Do I need to adjust derailleur for turbo?

p3eps
p3eps Posts: 7
in Indoor training and turbo forum
New to turbo training, and have just taken delivery of a Wahoo Kickr.

I’m in Scotland, and have dark evenings for the next 6 months now. 2 young kids... so cycling in the garage is better than nothing! Looking to do some Zwift training plans to build up my fitness for the weekends.

I’m a mountain biker, and have my old bike (2017 Stumpjumper) that’s not used much... which I intend using.
It has an SRAM Eagle X01 groupset on it.

The Kickr came with a Shimano freehub, so I bought the Eagle NX, as it’s Shimano rather than XD compatible.
When putting the bike on, the gears are all out of sync.
Gears 1/2/3/4 seem almost on, and then it starts missing when I shift and only ever gets to 11 and won’t reach 12!
I’m sure a high / low adjust would fix it.

Is it normal for the turbo trainer to need to gears adjusted to work on the trainer... or have I set something up wrong? My Stumpy is one of the best shifting bikes I’ve had, so I really don’t want to adjust it!
I can’t see the x01 and NX cassettes being spaced that differently?

Comments

  • davidof
    davidof Posts: 3,036
    You've done something wrong.
    BASI Nordic Ski Instructor
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  • thegreatdivide
    thegreatdivide Posts: 5,803
    I’ve had to re index the rear mech on the bike I’ve just stuck on my new Neo 2T. Dead easy job if you know how to do it.
  • dannbodge
    dannbodge Posts: 1,152
    I've never had to re-index my bikes on a turbo (two bikes on Tacx flux and 3 onto a Neo 1)
  • p3eps
    p3eps Posts: 7
    Ok - so maybe have a look at the alignment of the bike on the Kickr? It has a thru-axle, and I’m sure I’ve used the right spacers.

    It’s not just a little bit out - so there must be something wrong?
  • whyamihere
    whyamihere Posts: 7,700
    It's not really unusual for indexing to be necessary when putting a bike on a direct drive turbo, or changing to a different wheel. There's no real standard for the position of the cassette relative to the frame. You can get lucky, and most road bikes tend to be close enough to work, but it's not a guarantee at all. If the first few gears work then it's not far off, it will just need a bit of tweaking.
  • slowmart
    slowmart Posts: 4,480
    Re index your gears and you'll be fine. If in doubt look at the alignment of the rear mech to the teeth on the cassette and you'll see what you need to do to align the rear mech.

    There are plenty of tutorials on youtube and its an easy 5 minute fix.
    “Give a man a fish and feed him for a day. Teach a man to fish and feed him for a lifetime. Teach a man to cycle and he will realize fishing is stupid and boring”

    Desmond Tutu
  • p3eps
    p3eps Posts: 7
    Thanks... I just wondered if the first few are on because the NX cassette comes with the first 4 gears as 1 piece, and then they are separate cogs after that. Perhaps I used the wrong spacers for the rest or something?

    Away for a couple of nights for the kids holidays, but will have a look when I’m back.
    I’ve re-indexed many bikes in my time... I’d just rather not have to do it each time I swap the bike from trainer to wheel!

    It’ll probably be on the trainer most of the next few months though, so it’s not really a huge hardship. The bike is probably used more by friends who borrow it if they want to come riding with me.

    I just assumed with both cassettes being SRAM Eagle, that it’d simply be a case of removing the wheel and ‘plonking’ it on the trainer and it’d be good to go.

    I read something about just make sure 1 gear is perfect, and turn ERG mode on rather than shifting at all?
    I do find the Eagle cassette great for big hills... but not so good for road riding, as I can pedal too fast for it quite easily on flat / downhill.

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