KH crank alternatives

Has anyone tried to place a different crank on the KH 8-spline hub? I was noticing at

Bulletproof BMX Splined Crank Arms

8-splined, after-market chromoly crank arms for use on the DM ATU and DM Vortex. The raised spider braze-on has been removed on a grinder.


They’re 175’s which would not be my choice. Perhaps some other 8-splined BMX crank arms would work. Do splined hubs have a standard diameter for the shaft? Something with a little Q would be nice.


I would also like to know of any alternatives for a KH crank. I have a Summit 20 on the way with a KH hub. It comes with 140 cranks; I think I want something closer to 125 or 130mm.


In my post about the KH wheelset in the Yuni frame I posted about the alternatives to the KH crank.
Every 8 spline crank I have found will fit. The 20mm axle that the KH uses appears to be a standard in the BMX industry.
Cranks that I have personally fitted to the axle are: Specialized, Big Cheese (the makers of the Specialized) and the Diamondback. Redline also has an 8 spline that looks like it will fit, it is not the current crank, but the older model.
I asked Jordan at to try the DM cranks and they do fit. The Bulletproof is the same spline pattern as well.
The problem is that these BMX cranks only seem to have been made in lengths of 175 and 180mm.
The only one at 170mm is the DM (they also list a 150mm length)and they cost $ 215.00. From what I understand, they are custom made by Dave Mariner and the cost is reflected. But I just can’t bring myself to spend that kind of dough for a set of cranks. I decided to put it towards a Profile wheel.
My son has no problems whatsoever with the KH cranks and the set up will serve him well for a long time I’m sure.
I wonder if I was not used to riding Profiles if I would have been just fine with the KH set up, but I am used to Profiles and so …
My foot placement on the trails is sort of duck-like, toes slightly out and heels in. I wear a hybrid hiking/sneaker style shoe with a large heel. That in a size 13 and these other factors end up making for too much adjustment. I have to place my foot halfway off the pedal and that as you can imagine is not good.
The KH cranks were probably designed and made just for this project (I’ve never seen anything like them before) and I don’t know why they just didn’t copy an existing design in a 170mm length.

thier probably are other alternatives, but you’d almost ahve to go to a shop and measure up the spindles and test slip them on to find out. and even if thier are, there will be no 130’s, bikes just dont use that short a crank. profile has the shortest three piece at 145 I think. I could be wrong, but that’s my guess.

The only way you are going to get splined cranks that short is to have them custom made. The DM splined cranks might fit the KH hub (I don’t know for sure). DM can cut down cranks. See this thread
But that option is going to be very spendy (I can see the custom cranks costing as much as the Summit). And you have to get DM to do it. If you know of a local machinist with the necessary skills to cut and re-weld the cranks you could get it done locally. But it’s going to be expensive then too.

KH replacements

Would you need another spacer to use other cranks? The KH cranks have the bit on the outer side of the crank arm. Most cranks I have seen don’t have that. What would you do to keep the cranks from moving back and forth?

Hi Frank,

Thank you for the good information. Now that I know the KH spline is standard… check these out. They are available in 170mm and 175mm and cost $155 (USD). They appear to be 8-spline from the photo but it’s not in the description. I’d pay $150 if they fit. What you think?


Azonic 454 DH Crank Arms
Features 100% 4130 chromoly arms with the same unsurpassed quality that the Azonic brand name is known for. The arms have an incorporated pinch bolt mechanism that will keep these cranks tight in all types of riding conditions. Includes bottom bracket with 4140 chromoly spindle and cartridge bearings. Sizes: 170 or 175mm. Finish: Polished 680g
(Spider sold separately)


Hi Jason,
Unfortunately those Azonic cranks have a 10 spline pattern. I will continue to be on lookout but I don’t think you’ll find a production 8 spline crank less than 175mm long.
If memory serves, the way the BMX crowd figures it, an inseam of about 30-32 inches should use a 175. I guess the thinking was that a shorter inseam would be a smaller, lighter rider who would not need the extra strength of a splined crank? I don’t really know.
Some of the current crop of cranks are being made in 170’s but they are a different spline pattern.
The spline pattern on the KH is/was a standard for some companies but the current trend seems to be larger diameter axles and more splines.
175 is a lot of crank for a 24 X 3 , I installed some on my KH and rode around a while. They fit perfectly but they are longer than I want to use.
DM cranks will fit and has them in 170mm, but they are $215.00 a pair. It’s still alot less than a Profile wheel though.

Hello Frank,

That’s a bummer about the Azonics, I found them for $100. It’s nice to know we have options though and I might be willing to buy the DM cranks. Like you said, it’s cheaper than purchasing a Profile setup. The Profile kit’s $300 and that doesn’t include buying a rim and having the wheel built. Do you know if anything special has to be done for the DM cranks to fit properly on the KH hub? Also, do you ever smack your heal on your Profile crank protrusion, or is this problem strictly on the KH cranks? I would be very disappointed if I purchased either the DM cranks or a Profile setup only to find I was having the same problem. Thanks!


