best way to adapt to shorter cranks / street / slight hills

I know everyone is different and ultimately probably doesn’t matter…anyway…

I have a 26" Nimbus II I use for riding around the neighborhood. I started with 150 cranks to re-learn after a 30+ year break. Now that I’m riding 3 miles I got a pair of 125 cranks. I tried them one day, but the slight uphill / downhill parts of my ride were wearing out my quads. Also, there are some small 1" bumps on some bridges and such that are easier to deal with on longer 150 cranks. So, I switched back to 150 cranks and decided to just ride more and increase my leg power before I switch back to 125.

The 150 are of course a lot of work to get any speed or distance on. So, my question.

If the ultimate goal is to be riding on 125 for distance/speed would you…

a. keep going on the 150 until your physical level is higher and you make it up all hills no problem… then switch to 125.

b. switch to the 125 now and if a hill wears you out just hop off and walk. Eventually, you will make it up the hill after trying days/weeks.

Like I said - I don’t think one way is different from the other, just wanted to hear what others have done.

Right now I’m averaging 4.4 mph on a 26" with 150 cranks going 3 miles on a sidewalk by my local lake.

I bought the same Nimbus II 26" with 138mm cranks. When I started riding the paved park trails last year there were some hills I barely climbed. Months later I could pick up speed on the same hills. I switched them out for 125s and rode the same paths this year and had no problem, although the effort was a bit higher on the grades. I recommend 138s until you get stronger, then the transition to 125s will be less difficult.

I’ve made the transition from 145mm to 125mm on my 29er, then later on my 36er (both came stock with 145mm and I switched them to 125mm). I rode the 145mm until I could climb/descend every hill and was starting to feel the inevitable ‘pedalling too much and going nowhere’ feeling.

I don’t have any 138s ($65 @ UDC) - I bought the 125s because I got them real cheap.

so, my question then would be what happened when you hit the same trails with the 125s? were you still able to climb/descend all or did you find yourself bailing more?

My answer is “b”. I went from 150s to 127s on my 29er and did have some trouble spots, but they were sorted in a few days of riding. Also, if you can freemount, you may be able to get the rest of the way up a hill after a brief rest without restarting at the bottom. That was my experience, anyway.

From what you’re saying, it sounds like you need to work on placing more weight on the saddle, not on your feet.
Switching from 150mm to 125 on a 26" feels weird for a few miles, but it shouldn’t burn your quads. That sounds to me like you’re riding too much on your feet.

actually, as I think back on it I don’t think it was so much quad burning as me just thinking to myself “dang, I don’t remember this incline wearing me out this much…”

I think I’m doing pretty good on the weight in seat part… so much so that I need to stop after 1.5 mile and give my bottom a break. Also, I’m working on learning to take a little weight OUT of the seat so I can adjust the saddle while riding.

On the 29er it was a match made in heaven - I actually found my hillclimbing improved as I was able to spin far smoother! :smiley: It did take a bit to get good at going down hills and work tight corners though.

The 36er was a different story - I struggle with the hills a bit more, and yeah at first I fell off a bit more often. I’m slowly getting better though (and I’m already happy with how much better the 125s make me everywhere else) :smiley:

I’ve actually done quite a bit of climbing on the 36er recently so I reckon its just a case of practising it and working up the strength no matter what length you run.

I suggest keeping the 125mm cranks on a little longer. I moved from 150mm to 125mm on my 29er. Yes it was difficult at first and I did have to stop on the hills but over time it did get easier. Like all other unicycle skills it just takes practice.

I live on a hill and got tired of putting my unicycle in the car to drive to flat trails. I wanted to ride there and back, so I had no option but to learn how to ride up this darn hill. There are several ways to get up it so I scoped out all possible routes. Now I know which are easier than others. I started on the easier ones and try the harder ones when I need more of a challenge.

I recently moved from 125mm to 110mm because the 125’s were starting to feel a bit slow. I had to move back because of an injury but will be back to them soon enough.

One thing to note is that I’m 5’-5" tall. Shorter cranks seem easier to me but I think taller riders might find them more difficult to ride.

If fitness, is the only thing your worried about then switch to the 125.

When I switched from 150 to 125 on my 26" it seemed like I was going to fall so much easier. So I got 138.

If you want to ride distance, forget the 26" and get a 36" because they are easier to ride. Harder to mount and turn. I like control over speed so I ride my 36" with 165 and average 10 mph.

