Hi
I used to train on a TACX flow for a few years, and got a Kurt Kinetic R&R with the extra flywheel last week.
What is the benefit of the extra flywheel? I have the impression it only induce tire slip when I try to accelerate. If I do 5-10sec sprint it’s a real pain in the ass, it take forever to accelerate/slip/I have to change gears.
So, what is the benefit of a heavy flywheel exactly? I think I prefer without the extra weight (12pounds), since the system is much more reactive.
it just makes it more similar to real outside riding. you might find you can sustain more watts at a steady pace, and sprints might be more realistic.
however I do not think any trainer could even begin to handle a 5 second all out sprint. I never do that on a trainer.
I also have a KK R&R with the pro flywheel. For longer rides I like the pro flywheel a lot. Makes me focus on holding my cadence up because I don’t want to fall behind the flywheel and have to spin it back up. If I’m doing shorter intervals (Anything under 5 minutes generally) I take off the flywheel to eliminate slipping and so that my wheel speed drops between intervals.
The heavier flywheel helps to better maintain inertia so that the rear wheel does not spin down quite so quickly due to the higher levels of resistance and friction imposed on the tire by the roller, particularly useful during interval training. Not sure how the Kurt Kinetic adjusts tension for the roller/tire interface but seems to me that if your tire is slipping, then you need to adjust/increase the tension of the resistance roller on the tire.
I’m pretty sure Kurt Kinetic says to use the trainer without the extra flywheel for shorter intervals. I’m not sure why you would do sprint intervals on a trainer anyway. For anything shorter than 1 minute intervals (really anything under VO2 max, so under 3) I rely on racing, group rides or specific outdoor rides to get good training stimulus.
thanks for that
I LOVE to ride outside too, but it is -20 & snowing outside at the moment; so I don’t feel like taking my bike out…
I have the KK with the extra flywheel. Have had it for a year or two. It hasn’t improved my experience on the trainer. Hopefully you’ll have better results.
The goal isn’t specifically to make you faster. In a steady state effort the heavier flywheel should only require an infinitesimally greater amount of work to power because it has more surface area and thus more skin friction drag. The idea is that it allows your trainer to decelerate your wheel at a rate that more closely matches what you would experience in real-world riding.
It’ s all about inertia. Your heavier flywheel will be harder to acccelerate and decelerate (like outside). It is closer to the total inertia of a moving cyclist. I heared somewhere that a 40 lbs flywheel would be a close match to a moving adult on a bike.
Also, a heavier flywheel does help to pass the deadspots over a complete crank revolution.
+1 The heavier flywheel also makes the ride less straining on your knees if you do big gear lower RPM work on the trainer. The only trainer I have found where you can do short intervals well (pushing around 500 watts for under a minute) is the LeMond Revolution Trainer. Since it has a heavy flywheel, uses wind resistantce, has a large heavy base, and connects directly to the chain (no rear tire slip with roller), i can hammer away on mine like nobody’s business. The only thing it lacks is one more harder gear to simulate trying to ‘power through’ a rolling hill without dropping gears.
Agreed though that any trainer will only get you to 90% of what you can do outside.