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Discussion Starter · #1 ·
Mainly for the SS'rs out there : 175's or 180's?????
- I'm using 180's on my 26" & 34x18 gearing, but with the different wheelsize of the 29'r what has your experiance been? Does the bigger Crank make it harder to get "on top" of the gear? I'm plan on using 32x20 gearing to get started with and will be riding everything from rolling hills to mountains.

Happy New Year all, and thanks for any and all replies. :)
 

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I switched to 180's on my Leviathan and will be buying another pair soon. I don't know what the correct term is to use here, but I seem to get more leverage while pedaling. I kinda feel like I can pedal a gear higher too.

Anybody want some 175mm XT's in excellent condition? Its all 180's for me.

DMFT said:
Mainly for the SS'rs out there : 175's or 180's?????
- I'm using 180's on my 26" & 34x18 gearing, but with the different wheelsize of the 29'r what has your experiance been? Does the bigger Crank make it harder to get "on top" of the gear? I'm plan on using 32x20 gearing to get started with and will be riding everything from rolling hills to mountains.

Happy New Year all, and thanks for any and all replies. :)
 

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Recovering couch patato
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Longer cranks allow you to run a bigger gear as your natural rpm will drop. Interestingly, pedal pressure will level out. what I like about the lower rpm is being able to make better "rounden" pedaling circles. Just more time to complete each revolution. More knee angle also, and better seat-ass clearance when the cranks are level.
 

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HIKE!
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5mm ain't much....

Pull out a nice metric ruler and see for yourself. 5mm just isn't much, so don't sweat it. Run your 175s if you already have them, they'll work fine. Buy 180s if they come up without breaking the bank.

If you *think* that long cranks help your riding, they do, regardless of any University studies one way or the other.

But once you wrap your mind around the fact that it really doesn't matter much, you can save loads of money riding cast off 170mm cranks....
 

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Discussion Starter · #5 ·
Thanks guys, I'm fairly tall @ 6'5" so I like 180's for SS'ing but I still use 175's on my 26" squishy bike for clearance.
- My thoughts are the 175's will help give the Niner a lil' more "ooomph" outta the hole on technical climbs (I think), though I guess experimenting with different gears will help out with that too. - Choices, choices, choices.
 

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Not to split hairs but it's 10mm difference, 5mm on each end of the cranks. You may not notice anything 5 min into the ride but after 2+ hours you WILL be fresher.

(just another a-hole with an opinion)
 

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HIKE!
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10mm ain't that big of a difference either....

I always used to notice that 180s made me MORE tired, having to push over the top from such a deep knee flex. Especially after 2 hours of single speeding, just burned up legs trying to push that long crank. So, I sold off the 180s on Ebay for twice the amount I bought the same cranks in 170 for. Turns out I get tired on those as well, same darned "push over the top" feel. So now I've got bikes with 170, 172.5, 175, 180 and find it makes no difference to me.

But, DMFT has it down, experiment with gearing, crank length and figure out what works for you. You oughta be fine with the 175 or 180, conventional wisdom says tall rider = longer cranks. As long as you're buying new cranks, hunt down some 190s (or more), at 6'5" that wouldn't be out of the question. But, give 170s a try sometime as well.

(ditto)
 

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DMFT said:
Thanks guys, I'm fairly tall @ 6'5" so I like 180's for SS'ing but I still use 175's on my 26" squishy bike for clearance.
- My thoughts are the 175's will help give the Niner a lil' more "ooomph" outta the hole on technical climbs (I think), though I guess experimenting with different gears will help out with that too. - Choices, choices, choices.
Yow bud, at 6'5" you have an inseam of what, around 36" or so? My 6'4" pal likes 195mm cranks. A few of the other tall guys here have 190's and longer too, so if you have the cash you might want to try something on that order, just in case you love it and don't know it yet. It can get kind of pricey though, since they're hard to come by.

http://www.hscycle.com/Pages/customcrankset.html
.
.
 

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Witty McWitterson
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I've tried both 180 and 175 on the 29". In the beginning, I ran 180's on the 26" ss. So I started out that way on the 29". I thought I'd try 175's on the 29" on the advice of Bigwheel and others who run 170's(I just couldn't go that short). I left the 175's on for about half a season, but just couldn't get used to them, Geared or SS. I was never comfortable with them. I've got a 35" inseam and I just felt cramped with the 175s. I put the 180's back on and haven't looked back since. I'm not so sure I get more power out of them, but I sure do feel more comfortable with them! At your hieght, I'd for sure go w/the 180s.
 

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Discussion Starter · #10 · (Edited)
Right on....

Thanks again guy's, more & better advice!
This is gonna be interesting to say the least. More Toy's to aquire :D

My Fast Tracks & Boone 32t ring landed at the shop last week, this week it's Rims & Hubs. :)

I still need to find a Boone Cog or two. The Path is out right now & I really don't want to have to wait for a month or two going direct, anybody know of another shop that may have a couple - 18, 20, or maybe 22??? Any tips would be much appreciated!
 

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I'm running 11/32 and 22/32/42 gears but -- made the switch from 175mm to 180mm cranks when I got my 29er. I have a 34.5" inseam and still maintain an average cadence of 92. No change there even with the longer cranks. What did make a difference though was doing strength training for my legs and upper body at the gym. Now I can climb monster hills in the 32t ring when before I struggled in the 22t ring. I never use the small ring anymore. Hit the weights, get stronger, fly. Happy trails.
 

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sparrow said:
Pull out a nice metric ruler and see for yourself. 5mm just isn't much, so don't sweat it. Run your 175s if you already have them, they'll work fine. Buy 180s if they come up without breaking the bank.

If you *think* that long cranks help your riding, they do, regardless of any University studies one way or the other.

But once you wrap your mind around the fact that it really doesn't matter much, you can save loads of money riding cast off 170mm cranks....
Yes it's only ~3% longer. That 3% translates into one more chainring tooth if your concern is the maximum force you can apply to the pedal. Look at it another way, it's like taking a tooth off the chainring - making climbing a little easier.
 

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The body is very sensitive to any change in equipment regarded pedaling. Crank length changes don't just bad (if they don't feel good), they need adjustment. I best I could get somewhat adjusted to 165mm, but would it make sense? Cranks are all about your body. Inseam/femur length and muscular composition. The latter can even be altered over time.
I'm getting used to 185mm's, they're on one bike now. I have 180 on all offroad, and 175mm on all road. 175 only because of funds. 185mm feels interesing when I notice it, good even. Just my muscles need to get used to it, I got calve cramps on my past hard ride :s.
 

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HIKE!
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Crank length and Gear combos

http://www.sheldonbrown.com/gears/

Sheldon's "gain ratio" method is a purely mathematical way to compare gear combos, it takes crank length and wheel size into consideration. Pretty awesome tool to figure out some things. Given a 700 x 56 tire:

180mm 34 x 20 = 3.5
175mm 33 x 20 = 3.5

Still, climbing back over Sugarloaf on the way back to the finish in the Leadville 100, about 8.5 hours and 8,700 feet of climbing later, cramping, dizziness, nausea, and losing the will to go on will occur for many riders. Sort of a "Princess and the Pea" situation to feel the difference betwixt 175 and 180 cranks.

But use Sheldon's gear calculator and you can really get yourself stoked to buy a lot of cogs and rings to fine tune things. And you bet, crank length has to be considered in gear combos as well as in your own ergonomics.
 
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