TreeFarm
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I'm on a large 27.5" it has 170mm arms.
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- Thread starter bmxbryant9
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I'm on a large 27.5" it has 170mm arms.
I‘m on large and 170 is apparently what I have.
Shorter crank arms are to help prevent pedal strikes. Not really a problem on road bikes.
Newer bike geo has a lower bb is the reason for the shorter cranks. Lower bb helps the cog stay low for the steep stuff.
My new felt compulsion 27.5" has a lower bb than my 09 specialized enduro on 26" wheels.
My new felt compulsion 27.5" has a lower bb than my 09 specialized enduro on 26" wheels.
Ah! So it’s a vertical C.O.G. thing?
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'Downhilling' is the 'in' thing right now. So they try to put the rider further back - slack front ends, lower bb, and dropper posts to keep your weight back.
Jesus. I never thought about crank arm length, but the sizes and ratios have gone nuts ever since I stepped out of the bike game. Now everybody is riding on cartoon oversized Wheels, extra wide handlebars, little tiny gears and cranks,
Let us know what you find that works for you
I have kind of long legs and they have been to my advantage on my road bike with 180s.
I realize 170s are only 3/8” shorter per arm which is 3/4” from pedal to pedal but it feels like 2”.
When I last bought a new road bike I never felt the same on it until I put my old components on the new frame. Now I’m realizing it was the crank arms.
https://bikedynamics.co.uk/FitGuidecranks.htm
So do you feel like you don't have the same power while climbing (or even just going on flat ground)?
It’s most noticeable when climbing in that the pedal stroke feels too short for my legs but I think that even on flats the same logic applies but it’s just less (instantly) noticeable but has a negative impact on my mile pace.
When I was doing triathlon I was never able to ride a tri-bike because my thighs would push the breath out of my lungs at the top of the pedal stroke. I think now that I needed a much shorter crank for that and I now think that the multiple professional bike fitters I used missed that and let me down. I just always rode my road bike for triathlon.
gotcha yah that makes sense. I am also on a large (but a hardtail that's only 19lbs..) and am 6'2'' with long legs not sure about the length of the cranks and honestly never though about it lol.. I can see where it would make a big difference on longer road rides for sure.
so are you thinking about switching out cranks or switching bikes in general?? I looked at the stumpjumpers for a while and they are such a great all around bike! they had a bit too much travel for what I like to do- my last full suspension bike was an EPIC marathon with 100mm of travel
so are you thinking about switching out cranks or switching bikes in general?? I looked at the stumpjumpers for a while and they are such a great all around bike! they had a bit too much travel for what I like to do- my last full suspension bike was an EPIC marathon with 100mm of travel
You'll also want to work on bringing up your cadence. But riding an mtb will be slower. The latest I've read is you become more efficient up to about 95rpm. After that you start spending more and more energy just moving your legs around than putting into the pedals. But many cyclist hold well over 100 for long periods of time. I've had to work mine just to get it up into the mid 80s. I can hold 95 or more on my mtb but not on my gravel bike. But that will make up some of the difference you feel having the shorter crank arms.
Where was this in AK? we stayed near Sutton AK two summers ago and stole away, rented some bikes from the trek store and hit up Kincaid park. It was fantastic.. great flow and well maintained!
I'm thinking cranks right now.
I think I need the full suspension because I have a disc issue in my back which is part of my decision to transition to mtb.
I figure that with no experience I am going to get my ass kicked when descending on this off-road terrain stuff and my opportunity to make that up is going to be flats and climbing and I feel like the short crank just nullifies my only attribute.
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The bike you have is built for the downhill, Pemberton is ROWDY and STEEEEEP! Most of the climbing is done by logging road there. The bike has specs going against it for flats and uphills. Additionally, trail bikes have all but moved away from 175mm cranks. I'm not much over 6'1", but wouldn't go longer than 170mm on a modern trailbike. Climbs are going to be littered with rocks that will eat crank arms. Every mm will help, especially with a slack, low BB bike. Unless it's painful, I would ride it for 100-200 miles before making changes. Anytime I switch to a new geo, I always think things are wrong until spending some time on it.
Well obviously if you spend enough time with anything you retrain your muscles to adapt.
But I know at my age I wouldn't be doing that, I just find what fits me right, I have spent more than half a century training, I just want to maintain now
I read some articles years ago and trained myself to drop my heel on the down stroke and lift it on the up stroke.
That sounds like extra work but it's really just relaxing the ankle and letting it do what it wants to.
This technique also allows the muscles that drive the pedals to stay in their most powerful range through a larger portion of the circle. The larger the circle (to the extent it matches your range of motion and inseam) the more power.
Little rolling hills were my specialty with this technique.
I rode with plenty of guys that could out-ride me but that technique closed the gap for me on a lot of riders
So if you make the circle smaller then you reduce the value of the technique.
I'm already at a huge disadvantage because in our town where we usually had 15 to 30 riders on a Saturday ride, all of the ones who couldn't stay on the back of the draft switched over to mtb years ago.
Now I'm moving into their world with no skills against their 10-20 years worth of experience and my power is useless. Just frustrated and venting I guess.
@Abusfullofnuns I'll take your advice and ride it awhile before I make any changes.
That sounds like extra work but it's really just relaxing the ankle and letting it do what it wants to.
This technique also allows the muscles that drive the pedals to stay in their most powerful range through a larger portion of the circle. The larger the circle (to the extent it matches your range of motion and inseam) the more power.
Little rolling hills were my specialty with this technique.
I rode with plenty of guys that could out-ride me but that technique closed the gap for me on a lot of riders
So if you make the circle smaller then you reduce the value of the technique.
I'm already at a huge disadvantage because in our town where we usually had 15 to 30 riders on a Saturday ride, all of the ones who couldn't stay on the back of the draft switched over to mtb years ago.
Now I'm moving into their world with no skills against their 10-20 years worth of experience and my power is useless. Just frustrated and venting I guess.
@Abusfullofnuns I'll take your advice and ride it awhile before I make any changes.
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TreeFarm
Internet fabricator.
That’s at Kincaid
