Pros and cons?
Espen
Espen
180mm vs 175mm arms?
Espen
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180s - more torque, especially useful for those nearly stalling and toppling sideways technical climbs. Not so good for spinning, makes it feel like your legs are flapping about a bit, although you'll probably get used to it fairly quickly. Depends on how tall you are too - I'm 6'2" so they feel fairly natural to me. Shorter legged people may not agree.
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2,767 Posts
i didn't notice a huge diff when i switched to 180's but now when I go back to 175's I struggle...perhaps I am just trying justify the switch to myself...
as for hitting obstacles, when i connect with a rock or log etc it is generally b/c i am stupid not b/c the cranks are 5mm longer...
as for hitting obstacles, when i connect with a rock or log etc it is generally b/c i am stupid not b/c the cranks are 5mm longer...
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1,706 Posts
180's for me
180mm XT's with external bearing BB and Surly 32t ring.
I am 6'0 tall.
Pretty much a personal preferance thing; you are gonna see all different responses to your question- none being totally right or wrong.
The way I see it; spinning out is not nearly as much of a concerning as stalling out is. I would rather be more efficient when the going is tough. If I am spinning too fast, I just coast. To me, that is like a no brainer. Coasting is fun!
OGG
180mm XT's with external bearing BB and Surly 32t ring.
I am 6'0 tall.
Pretty much a personal preferance thing; you are gonna see all different responses to your question- none being totally right or wrong.
The way I see it; spinning out is not nearly as much of a concerning as stalling out is. I would rather be more efficient when the going is tough. If I am spinning too fast, I just coast. To me, that is like a no brainer. Coasting is fun!
OGG
Without intending to be disagreeable...
...I disagree with this statement: "...180s ... hit the ground, logs, rocks, ledges, etc..."
Personally I don't believe a rider should blame long cranks if their pedals frequently hit the ground. Assuming 180mm+ length cranks are the "right" length for said rider, the rider should instead blame a frame that incorporates a bottom bracket that is too low.
If thought to crank length is given when the rider chooses his/her frame, 180mm (or longer) cranks will not be a problem. If the frame has already been purchased and no thought was given to the proper crank length prior to frame's purchase, the rider should be accountable for failure to take this aspect of frame design into account at the time the frame was purchased. In other words, blame the frame not the cranks.
This is not a flame on anybody, it's simply my opinion. Without meaning to offend anyone, my motivation to drone on about this subject stems from the fact that I tire of frequently coming across the implication that 180mm cranks intrinsically hit the ground more often as say, 170 or 175mm cranks. That's like saying a lay-back style seat post makes your bike fit worst than a straight piller post. This statement can't be accurately made without knowing a lot more about all the factors that go into individual bike fit. These aspects are a matter of proper frame fit and component compatibility, the decisions about which should be made prior to the purchase of the bicycle (&/or components & frame).
In considering the bike as a whole, one would do well to compute the crank length he/she needs FIRST based on leg length and preferred spinning style. Then look for a frame that meets the needs. If no production frame can be found that meets a specific rider's needs, a custom frame should be considered.
But it's incorrect to say that 180mm cranks hit the ground more often than shorter cranks and then blame the crank length. If long cranks do impact the ground more often, then one of the following is true: either the rider is riding the wrong length cranks or their frame incorporates a too-low bottom bracket.
Have a smiley...
--Sparty
...I disagree with this statement: "...180s ... hit the ground, logs, rocks, ledges, etc..."
Personally I don't believe a rider should blame long cranks if their pedals frequently hit the ground. Assuming 180mm+ length cranks are the "right" length for said rider, the rider should instead blame a frame that incorporates a bottom bracket that is too low.
If thought to crank length is given when the rider chooses his/her frame, 180mm (or longer) cranks will not be a problem. If the frame has already been purchased and no thought was given to the proper crank length prior to frame's purchase, the rider should be accountable for failure to take this aspect of frame design into account at the time the frame was purchased. In other words, blame the frame not the cranks.
