatible rear hub that would work? I can find Hope hubs, but can't really afford them. I have looked at the Novatec website & I am sure that they would sell something, but can find no useful way to search their site....
  • timothywtimothyw Posts: 2,482
    The cheap shimano option is the RS505 road hub, you'll need a centrelock rotor/adapter:
    https://www.evanscycles.com/shimano-rs5 ... b-EV253044

    Planet X have this one for £34 at the mo, but haven't had a proper look at mine to confirm if it's 11/10 speed yet:
    https://www.planetx.co.uk/i/q/HUELGRS/e ... esnake-hub
  • timothywtimothyw Posts: 2,482
    These are the novatec budget options:
    https://thecycleclinic.co.uk/collection ... brake-hubs
  • Richrd2205Richrd2205 Posts: 1,267
    That's great, thank you.
    I'd be interested in hearing if the Planet X hub is compatible. Otherwise the Novatec ones will work well enough.
    Feel free to post if there are any further options!
    TY
  • veronese68veronese68 Posts: 24,327 Lives Here
    Richrd2205 wrote:
    I have looked at the Novatec website & I am sure that they would sell something, but can find no useful way to search their site....
    I've got Novatec D771/772 on my bike and I've been happy with them, worth getting a freehub with the bite guard though. I've got 2 sets of end caps for the front so it can fit my MTB and CX bike. The rear I have is just 135mm with a QR but looking at the link above there are adaptors available for 142mm as well. The other place to look for Novatec is Bdop in Taiwan or Fleabay. If the Cycle Clinic has stock I'd buy from there as it's a proper bike shop in the UK and worth supporting as he's very helpful on here.
  • timothywtimothyw Posts: 2,482
    Just to confirm, the el guapo hubs are 11 speed road compatible (and come with a spacer).

    The freehub design is interesting - 72 points of engagement apparently, means no lag going from freewheeling to pedalling. Interested to see how the hold up.
  • simonsays wrote:
    Hmm, odd. I cannot think why. I would ask. Maybe they mean it won't fit in a road frame being a different axle length.
    Because spokes slope inwards from hub to rim, as the biggest cog on a cassette becomes larger, the teeth on the cog (and hence the derailleur when in bottom gear) get more clearance from the spokes. This means that the cogs on an MTB cassette can overhang the cassette more to the inside and still give the same clearance to the spokes. If you compare Shimano 11-speed road and MTB cassettes, you will see that the large cog on the MTB cassette overhangs the cassette body more, and that's why 11-speed MTB cassettes don't require the longer cassette body that 11-speed road cassettes do, and why you can't fit an 11-speed road cassette on an MTB hub.

    As for the OP's question, most road disc wheels that are QR use a 135mm axle. And Shimano make some very reasonably priced ones - their RS505 rear 11-speed road disc hub, for example, is just over £30 and has 135mm OLN.
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