Bad idea! 89' cranks on Coker

Today I tried for the 2nd time to egg more speed out of my Coker for some distance riding. Bad idea! Although the speed did improve about 5mph(for estimated total of 15mph), the unstableness and the effort put in(for control) is unacceptable. During the ride, I felt at any moment I would experience a painful UPD. So, I’ve decided 110’ are the best choice when I need speed. Lesson learned. Does anyone want to buy a slightly used 89’ cranks? :roll_eyes:

For tomorrow, I MUni so back to my 170’ tonight! :smiley:

Wow. Eighty nine foot cranks are really long. How do you pedal with cranks that long? The one hundred ten footers must have been even harder.

I’m convinced that 125 mm is the best size crank for an experienced coker rider. I had 114 mm during my Denmark unitur and it was OK, but since they were pretty short it was actually harder and slower to go down hills because of having less control.

I’ve only ridden with 150s and 170s. the 150s are great all around, and the 170s are good for hill riding. I want to try the 125s sometime, though…
didn’t Brian M once put 44mm cranks on his coker once, and film it? it was awesome.

hahaha, whenever I see people (including myself) accidentally confuse feet and inches I think of the movie “This is Spinal Tap”.

i went from 150’s to 125s… i cant feel much of a lose of control . and i can feel a little bit of a speed difference… but it is just so much more smoothe i like the 125s


I have only tried 89mm cranks on a 29er and it was quite fun because it was challenging at first. I plan on getting 150 mm cranks for my (future) coker because I will be using it on campus and on mountainous roads, but once I get a brake I might go down to 125s.

I got that for Christmas!

i feel your pain but you have the wrong solution…the correct one is to annex the Coker and put the 89’s on a 29er or 26er.

What about 102mm then? I’m planning to try those next.

That’s why I love good ol’ Harper :<

I’m going down hills quite fast on my 114’s (Holland is quite a flat land though) and I have plenty of control on it, 114 is my only crank size, so I can’t judge if you have more control on 125’s.

That’s quite ambiguous. Did your speed improve by 5 mph TO 15 mph, or FROM 15 mph?

I have occasionally hit a top speed (as shown on the computer) of 16 mph on the Coker, on the flat, on 150mm cranks, and 15 mph is fairly easily achievable. 125s would be a little bit quicker, at the expense of some control. If I became acclimatized to 125s, I would then find 110s a little bit quicker, at the expense of some control.

Any sudden change by two or more sizes is likely to give you mixed results. I still find it confuses me to change from the MUni to the Coker or the 700c - it takes a while to get used to the different feel. I took the 700c down to 89s and found it perfectly rideable but stopping distances were of oil-tankerian proportions. I had 102s at one time and found that gave me the best consistent speed, but at the expense of hill climbing and cross country. 110s seem to be my best compromise on that wheel.

Look at what Aspen Mike achieves on a Coker on 170s. :astonished:

Having done all the experiments, I think that super short cranks are more to do with the entertainment factor than any genuine increase in useable speed. But these things have to be tried, because they’re there.:smiley:

127 mm gives me a very smooth ride. It has nothing to do with speed.

With 150 mm or longer cranks it is not so easy to keep an even and continuos pressure on the pedals. A couple weeks ago I put my 170 mm muni cranks on the coker and it was not fun at all. At low or zero speed they give a terrific control so they would be good for a beginner, but riding on flat land at an even speed trying to reach the sweet spot where it feels as if the coker runs by itself, is not attainable for me with anything longer than 127 mm. Mind you, I haven’t tried shorter cranks.

Your crank preference will be a factor of your height/leg length and also riding style.

I’ve tried 102mm, 110’s, 125’s and 150’s on the Coker.

My preference for perfectly flat terrain is the 102’s- for me it’s about 5% faster and much smoother than 110s. I’ve not tried 89’s yet. 102’s are absolutely hopeless for climbing though.

The 110’s I use for general riding- uphills up to 5%, and dowhills to 10% works really well on 110’s. It’s really smooth and safer going downhill on these than on longer cranks- you can pedal really fast without any wobble, which makes you more stable.

Most people believe long cranks give you more control- so I’ll qualify my above statement. In terms of riding downhill there are two schools of thought- you can use long cranks because it gives you more leverage and therefore in theory you can stop better. Or you can use short cranks and pedal really fast (but look where you’re going!) and that gives you more control because your lower limbs will not be flying all over the place. It’s also much harder to let your wheel “roll” underneath you with long cranks: Because your limbs are travelling in a bigger circle, it’s difficult to relax. If your muscles are tense- you lose control, you get tired, and it impairs your ability to slow down. On downhills you should only have enough pressure on the pedals to correct your balance. The only time to put hard pressure is when you need to slow down.

The 125’s I like for climbing- I used it for about half the AUT, where the passes were over 10% in places. I would have swapped it back to 110s for the downhills but it wasn’t worth the trouble every time I got to the top of a hill. I certainly had the most fun descending on my 110’s.

I use 150’s for off-road. It’ll climb most things.

Also, note that the above is for an Airfoil Coker with Tommy Miller spokes and a tubeless kit and standard UDC hub. That makes it about 500g lighter than a standard airfoil wheel. I would probably go up a crank length with a heavier wheel.