How to change the cranks on the Bikeerg

[johnlvs2run]

I want to change the cranks to 155mm so they won't keep bothering my sacrum and knees.
Has anyone here changed the cranks, and if so did you have any issues with connecting them?
I did send an inquiry to C2 but haven't received a response. Suggestions will be much appreciated.

[Cant Climb]

I thought about changing them to 165mm when i got mine. Kind of sort of would still like too, but i figured i could live with 170mm.

Have you found 155mm crank arms that fit......?

[johnlvs2run]

Ebay has 155mm cranks for ~$50, and 160 to 165mm cranks for half that or less.
A person from C2 said the cranks can't be changed or modified and to try crank shorteners.
However, those would make the span wider, so I have no interest to try them.
Here's a Youtube video <--- of someone who shortened Shimamo cranks from 170 to 150mm.
I asked to speak to someone at C2 who can help me make the change, but so far haven't gotten a response.

[Cant Climb]

Thanks for the info. Just going to stick with the 170's.

[johnlvs2run]

You're welcome. The same for me.
I see no reason to change this myself, when they purposely made it to not be changed.
I used to ride my regular bike on a trainer, so I might get rid of the Bikeerg and start doing that again.

[Cant Climb]

I did that for 15 years - bike on the trainer.

I'm much happier and comfortable on the BikeErg.
I like the feel the Flywheel 'resistance' gives my legs, seems like something extra in terms of development.
I also feel safer doing different types of drills on the BikeErg - hitting the leg muscles jut a little different.

[johnlvs2run]

I'm making some adjustments.
How do you feel safer on the Bikeerg, and what kinds of drills do you do?

[Cant Climb]

I'm a mountain biker. So there is not too much just constantly being in the same gear and in the same position for long, so I do sets on the Bikeerg to replicate that to a degree.

I'll do different saddle heights and positions on the Bikeerg like standing of course but then sitting high rpm then hands on the lowers low rpm. Plus do sets where pedaling and sort of in a crouch with quads fully engaged. Also sets standing with no hands - is quite fatiguing trying to maintain balance.

Have a few different combos of the above and do in groups of 4 or 5. Passes the time better too. I do plenty of regular optimal interval sets also and just single distance spins.

Try some intervals sitting up with hands off the bars. Blasts the quads a bit different.

[johnlvs2run]

You have some nice variations. I was riding half the time with elbows on pads, primarily to save my hands from the generator-handlebar buzz, but have removed the pads to reduce any stresses on my knees and back. I've got several layers of wraps on the bars, and sitting more upright gives me better angles and is faster.

I visited with the owners of a nice machine shop this week, and they quoted me a reasonable price for drilling the holes. I'll need to get the pedal taps though because they don't carry that size, which will make this a more expensive endeavor. They said the forged steel should be plenty strong enough (but no guarantees).

I'm planning to have the holes drilled and tapped at 145mm, and am looking forward to doing this in early to mid March.