I’m curious to hear if anyone is fairly proficient at riding a 36er around with 89mm cranks. I have a set on my 36er, and I’m far from used to them. I can climb small inclines alright, but larger ones that are no problem with my 127’s are out of the question. And of course I am currently completely dependent on my brake when going down hills. I’d like to know if it’s worth my time trying to get used to this crank size, or if I should just buy some 114’s or 102’s instead.
I have tried the 89mm ones on my 36", but I swapped them out for 102s pretty quickly. I just didn’t have enough control with them, and I wasn’t able to go any faster than with the 102s. So I would recommend 102s rather than 89mm. For both lengths I think you should have brakes, otherwise it can be hard to stop in time for traffic etc.
89’s seem a little severe. After a while, the little speed you may (or may not) gain from the shorter cranks is offset by the lack of control, etc. Basically what he^ said.
I rode with 102mm cranks for quite a long time on my N36. After that, I had 89mm cranks on it for about a week. Looking back on it though, it seems like I was just a glutton for punishment. I used to be a freak about really short cranks for speed reasons. But after a long period of experimentation, I just ended up embracing 125’s.
I’ve never done really short cranks on a Coker, but I’ve tried most other wheel:crank combinations, down to 80mm on a 700c.
Super short cranks have a “macho factor” but I think the practical disadvantages make them no more than a novelty. There will always be an absolute limit on how much leverage you can apply to accelerate, decelerate, climb or descend. On the other hand, if you can spin longer cranks you have more versatility.
But we don’t do it to make it easy, do we.
I tried them once, before I settled on my quax 114mm cranks as the best all-around size for me. The 89’s were just too uncontrollable and then I tried 102’s, and still those were hard to stop quickly with. You really have to just go with what works best for you, there is no “one size fits all” when it comes to crank length. Some people are perfectly happy with really long 125’s or super long 150’s, which I still use for offroad and 36er trials. 
Well since no one seems to like 89’s I’ll probably just try them out for a couple of weeks. If I’m still not happy with them I’ll just buy a pair of 102’s and 114’s. Thanks for the input, guys.
I just wanted to add that I do like longer cranks like 114, 125 and even 150mm on the 36 as well. It just depends on the terrain and the required cadence/speed. So I put 102s on in order to be able to spin very fast because I am currently training for my first marathon. After the marathon I might want to put on some longer cranks for some less speed oriented riding in more varied terrain.
Yeah, I was just talking about speed here. I’ve also tried 152 and 170 mm cranks as well, both of which serve their purpose.
Dustin Schaap is a short crank freak. He rode 80 mm cranks in races. I think he hit a top speed of 39.3 km/h on those (on a 36").
Progress Update
I’ve been riding around with these cranks for the last week or so, and I have already gotten much more comfortable with them. Today I was even able to climb up a pretty steep hill, albeit with much effort on my part. And on straightaways these things really shine once you get used to them. It looks like I’ll be keeping these cranks on for a while and see what’s possible with them.
Be the first to ride them like a champ.