Looking to build 1x10 Drivetrain

Redkyte
Redkyte Posts: 16
edited May 2016 in MTB workshop & tech
Hey,

I'm going to replace the drivetrain on my Giant Stance 2016 both for the mechanical experience and to improve my jaunt around the trails.

I'm making the build around the uberbike components below so welcome suggestions when it comes to the other parts. I'm going 11-42t on the rear and 36t on the front unless anyone has a better suggestion? I've found that using uber bike components with a 11-36t cassette is roughly the same price as if I where to get a 10spd cassette with 11-42t out of the box; plus it's a bit more bling!

I've picked out some sample components and was hoping someone could give me advice on the derailleur? I assume that the standard 10 speed derailleur is use to a 11-36t configuration and as such has issues adapting to a 42t expander sprocket? I'm in to minds whether a 11speed deraileur would be more appropriate as they typically deal with a larger range of sprokets however, would that be incompatible with a 10 speed chain?

Another question, does anyone know how many links in my chain I would need? I know you need to get it right as the length difference will drastically change from 42t down to 11t... I've seen 114 links is pretty standard?

Many thanks!

Shimano XT M771 10 Speed MTB Cassette
Uberbike Expander Sprocket - 42T Purple
Shimano SLX M7000 11 Speed Rear Derailleur
Shimano SLX M7000 10 Speed Rear Shifter
Uberbike Narrow Wide Single Chainring - 36T Purple
Shimano XT HG95 SIL-TEC 10 Speed Chain

Comments

  • supersonic
    supersonic Posts: 82,708
    The Sunrace MS3 (11-42) is available for less than £40, nice piece of kit too - a little weighty, but the steel outer ring will last longer and you wont have a big a gap in the middle of your cassette (unless you remove the 17 and 19, and replace with an 18).

    Your front ring is dependent on how you like your gearing - need to try and compare to what you are using at the minute.

    11 speed Shimano mechs will not work with a 10 speed Shimano shifter (not without mods or fiddling with the cable entry, though a SRAM 9 or 11 may work quite well with a 10 speed Shimano shifter), you will need to stick to a 10 speed Shimano mech to be on the safe side. Medium cage XT or SLX work pretty well, though you will have to screw the B tension adjuster practically all the way in and, in some cases, even need a longer screw.

    I'd go for a KMC 10 speed chain, I find them more reliable.
  • Redkyte
    Redkyte Posts: 16
    supersonic wrote:
    Your front ring is dependent on how you like your gearing - need to try and compare to what you are using at the minute.

    At present I'm using the standard FSA Comet 22/30/40 that came stock. Around Swinley I never go into the 40t chain ring. I normally just stick to 2-6 sprocket on the rear and swap between the 22 and 30 chain ring. Does that allow you to make an informed guess at what's best for me?

    Thanks for your help!
  • supersonic
    supersonic Posts: 82,708
    If you are not using the 30/11 (smallest rear sprocket) gear then I see no need to go as high as a 36t up front. I'd probably go for a 32t - a slightly higher gear than normal, should you need it, and a good spread of lower gears.

    In fact I'd question even the need for an expander or the need for a wide range - the 32 ring/36 low gear of a standard 10 speed cassette is the equivalent gear of a 22 ring/25 rear sprocket combo on your current set up, which is probably a touch lower than what you use regularly anyway.

    Or maybe even a 30t, with 11-36.
  • supersonic
    supersonic Posts: 82,708
    I was assuming in your 2-6 meant the second smallest rear cog (2nd highest gear).
  • Redkyte
    Redkyte Posts: 16
    supersonic wrote:
    I was assuming in your 2-6 meant the second smallest rear cog (2nd highest gear).
    I meant 30-26-23-20-17-15t.

    From your previous quote I have been away doing some research into gear ratios and decided on 11-40t cassette and a 32t chainring and feel pretty confident! Seems this config will have slightly more pressure on ascents than my previous lowest gear, which sounds more suited to my style and I'll lose my two fastest gears which won't be a loss as I can't utilize these on trails anyway!

    I did check out the gear ratios on 11-36t cassette and a 32t chainring but felt like the low gear might be too heavy compared to the existing config.

    Now just to find a 10 speed Shimano mech!

    Thanks again :mrgreen:
  • The Rookie
    The Rookie Posts: 27,812
    A Suntour MX3 is lighter than an XT cassette plus expander, cheaper as well at £54 from Charlie the Bike Monger.

    I'm 'cheating' (I would prefer to call it being smart) on mine and using my 9 speed XTR mech with a 10 speed Tiagra shifter (Evil bay bargain). Will be getting a new cable and chain this weekend and fitting it - subject to SWMBO's alternate orders!
    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.
  • swod1
    swod1 Posts: 1,639
    Uberbike are now stocking the sunrace cassettes so maybe similar price.

    After Mondays ride I'm going to have a change and fit the mx3 11-42t and try it with my existing 34t n/w before trying an oval chain ring of a similar size.

    34t round ring to 34t oval or do you drop a size down?
  • cooldad
    cooldad Posts: 32,599
    Same gearing so stay the same.
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  • The Rookie
    The Rookie Posts: 27,812
    If anything with an oval you go a size up.
    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.
  • swod1
    swod1 Posts: 1,639
    The Rookie wrote:
    If anything with an oval you go a size up.

    Might just try a 34 oval as I think a 36 would be too much.