This is not a flame on anybody, it's simply my opinion. Without meaning to offend anyone, my motivation to drone on about this subject stems from the fact that I tire of frequently coming across the implication that 180mm cranks intrinsically hit the ground more often as say, 170 or 175mm cranks. That's like saying a lay-back style seat post makes your bike fit worst than a straight piller post. This statement can't be accurately made without knowing a lot more about all the factors that go into individual bike fit. These aspects are a matter of proper frame fit and component compatibility, the decisions about which should be made prior to the purchase of the bicycle (&/or components & frame).
In considering the bike as a whole, one would do well to compute the crank length he/she needs FIRST based on leg length and preferred spinning style. Then look for a frame that meets the needs. If no production frame can be found that meets a specific rider's needs, a custom frame should be considered.
But it's incorrect to say that 180mm cranks hit the ground more often than shorter cranks and then blame the crank length. If long cranks do impact the ground more often, then one of the following is true: either the rider is riding the wrong length cranks or their frame incorporates a too-low bottom bracket.
Have a smiley...
--Sparty
pitmang1 said:
Sorry. I did not mean to hammer you. After reading back it kinda comes off that way, doesn't it. Not my intention!pitmang1 said:
I'm over 6 feet tall myself and I ride 195 to 202mm cranks on both my mountain bikes and my commute bike. I've studied and been an advocate for the virtues of long cranks (for those they are appropriate for) since 1992 so I sometimes get carried away. Please forgive me. No flamage intended, honest.
--Sparty
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380 Posts
Choosing a crank length should be a matter of physiology. For example, it's probably not good if your knees bend beyond 90 degrees on the upstroke (that's a big risk factor for overuse-type injuries). And you certianly don't want your hips to sway back and forth at all as you pedal. Obviously, saddle height comes into play here too. I, for one, think it is totally worth it to have a proper fitting done to make sure what you're riding is appropriate for you. Leverage schmeverage.
I'm not a doctor, but "proper bike fit above all else" is of the things I picked up from my doctors and chiropractors after I was sidelined for months with a chronic knee injury.
OK back to studying for finals...
I'm not a doctor, but "proper bike fit above all else" is of the things I picked up from my doctors and chiropractors after I was sidelined for months with a chronic knee injury.
OK back to studying for finals...
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216 Posts
No offense taken Sparty. I happen to ride my singlespeed for all types of riding. That includes dirt jumping, trials riding(I'm not very good, though), urban freeriding, and when I get the chance to make it to some good trails, freeriding. Maybe if I was just pedalling, I would want some longer cranks. I wonder if longer cranks would make my knee problems worse? Anyone know?
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358 Posts
175's here
I went back to 175's, knee pain gone, much easier spinning. I can't 'reef' myself over the odd boulder but my perception is that the bike rides better.
I'm 6'0" with a 31 (ish) cm inseam for what it's worth.
b.
Found I couldn't spin well with the 180's, but they did have more leverage for cranking up tech stuff. That said, my knees got sore with them, especially on heavy climbs.Espen said:
I went back to 175's, knee pain gone, much easier spinning. I can't 'reef' myself over the odd boulder but my perception is that the bike rides better.
I'm 6'0" with a 31 (ish) cm inseam for what it's worth.
b.
Tried 'em..
but they made my knees hurt. I like the leverage of the 180's, but I just couldn't get used to them. The 175's are the best balance of spin and power for me. I have had both of my knees reconstructed (ACL/MCL) so they are a little sensitive to changes in crank length.
I think I'll stay with 175s
but they made my knees hurt. I like the leverage of the 180's, but I just couldn't get used to them. The 175's are the best balance of spin and power for me. I have had both of my knees reconstructed (ACL/MCL) so they are a little sensitive to changes in crank length.
I think I'll stay with 175s
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1,164 Posts
Yes, there are numerous factors at play here. The bottom line is that individual preference is the greatest determining factor in the end.Sparty correctly pointed to all the pre-purchase factors most people don't even know to consider. Big29 outlined some serious physical issues. My finding (and I have been a fan of long cranks since the IRD's of the late 80's-early 90's) is that I seldom sit on my SS, so I am not sure how much the spinning position applies to this (new to me) SS world. That being said, it is a fact that most of our rides here in the Pacific NW are either up or down, so I am always standing to climb. My old Cook Bros 180mm RSR's are the s**t for me. If you can try both, do so and see what works for you. I like the leverage and set my EBB in the upper quadrant to get the clearance I want.
