I’ve been using TR the last couple of years with a smart bike. Recently my smart bike broke down and it can’t be fixed. For now I’m coping with a replacement smart bike, which can only serve as a temporary solution.
So I’m thinking about buying a direct drive smart trainer (Wahoo Kickr Core probably). I’ve got a single front chainring MTB with 26" wheels lying around, which I don’t use anymore (outdoor I only use my road bike or gravel bike).
Would it be a good idea to use that MTB with a direct drive smart trainer? Just curious about how the TR-workouts would feel on such a setup. Would ERG-mode feel the same? Would the workouts feel/be as efficient as on a ‘normal’ road bike?
The wheelsize doesn’t matter for a direct-drive trainer. Your smartbike didn’t have any wheels at all.
What matters more is if you can get to a similar geometry with your old MTB to your roadbike.
With regards to how erg mode feels: that has to do with the trainer, not the bike.
One other limitation that I can think off is that when you are not in erg mode, the bike will likely have pretty low gears, and you might need to compensate somehow. The most likely place where that might be a problem is Zwift racing.
Inertia matters, the smaller chainring on the MTB, will reduce the flywheel speed. Erg mode is more responsive at low flywheel speeds, one of the consequences of this is that if you are riding at a low cadence it can feel draggy/choppy and harder than if you were using a bigger chainring.
I think it’ll work fine if you can get a reasonably close position to your road bike or are just generally comfortable on the MTB.
I ride road and gravel, but repurposed an old Trek hardtail as my dedicated trainer bike on my Wahoo Kickr Core. I could get the seat in the right spot relative to the bottom bracket, and I ended up using bullhorn bars that put my hands in a similar postion to the hoods on my road bike. This allowed me to keep the MTB shifter without having to get brifters and a new derailleur.
I’ve been loving this set up and don’t have to worry about fouling up my good bikes with salt and sweat!!
As @splash said, wheel size won’t matter for your direct-drive trainer!
It should work since you’re in a pinch. As mentioned above, the geometry will be quite different, so it may not be ideal to use long-term or for longer-duration rides. If the fit is too far off/too uncomfortable, it could lead to injury.
In that sense, it won’t feel quite the same, but it may also feel different due to the impact your MTB gears may have on your trainer’s flywheel speed. The video @JonGreengrass linked does a great job explaining how gear selection can affect the feel of your smart trainer.
In short, it will work, but it won’t feel the same as your road bike/smart bike. I’d say it’s worth giving it a shot and seeing how it goes, though! If you start to feel “off” because of the difference in the bike fit/position, you can always pull the plug on a workout/ride to keep yourself feeling healthy and uninjured.
I had the same setup with a 26” spot mtb and used a 34 chainring. Only use erg mode so this worked well for me especially since I mostly ride mtb. If it’s an “old” bike I would make sure your chain and bottom bracket are tuned up to optimize performance.
One other thing to consider is the lack of hand positions……you basically have one position with a flat bar. You could consider putting on bar ends or the inner bar ends that sit inside the brake levers.
!