ISIS Hub/Crank for Coker.

I recently broke my hub/crank on my Coker, and I am looking to replace it with a splined set. Has anyone out there ever put and ISIS set on a Coker, and if so, what can you tell me. Advice needed!!!


Is a splined wheel set remotely necesasary for a coker?

please forgive my ignorance:)

you would not want any of the splined/ isis hubs for a coker right now because they weaken the wheel because they are skinny.

Well which one was it, the hub or the cranks? You didn’t break both at once did you?

I believeQu-Ax has a 36" unicycle with their ISIS hub…

It’s a 48-spoke setup, though.

Not in terms of strength. It might be handy in terms of standardisation / compatibility, though - for instance if you have other ISIS unis. Personally, I wish I had an ISIS setup so that I could just buy the KH double-drilled cranks rather than going through the hassle of getting cotterless ones diddled with at the bike shop.

You can get a splined hub that is just as wide as the Suzue hub, and thats plenty wide enough. Talk to Ken or a few other riders if you have doubts. I’m pretty sure its 100 mm wide which is the same as the KH hub if I’m not mistaken.

I would recomend staying away from the Koxx-one hubs as they seem to be a bit smaller (at least it looks like that) and the KH ones are larger, I would recomend going with the Kh hub and whatever cranks you wanted, the Kh hub is the most versatile I think. I’m pretty sure all ISIS cranks can fit onto it including Koxx-one (which Spencer tested for us if anyone doubts me).

The KH Moment ISIS hub flanges are about 74mm apart, not 100mm. 100 is the accepted standard for “wide” hubs, meant for the bigger rims. Not that a 74mm flange width is unacceptable for a 36er, but at that rim size, the wider the better for wheel integrity.

Which hub did you have on the Coker? Was it the stock Coker hub or one of the hubs? Do you have a wide hub or was it one of the standard narrow hubs?

If it was a stock Coker hub then switch to a UDC hub. The UDC hub is stronger. If you broke a UDC hub then you’re dong some impressive Coker riding.

The 100mm measurement is the bearing separation, whic is standard for most hubs except the standard Suzue hub (92mm) and the UDC extra-wide hub (125mm).

For the strength of the wheel the flange separation is more important. The standard Suzue hub is not that wide, with a flange separation of 62mm (same as the Koxx). The Suzue is a millimeter or two wider than the standard hub that comes on the Coker 36", but the flange separation on the UDC CroMo hub is 71.5mm, the KH ISIS hub is 74.5mm and the UDC Extra-wide CroMo hub is 98.5mm.


to be fair, if he was riding a UDC wide hub it was probably defective.

I have the newer Qu-ax 36" which is splined, I can say the narrow hub is more of a blessing than I thought it would be… Depending on what you do though, I can’t say if I’d suggest that wheel to you… If you’re using an airfoil rim, then yeah, you can probably switch to the ISIS splined hub/cranks as long as you get a professional wheelbuild. Otherwise you’d probably best be off with the UDC extra wide hub and some decent steel cranks. If you’re set on getting splined, try if the new Nimbus ISIS hub is available where you are, it will probably be the same price as the Qu-ax hub, 29.90 EUR and get some Qu-ax aluminium cranks to go with it, they are the lightest there are and theyre deffo strong enough.

have you got a link to that?

Another option is to get a KH Moment hub, cut it in half, sleeve the two halves with steel tubing and re-weld it with a wider flange separation. That way you’d have a wide ISIS hub. It does require some precision with the alignment of the two halves when welding the sleeve in place so that your cranks end up parallel.
Not cheap if you don’t have the metalworking gear yourself, but its the only way to get a wide splined hub currently.

that’s the best idea ever!

edit: tim’s current (broken) hub was the one just short of the longest one (80mm?) it had seen all the abuse i gave it since the beginning of TWNR. So 3 years or so of very aggresive riding on that hub

Except Roger suggested i braze rather than weld when I suggested it to him, to avoid altering the heat treatment of the material.

Wikipedia: (I looked because i wasn’t sure what brazing was)

Brazing is a joining process whereby a non-ferrous filler metal or alloy is heated to melting temperature (above 450°C; 842°F) and distributed between two or more close-fitting parts by capillary action. At its liquid temperature, the molten filler metal and flux interacts with a thin layer of the base metal, cooling to form an exceptionally strong, sealed joint due to grain structure interaction. With certain metals, such as Nitinol (Nickel Titanium) and Niobium, a low temperature eutectic can form. This leads to the bonding of the two metals at a point that can be substantially lower than their respective melting temperatures. The brazed joint becomes a sandwich of different layers, each metallurgically linked to the adjacent layers. Common brazements are about 1/3 as strong as the materials they join because the metals partially dissolve each other at the interface and usually the grain structure and joint alloy is uncontrolled. To create high-strength brazes, sometimes a brazement can be annealed, or cooled at a controlled rate, so that the joint’s grain structure and alloying is controlled. It is also at 1/3 strength because the metal used to braze is usualy weaker than the other metal because it is easier to melt and will melt first instead of them both melting.

edit…although, if both ends of the axle are inside a tube, this doesn’t really count as the same thing, there would be no need for the sleeve/axle combo to be as strong as both ends are fairly secured in there i guess

Machine the center of the hub axel to a square shape before you cut it in half, then use square tubing to join it. Then when you braze it, you won’t have to worry about it breaking.

Oh i don’t deny brazing is less strong, but its still pretty strong, and this discussion was with UDC UK Roger, creator of the nimbus frames, UDC CrMo hubs etc., he knows his stuff. Also i believe brazing was used for the widened suzue hubs (built by TUC?) that people used for unicycles before sotck wide coker hubs became available.

The Unicycle Factory could probably do that. He made widened Suzue hubs before the UDC wide hub was available. He could probably do the same on the KH ISIS hubs. It’s going to be expensive. The widened Suzue hubs were $120+ USD. I don’t think he’s done any work with ISIS hubs so he’ll have to make a new jig to align the two halves and that will add to the cost.

I’m not sure how the KH ISIS hub is all put together. That’s going to be a factor in figuring out how to do the widening modification. Rodger should have sketches showing how it’s put together.