Crank length and hill climbs

This will be my third year racing in the Whiteface Mtn Uphill Bike Race. It is 8 miles and 3500 vertical feet, with no letup, that is the grade stays above 6.5% and below 11% the whole way - no flat or down to rest on.

My first year, 2005, I’d been unicycling for less than a year, and I rode my KH29 with its stock 150mm cranks and a Big Apple 2.3 road tire. My time was 1:59:14 and I had trouble with too slow of a cadence.

My second year, 2006, I used the same uni with 165mm cranks and a Big Apple 2.0 tire instead. During training, I was climbing hills I hadn’t been able to the previous year, and this showed in my 2006 finish time of 1:25:53.

Now this year’s race approaches (June 16, 2007). I’ve been doing extensive muni with the KH29 and the 150mm cranks (including the 24 HR race a couple weeks ago), and I’m climbing all those training hills on the road even more easily than I did with the 165s last year. I’m either stonger and/or more skilled (probably both) thanh I’ve been in previous years.

So, given this, I’m considering doing Whiteface with the 150mm cranks again, even though my first year w/150s (as a wobbling newbie) my time was so slow and second year (w/165s) the time was much faster. I think I don’t need the longer cranks now with more strength and better technique.


It sounds like you should be good with 150s. I switched from 170s to 150s on my MUni, and have been doing fine on uphills, it’s really the downhills that kill ya’.

I’ve been cokering for only about three weeks, I started with 150mm cranks and had those for two weeks. There were certain hills I couldn’t climb and some longer not quite as steep hills which posed problems. The past week I’ve been riding a lot with 125mm cranks and I’m able to conquer both the steep and the long hills now which posed problems on the 150s. With having said that, my speed, technique and strength have all improved. I suspect similar results for you and encourage you to give it a shot with the 150s.

Are there any times during the climb with the 165s that you felt your speed was being cadence limited? Meaning that you could have gone faster if you could only spin the pedals faster for that section of the climb?

My comfortable max pedaling cadence with 170s on my Coker for climbing is right around 100 rpm. That translates to about 10 miles/hr on the Coker. Faster than that and the long cranks feel like they’re slowing me down as I could spin shorter cranks more efficiently.

Your average speed on the Whiteface climb is about 5.6 mph. That’s maintaining an average cadence of under 70 rpm on a 29er by my rough calculations. That’s a nice comfortable climbing cadence with long cranks.

If you’re comfortable with climbing efficiently with long cranks those speeds on the climb are not cadence limited. So I doubt the long cranks are slowing you down due to cadence.

So the question becomes are you able to pedal the 150s more efficiently while climbing so that you save energy and thus can go faster? Do you think you’ll be able to pedal 150s while remaining seated for the fast majority of the climb? Having to stand on the pedals slows the cadence down (and thus slows the unicycle down) and uses more energy. So being able to stay seated with longer cranks and just spin them can end up faster than going with shorter cranks where you have to stand on the pedals more often.

When I go for a hill climb on the Coker I use 170s. For a pure hill climb the 170s are not slowing me down since I’m not fit enough to be doing 10+ mph going up long hill climb grades. And I’m able to stay seated for the climb and just sit and spin my way to the top of the climb.

One of the primary problems that Ben and Mike had at Mount Washington was dead/cramping/seizing-up quads, forcing them to walk at times. I see this as too much exertion of strength. To me, it might be better to describe larger circles with less force per degree. This would allow you to trade system fitness for leg strength.

This approach argues for smaller wheels and longer cranks. Lower your gear and increase your leverage to shift the load to your cardiovascular system away from your quads. If the road surface allows, raise your seat and try to rest more of your weight on it.

Secondary complications include choice of tire, your leg dimensions, the road surface characteristics, and the like.

One of the reasons Lance Armstrong did so well was just that – using a lower gear and spinning faster. He could go the same speed but had a lot more left at the top of the hill.

There are lots of lower-level energy transfer arguments that support this view.

