Different casette on trainer and bike - gear adjustment issue

Hoping for some advice with whether changing the cassette on my Kickr Core to be the same as my bike will fix the issue of having to change the alignment on the bike whether it’s on the trainer or not.

I’m currently using the Sunrace CSRX1 11 Speed 11-28T cassette on the trainer and an Ultegra CS-R8000 11-30T on my bike. Without adjusting my gearing my bike won’t shift into the the 11T if on the trainer.

I wasn’t sure if putting the same Ultegra cassette on the trainer will fix this issue?


It might, but it probably won’t.
Just checking, but as the Core comes without a cassette, you didn’t install the spacer when putting the cassette on, did you? You don’t need that for the 11sp. I doubt you’d get the cassette secured with it, but if you did manage then it would push it in that direction.

The problem is you don’t need to be that far out before it’s a problem, so re-indexing is a fairly common requirement when changing between wheels as much as between a wheel and a trainer.

1 Like

Thanks @Jon, I didn’t use any spacers before fitting the cassette. I just assumed that the tolerances and spacing should have been the same to the inside of the cassette. Just a pain to keep changing the indexing.

Agreed. I actually got a killer deal on a decently specced road bike (105 gruppo) and made it my permanent trainer bike. The only time it saw pavement was when I gave it a quick test ride. Sooooo worth it.


I went through this decision making, as I had an old Giant TCR which would have been perfect. Decided to sell it and use the extra cash to buy a better bike. Also when I looked at the cost of buying another suitable bike for the trainer, plus the costs of maintenance, cost of trainer etc it’s not far from the cost of the Kickr bike. If I were to start again, I’m really not sure what route I would take.


Yeah, I’m working on same. I have the Snap, so swap rear wheels between the road and trainer. And unfortunately I run Ultegra 10 on the road, but Ultegra 11 on the trainer…because that’s what I have. I don’t mess with my indexing, I just accept that there are a couple of cogs on the back that are hit-or-miss when I’m in SYSTM.

Semper Gumby.

Side note @Glen.Coutts, caught the replay of the ToS 2022 announcement Youtube and saw your comments/avatar. THAT BEARD!!! Legend. That was you, right?


1 Like

My whole setup is still cheaper than the Kickr bike. Though it’s pretty close. Maybe I will trade up whenever the next gen Kickr bike is released.

That was me and that was my beloved beard. Alas, no more. My wife tolerated it for about a year but absolutely hated it, lol. I’ve been clean shaven for several years now :disappointed: but still married :blush:

1 Like

I got myself an alloy bike with 105 group set that will never see the road to use as my donkey for the trainer.
I’m sure you could find your donkey 2nd hand that will not affect the budget?

1 Like

possibly, maybe, but even 2nd hand bikes are fetching a pretty premium these days and parts are also pretty hard to find atm. I was very lucky to get an incredible deal on a new alloy 105 bike from my LBS.

With no urgency, one can find a donkey deal to be had. It’s literally a frame and an operating group set one is looking for. The very few workouts one uses Level mode, it doesn’t need to be great.
But yeah, sellers are seeing the value of 2nd hand bikes in the current market.

1 Like

Shimming cassettes on several wheels for a rider was a common job back at the bike shop. The purpose was to enable to swap wheels without having to adjust the rear derailleur. Most often these were triathletes who would swap between training wheels and race-day aero wheels. Myself, I just knew one wheel would take a few clicks more or less cable tension than the other (much quicker/easier to accomplish with mechanical than electronic).


I recently purchased a couple of Tiagra cassettes and a chain so I can now move my winter bike between trainer and wheel seamlessly. Works a treat. 30 seconds re index is all it takes and then I have my winter /trainer bike ready.

It’s 105 and I already have too many bikes to justify one to dedicate to the trainer, so this setup works for me. I even leave the mudguards attached.


And by “very few” you of course meant “as often as possible”?



1 Like

Never thought about that, will take the trainer in to the shop with the bike’s next service.

Well two shops didn’t seem keen on shimming for me, I think it’s the fact that taking the bike on/off a trainer etc and the floor space was an issue.

I looked into buying a second trainer only bike, and the prices for something which I consider a good trainer bike are stupidly priced.

Solved the issue, through a very expensive route, ordered the Kickr Bike, I will have a heart attack if a Gen 2 is released at Eurobike.


Gads, you couldn’t find a decent trainer bike for cheaper than the Kickr??? Guess it might take me longer than I’d hoped to find an indoor bike!

(though I would grant that our definition of “good” could be wildly different!)


1 Like

In hindsight I should have spent more time on the above comment.

In Australia, at the moment a typical old bike is around $1500 (worth circa ~$800 pre Covid), add the cost of a Kickr Climb ($1000) and the resale value from my existing Kickr ($1000). It comes to $3500, without adding any ongoing maintenance/repairs for running a fixed bike.

The Kickr bike had 15% off, so it was $5100. They are currently selling second hand for ~$4500-5000. So the way I sold it to myself, was that it was only really about $1500, and almost the same price as a second hand one with warranty and delivery. For essentially (hopefully) a maintenance free brand new training bike and stops the wear on my road bike.


I’m planning to win the Kickr Bike this year. Then I can sell my current set up and maybe get another outdoor bike :slight_smile: