Some facts about me and reason for shorter crank experiment. I’m short guy at just under 5’8". Raced first 2 years on a road bike, and the last 5 years on a tri bike. All my bikes have 170mm crank arms. On my tri bike with 170s, I always feel jammed up at the top of pedal stroke. That’s the reason for the change.
I installed 165cm crank arms, raised my seat 5mm and left everything else the same. Rode 20 miles yesterday morning then ran 4. My average speed was about the same as usual given the level of effort. I felt great in the aero position. The dead spot at the top of my pedal stroke was gone. However, I felt horrible on the hills, even small rolling hills. Literally, felt like I was towing a piano. Seems I made up some of that time on the flats (figure 12 miles of the ride was flat, 8 miles of rolling hills and small climbs). On the other hand, I felt fantastic on the 4-mile run.
Questions for anyone that switched to shorter cranks:
Is my experience on hills normal for a first ride on shorter cranks?
With mileage, will my climbing with 165s feel similar to the way it did on 170s?
Is there a breaking in period where my legs need to adjust to the change?
Do I need to accept the trade-off that shorter cranks will feel more comfortable on flats and on the run, but come at the expense of my climbing ability?
Hills will feel a bit odd, but you have to spin them. You don’t have the same kind of leverage and will probably need to go with a lower gear at a higher rpm.
If you do anything enough, it will begin to feel normal. The truth is, if you are 5’8" then 165 is probably still a fairly long crankarm for you when in a tight aero position. I’m 6’ and love 165s on my tri bike. I’ve even gone away from longer cranks for climbing and just use a lower gear.
I sort of remember feeling pretty fast the first time out, but didn’t have a PM at the time to document it. I don’t think it takes very long, but others have argued otherwise, so only you can say.
If you keep shorter cranks without changing out the gears, then you will probably always feel limited. I use a 50x13 high and a 36/27 low with my 165s and on rolling courses I always use the 36x27 to spin up hills. When the speed picks up above 22-24 mph I soft pedal and only apply a lot of power when it will benefit me the most. I averaged 24+ mph the last race and passed a lot of people by applying high power on the hills and flats into the wind and low to moderate power on the faster sections with a focus on staying very aero. Most of that is done at a fairly high (95-105) rpm.
I know I need to test buty what would be a recommended starting length…I am also 5’8" with short legs.
If you do anything enough, it will begin to feel normal. The truth is, if you are 5’8" then 165 is probably still a fairly long crankarm for you when in a tight aero position.
Chad
I’m one of the other guys. I went from 175 to 170’s and back to 175’s. I could feel alot of difference and it killed my climbing, which is all we have around here. I used 180’s for along time, but changed to the 175 when I got my new bike. I hated the 170’s and my race times were not good either.
The change to 170 and back to 175 was easy since I have the lobe technology pedals that allow the change in just a few minutes.
Interesting, at 6’ you prefer 165s. I felt fast on the flats first time out. Really noticed the bike felt more stable; I could mash hard in the aero bars and the bike didn’t zig or zag.
I’m using 53/12 high and 39/27 low. I’ll need to relearn when to shift gears as my timing is off on the roads use near my house. Do you ride a road bike as well? I’m wondering if riding 165s on the tri bike will make the road bike with 170s feel “foreign” to my legs.
I’ll try your advice on spinning and soft pedaling…makes good sense. Thanks
Paul, I see your point. I like being able to hang with my roadie friends on the local hills. I need to give this a shot though. I watched myself spin in a mirror on the trainer and my legs really jam up at the top of the pedal stroke. I can relieve this by raising my seat, but then my “seat is too high”. The 165s solved that problem, but created another one. I’ll work on finding a happy medium.
I have been on 170’s now for over a year and on my TT bike 167.5. I am running larger rings 54 and 55 respectively. I honestly believe it works thanks to John Cobb for setting me up this way. To each his own.
Well, after a fairly long 6 month experiment including 2 half Ironmans, 1 Ironman and a sprint tri as welll as a bunch of training TT’s I can say that anyone who wants my 165’s can have them.
I was no faster on 165’s and I never liked how they felt on hills even though I did go from 34x25 to 34x27 as my smallest gear. My half IM’s were Wildflower, Mooseman and IM France and I never really felt right on hills. My position was never really low for a number of “neck” related issues anyway, so the 165’s never bought me anything more. Maybe it would help if I was riding a lower position. I was hoping that the 165’s would help me for the run off the bike, but I can’t say I was running any faster off the bike even though my open marathon split between last May and this May were only 6 seconds or so apart.
My aero power on 165’s was no lower, nor any higher than on 170’s. It was certainly lower on my hillclimb TT’s.
Yes, the shorter crank length has been beneficial in competition. After much research and thought, it was the only way to address fit/spin issues unique to short folks on TT/Tri bikes in the aero position. It promotes a quicker/smoother spin, better aero fit (proper leg extension and hip angle, seat height), and eliminates knee-elbow banging! I am happy with the set-up.
(I still ride 170s on the road bike - climbing, torque, etc.)
I think the responses will vary as much as Oprah’s scale. I’m 6’1" with a 34" inseam and ride 165’s. Did it out of knee problems and not for fit issues. I can easily grab another 5+cm of drop now, but won’t do it b/c it puts too much strain on my neck…11cm is more than enough for me even though I could approach 20 comfortably. I went from 175 to 170 to 165 in about 3 months. Didn’t lose any speed, but didn’t get any faster either. My cadence picked up a bit, but I ended up liking it. No hills where i live so unless I move they are a permanent fixture for me. Love 'em.
Bottom line is who cares what others think, if it works for you that’s all you need to know!