Since your big thing is being light and system-fit from frisbee et al, to me this would be the best approach for you. You will need to practice spinning at higher revs with longer cranks to be effective with them.

Don’t think of using longer cranks as a baby thing or whatever. Just choose the right tool for the job, and off you go!

The last time I did Mount Diablo, I did it on a 29er with 125mm cranks, after using 150mm for my previous attempts. I beat my previous fastest time by five minutes, and was the only one in the group to make it up the extremely steep (14%) bit at the top.

Diablo sounds a little less steep than Whiteface; it’s something like 11 miles of climb for 3300 meters. But I wouldn’t worry about the shorter cranks; if you’re trained up with them, you’ll do fine.

My main concern this year is there’s competition. I’m one of at least 5 unis, as opposed to 2005 and 2006 when there was just me. Also, everybody entered is strong and at least 3 of us are pretty sure we’re going to win the uni category.

Er…3300 feet I assume you meant? So you spun the shorter cranks a bit faster. Hmm.

However, Whiteface is nowhere near as steep as MW. The grade on Whiteface allows for constantly seated pedaling. So I’m still wondering if the right tool might be the 150s. This morning I rode up a 3 mile, 1100 foot climb, but it’s a bit different because it has many changes in grade, from flat to around 25% on the last stretch. That part required standing. Maybe I’ll try the same climb with the 165s and compare.

Hmmm. Yes, on Whiteface I’m able to sit and spin. There is no place standing is needed. But with less force to push, as with the longer cranks, I might be able to spin the 165s faster overall. Still, my legs are kind of short (I’m 5’6") and the 165s always felt like a bit too large a circle.

Decisions, decisions. :thinking:

Yes, sorry. 1000 meters, 3300 feet. I think the shorter cranks kept me more honest, working harder to keep the spin going on the steeper sections.

If the longer cranks don’t suit you because of short legs or general body mechanics then go with the 150s. You said you were able to sit and spin up the climb with the 150s so they’re good.

If you’re not able to efficiently pedal the larger cranks in a proper pedaling circle then they can easily slow you down or waste energy. It’s very easy to lose pedaling momentum at the bottom of the pedal stroke if you’re not able to properly spin them in a circle and keep the pedaling force going at the top and bottom of the pedal circle. That waste of energy and speed can slow you down on a climb. Wasting energy is bad when racing up a climb.

Well I race single speed mtn bikes so I’m going to try to help you out here a little bit. Riding a harder gear on a bike is like having shorter cranks on a unicycle. So the trick to single speeding is to have as hard of a gear that you can get up most (or all) of the climbs on a course with. So if you have a harder gear, it forces you to push harder to maintain your speed going up a hill and therefore get up the hill faster. But if you have too hard of a gear, you will either be wasting energy standing up trying to push that heavy gear up a hill or just have to walk. Where as having too easy of a gear just completely ruins the whole point of singlespeeds which is to accel on the climbs and pass the people with gears. So on a hilly course I tend to go with a harder gear which does seem kinda backward but it makes you pass those people dare I say “like lance armstrong” who just spin those easy gears. So in that regard Ian ulrich rides like a singlespeeder but he got banned for doping along with the other 1/3 of the road racing community. well it got kinda off topic there but I hope that helped and good luck in your race


Crank Length.

Hi Steveyo!

First of all good luck to you this year! I would go with the 150’s. After many years KH has made them standard on his Muni’s meaning that as he and others got more experienced the shorter crancks became better. I love MUni much more and therefore don’t ride my KH29 that much. I have the stock 150s on it. However I still notice that the 150s are getting much more comfortable. Also there are less and less times that I just can’t climb a section with them. One of the most annoying things is when you just can’t spin your legs around any faster but you aren’t using much muscle power.
If you want to invest some money in this passion of yours you might want to consider a Guni. Higher geared power with longer cranks. I think Gunis are manufactured by Livewire. If I remember correctly they have a pretty good site with a lot of links and usefull info.

All the Best!


I’d say go with the 150’s. In fact, I’d wager that once you are done, you will wish you had used 137’s on that 29er.

Good luck with the race!