Cheers,
PS, See you out there tomorrow night Sparty?
Cheers,
PS, See you out there tomorrow night Sparty?
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142 Posts
!
175 's
I'm 6'2" & used 180's before.I use 170mm on my Freeride bike & would also on my SS too.I hate clipping stuff with the arms .I try to ride as fast as possible all the time .
Big difference from 170-180.. But like i said 175 is my vote.
Try some 180's you might love em.
175 's
I'm 6'2" & used 180's before.I use 170mm on my Freeride bike & would also on my SS too.I hate clipping stuff with the arms .I try to ride as fast as possible all the time .
Big difference from 170-180.. But like i said 175 is my vote.
Try some 180's you might love em.
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149 Posts
flip side of long cranks
Yeah, crank lenght is personal.
I'm 5'6" and ride a 29er SS. I had the frame built (accounting for crank lenght) and use a 170mm. I generally ride steeps and technicals. But when I had the frame built, my philosophy was to use the shorter crank arms so I could keep the center of gravity lower. That gives me more stability, especially on fast rocky descents.
You jack up the bike for longer cranks, you jack up your center of gravity. You decrease stability.
As a test, I put two different sized-crank arms on the same bike that were 5mm different. After a while of riding around town, honestly, I could hardly tell which one was the shorter arm.
Perhaps 10mm makes a difference, but really, it comes down to the gears and how comfortable you are over a longer period of time. The guy makes the gear, not the gear makes the guy.
For me, I crank up hill, passing most geared bikes, and don't hit crap along the way.
Yeah, crank lenght is personal.
I'm 5'6" and ride a 29er SS. I had the frame built (accounting for crank lenght) and use a 170mm. I generally ride steeps and technicals. But when I had the frame built, my philosophy was to use the shorter crank arms so I could keep the center of gravity lower. That gives me more stability, especially on fast rocky descents.
You jack up the bike for longer cranks, you jack up your center of gravity. You decrease stability.
As a test, I put two different sized-crank arms on the same bike that were 5mm different. After a while of riding around town, honestly, I could hardly tell which one was the shorter arm.
Perhaps 10mm makes a difference, but really, it comes down to the gears and how comfortable you are over a longer period of time. The guy makes the gear, not the gear makes the guy.
For me, I crank up hill, passing most geared bikes, and don't hit crap along the way.
Groan...
The implication buried not-so-deep in the following type of comment is what irks me:
he's so inclined).
Evidently some people who try 180mm+ cranks don't understand that if proper consideration is given to frame design prior to frame purchase, the rider's pedals will be NO CLOSER TO THE GROUND while riding 180mm cranks (or 235mm cranks, for that matter) than they would be if (s)he were riding 170mm cranks (or 140mm cranks for that matter).
I submit:
IF YOU ARE RIDING THE CORRECT LENGTH CRANKS FOR YOUR HEIGHT/LEG LENGTH/RIDING STYLE AND YOUR PEDALS ARE TOO CLOSE TO THE GROUND THEN YOUR CRANKS ARE NOT TOO LONG. RATHER, YOUR FRAME'S BOTTOM BRACKET IS TOO LOW.
Please notice the statement above starts with the words "If you are riding the correct length cranks..."
The problem so many people have with "long" cranks is that the rider decides to put them on a frame that wasn't designed for anything longer than 170 or 175mm. That's not the fault of the long cranks, that's the fault of a frame that wasn't designed to accommodate long cranks.
EVERYbody needs adequate pedal/ground clearance. For heaven's sake folks, please purchase a frame that gives the cranks of your choice that clearance in the first place.
Just one more comment before I briefly pause my interminable diatribe. For the record, I hate clipping stuff with my cranks and I like to ride fast, too. And I DON'T clip stuff and I DO ride fast -- with 195mm cranks and a frame that was designed to utilize them.
--Sparty
P.S. freerider33, I don't mean to single you out (so to speak). You are just one straw in a heavy bale that continues to bear down on this camel's back. No offense intended.
