Ebike on smart turbo trainer.

[Jesus H Christ]

I want to attach an ebike to a direct drive turbo trainer (the type where the back wheel is removed and a cassette drives directly into the turbo).

The bike is powered by a Bosch Performanceline motor. When attached to the turbo, the rear wheel will be removed so the spoke magnet won’t be present to send a signal to the motor sensor pickup on the chain stay.

My questions:

Does not having a magnet passing the pickup matter?

Is there a way to by-pass / fool the sensor when the bike is on the turbo?

This might seem like a strange thing to be asking, but I’m trying to help a friend who has a disability and wants to ride her ebike on social Zwift rides / turn her legs without going out risking injury on the ice. Riding the bike unpowered on the turbo would be too much effort for her. It has to be low motor power on a turbo.

Thanks.

 

[Raboa]

Could you buy a small round magnet or remove the spoke magnet and stick it on a spinning piece of the turbo trainer. Buy a seperate Bosch spoke magnet and cut it at the end so it is just the magnet, no spoke thread / attachment. I don't know if yo can remove the motor sensor pickup on the chain stay.

 

[vfr400]

The magnet has to be on the wheel or your Bosch won't work unless it's a mk1 with original software.

What about getting a turbo trainer with a roller. That's what I had, and it was really good. Tacx.

Why do you need the motor? You can normally adjust the resistance, so if you use the motor, you'd have to turn the resistance up and the pedal effort would be the same.

 

[Raboa]

These two videos may help explain how to use a normal (wheel attached to bike) on Swift.

 

[soundwave]

 

[Gubbins]

I have a bkool smart trainer which my ebike fits like any other bike. It can be used without any power but if I ,70+ years, want to video ride up any hills then power is needed just as it would on the road. The smart resistance created by the trainer when going up hill is impressive to say the least.

 

[jokskot]

These two videos may help explain how to use a normal (wheel attached to bike) on Swift.

Is there a way to set this up for a rear wheel motor?
I'm thinking the axle mounts would interfere with the power cable entry port.

 

[vfr400]

Is there a way to set this up for a rear wheel motor?
I'm thinking the axle mounts would interfere with the power cable entry port.

Not really. I got one to clamp tight enough to be able to measure the motor output, but it wasn't secure enough to use it as a trainer. If you're handy with the spanners, you could make custom axle clamps out of suitably sized sockets welded to the mechanism after cutting off then old clamps. You need clearance for the motor cable if your cablem comes out of the axle, and if the cable doesn't have the slot at the end, it's a no go.

 

[Gubbins]

Mine is a Giant road ebike which uses a normal QR spindle so just needed to swap it with the one that came with the trainer.

 

[ChrisGla]

Sorry to raise thread again, but for anyone using an ebike with smart trainer do you know if the motor resistance greatly impacts power readings ( motor off)

I have Giant road-e and managed a couple of thousand miles over summer, getting pretty fit and lost over 3 stone!

I‘m going to try a smart trainer over winter and don’t want to spend money/ space on a cheap bike yet, interested in getting power readings to gauge better how I’m coming on.

Looking at either an Elite Suito or maybe a Saris H3 as I quite like the sound of Zwift and other virtual riding apps- think I’ll get into them a bit more than just spinning.

 

[Gubbins]

Sorry to raise thread again, but for anyone using an ebike with smart trainer do you know if the motor resistance greatly impacts power readings ( motor off)

I have Giant road-e and managed a couple of thousand miles over summer, getting pretty fit and lost over 3 stone!

I‘m going to try a smart trainer over winter and don’t want to spend money/ space on a cheap bike yet, interested in getting power readings to gauge better how I’m coming on.

Looking at either an Elite Suito or maybe a Saris H3 as I quite like the sound of Zwift and other virtual riding apps- think I’ll get into them a bit more than just spinning.

I used my Giant road e on a bkool smart trainer snd to be honest it wasn't much different to using any other bike. Bkool offers a lit of video rides.

 

[ChrisGla]

Thanks! Got it all setup today and tried RGT as it was free, all seems fine. That said, without the motor I now remember how hard hills are!

@Gubbins , I noticed you’d played about with chainrings, I‘m thinking of putting a single side 4iii/ stages LH crank power meter on but it mentions here that Giant use offset cranks as well:-

Things You Didn't Know Your Electric Bike Could Do Guide | Giant Bicycles UK

Considering all the technology going into the latest electric bikes, it can be hard to keep up with all the new developments. Therefore, we’ve put together all ...

www.giant-bicycles.com

Have you tried 105 or similar cranks, or came across anyone doing this?

 

[Gubbins]

Thanks! Got it all setup today and tried RGT as it was free, all seems fine. That said, without the motor I now remember how hard hills are!

@Gubbins , I noticed you’d played about with chainrings, I‘m thinking of putting a single side 4iii/ stages LH crank power meter on but it mentions here that Giant use offset cranks as well:-

Things You Didn't Know Your Electric Bike Could Do Guide | Giant Bicycles UK

Considering all the technology going into the latest electric bikes, it can be hard to keep up with all the new developments. Therefore, we’ve put together all ...

www.giant-bicycles.com

Have you tried 105 or similar cranks, or came across anyone doing this?

I just changed the double rings for one narrow wide ring and it is absolutely fine. The lowest gear allows climbing the steepest of hills and the highest allows 25+mph.