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Another festivus MIRACLE!
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Discussion Starter · #1 ·
Hey,

I have a Redline MC Flight SS 29er and destroyed the stock cranks. Soooo I replaced with 180mm XT crank and although I've been riding those cranks for about a year lately the knees have been sore after a ride. I'm a big guy (230lbs) and ride a local hill trying to remain seated to do the entire hill only standing on the most difficult sections of the climb.

I did a search and it seems that staying seated isn't a great idea (which means I'll have to stand and hammer then rest and repeat until I get to the top). But I'm thinking that the longer crank arms may have a negative affect on the knees too.

Thoughts?
 

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Another festivus MIRACLE!
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Discussion Starter · #3 ·
velomatt said:
I had a similar problem.
How long is your inseam? Your height?
I'm 6'3" and inseam of 34 (probably closer to 33). I've gained some weight due to the holidays, shorter days and rain. That probably doesn't help either.
 

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Well i would guess you are long enough, so to speak.
I've been a steady SS'er for almost 10 years now.
I have had three major knee problems on the SS.
One was pushing to hard.
Two was 180 cranks (5'10" 31" inseam) 175 seemed to fix that one but it could be just the excitement of new cranks???
Third just one knee hurt, bad cleat setting.

I know that general health, weight and how hard you push yourself can be a big factor when you get to 40+ (like I have)
I just dont bounce back as fast as I once did and I cant carry any extra weight without having back and knee pain.
Im not near as heavy as I have been, as heavy as 230.
But you are much taller than I.

get some other opinions and try different things to exercise the knee demon!

Good Luck
 

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I am 5'8 and ran 180mm cranks for a year or so with out any problem. I tried them because of the extra leverage and the fact that I raced bmx with that length for years.

Yes, they are too long per the suggested crank length. But, I really liked them. The reason I do not use them any more is the fact that I started spending a lot of time on the road bike with much shorter crank arms. It made too much of a difference going back and forth.

I opinion is no matter how long your cranks are, if you are running too big of a gear or sitting down past the point where you should stand or even a combination of the two, you knees will hurt. Mine always do if I try and sit too long.
 

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I'm 5' 6" 155# 29'inseem. I run 180mm RaceFace X-Type cranks. Seriously it all depends on your fitness level and the strenght of your knees. This combined with picking the right gear to match the hills you climb. I'm not a spinner and I like to hammer in and out of the saddle. I run a 32 X 17t and the mountain I climb is Brown Mtn in Pasadena which is pretty much a mod to steep climb for 6 miles.
No my knees are NOT pain free 100% of the time but when they hurt I change my gears, my training and up my supplements. And most import of all, I rest.
I like the advantage of 180's and IMO make attacking the quick up shoots on singletrack that much easier.
 

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longer should be better for the knees, no? more leverage = less leg required?

i have a 29" inseam (way short for my 5'11" height!) and ran 180s for a while. the extra oomph was plenty apparent, but i went back to 175s because they spin better and because i kept bashing my pedals on everything.

that said, no knee pain here. i SS a lot offroad, and logged over 2k miles on a fixed road bike with a 78" gear last year (~1/2 of my total mileage). so i 2nd (3rd?) the 'ride more' comments already made. get 'em used to the load...
 

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I'm 6'-2" w/a 34" inseam & not-good knees and use 180mm cranks. I followed an online recommendation for seat height. The idea was minimize knee angle while pedaling; when your foot is at the bottom of the stroke, there should be just a slight bend to the knee. I had my seat lower at first and had some soreness in my knees. Since I've raised it, I've have no trouble. My knees do hurt though if I'm pushing it too hard or if I'm pedaling standing. It helps that I have a 7-speed hub, I can usually avoid pushing too hard.
 

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i call it a kaiser blade
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i love using 180s. you can feel the difference in effort, which i think is cruicial on starting off on a SS bike, or on serious climbs. i'm about your height and never had trouble with my knees. if anything i think 175s are too short, and think that all bikes with 21''-ish frames need to have 180s and they should be offered on 19" frames.
 

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I don't huck.
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I was having some knee issues kinda early in my mtn biking 'journey' of life. I asked a very wise and experienced frame builder and 6'4" guy about it. He said, "longer cranks". I am 6'2".

Fixed the knee issues....never looked back.

180s rule.

Ditto on sitting and pushing very hard, slow grinds. Death to the patella.
 

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I've used both 180 and 175 cranks for my SS, never had pain with either. What DID give me horrible knee pain was riding a multi-speed pedicab for a couple of weeks. I sometimes had 400+ lbs of weight in the back of that thing. Even gearing way down to granny did not help. I had so much pain, I could not walk down stairs at one point. I rode most of the time in the saddle(standing was kind of awkward on the pedicab) and tried to gear appropriately on any incline. The only thing that helped was two weeks of rest and glucosamine supplements.
 

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Sparticus said:
Cranks are levers. The longer they are, the more leverage you have. Long cranks don't make pedaling harder, they make it easier. If you're experiencing knee pain, consider lowering your gear ratio.

http://www.nettally.com/palmk/Crankset.html

--Sparty
That link and forumla (5,48 x inseam) says I should be on 165mm cranks (30" inseam). Maybe that's why I seem to like 170mm? I has also used 175mm, but never had the chance to try 180's.
 

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Wish I Were Riding said:
That link and forumla (5,48 x inseam) says I should be on 165mm cranks (30" inseam). Maybe that's why I seem to like 170mm? I has also used 175mm, but never had the chance to try 180's.
Exactly. Ergonomics.

--Sparty
 

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Exactly. Personal preference.

--Sparty

one piece crank said:
FWIW, I'm 6'4" and only run 175mm. I run a relatively low gear ratio on my SS, so I like the spin-ability. For me, a longer crank arm begs for a higher gear ratio when standing...

Tom P.
 
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