The implication buried not-so-deep in the following type of comment is what irks me:
The implication here is that long cranks cause a rider to clip stuff with their cranks &/or keep a rider from riding as fast as possible at all times (iffreerider33 said:
Evidently some people who try 180mm+ cranks don't understand that if proper consideration is given to frame design prior to frame purchase, the rider's pedals will be NO CLOSER TO THE GROUND while riding 180mm cranks (or 235mm cranks, for that matter) than they would be if (s)he were riding 170mm cranks (or 140mm cranks for that matter).
I submit:
IF YOU ARE RIDING THE CORRECT LENGTH CRANKS FOR YOUR HEIGHT/LEG LENGTH/RIDING STYLE AND YOUR PEDALS ARE TOO CLOSE TO THE GROUND THEN YOUR CRANKS ARE NOT TOO LONG. RATHER, YOUR FRAME'S BOTTOM BRACKET IS TOO LOW.
Please notice the statement above starts with the words "If you are riding the correct length cranks..."
The problem so many people have with "long" cranks is that the rider decides to put them on a frame that wasn't designed for anything longer than 170 or 175mm. That's not the fault of the long cranks, that's the fault of a frame that wasn't designed to accommodate long cranks.
EVERYbody needs adequate pedal/ground clearance. For heaven's sake folks, please purchase a frame that gives the cranks of your choice that clearance in the first place.
Just one more comment before I briefly pause my interminable diatribe. For the record, I hate clipping stuff with my cranks and I like to ride fast, too. And I DON'T clip stuff and I DO ride fast -- with 195mm cranks and a frame that was designed to utilize them.
--Sparty
P.S. freerider33, I don't mean to single you out (so to speak). You are just one straw in a heavy bale that continues to bear down on this camel's back. No offense intended.
G
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·My take
First of all I have ridden 170 -180 and never noticed hitting rocks anymore or less the difference between 175 and 180 is 5mm different pedals have more difference than that I just can't imagine 5mm makes that much difference.
I ride shorter cranks now, I liked longer cranks for leverage which to me makes them nice for short especially technical trails they help to muscle your way over rock ledges and other obstacles.
I like shorter cranks because I can spin better and I feel than when I spin more with shorter cranks I feel more effecient and feel better longer I now have more energy at the end of my long rides.
Personal preference is a big part of choosing your cranks you can adapt to whatever length you choose the most important thing is that when you make the cranks go around you propel your bike forward.
First of all I have ridden 170 -180 and never noticed hitting rocks anymore or less the difference between 175 and 180 is 5mm different pedals have more difference than that I just can't imagine 5mm makes that much difference.
I ride shorter cranks now, I liked longer cranks for leverage which to me makes them nice for short especially technical trails they help to muscle your way over rock ledges and other obstacles.
I like shorter cranks because I can spin better and I feel than when I spin more with shorter cranks I feel more effecient and feel better longer I now have more energy at the end of my long rides.
Personal preference is a big part of choosing your cranks you can adapt to whatever length you choose the most important thing is that when you make the cranks go around you propel your bike forward.
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578 Posts
I would like to throw my .02 cents in here.
I currently ride 175mm cranks on all of my mtb's. I race bmx with 180mm cranks.
I put my bmx cranks on my SS one day and didn't do so well. Stupid me tried it at a race. I am sure that played a part in my experience. If I had some extra 180mm cranks I would try them again.
Now. As far as hitting ones pedals more. Something I found when I first started riding SS. I started pedaling more to keep my momentum so, in some tighter sections or turns, I hit the bottom of my cranks (These are 175mm) in places that I normaly would not.
Now that I have been riding more, I do not hit them as much. It is just stuff that I never had to think about before.
I currently ride 175mm cranks on all of my mtb's. I race bmx with 180mm cranks.
I put my bmx cranks on my SS one day and didn't do so well. Stupid me tried it at a race. I am sure that played a part in my experience. If I had some extra 180mm cranks I would try them again.
Now. As far as hitting ones pedals more. Something I found when I first started riding SS. I started pedaling more to keep my momentum so, in some tighter sections or turns, I hit the bottom of my cranks (These are 175mm) in places that I normaly would not.
Now that I have been riding more, I do not hit them as much. It is just stuff that I never had to think about before.
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