Gusset Pygmy 165mm


P.S. The Profile trials cranks on the same page are the best square tapered cranks I’ve seen


 The Profiles and the other "normal" splined cranks I have used do not present any of the heel strike issues that I experience with the KH cranks. Have a look at the cranks Leow supplied the link for, looks promising.


Thanks for the link. Those 165 pygmy cranks look like the answer. All we need to do is find a way to buy them. The site states that they do not sell to the general public.

I have never tried the KH ankle bashing cranks. I have a set of profile 170mm cranks and there is no problem of hitting the center part. I am keen to get myself some 145mm cranks when I can afford it because compared to the amount of steep hills I ride up I would like some extra speed for cruising (before buying a larger unicycle). In the site that Leo linked to it says “Coming soon, New tall Pigmy 175mm, New Full sized version because some folks asked for them”. This implies that they are open to suggestions. Maybe if enough Unicyclists ask for them to provide an alternative short length splined crank they might consider it. Since I have a Profile hub I won’t ask them, but it could be worth letting them know that theres a gap in the market for short 8 splined alternatives to Profiles.

I don’t think all 8 spline cranks are all exactly the same.

Some BMX axles are based on 20mm axles, some on 3/4" (19.2mm)

Also the KH cranks I saw didn’t fit on all of the possible orientations on their own splines.

Ask John Drummond to try DM cranks on a KH axle to be sure.

The Gusset cranks are marketed in the UK and sold by several outlets here’s one :


I have asked to try the DM cranks. I held on the phone while they tried them and got the verification. I spoke with them the next day and Jordan told me he did a complete installation and rode it around. They fit.

The 20mm BMX and KH axles taper down to 19mm +/- at the splined section. This would also explain why the Profile washers fit the KH crank at the spline, which I have on my axle in place of the KH dust cap washer.

Every Taiwanese made 8 spline crank made to fit the twenty mm BMX axles that I have found fits the KH spline. For all we know they are probably all made in the same factory. I’ve done a fair bit of research on this and while I can’t say for sure that the Gusset cranks would fit as I’ve never heard of them or seen them before, if they have 8 splines and a 20mm axle, I think it’s a pretty good bet that they would fit.


Good job leow! I’ll keep on the hunt for cranks too! Let me know if you come across any 170mm ones.

Frank A,

Wow, Jordan did a full install and test ride! That was very kind of him and above and beyond the requirements for a company to help it’s customers. I really like for this very reason- they go the extra mile for guys like us.

My problem is that I really want 170mm cranks and apparently it’s an odd size in the BMX world of cranks. I almost ‘need’ this size crank to accomidate my ailing knees as they provide just the right tork ratio to not put a lot of strain on my knees. At $215.00 the DM cranks are a bit spendy and I would like to find an alternative before I drop the cash. On the other hand, is a great company and takes care of it’s customers making it a toss up. I think I would like to find an alternative just to know there is one even if I end up buying a pair of DM’s, but they are now tried and proven!

Also, I am wondering why you changed out the KH dust caps with Profile ones?


try danscomp. it looks like they have two cranks in the 170 mm dept.

  1. poverty p.o.w. ($90)
  2. demolition ($140)

Very nice.

The Poverty p.o.w’s for $89.99 look like they would work fine and the price is right. I also like that there’s a choice of black or chrome. The spline in the photo looks remarkably like the KH spine.

Does anyone know if the riased spider braze-on needs to be ground off for a proper fit on a unicycle or is it strictly a cosmetic change when done by (or whoever)?


now, i have an idea,

iirc, profile will make custom size cranks to order, however they cant make them shorter than 145mm because therir macjines don’t go any smaller.

perhaps theres a company out there that makes 8 spline cranks in custom sizes that isn’t encumbered by the same restrictions as profile?

if their is i know what i’m saving for.


On some frames the spider bolt thingy may hit the frame. In that case the bolt attachmet would need to be removed. Other than that, it’s cosmetic.

I've been trying to tell you guys, I've tried alot of cranks attempting to solve this problem :) 

I too saw the Povertys a month ago and got real excited. I spoke to the guys at Dan's Comp on the phone, I asked the guy to check them for me and count the flutes to make sure they were an 8 spline pattern. He said yes they were. I ordered them and felt happy, I thought my quest was over.

When they got to my door, they looked great. Then I looked at the splines and they were a 10 spline pattern. They will not work.

Maybe John Drummond will read this and get some ideas. Maybe he could source a batch of cranks from somewhere ($$$$)= either way, it won't be cheap. Maybe offer the KH standard and with a crank upgrade option? 

Personally I just didn’t want to wait any longer, I had the money and I am building up another Profile wheel for my frame. The stock KH wheel is getting plenty of use and doing just what it’s supposed to do…for my son. :sunglasses: