Crank Lenths?
- Thread starter tsamps
- Start date
Can't imegine a Sunday with other cranks than 165mm
my sunday came with 170mm by mistake, i eventually changed them
to 165mm its made life so much easier, i was clipping almost every rock before hand
to 165mm its made life so much easier, i was clipping almost every rock before hand
im running 165's and i still clip my pedals every now and then. anything longer i dont even want to imagine how bad it would be.
what would be the correct threshold for bikes in terms of crank length v.s. BB height?
at what point is 165mm too short & 170 to long and 175???
at what point is 165mm too short & 170 to long and 175???
Crank length talk seems to piss a lot of people off for some reason and most people are afraid to step away from the norm. This used to be my favorite argument but I gave up a couple of years ago since not many people are open to alternatives. If you're on the taller side, get a little crazy and try 170s to see if they work for you. Just don't tell anyone or you'll be flamed to no end. If it doesn't work, then go back to 165s. There are a few people on this board who run 170s with their Sunday and they're still alive.
About 1,000 people told me it was impossible to run 175s on my SXT in the low BB setting. But you know what, I did and I only hit a couple more rocks - no big deal. I use this as my trail bike so I like the longer legnth for climbing since I only use one chaingring and want the additional torque.
For true DH, my stregnth is my power so I like longer cranks for powering out of turns, so I will give up that 1 extra pedal stroke that I could have made through that 20 foot long rock garden with shorter cranks. I am also 6'2" so I would give up a considerable amount of my leg strength pedalling small 165s.
About 1,000 people told me it was impossible to run 175s on my SXT in the low BB setting. But you know what, I did and I only hit a couple more rocks - no big deal. I use this as my trail bike so I like the longer legnth for climbing since I only use one chaingring and want the additional torque.
For true DH, my stregnth is my power so I like longer cranks for powering out of turns, so I will give up that 1 extra pedal stroke that I could have made through that 20 foot long rock garden with shorter cranks. I am also 6'2" so I would give up a considerable amount of my leg strength pedalling small 165s.
I love Crank length arguements. Serious question for anyone running shorter cranks to get more clearance. In going from a 175 to a 170 or to a 165, how much clearance do you really think your getting? Your talkigng 5-10mm's.
Now with that said, crank length should be established according to leg length, If you feel good on the 165's keep running those, if you do beter on 170's same thing, if your Massive and have a 38 in inseem stick with the 175's. I am 6ft and I have a 32 in inseem, I run 172.50 for my road bike, and 170 for DH. I still hit rocks just the same as when I had 175's and it only happens when I am trying to pedal out of a nice rock garden.
Most people will not be on a 175 for DH mainly due to the lowered seats and angle of your legs while pedalling, alot of pweople should in fact be on 170's. go with a 165 is your nice and short.
Please do not get me wrong here, the 165 crank has its place here in DH, But please do not think its going to make that hugs difference in clearance.
Now with that said, crank length should be established according to leg length, If you feel good on the 165's keep running those, if you do beter on 170's same thing, if your Massive and have a 38 in inseem stick with the 175's. I am 6ft and I have a 32 in inseem, I run 172.50 for my road bike, and 170 for DH. I still hit rocks just the same as when I had 175's and it only happens when I am trying to pedal out of a nice rock garden.
Most people will not be on a 175 for DH mainly due to the lowered seats and angle of your legs while pedalling, alot of pweople should in fact be on 170's. go with a 165 is your nice and short.
Please do not get me wrong here, the 165 crank has its place here in DH, But please do not think its going to make that hugs difference in clearance.
my buddy has 175s on is sunday.
o.k....so insem length is important also
but how could you relate that to bb hight and crank length?
but how could you relate that to bb hight and crank length?
lthumbsdown:.... this is DOWNHILL
Put your thumb and finger 5mm apart and tell me how that difference in crank length could possibly be earth-shattering.
Ride whatever works best for you.
The point of 165mm cranks is not hitting rocks, it's not how tall you are....
Is that you can pedal with higher cadence as track cyclists do... they normally run 162.5mm..
10mm doens't make any difference, just having not the bike completely straight or having it straight when pedalling the variation of the pedal is way more...
Is that you can pedal with higher cadence as track cyclists do... they normally run 162.5mm..
10mm doens't make any difference, just having not the bike completely straight or having it straight when pedalling the variation of the pedal is way more...
Overthought topic.
Dont run 190's.
Dont run 190's.
Yes, but we're all not vertically challenged.
I hope this is just sarcasm because you are wrong on so many counts.
Dammn! I said I wasn't going to get into this arguement again.
Yeah, you probably shouldn't as your logic is woefully wrong, and your conclusions are rubbish. You are using semi-annecdotal half-cocked highschool physics and 80's bmx logic to argue a question that actual physiologists determined a long time ago to be a moot point.
Crank length has no effect on peak power output, as you get losses in angular rotation with added length. Force is totally meaningless without velocity, and unless you are an invalid, you are capable of producing far more force than you can apply through the drivetrain to generate power anyway.
For a sport that is 100% about acceleration, equipping your bicycle with parts that emphasize angular rotation *the limiting factor in power production for a human on a bicyle* seems like a good idea.
Added ground clearance, so you can actually pedal, is another good idea. 2.5mm is a SIGNIFICANT margin when it comes to ground clearance, but a completely insignificant amount when it comes to peak power production.
If you can't pedal, you certainly will make no power whatsoever...
Crank Length is not about clearance, its not about Cadence, its not about the power output, its about what length works best with your leg length on a certain geometry. That my friends is where 5mm makes a real difference, In your knees and how they feel after a day of hard riding. I understand this is DH, and if 165's work for you, great, if 170's work great, 175's same thing. My challenge to anyone who does not belive this, let me install a set of cranks on your bike, I will not tell you the length, go for a ride, and I will change your cranks, go for another ride, come back and tell me which set is shorter. then I will tell you which was which, and youll crap yourself when I tell you they were the same.
Exactly
Are you kidding???? I think you have no idea what you talking about.... So next time before telling bull $hit just read two times....
Also when I used to race DH. In my team where from really tall to not that tall and everyone asked for 165mm for this meaning, get more cadence... But I'm sure they didn't know anything about DH... Or you probably will tell me that they are also wrong... But I think you won't like to know who they are...
Also when I used to race DH. In my team where from really tall to not that tall and everyone asked for 165mm for this meaning, get more cadence... But I'm sure they didn't know anything about DH... Or you probably will tell me that they are also wrong... But I think you won't like to know who they are...
I wonder if you would be saying that if we took a 14" BB up to 14.5". It is only 12mm.
Personally I run 175's but next set of cranks will be a lot shorter. I am 6'2" And used to ride road ages ago. Fair enough I noticed the difference on Road. But on DH we pedal A) DH (we have gravity on our side) B) in short bursts. C) Whenever we can. So if you can get away with an extra pedal cause you have extra clearance then your ultimately better off IMO.
IMO, short cranks make a bike feel like this to me...
http://www.cpsc.gov/cpscpub/prerel/prhtml02/02012.jpg
[edit] Why the heck can't I upload images here anymore?!!!
http://www.cpsc.gov/cpscpub/prerel/prhtml02/02012.jpg
[edit] Why the heck can't I upload images here anymore?!!!
10mm on the crank, 5mm on the pedal thickness and other 3mm on the pins and you can have a bike with 18mm lower center of gravity... Thats a lot for cornering and exactly what designers have to handle when thinking a downhill frame.
Please I hope noone takes me teh wrong way, I really dont care what cranks you want to run, Just that there are alot of Misnomers<SP> as to why you would want a certain length. I will sell you whatever you ask me for. But I still offer the challenge to geo for two rides and tell me which set of cranks was shorter. Hell I would go so far as to put a 175 on one side and a 170 on the other just to see if you notice it. My money says you cant tell
I´ve got to ride 175mm at one side and 170mm at the other on my XC... it was horrible.
And on a DH bike, you will really notice it when you hit a rock.
The mind is a deceitful thing.
Angular bah, clearance meh, cadence HA.
I dare anyone to take DirtyMikes challenge.
Angular bah, clearance meh, cadence HA.
I dare anyone to take DirtyMikes challenge.
Actually it's pretty noticeable.
I'll admit that it seems to be moreso a function of what length the 'last cranks you rode' were but I can definitely tell a difference hopping between the different bikes I have with different lengths. It's not a power thing.......you can just tell your feet are moving in a different radius when you pedal. I also forget about it after while but right off the bat it's something that's detectable.
If I can make some money on it I'd GLADLY take that challenge.
You moved out to California, right?
Maybe in California you can ride 170+ cranks on a bike with a sub 14" bb height and 8"+ of travel running 30% sag on a DH course and pedal anywhere and everywhere, but In the eastern US, Central US, Australia, Southamerica, Europe and Africa it just seems like a really freaking stupid idea of no merit whatsoever....
Actually it's pretty noticeable.
I'll admit that it seems to be moreso a function of what length the 'last cranks you rode' were but I can definitely tell a difference hopping between the different bikes I have with different lengths. It's not a power thing.......you can just tell your feet are moving in a different radius when you pedal. I also forget about it after while but right off the bat it's something that's detectable.
If I can make some money on it I'd GLADLY take that challenge.
You are the Woo, normal principles dont apply...
lalalalala
California? Nope, Northeast.
Did anyone know that Marlboro Lights make you sterile? (its the filter!)
Its not completely invalid, but it is way overthought and not nearly as significant as people make it out to be.
well then what do i do if i still clip ****. ohh and if length is such a mute point to you fellas then lets see you ride a sunday with 175mm cranks and see what your conclusion is after that.
Have you ever even ridden in california?
There are rough dh trails everywhere on the planet. (okay maybe not florida or kansas)
Making an absolute statement like that is silly. Just because YOU can't do it doesn't mean squat.
Here's some buff CA singletrack for you
Generally cranks out there are the same length be them 165, 170, 172.5, 175 or whatever. Not all I’m just talking most mass produced cranks. Its just where the hole is drilled more often then not. Also as said your only talking mms between pedal highest as well. Tyre size, pedal thickness, sag and so on can make even larger differences. Then if were talking cornering the BB length will make a huge difference on ground clearance in the bends as well. Even between stock bike geometry BB height very massively.
So in other words what works best for one is not best for others. Plenty of people run long cranks for DH and are perfectly happy with them. If they work for you then great go with it. If you like short then that’s good to. There is one thing that people tend to forget and that is basic ergonomics. The length on the crank will actually effect how much power you can produce and how effectively you can produce it.
So in other words what works best for one is not best for others. Plenty of people run long cranks for DH and are perfectly happy with them. If they work for you then great go with it. If you like short then that’s good to. There is one thing that people tend to forget and that is basic ergonomics. The length on the crank will actually effect how much power you can produce and how effectively you can produce it.
Well... Back to the original question... On a Sunday, as a very low BB downhill race bike, you will not get its full potential with cranks longer than 165mm.
MDJ, DirtyMike, Bulldog and Huck Banzai are not talking about cranks for a Sunday.
MDJ, DirtyMike, Bulldog and Huck Banzai are not talking about cranks for a Sunday.
Go 140. Everything you've stated for 165s would be moreso for 140s.