Wheel-on trainer vs. thru axle

The problem I face is simple: I have a Tacx wheel-on trainer and my new bike has a thru axle.

The solutions are equally simple:

  1. You bought an expensive bike, you buy a direct drive trainer and shut up.
  2. You use your old bike on the trainer and the new one on the road.
  3. You buy a replacement trainer axle.
  4. ?

Ad. 1. Right now it seems almost impossible to buy a trainer anywhere. No Tacx, no Elite, a Kickr perhaps, but I don’t want to spend all that money.

Ad. 2. I think I’d rather sell my bike for someone else to enjoy. I don’t think I NEED two carbon road bikes, even though they are different.

Ad. 3. I managed to buy the Elite Thru-axle. It fits the bike, but (probably owing to the clamp) it is to wide for the Tacx trainer, so I’m sending it back to the shop. The correct Tacx adapter is not available at any shop (online and offline I know, and I got info that the country distributor has none left). Shipping a Robert Axle Project axle to Europe is waaaaay too expensive and no one knows how long it would take.

And then comes this guy:

You think this would actually be safe? I’m not an engineer but if the diameter of the axle (bolt) is smaller than the internal diameter of the hub opening and the frame opening, then it will not hold everything centered.

What do you think? I’m kind of reluctant to risk a rather expensive frame and trying to bodge it… or maybe its a hack?

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I like option 2. Almost never get good value selling a secondhand bike, and it’s often useful having a second bike around. Whether that’s having a spare bike for friends, having one bike setup with durable training tires and the other with race tires, one as a spare when the other is being serviced, etc.

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I didn’t watch the whole video but it looks like those bolts just slide into the thru axle so if the wheel is centered and the thru-axle tight, I don’t understand how the bolts wouldn’t stay centered once the trainer is clamped down tight. The bolts just look they serve the same purpose as using an old steel skewer with your trainer; something for the trainer to hold onto so you don’t damage the frame.

I like option 2. If I had a bike on the trainer at all times, I’m more likely to ride the trainer and thus put in more time on the bike.

If you really don’t want to keep two bikes then I’d get the proper Tacx adapter part. I don’t like the way the DIY adaptor doesn’t fit perfectly tight into the thru-axel and it isn’t clamped solidly together like quick release.

I did not notice that at first. He put the bolts into the thru axle, not directly into the frame. So that answers my question how it stays together. Still a no-go for me as I would need a different axle as mine has a handle…

So by any chance does someone know where you can get the Tacx T1710 axle in Europe?

I’m not sure I understand your quandary. Facing a problem where one of the solution results in one more bike, and hesitating? I would seriously question my priorities in your place.

Hi, not sure which model you have but I have a Tacx Vortex and the T1711 E-Thru adapter. Works fine. In stock at Rose Bikes which is where I got mine from.

I checked and I would need the T1710 axle for my bike, but you can’t buy it anywhere right now. The axle I have and doesn’t work is from Elite (it’s a completely different design than Tacx axle and fits my bike but not my trainer). :slight_smile:

I currently own a Tacx Bushido, and recently purchased a Chapter 2 RERE which comes with thru axle. I purchase a thru axle from https://robertaxleproject.com/ for the trainer and it works great. no issues here. Highly recommend giving them a shot or a call.

That is a really smart design…

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i used one of these but it was on an Elite trainer…


it was a tight fit but it worked until i killed my trainer and now have a direct drive trainer that has no issues fitting the bike on.

@Jarenty having watched the video… The bike doesn’t need to be held centrally in a wheel on trainer it just needs to be held secure in the trainer. If the bolts are smaller than the hole for the through axle the distance between the tyre and the roller of the trainer will be fractionally smaller. Once it’s in place there is only one contact point between tyre and trainer so the bolt does not need to be central. You could always add a further plastic sleeve to pack it out to the right size.

Yeah but if there is play in the axle (in the vertical plane) it means that the bike will only be stable when you sit on the saddle (and preferrably not pedal) because then you would press the bike down… but when pedalling and sprinting?

This means losing grip between tyre and roller at best, and damaged opening and thread in the frame at worst.

I think, as someone pointed it out already, the bolts are inserted into the hole IN THE THRU-AXLE not the frame and that makes it work. Unfortunately it won’t work with my axle as it has a hole on one side only.

Are you sure it wont fit in your trainer?

Mine was too wide initially, but I unscrewed the drive side support and took out the blue spacer, then it fit just fine :slight_smile:

I may try that but I looked at dimensional drawings of Tacx axles and the nuts that fit outside the frame and are used to attach the trainer are just 10mm “high” i.e. quite flat.

The Elite axle is of a different design and it has a skewer. The parts outside the frame are about 25 mm high each. That means the entire axle assembly is 30 mm wider (1 1/8 inches). The openings in the trainer are too shallow to accept that.

Personally I wouldn’t worry about that, I wouldn’t want the trainer to clamp directly onto my frame anyway. I’d rather I just clamp the axle and not have the possibility of damaging my frame.

I tried what @jzhowie suggested. Removing the blue part from the trainer to make more room for the axle. It still wasn’t wide enough though.

Anyway, I sent back the Elite axle and I can now safely say that it is not compatible with Tacx trainers.

But wait, there’s more. I fund the original Tacx axle in my country (well, the national distributor found it), but I’m still taking all the credit for myself for actually contacting them.

I should be ketting the part any day now, so keep your fingers crossed :smiley:

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Hi sorry to revive this thread, but I’m in a similar situation. I have also ordered the elite axle hoping it works. Based on sigma sports page

it seems like it works for a tacx vortex, so I was wondering which tacx trainer you have?

No probelm. I have a Tacx Flow.

Depending on what shop you buy this axle from, it either says nothing or that this adapter only works with Elite trainers (I found out too late).

I am assuming that all TAXC wheel-on trainers have the same frame (why wouldn’t they). In my case, the axle was too wide and I could not “lock” the trainer. The nuts on both ends are too long. Compare that with the dedicated Taxc axle, you’ll see the difference.

Hey all, somewhat similar question…

I have a TACX Flux S direct drive trainer, and I’m switching from a rim brake bike to a disc brake bike. What all do I need to be able to use my disc brake bike on my TACX flux S?