It is definitely easier to spin a pair of short cranks. However, cadence can be increased on a set of longer cranks. The conventional wisdom is, I think, that longer cranks require greater angular velocity, as well as a greater distance traveled in one cycle, for a similar cadence…than do shorter cranks. Another factor, as well, makes longer cranks harder to spin fast. The amount of motion in the legs, with longer cranks, tends to throw off the balance. It is hard to ride fast when you’re wobbling. When I started using handlebars, I was able to offset the wobble produced by trying to spin big cranks…and my cadence increased quite a bit. Now I don’t feel it is necessary to move to shorter cranks. I live in a hilly place as well. I also think long cranks will save the knees, and they make me more confident about riding on uneven surfaces. My closing advice: experiment!

The best way to adapt is to do it lots.

Definitely go straight to the shorter cranks and just go for it. If you wanted to take the easy root you would still have a training wheel.

update after ride

okay I put the 125s back on and went for a ride. Here is my report for you guys to comment on.

I rode a 2.5 route that I have ridden before with 150s. The route has moderate uphill / downhill. It has sidewalk ramps and two bridges to deal with (each bridge has uphill/downhill + bumps where the bridge connects to the sidewalk).

I can do this route with 150s and will only dismount 1-2 times. When I’m done I am sweating good, but not winded.

Tonight I tried it with the 125s. I dismounted about 10 times and 2/3 of the way through was pretty winded which made free mounting quite a challenge.

I was able to make it up/down all the hills without dismounting. The dismounts come when I get going too slow trying to navigate corners of sidewalks and cannot power through the tight turns due to the shorter cranks.

The other thing that kept freaking me out was the falling forward sensation every time I got any speed going.

I’m going to try to post an illustration of what I think is going on. I think that it has something to do with the center of balance of my body going beyond the pedal range sooner. Imagine if put the pedals in a 3 and 9 o’clock position and then draw a vertical line straight up from the front pedal. Your body is going to pass through that line sooner on shorter cranks than it does on longer cranks. I think when you pass through that line you get the “falling forward” sensation.

Normally, when I hit 2.5 miles I feel like I can keep going. Tonight with the first time on 125s I was glad to reach the 2.5 and stop. Face red and out of breath.

I will keep them on and keep riding hoping that this will go away as I get more proficient.

Also, I think what really gave me a workout was that I was going too slow and really having to use a lot of leg work on short cranks to keep balanced.

What you’re saying about your center of mass and the position of the pedal seems reasonable enough to me.

I think it’s more common for new-ish unicyclists to make half-inch jumps when changing crank lengths, so you’ve effectively skipped a step. Not impossible to pull off but yeah, definitely a bigger adjustment to make. I’d say give it a few more days, let your body have a little time to adapt to the different dynamics, and stick to an easier path without as many bumps or as much tilt if you can while getting used to them. Before long you’ll be wondering why it seemed like such a big deal.

Ken Looi can explain this much better than I (Look for his write-up after doing serious miles on a standard 26er with long cranks) but I’ve found this to be true as well shorter cranks reduce saddle pain. It’s true! Also, flat (no hills) asphalt paths wreak havoc on my rear! I need those hills to get me out of the saddle. Riding mUni never, ever results in saddle pain for much the same reason. As for crank length advice, I’d say ride what you are comfortable with until you feel you need something shorter. I personally love me some 165s for mUni. Then again, when I’m riding off road, I’m in no hurry. There is a downside tradeoff that Kris could explain better but longer cranks increase your dead spot when you roll over a root or go off a drop and don’t land with your pedals perfectly level in the 3 o’clock and 9 o’clock position. The solution is always time in the saddle. The more you ride, the more you know. Good luck!

I’m trying to decide it I need to drop $65 to get some 138s. Like I said, I bought the 125s because they were crazy cheap ($27).

$27 really is crazy cheap! ISIS cranks in good condition usually go quickly on the Trading Post here, so you wouldn’t stand to lose a huge amount if you bought some 138s and wound up not wanting to keep them forever.

But most of us took up unicycling because we wanted to take on a challenge. That’s why I think you ought to give it a few more days and see how the adjustment goes. It sounds like you’ve gotten out of your comfort zone but I think you can do it. There’s a good chance you’d be doing a lot better with the 125s by the time the 138s got to you anyhow.

I just checked the price to make sure I was not lying. Yep… $27 AFTER SHIPPING. They sell them for $22.95 @ and also have 114s and 145s. The 125s are out of stock right now.