Gen 5 crank compatibility

[2supple]

I would have assumed any cranks that work for Gen 4 Bosch will also work on the new Gen 5 motor, but Praxis updated their cranks specifically for Gen 5 (link below) and state that their Gen 4 cranks will NOT work on Gen 5. Does anyone know if this is just a Praxis thing? I'd like to get some XO T-type cranks that are listed to work with Bosch (Gen4), but would like to confirm they will fit Gen 5 before buying.

E-CRANKS | TYPE1

praxiscycles.com

 

[RoJo]

I was curious about the same thing so have sent them an email to ask if this is a Praxxis specific thing or whether all Gen4 cranks are not forward compatible.
Will report back...

 

[2supple]

Nice, look forward to hearing what you learn. If I manage to get more info in the meantime I’ll report back as well

 

[TheMirrorVision]

Based on Praxis’s website when comparing the cranks for old vs new Bosch they show that the Q-factor increased from 180mm on Gen4 to 188mm on Gen5 so it seems like older cranks may not be wide enough to clear the motor/frame.

 

[RoJo]

The Mirror Vision is exactly correct:

Thanks for reaching out!

Tthe new Bosch BDU38 Gen 5 motor has a wider motor shell, which requires a new crank arm shape for proper clearance. That’s why we’re developing our Type 2 cranks specifically for this model. Our current Type 1 arms won’t fit the new motor due to this difference in design even though they share the same ISIS interface.

 

[2supple]

Makes sense, thanks for sharing! Sounds like it might just be a praxis thing? It looks like the Vala is running T Type XO cranks as well as e13 cranks on the cheaper model.

I’m guessing we’re probably fine getting other cranks from Gen 4 to Gen 5?