A few years ago every triathlete with some ambition drove as long cranks as they could on their bikes. My standard over the years (and I´m 190 cm/6.3 ft) has been 175 mm. When I was at my strongest I rode 177.5 and even 180 mm and pushing huge gears. It made sense for getting more leverage and being able to crank away with power and low cadence.
Now it seem that a lot of triathletes are moving down to shorter cranks, A LOT shorter (Crowie, for instance…)! The point being to open up the hip angle and also to relieve some added stress (from longer cranks) on lower back and glutes.
As far as I understand one need to make a substantial down shift in crank length in order to really create a difference. Some advice I´ve got is to shift from 175 mm to 167.5 mm.
Does anyone have any experience or thoughts on this? What´s the potential positive effects for me, as well as the negatives? In the past I´ve typically ridden in a lower cadence but would like to see an increase in cadence… Is this the right move?
Hi Jonas I can only give my experience b/c just as many can’t stand them as like them. I came from the old school like you. In the early 90’s we all wanted to be like Mike Pigg and roll a 56T with 180’s and grind out 60 rpms. I’m 6’1" and ran 175’s for nearly 25 years, but went to 165’s about 3 years ago. For me it was huge in every way and a win.
I didn’t realize how tight I was at the top of my stroke until I put 165’s on and my aero position just became a joy. Some people complain about a slightly higher cadence to which I respond, try shifting gears. I tested with power for a long time and I definitely put more watts down for longer ~ 90 rpm’s with 165’s than I did @ 75 rpm’s on 175’s. Plus my legs just felt way better.
In the end I don’t think you can lose by trying. Only wish I’d have let my ego take a seat long ago b/c I was shortchanging myself…and my knees.
Hi! Jonas,
We met at the Bonelli start a few years ago.
Dan put me on 165s (from 172.5) a few years ago. My position and speed were instantly better and I’m more comfortable. You’re a bigger person, so I can’t speak to how they would work for you, but it’s definitely worth a try, IMHO.
My knees are fine. My lower back and hips, not quite so:)
If you train with power it will be really easy to quantify. I used to ride 175’s on road and tt, but my tt power for a 20 minute test was ~ 20 watts less than my road power. After I went to 165’s my power difference was down to less than 5 watts b/t the two. I narrowed the huge gap of power by one change only and that was shorter cranks on tt as I still ride 175’s on the road bike.
Holy mackerel I didn’t realize this was Jonas Colting!!! I looked at your info and about died. You are one of my all time favs.
Do you by chance have any links or reading material beyond what I find on Google regarding your low car/higher fat diet? Really found that interesting and would love to read any updates or detailed info. Thanks and ride safely out there!
A few years ago every triathlete with some ambition drove as long cranks as they could on their bikes. My standard over the years (and I´m 190 cm/6.3 ft) has been 175 mm. When I was at my strongest I rode 177.5 and even 180 mm and pushing huge gears. It made sense for getting more leverage and being able to crank away with power and low cadence.
Now it seem that a lot of triathletes are moving down to shorter cranks, A LOT shorter (Crowie, for instance…)! The point being to open up the hip angle and also to relieve some added stress (from longer cranks) on lower back and glutes.
As far as I understand one need to make a substantial down shift in crank length in order to really create a difference. Some advice I´ve got is to shift from 175 mm to 167.5 mm.
Does anyone have any experience or thoughts on this? What´s the potential positive effects for me, as well as the negatives? In the past I´ve typically ridden in a lower cadence but would like to see an increase in cadence… Is this the right move?
Jonas, also a higher position might take care of things for your issue, but you will be less aero.
Echoing what other’s have said, a couple of year ago I switched from 175s to 170s and then down to 165s last year. The extra clearance while in my aero bars has really helped, and allowed me to ride in a more aggressive aero position.
The downside is that I still have 175s on my road bike and I switch back and forth between them frequently enough that I never really feel like I fully adjust to one or the other. If possible, I recommend keeping consistent crank length on the bikes that you ride.
I started out on 170. I’m 5’7". I used to find a huge gap in power between road and Tri positions of about 10% which I just could not close. 3 years ago I went to 165s and FTP stayed the same. This year I went to 155s and managed to equal my road FTP on the Tri bike for the first time ever.
I did notice the increased resistance from the pedals at the same gear and same cadence but after a while that sensation went away. My cadence has also stayed pretty much the same from 170-155 cranks at 90-95rpm.
