It’s totally possible to ride fairly technical single tracks on the Coker but the limiting factor is gear–unless there’s gear I haven’t heard of. I slapped some Black Widow 175’s on and bent them (slightly) on a measly two foot drop. Rolling hops (drops) seem to be are okay. But I’m not much of a Coker dude so far as knowledge and experience goes–maybe there’s some way to string a Airfoil rim to a Profile hub or something since the other hubs are garbage–like tin.
Don’t know what the outter envelop is here but I reckon to find out tomorrow with the OC crew.
I’m using the PDC modified Kooka cranks with my Coker now. They’re drilled for 130, 150, 170. The Kooka cranks are strong. If you can find some, get them.
The Black Widows aren’t that strong for more aggressive muni riding. An inexpensive alternative would be Sugino tandem cranks. They are available in 170 or 175. The captain’s right crank on a tandem has no spider. So you get a RH captain’s crank and pair it with a matching LH normal crank. You can get the Sugino cranks from any bike shop that has the QBC catalog. Price is $15-$20 for each crank (so $30-$40 for the pair). Alfred E. Bike has them in their online catalog (search the catalog for “tandem”). They’re better than the Black Widow’s, but still not the strongest cranks around.
The problem with a Profile hub is that the hub is too narrow. The wheel build will not be very strong. You need a wide hub.
The other problem will be keeping the wheel true. I regularly knock my Coker wheel out of true doing XC muni with it. It will go out of true and rub the brake. A Stockton wheel build would do better (mine is a local wheel build). But the big wheel can only take so much before it will go out of true.
I agree with John, you need a wider hub than a profile or even the KH (this is about 6mm wider than the profile if my figures are right). This is 25mm narrower than the UDC special wide flange hub!
For road work I have a narrow hub (UDC wide flange hub) but for off road I switch in the UDC special wide flange hub. The wheel needs it for races like the Mountain Mayhem.
I think that it was Tom Miller who was cutting and widening the Suzue hubs. It may be worth asking him to manufacture a wide flange splined hub. It should work quite well, especially since the hub material is CrMo and will cope better with the welding better than the Susue hardened standard steel.
Why not simply cut a KH moment hub and sleeve it in the manner of widened Suzue hubs? Should be no more difficult than widening a Suzue. KH moment cranks come in a pretty good range of sizes - 125, 137, 150 and 165mm - certainly enough selection for offroad cokering!
Standard coker frames will accept both 40mm and 42mm bearing sizes, though many custom frames won’t.
I have a widened Suzue hub for sale if anyone is interested. Photo here. Make me an offer.
Vivalargo - Kookas are good for offroad cokering, as JC mentioned. They’re just kinda hard to find.
Then make the frames to fit a 47mm OD bearing and include a shim so the frame could be used with 42mm or 40mm bearings.
If the Moment hub and KH frame requires a special custom bearing size, why not just make the frame to fit a standard bearing? 47mm bearing holders on a frame would seem reasonable. Being able to use stock bearings that are more durable would be a win win.
Offroad cokering is really good fun. My airfoil / extra wide hub / slick tyre combo is holding up fine so far. I have 150mm ProWheel alloy cranks installed which give me a decent amount of torque on any inclines of gnarly bits.
For added fun, I often do offroad stuff in the dark
With the coker it’s really fun to blast round gnarly trails and singletrack - this kind of riding has the bonus of not putting too much strain on the hub / cranks / wheel. I guess if I was going to go off lots of drops I might want a smaller wheel and splined hub, but there isn’t really that kind of terrain in this area
Already tried it… you will understand when you see what is needed to be done and why it is was not a prefered option. It makes a big heavy lump at the bearing interface. There is also a problem with making shims that are bigger than 1.5mm in thickness due to the size of the lip; the bearings would just not be supported.
The bearings will become more available with time.