Mountain Bike Reviews Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
225 Posts
Discussion Starter · #1 · (Edited)
Well, i've got a modern geo trail bike (steeper seat angle)
i'm 5'10" (1,78m) and i have 33,5 inseam (85cm) i don't know femour/tibia ratio, but apart having slight longer legs than torso, the legs seems proportional.

My bike (L size) comes with 175mm cranks. Really enjoy the new steeper seat angle. And being more over the bb, i felt faster and stronger in every pedaling aspect. Also some minor knee pain gone away when i followed this steeper angle compared to my previous mtb. However the plumb method show that the knee is far forward than how the old theory should be. But who cares as i'm stronger, faster and without pain.

After some readings about everyone benefit from shorter cranks... i bought a 170mm... i've done many many back to back testing in the last year, saddle adjustments (from 5mm higher and 5mm to the rear), ecc.
I found 170mm cranks could have some advantages (but pedal strikes are also timing, technique and maybe too much sag. i personally don't have many strikes problems on 175, yes 170 help a little) . I keep at the end of the ride a slight higher cadence(but increase slightly medium hearth rate)
The gearing seems a little too hard, but as i have a 30t -10-51 cassette, i have always what i need.
They seem to initial spin and accelerate faster(and i like it), but then when uphill continue i seem to struggle to "mantain torque"...i try too keep one gear lighter, try to keep a higher cadence than what i "feel" normal to me...and hearth-rate raise...
For complete the scenario, i must say i have spd cleats quite rearwards, and after 3year of oval absoluteblack chainring, i went back last year to round as i felt i was pedaling too "piston style"... i still love oval chainring and his advantages, but maybe more suited to flat pedals..

My real doubt is that with 170mm it seems to me that" i can't express my potential".
In the first rides with 170 i also feel some minor knee pain(maybe it's muscle adaptation to a shorter lever?)

For me and for my body, i feel more comfortable and stronger with 175... i'm wrong?
Almost everyone reading on internet(even tall people) have only advantages going shorter... i'm a little confused...maybe it's my body that like better slightly slower cadence so the 175 seems better to me? I force myself to keep a higher cadence with 170... but in the end i feel more tired but not faster...

Someone says they ride 170 and 175 cranks and feel almost no difference... i feel it really different also if only 5mm.
 

·
Candlestick Maker
Joined
·
3,799 Posts
Someone says they ride 170 and 175 cranks and feel almost no difference... i feel it really different also if only 5mm.
I ride both and feel no difference. 5'9" 31" inseam. Your post shows you to be WAY more analytical than me. I switch between about 5 bikes with different seat heights, pedals, geometries, crank lengths, etc. It takes me 65.4 seconds to adapt when switching from one to another. That being said, I have my race bike set up the way I like and try not to touch it anywhere close to an upcoming event. And, I've gravitated towards all 175's over time. I didn't find the 170's to be of any particular advantage. Pedal strikes for me tend to come when I've got my sag set incorrectly.
 

·
always licking the glass
Joined
·
4,428 Posts
I’m with you on oval chainrings as I don’t like them, but I also ride flats.

I went from 160 to 155mm cranks recently, and I will take you I’ve been on them about six weeks and I’m still getting used to them. The more I ride them, the more I like them. I have short femurs, and I’m 5’5ish.

It really depends on each individual, but I found anytime I’ve done crank length changes in either direction, I really need to get used to them for a few months to really judge.
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top