Frame flexing while clamping to direct drive trainer?

trainer

#1

I’m using a (carbon) SuperSix Evo Frame on an Elite Direto direct drive trainer.

Something I noticed recently: When I tighten the skewers on the rear dropouts, they slightly flex inwards (maybe 1mm). I rechecked the manual and the trainer is set up exactly as described. Using the exact same model of 11 speed cassette as on my rear wheel, so no spacers.

Does anyone observe something similar? I used it like this for a couple dozen hours already without obvious damage - but I feel like this is not desirable? On my rear wheel, there is no flex while closing the skewer.


#2

Petty typical. Frames are designed to a nominal axle width, but there are tolerances and so they can be a bit wider or narrower. That minor amount of flex is perfectly acceptable.

Saying that, everyine should always make certain they know the nominal axle width of their frame, and have the trainer setup to match that standard.


#3

I have exactly the same issue with my Cannondale Synapse carbon frame flexing when I put on my Wahoo KICKR. The flex is to a fairly high level and puts all my gears out, meaning I have to tweak gear cables etc every time I put on and take off the turbo.

I’d welcome any suggestions on what I could do differently to make this an easier / smoother approach with less faffing.


#4

Do you have a rim or disc brake model?

If disc, is it quick release or thru axle?


#5

Hi Chad (definitely not Brad :sunglasses: )

It’s the disc brake model with a quick release lever. The KICKR has an adapter that allows you to move it between quick release and thru axle type bikes. I have tried flipping this round. It actually gives less flex when I put it in the thru axle way round, but still not spot on.

Thanks


#6

Thank you for the insight and peace of mind!

The trainer is set up to the nominal axle width of the frame (rim brake model). There definitely are no 5mm of play, more like 1mm or even less.


#7

Ok, that means you have a bike with a 135mm wide rear axle. This is the same as MTB.

The Kickr ships in the 130mm configuration, so you would have needed to swap the spacers to fit the slightly wider axle.

So when you swapped it (as mentioned above) it was probably at the proper 135mm spacing for your bike.

Either way, confirm the spacer setting and make sure you are in the widest QR axle configuration.

Then we can diagnose shifting after that.