couldwheels

I have inseam length of 83 cm and crank calculators tell me I should use 170 mm crank.

I have 170 mm crank length on my real bike (sounds good right??). But on my stationary indoor bike trainer, the crank length is only 145 mm.

Everything else fit-wise is identical and I spend roughly the same amount of time on the trainer as on the real bike per week. However, it seems I can hold more intense efforts (~160 bpm heart rate) for longer periods on the trainer. The same effort on the real bike, I can feel my quads getting sore sooner. The same effort on the trainer while similar intensity in terms of breathing and heart rate, feels significantly easier because my legs feel fresh for longer.

I've done some research and read that shorter crank does make things feel easier and less fatigue for the leg muscles.

However, I still would like to adapt to the 170mm crank of my real bike and I suspect my short crank trainer won't help much. Increasing the crank length of my trainer is not possible. It's the dirt cheap variety with single piece crank like in BMX but totally incompatible. I can't install 150 mm crank on my real bike either because 150 mm cranks are simply not available where I live, even 160 mm crank are very hard to come by. But I doubt the 160 will make much difference, given my proven better performance with even shorter crank.

I've wondered if lowering the saddle on the trainer could stimulate similar effort to my real bike with 170 mm crank??