Thanks, yes that´s me:)
We have lot of websites and material in Sweden, as it´s been almost a national revolution over here regarding low carb-high fat. You can check out www.kostdoktorn.se and look through his English-written material.
Jonas…we are planning the Mauna Kea 10000 and Mauna Kea 14000. The first version has a swim in Kailua peer, ride to the visitor centre, short run to 10,000 feet. The long version will have a 7 mile run to 13,800 feet. I did a recce for this and will have an overall article on that, but here are some personal notes from this year’s workout:
I hope your hamstring injury comes along. Your position did not “look” too high when we did that piece on your ultraman race, but photos can be deceptive.
I think everybody has a sweet spot and that spot has little to do with their height or leg length. If you read all the various accounts out there (many on this particular forum) you’ll see a full range of experiences, good and bad. The problem is that you don’t know how they tried various lengths and how they tested.
The only way to be sure is to try a range of lengths. The toughest part is getting the various lengths you want to test. Borrow maybe. Or find some cheap alternative models – use ebay, something like that. But you would also need to normalize your fit across each crank lenght, adjusting seat height, reach, etc. I’m guessing someone with your resume would probably have access to a fitter who could help you out with that. Or maybe you know enough about fit to do it yourself, I don’t know.
Personally I did not. I have one professional fit on my tri-bike that I loved. But at one point I had access to a slightly shorter crank and found I liked it better, with only a tiny adjustment of my seat height. Nothing scientific about the change. At the time, I did not even own a power meter so I had no objective way to tell if I was better off or not.
But with my road bike, I never had a fit to begin with. So I monkeyed around a lot with it. With various sales and eBay purchases, I have 3 copies of the exact same Shimano crank with 3 different lengths. 165, 170 and 172.5 I’ve played around with it but only for feel. Nothing objective. Right now I find that 165 feels too short and I like 170 a tiny bit more than 172.5. Eventually the idea is to make an objective test.
I think one would do well to devote a summer to it. A few weeks at each crank length to get used to the differences. Run the same power tests a few times and compare numbers. Go to your fitter and have him make adjustments. Or if you can do it yourself (or be shown what adjustments to make in my case), you could test each length on the same day if you wanted.
My N=1 experience has been that going from 177.5 cranks down to 165s allowed for slightly more comfort in the aero position, with the trade-off coming in reduced maximum power bursts. Standing in the saddle, the small pedal stroke feels cramped and I don’t have the same ability to surge or sit up and sustain a long, hard effort. I tried changing my gearing, but it’s not the same.
I’m going to be doing ironman lake tahoe, and will be switching my TT bike back to either 177.5s or 175s.
Thanks Jonas that is an awesome site I’m ‘devouring’ it now.
Best of luck in working on your low back issues. One little caveat I will suggest to be aware of…and let me say I feel really stupid for saying this to someone with a pedigree like yours, but will anyway since it’s almost always left out of crank shortening discussions. If you want to keep your 3 o’clock position the same with subsequently shorter cranks you have to actually add some setback. So in my case I went from 175mm to 165mm and had to push my saddle back 1cm. Most people get the saddle height issues and effect on drop, but the setback issue gets little to no coverage and it was huge for me dialing in the 165’s.
From personal experience, I would get yourself into reasonable shape on the 175’s before switching. Once there, start setting some recent standards (over the course of a month or two) for some time trial routes, and some standards for power data. (also have for reference previous years times for these tt routes, and previous personal best power data). Then make the switch. Give it a month or two and see how you do relative to these recent bests on your tt routes and with the power numbers. Also compare to all time bests. If you start beating the recent bests right off the bat, and eventually start beating all time bests you know you are on to something. If you don’t do this you may start 2nd guessing your switch.
For an experienced athlete like yourself, you’re gonna feel a difference even just going to 172.5. I would only drop down to 170 maximum right now. Also change your front ring down to 52 or 50 (prob alright w 39 little ring, unless it’s a really hilly area then consider dropping that too), it’ll spread your gearing better so you don’t get bogged down with too big a gear. After you adapt you may be able to switch back to harder gearing again. You cadence is definately going to go up if you want to produce the same power.
You’re probably not going to be as good on steep climbs unless you really learn to spin up them, and you may have a higher heart rate at the same wattages until you adapt to the higher cadence. You’ll have to see if you can bring this higher heart rate down over time as you adapt to a higher cadence, and if you can sustain that higher cadence over the course of a hard 56 miles or 112 miles, or whatever you distance. It’s easy for short time trials, but the longer distances the cadence can slow a bit and when that happens you may miss that extra torque you have with the longer cranks.