Part of the reason I like the 165s is that I ride with a much more than normally restricted hip angle. Think the Obree Egg that he used for his hour record and you would be there. As such, I kept going smaller and smaller until I ended up at 165. I’ve raced successfully on 180s, 190s and 170s but my present position really feels better with the smaller arms. My road bike used to have longer arms as well, but I’m finding I prefer to spin faster in a smaller gear than grind the bigger gear with longer arms. I doubt you will notice the difference between 5mm of crankarm. In truth, I spent a great deal of time this summer riding with two different length arms as an experiment because my leg length is off between right and left. Once I had ridden it that way for a bit, I never even thought about it (left arm was a 180 and right was 175. Normally just ride 170s, but that combo was for climbing in Utah.)
I firmly believe, after trying 165mm, 172.5mm, and now riding 177.5mm, that your riding style dictates what you should use.
High cadence spinner = short crank arm
Low cadence masher = long crank arm
I’ve tried (Lord knows how hard) to be comfortable at 90rpm. Because the “pros” ride that way. Just isn’t gonna happen.
So I’m a masher and the 177s work for me.
Well, after a fairly long 6 month experiment including 2 half Ironmans, 1 Ironman and a sprint tri as welll as a bunch of training TT’s I can say that anyone who wants my 165’s can have them.
I was no faster on 165’s and I never liked how they felt on hills even though I did go from 34x25 to 34x27 as my smallest gear. My half IM’s were Wildflower, Mooseman and IM France and I never really felt right on hills. My position was never really low for a number of “neck” related issues anyway, so the 165’s never bought me anything more. Maybe it would help if I was riding a lower position. I was hoping that the 165’s would help me for the run off the bike, but I can’t say I was running any faster off the bike even though my open marathon split between last May and this May were only 6 seconds or so apart.
My aero power on 165’s was no lower, nor any higher than on 170’s. It was certainly lower on my hillclimb TT’s.
I’m back in 170’s
That’s because your seat was 5mm too low for effective climbing
Some facts about me and reason for shorter crank experiment. I’m short guy at just under 5’8". Raced first 2 years on a road bike, and the last 5 years on a tri bike. All my bikes have 170mm crank arms. On my tri bike with 170s, I always feel jammed up at the top of pedal stroke. That’s the reason for the change.
I installed 165cm crank arms, raised my seat 5mm and left everything else the same. Rode 20 miles yesterday morning then ran 4. My average speed was about the same as usual given the level of effort. I felt great in the aero position. The dead spot at the top of my pedal stroke was gone. However, I felt horrible on the hills, even small rolling hills. Literally, felt like I was towing a piano. Seems I made up some of that time on the flats (figure 12 miles of the ride was flat, 8 miles of rolling hills and small climbs). On the other hand, I felt fantastic on the 4-mile run.
Questions for anyone that switched to shorter cranks:
Is my experience on hills normal for a first ride on shorter cranks?
With mileage, will my climbing with 165s feel similar to the way it did on 170s?
Is there a breaking in period where my legs need to adjust to the change?
Do I need to accept the trade-off that shorter cranks will feel more comfortable on flats and on the run, but come at the expense of my climbing ability?
Thanks for you input.
Rich
My guess is your issue number 1 is purely psychological. A change in crank length from 170 to 165 is less than a 3% change in leverage. A change from the 23 cog to the 22 or 24 cog is a more than 4% change in leverage. Do you think you would be here complaining that you changed your 23 cog to a 22 and it made climbing a lot tougher, especially when you still had a 24 available?
I am 6’ 2" and currently riding 145mm cranks. I love them even though I had to move to a triple to climb some of the steeper hills around here.
Is my experience on hills normal for a first ride on shorter cranks?
Felt good to me as well. I was not faster
With mileage, will my climbing with 165s feel similar to the way it did on 170s?
I could never get used to climbing on short cranks- I was always slower, hard time on slight grade changes on flats as well
Is there a breaking in period where my legs need to adjust to the change?
Maybe but I did not get faster on them
Do I need to accept the trade-off that shorter cranks will feel more comfortable on flats and on the run, but come at the expense of my climbing ability?
Yes, you need to accept this. For some people the net-net will be better. More comfort, better run, maybe better position. but not more power IMO.
I went back to 172.5 and am pondering 175.
Interesting but not surprising. I seem to recall a thread and me saying to you that it may be better for you or it may the same or you may be worse. The problem, is that people are looking at this first as a speed and power gain, when that is the wrong approach to be taking. You should go shorter if it is a fit issue for you - in other words longer cranks are too long for you and shorter cranks and a more open hip angle are better. This will vary from person to person.
In the case of MissP going to 165’s was very helpful for her. She could ride in the aero position in much greater comfort for longer. The jamming feeling in the hips at 12:00 went away as did some minor lower back problems. Was she faster? Hard to know - she sure was not slower, but my guess is that she was overall a bit faster, due to being able to stay aero for longer and get off the bike in better shape to run.
Do not go to shorter cranks for any other reason than fit or comfort concerns, because the power/speed difference can go either way for different folks. Some claim improvements, some see losses. However, neither difference should be hugely significant either way.
My experience has been much improved comfort overall (all the same things Steve mentioned for MissP), although I do curse the shorter cranks on grinder climbs. However, that inconvenience is still greatly outweighed by overall comfort gains (for me - as with everything, YMMV). I’m a wee bit faster overall with shorter cranks (I definitely manage my cadence more consistently with them), but I don’t know about power differences - I don’t have that cool toy yet…
As Jordan has mentioned on many of these 165 threads, if you are interested, then just get some and try 'em - they won’t be hard to re-sell if you want to get rid of them later.
