looking for a crankset

[mack_turtle]

@ATXZJ what do you use on your road bikes? That's the question here.

Idon't think crank arm length would make that much difference on a mountain bike because I do very little seated spinning. The gravel bike is a different story.

In the meanwhile, I'm putting a slightly easier gear on the bike so that I can spin a little easier. I still want to try an oval ring, but that requires a different crankset. So if I'm going that route at all, might as well swap the old 105 or a slightly newer Ultegra or something.

Interesting idea: I just read a study on running gaits that makes sense. When you walk, your feet find a pattern based on how your body naturally moves. But as you move from a walk to an amble to a jog, run, and sprint, your gait gets narrower. Because the horizontal spacing of your feet on a bike is not adjustable while riding (I've seen experimental pedals with cleats that float sideways), riders start to shift the whole bike side-to-side as the spin spin faster. You see this in any race or in any person trying to go fast. As the RPMS go up, the gait gets narrower. when you walk with a lower cadence and more force, like climbing stairs, your stance widens, probably to help stabilize your body. 

Edited April 20, 2021 by mack_turtle

[AntonioGG]

I forgot to add this tidbit.  As I'm approaching 50, one of the things I notice is I can no longer mash up a hill at low RPM before I'm fully warmed up, and it takes me longer to fully warm up.   Since I live in a valley, I got hills on all sides, and if I try to big-ring up them I can feel some knee pain.  Once I'm warmed up I can go back to stand-up mashing at low cadence.

[mack_turtle]

Gotta hand it to you folks, this thread went from "I want to buy some new cranks" to "you probably have arthritis because knee pain sets in after pedaling a singlespeed bike for 50+ miles"  in no time. Thanks WebMD! 

Edited April 20, 2021 by mack_turtle

[ATXZJ]

1 hour ago, mack_turtle said:

@ATXZJ what do you use on your road bikes? That's the question here.

Idon't think crank arm length would make that much difference on a mountain bike because I do very little seated spinning. The gravel bike is a different story.

In the meanwhile, I'm putting a slightly easier gear on the bike so that I can spin a little easier. I still want to try an oval ring, but that requires a different crankset. So if I'm going that route at all, might as well swap the old 105 or a slightly newer Ultegra or something.

Interesting idea: I just read a perspective about running gaits that makes sense. When you walk, your feet find a pattern based on how your body naturally moves. But as you move from a walk to an amble to a jog, run, and sprint, your gait gets narrower. Because the horizontal spacing of your feet on a bike is not adjustable while riding (I've seen experimental pedals with cleats that float sideways), riders start to shift the whole bike side-to-side as the spin spin faster. You see this in any race or in any person trying to go fast. As the RPMS go up, the gait gets narrower.

I wouldn't overthink it. In the end, it's just a bicycle........

[mack_turtle]

I "overthink" these things because they're fascinating. I'm sorry to hear that my persuit of knowledge troubles some people. If understanding them helps me avoid hurting myself, even better. I asked a simple question and instead of a solution, I got the Spanish F-ing Inquisition!

Please respond if you have a crankset for sale that has:

•170mm arms

•24mm straight spindle

 

Edited April 20, 2021 by mack_turtle

[TheX]

1 hour ago, mack_turtle said:

I "overthink" these things because they're fascinating.

I have that same illness.

[AntonioGG]

23 minutes ago, TheX said:

I have that same illness.

Same.  Also:

https://www.youtube.com/watch?v=sAn7baRbhx4

[Chief]

On 4/19/2021 at 6:01 PM, ATXZJ said:

It happens

Wife started complaining of shoulder pain a little over two years ago. She blamed everything, playing the drums, tennis, MTB, sitting at the desk for a year working from home, ETC, ETC.  So in mid/late 2020 she decided to seek medical help. First chiropractor said she had some sort of atrophied muscles in her shoulders and started PT for a couple months. That only made it worse and spread the pain down her arms. BTW, F chiropractors. She then went back to her primary doctor and they did a blood draw for rheumatoid arthritis and found nothing. FINALLY they sent her to an orthopedist and after a series of examinations, x-rays and whatever, they diagnosed her with tendonitis, bursitis and arthritis in her shoulders. She was bummed but understood that everyone will have some form of arthritis and is currently getting PT & treatment for it. She's in her early 40s.

 

Lastly, I have 175s on my trailbike and 165s on my park bike. Normally run 170s. Cant tell the difference from any of them.

Testing for rheumatoid arthritis won't disclose osteoarthritis. Rheumatoid arthritis is an autoimmune disease, osteoarthritis is caused by wear and tear. Everyone will eventually get osteoarthritis if they live long enough. Previous injuries are also a factor for osteoarthritis usually a joint that has had a serious injury will develop arthritis. Best thing for osteoarthritis is to keep moving.

[ATXZJ]

On 4/19/2021 at 8:19 PM, mack_turtle said:

I asked a simple question and instead of a solution, I got the Spanish F-ing Inquisition!

 

 

[mack_turtle]

Hold the freaking phone.

I asked around and found someone who has a 170mm crankset for me. I took mine off an discovered my old ones are 175s! Not sure why I had 172.5 in my head.

Anyhow, I have some nice shorter cranks now to see if they help my knees not flare out but that oval ring is not going to happen. One thing at a time!

[dlstyley]

FWIW - I put on an oval ring, 2 teeth smaller, and then went from 175 to 165mm cranks, all in hopes of heading off some new, currently occasional but sharp knee pain. I can tell the difference in the ring (duh, 2 teeth of addition gear ratio) but the only thing I feel with the shorter cranks is a sense that they are more stiff - less lever to bend? Don’t notice any decrease in power and in fact am cleaning shit I hadn’t previously, probably because of the smaller ring. Also noticeably less pedal strikes. I went straight for 165mm because I wanted to make sure it was short enough on the first buy. 170mm could be the sweet spot for me, but I have no motivation to try longer since I don’t feel like I lost anything. Pain seems less frequent and decreasing. Hoping that continues but it’s early yet.

BTW - I mostly ride steep, slow tech, so have no use for higher gears. I’m 6’. Agonized over spending money on this, but no regrets yet.

so +1 for shorter cranks.

[mack_turtle]

8 hours ago, dlstyley said:

so +1 for shorter cranks.

I've probably used a lot of different crank arms on different bikes. On a mountain bike, I can see a lot of value in erring on the short side. Specifically for a singlespeed bike, I spend so much time out of the saddle wrangling the bike over terrain that it makes even more sense. I'm on a 170mm crank with a 30/20 gear now, which is considered low and spinny by most. I've tried an oval ring and could not feel a difference on the trail.

In the case that started this, it's my (gravel) road bike, that sees more miles of just spinning in the saddle, which is where an overly long crank will cause problems at the top or the bottom of the pedal stroke. The big old 130mm BCD on what I have means oval options are limited at least, but at least the spin is more likely to be kinetically appropriate for my body now.

Hey, Garbaruk makes one. Maybe I'll grab one of those!

https://www.garbaruk.com/130-bcd-5-bolt-oval.html?category=6

Edited April 22, 2021 by mack_turtle