I won’t be trying the standing start sprints again anytime soon tbh, both for pragmatic reasons and also because I am headed into an off season break.
I’ll double check with the Garmin guys though if this is something that fell outside of the normal expectations or if they think I got a bad belt.
The rolling sprints I did were totally fine btw, so I have no concerns there.
Before I sent my bike back I had a belt issue as well. In high torque situations I could make the belt slip and squeal on the pulleys. Fortunately, nothing broke.
Stevemz,
Would you mind snapping some photos of the belt replacement? I’m curious to see what it looks like, in there. You’re the first I heard of, to break the belt. I haven’t seen anyone post the internals, yet.
Unless you’ve already done it and buttoned it up, then don’t worry about it.
Thanks!
(photo from instructions tacx sent me, but mine looks exactly the same inside)
Is that an automatic belt tensioner? It looks like it, with a spring and a pivot bolt. I’d imagine that there would be replacement parts for the spring (or a part number), when it wears and the belt starts to slip.
I’ve always wondered why Wahoo doesn’t use tensioners that you would find in a car with a serpentine belt, that has wear indicators and automatically tension correctly, vs a screw and some mystic art to properly tension the belt.
On my Kickr1, I had managed to have support tell me the torque specs to tighten to, and to verify that audibly, to measure the note when plucked. The tensioner on the Tacx bike is a definite welcomed sight to see.
A direct-drive trainer with a step-down belt-pulley system makes use of the bike’s gearing to drop the torque down, so the belt system faces lower torque values (and higher rpms). The Tacx system is from the “chainring”, so faces a higher torque. This said, step-down belt-pulley systems on trainers have not proven to be too great so far - both Wahoo and Tacx have seen multiple reliability issues. It appears the design decisions may have erred a little too far to the cost management side.
Could you share those Kickr belt specifications? I too have found the guidance very vague regarding belt tension.
I’m guessing a bit here, but I’d imagine that the profile of the belt will play a role in whether a tensioner is possible or not.
I know that for many belts, you don’t want to fold them past a specific point (i.e. the Gates belts) and I’m not sure how this plays into a toothed versus v-belt 
I may have misspoke. It was years ago, and finding it in my emails aren’t easy to search.
I did find that I was told to use https://apps.apple.com/us/app/carbon-drive-bicycle-calculator/id438346486
and then tune to 100Hz.
That is pluck the belt, and adjust the tension until you reach 100Hz. Going by feel, I do recall I was too tight, and had to loosen it.
I will continue to look for the torque wrench values, I’m sure I saw that one come through too, but I can’t find it at the moment.
Even with the tensioner I was able to get my belt to slip and make squealing noises on the pulleys. I would think that means that the belt was too loose for the torque that I developed by standing up. It’s not like I am a huge powerhouse or something. The power was set for 350W and I was just accelerating from a stop. TR kicked the resistance in and I stood up for 5 or 10 seconds. At least it didn’t break.
Thanks, this is very helpful. I don’t recall the tension bolt requiring much torque, so I don’t know how precisely I could measure the torque.
After almost a year since I ordered the bike, my Tacx Neo Bike arrived today. Its one heavy unit!
Unfortunately I have the same problem with my thighs rubbing against both the saddle ‘slider’ unit and the seatpost itself in the same manner you describe.
The unit also had a ‘pinging’ sound every few seconds in the resistance unit at some RPMs.
Whilst this second issue may resolve itself, or under warranty, the first is a fundamental design issue (at least in relation to my body type), and so sadly I’ve already sent a note over to the shop for a return.
Definitely a ‘try before you buy’ if possible.
Matthew
Matthew, or anyone else with a unit and a ruler – how wide is the seat post? Hoping to compare to my current setup, or perhaps mock it up (cardboard?) and see if it’s likely to be problematic.
Thanks!
Roughly 6cm wide total, with 4cm in the center and 1cm taper on each side
Thanks, Steve. But to confirm: mm, or cm? I meant the area(s) where everybody’s thighs are rubbing on the bike.
Yes sorry, cm!
Thats helpful. My SO has some thigh touch but it looks like it would actually be worse with the Wahoo bike.
For those with the bike, is it easy enough to clip on aerobars? Looking at the images I can find online, it looks like it should be - although of course it will need to be set quite wide to clear the centre console.
Thanks
No problem with clip on bars fitting on the handlebars. However the display is really in the way and makes the bars quite far apart. Not that it matters for aero reasons . However, I wanted to have the same position as on my actual bike and that didn’t work.
