crank arms....any suggestions?

any help is appreciated…I have a 24’’ muni with no crank arms. I bent the stock arms while jumping off of a 4’ wall. I am looking to put new cranks on there that will do a better job. My question is what length should I get to go off road and have a good time, and that will be strong enough to not bend after every wall jump, and that will work on my muni. I was looking on at the black widows. Just need some help. I dont’ know what length or type I should get.

if you’re looking at black widows that probably means you have a square taper hub, right? if you do, then they are a great choice, but a splined set up is what you need if you’re going to be jumping off of things routingly.

150 mm cranks work well with a 24" wheel. I find I can tackle very technical trails and steep terrain just as well with 150s as with 170s. It takes a little adjusting to the slightly shorter length if you are used to 170s but the little you lose in power is more than compensated by the extra speed you gain.

I would not go shorter than 150s if you are going to be doing agressive riding.

If you are jumping off 4 foot walls you really should consider upgrading to a splined axle and cranks. In the long run you will save money. I have found even the best square taper cranks I can find only last 6 months, and that is with careful use (ie plenty of sub 3 ft drops but nothing bigger). In general I find aluminium cranks are less likely to bend but they tend to need constant tightening (often multiple times during a hard core ride).

The best non splined cranks I have used were Kookas.

You need to be careful OJ, you might have twisted the hub on a square taper, especially on a 4ft drop… Check its still true, hopefully it’ll be fine.


yes. I bent my 20" norco going off a 1.5’ drop. Now I’m trying to find the cash to get myself a proper freestyle uni!

I like the Black Widows but I don’t know how strong they are for doing the style of muni riding where you’re jumping off of things and doing 4 foot drops. That’s an unknown.

I used the Black Widows for basic XC muni riding back when I had my Pashley. I wasn’t doing big jumps or drops. Just XC style riding on rooty trails.

What I like about the Black Widows is that they are made from 7075 aluminum alloy. That alloy is harder and stronger than the 6000 series alloy used for cheaper cranks. The Black Widows have a very nicely machined taper. The 7075 alloy means the taper holds its shape and doesn’t deform as easily as cheaper cranks. Once the Black Widows are installed correctly (with a torque wrench to 40 foot-pounds and Loctite on the nut/bolt threads) they will stay tight.

I have 150mm, 160mm and 170mm Black Widow cranks. I now use them on my Coker. They work great for the Coker. I just wish they came in some shorter lengths too like 140’s and 130’s.

If you’re looking for 170’s you can try the Sugino tandem cranks. See this thread for links on where to order them online. You can get tandem cranks without the spider on the right crank. The Sugino cranks are good quality and not expensive. If you do manage to break one you can replace them for not too much money. If you bend or break a Black Widow crank you have to buy a new pair for $90. If you bend or break a Sugino crank you can buy just the single crank for about $15.

As for what length to get it depends on the terrain that you ride. If you have steep ups and downs you may want longer cranks like 170’s. If you have lots of roots and rocks and curbs to roll over you may want 170’s. If you want more speed and smoother pedaling you may want 150’s or 160’s. It all depends on the terrain and your riding style.