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ferrousness

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Discussion starter · #1 ·
Gots' me a dilemma... Got this 29er and...

I've been toying around with the idea of 180mm cranks for some time and I've got an opportunity to convert over to the larger crank. I am currently running a 32 front and 9 speed rear with a 175. My inseam is 33 in. and I'm 5' 11". Everyone, even singlespeeders, keep telling me I'm crazy for even thinking of the 180. "That's for only super tall guys!"

My question is this: what do I gain or stand to lose by going larger? I tend to be a masher and climber rather than a high rpm type of guy. Definitely NOT a roadie!

Your insight would help a bunch...
 
#2 ·
Look at it this way : if your legs were 1" shorter, would you still be able to handle 175's?
If the answer is yes (much shorter riders use 175's), you can handle 180's as well.
For me, longer cranks allow me to transfer more power to the rear wheel. Short cranks lock me up, like a door with too short a handle, hard to open.
IMO a grown man has to go quite a bit longer than 180 to have the cons outweigh the pro's. A transition period is to be taken into account though.
 
#3 ·
Here's the calculatio

Cloxxki said:
Look at it this way : if your legs were 1" shorter, would you still be able to handle 175's?
If the answer is yes (much shorter riders use 175's), you can handle 180's as well.
For me, longer cranks allow me to transfer more power to the rear wheel. Short cranks lock me up, like a door with too short a handle, hard to open.
IMO a grown man has to go quite a bit longer than 180 to have the cons outweigh the pro's. A transition period is to be taken into account though.
Click to expand...
This is the calculation according to Leonard Zinn's website for calculating a riders optimum crank length: inseam in mm x .216 or [more conservatively] .21. Hope this helps.

Hey Cloxxi, how long did it take you to adapt to the longer length cranks? I ask because I have a set of 190mm's coming.
 
#4 ·
From 175's to 180's back in the day was just right away.
A guy I know who went from 175 to 195 was in agony and dispair for 4 weeks, then hit heaven right on.
From 175/180 to 185, it took me a daily commute (well, I actually had 180 left, 185 right and didn't realize) for a couple weeks to feel 100% at home.
I'm trying 195mm again now from time to time, and having ridden it before and 185's freqently now makes it an easier transition. The first rides last year I was really looking for a seat position and gear. 2 weeks ago it was a re-acqaintance, and not too bad at all. Just loads of low-rpm torque. using muscles I never really trained, but that's good.
 
#5 ·
I'd say save your money, it won't matter. Or if you want them, get them, it'll be easy to adjust. In fact, there will be no adjustment period at all.

There is something about getting what you want so it might be worth it. I want 180's on my mtb's.....but 175's would be just fine.

But there still won't be any adjustment period. You'll amaze your friends!
 
#6 ·
I have a 1 x 9 with the same setup and am in the process of changing over to a set of Middleburn 180's--but will be running a 30t front ring as well. For me it was a good way to kill two birds with one stone, I get slightly better leverage on climbs and the gearing I get from the 30t will be perfect for the hills where I live.

I have a 35" inseam, BTW.
 
#7 ·
If you have 175's or 180;s and are upgrading to 190's, you'll be lowering you seat accordingly.
However, the top of the pedal stroke reaches higher over the BB. So there, the long cranks make the seat feel way lower, while extended the pegs will briefly feel "at home". This requires a transition period, depending on the length diference.
Princess on the Pea will need to adjust to 2.5mm on the road bike or 5mm on the MTB, for me it's hard to tell the difference at all times. Swapping bikes all the time during a ride, I did manage to zoom into the cranklength difference between 175 and 180. Both me and the other rider started to hate 175 through the test.
 
Discussion starter · #8 ·
Well they're on and BABY!

Words cannot express how wrong my bike was until I put these 180 cranks on!

It's almost like a secret I don't want to share. Those big circles I've been trying to spin for years are finally crystal clear. I've never felt such a complete rotation before. Climbing leverage feels natural and the biggest advantage I've noticed is the stability. The bike is like a steamroller.

Thanks again for leading me down the path of enlightenment... Best thing I've done for myself since the 29" wheel.
 
#9 ·
Wow, congrats! Is it a boy or a girl? :)

You clearly are more sensitive to crank length than I am, or simply a pedaling master. Good to hear it works out so well for you.

Last night I rode 195's again, where I daily commute 185mm now. I'll have to open a new thread with the findings.
My buddy (175mm) last night said he's done with short cranks. He's now even telling the difference when he's NOT swapping to my frankenbikes that alsways have 180mm+ now. He IS getting a baby though, so a pair of cranks would be an inappropriate gift now. :)
 
Discussion starter · #10 ·
It's a girl...

A powder blue bike with a white Reba MUST be a girl!

I guess my excitement was a bit too much. Sorry...

The cranks really are that good. I always thought that I had a "hollow spot" in my crank rotation and that I was just a poor spinner. If this makes any sense, the "hollow spot" or gap isn't there anymore.

Immediately apparent.
 
#12 ·
Peter White Cycles

Not sure of the web address, however, if you do a search on google for Peter White Cylces, they/he has TA's in 185's in a number of configurations. Enjoy.
 
#13 ·
jms said:
Not sure of the web address, however, if you do a search on google for Peter White Cylces, they/he has TA's in 185's in a number of configurations. Enjoy.
Click to expand...
thanks, i know the shop, he built a dynamo hub for me ages ago.

rumor has it that xtr also made a 185 some time back.... anyone know about this?

e
 
#14 ·
Never heard of that XTR.
High Sierra Cycles makes custom cranks, the ones I got though required a 127mm square taper. Not the most practical of designs.
 
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