An interesting story

Congrads on your large improvement in the second race. It sounds like your gut is telling you the 150’s are more fun.:wink: Perhaps that should settle it.
However, if you are real competitive, perhaps your best fun would be the shortest time. So then there is little option but to break out the stop watch .
The racers friend !:smiley: On the bright side, uni testing is cheap and not as much of a pain as swapping engine parts etc. So have some fun testing. Let us know what you decide.:slight_smile:

Whats the difference between them, exept length, which is faster, which is easier?

What kind of cranks are on a DX 20 inch?

Good luck this year.I’ll be waiting to hear about your climb and win. Your results will help me out alot. I want to drop down to 150’s, but I can’t seem to get off of my 170’s. I can’t imagine climbing San Francisco hills on 150’s[> 20% grade]. The responses from your thread are exactly the type of info that I need. I have been wondering if my 30 inch inseam legs are too short for 170’s. that’s a big circle to have to push on. I think you should choose the length that will be the most FUN.

Well I climbed that 1100 foot vertical training ride again with KH29 and 150mm cranks. This time I was a bit more tired from a muni ride the previous evening and found it a little bit tougher. I still made the last pitch of 25% grade all the way to the summit but it was a bit more effort. Then I lay awake this morning ruminating on it and decided to swap on the 165s and ride the climb again. I think now that I may go with the advice of U-Turn:


Sitting and fast spinning appeals to me now more than mashing. I’ll post once more (at least :wink: ) after tomorrow training climb with the 165s.

OK - I did this training climb once more with longer cranks (165s vs 150s). I still had to stand, but only on the very steepest bits. After the climb, the descent was easier on my knees, which I’d expected. On the medium grades of the hill, (which is like my upcoming race) I was spinning the wheel more easily than with the 150s. Most significantly, at the end of the workout, I had plenty of steam left, and added another steep, long hill to top off my endorphin buzz. This last hill I’ve never before succeeded in climbing continuously.

I’m afraid, since the race has no letup, that the 150s would eventually tire out my quads too much. With the 165s, I can stress my aerobic capacity more and spin rather than mash the pedals.

So… I’m going to leave the longer cranks on for the Whiteface climb on Saturday 6/16/07 and hope to break my record of 1:25:53. A nice bonus would be winning the Uni category, which, this year, will have at least 4 other entrants. In 2005 I was the first and only uni, and I was also the only uni in 2006.

I will post a race report after Saturday’s race.

I was going to say stick with the 150s but your research should be more reliable than my opinion. :slight_smile: I was going to note that all (or nearly all) of us on the Tahoe ride last week used 125mm on Cokers, but that ride is a mix, of up, down and (not enough) flat.

Certainly your fitness has improved in the last two years, as well as your skills. But if you feel better on the 165s, that’s all you need to know.

I’ve always been fit from playing competitive ultimate, but my unicycling-specific fitness is way improved, esp. from two years ago. Training for the 24 hr muni race, and now this race has gotten me to a personal high point re: uni-speciifc fitness. (I hope :astonished: )

I did notice more saddle-soreness from using the longer cranks, and, yeah, John, if I had any real distance to worry about I’d go shorter, but this ride is only 8 miles, all constant-grade, and all up.

I’m still torn, really, and maybe next year I’ll try the 150s (or shorter?).

Sounds like you’ve done your research and your training Steveyo, so I’m guessing you’ll have a great ride. I’ll be there too, and over the last week I’ve been trying to decide on wheel size and crank arm length. I have a 28"wheel that feels really good with 175 mm cranks I robbed off of my tandem bike, (I’m 6’2) and also a 26" wheel with 170’s. I did a practice ride last weekend and hit the wall with the bigger setup, just used up my legs after 4 miles with pitches a little steeper than Whiteface. The other day I did the same climb with the 26 and felt like I could go all day. I’m thinking I’ll go the spin route rather than the mash, especially since I haven’t done Whiteface before and don’t really know how hard it will be. I don’t have any expectations of winning, just fantasies! :roll_eyes: