Lol, yeah. Even a one off from a company that makes similar items won’t be cheap. Might put my plans for a new uni on hold. 
It will be worth it, once the hub is done you can make an awesome free wheeling unicycle!
I decided to google for the ''Kettler’s automatic freewheel facility", and found the below item. To me, this sounds and looks different to the idea that I have put forward.
Do feel free to mention anything you think I may have overlooked.
Yeah, there is that, but if it works then I’ll have to get a few made up for testing, then if it is deemed good enough, I’ll have to get a fair few run off.
yes, it does look different. But I presume yours would be unicycle specific, so that would make it different anyway (isis, 36h, basic unicycle attachment with bearings spaced apart a certain distance etc)
I was thinking whether to go for 36h or 48h, might just make it in both, same for ISIS and splined.
36 is much more common, but there has to be a qu-ax version too really.
Yeah 36 may be more common, but my street / trials uni is 48h, as is my freestyle uni. I’d prefer 48h to 36h any day, but i’m not looking to make this just for me, so gotta have options, lol.
That’s another thing, it could open up more in the way of freestyle and flatland. OK there are gonna be some tricks that will be harder on it, but how many new tricks / new variations could a hub like this enable?
Oh I see, yeah that makes sence. From a marketing point of view 36h would be more successful and the main choice as it is more wide spread.
For marketing purposes, I’d put a poll on here, and the results could be the ratio in which I get them made, IE: one 48h to every five 36h. Anyway, that’s not for a while yet, lol, if at all.
Yeah you just need the design first and to know if the basics of it will work. worry about appearance, marketing and manufacturing later.
Another thing or two that I forgot to mention in my first posts.
It will not matter what way the hub is put on, whatever way round the hub is, the crank is on the right will drive the unicycle forwards and the crank will drive it backwards.
BMX freecoasters are rumoured to need a fair bit of maintenance, I say rumoured because of the 3 freecoasters I have had, I have only needed one bearing to be replaced. The unicycle freecoaster hub, needless to say, will be direct drive 1:1 ratio, whereas the setup on my BMX is on a 1:2.5 (I think), so the unicycle freecoaster will be under less stress than a BMX freecoaster.
yeah, we don’t want it breaking all the time like when the KH geared hubs came out.
Lol, yeah. To be honest though, there’s bound to be a few problems to be ironed out, nothing that testing won’t find out though. Also, I think I can safely say that the freecoaster hub will cost a lot less than the KH / Schlumpf hub.
It seems like the hard bit here is how you get the pedals attached to a bike rear hub, or are you thinking a twin chain giraffe?
I can see it’d be quite easy with a giraffe, but for a normal unicycle you obviously need a replacement axle of some kind. What size axles do freecoasters have - it needs to be at least 17mm (or something like that) for a single piece axle with a square taper on the end to fit in it - more for a splined axle. You also need a link between the axle and the sprocket on the hub.
Joe
10mm, or 14mm are usual freecoaster axle sizes.
Instead of a sprocket on the driver of the freecoaster, I am planning on having the crank arm bolt straight on, to either an ISIS or splined fitment. Inside the hub could be an axle connecting the two drivers, with a square taper fitment, to keep the cranks aligned, making it a 3 piece axle. Or, it could have a hollow axle right through, for the crank bolts to go into.
Fitting it to a giraffe unicycle, would be just a sprocket of the desired size on the driver, instead of the ISIS or splined fitment.
Ok, I realise some of you may be thinking that it’s gonna be heavy, its a freecoaster, they are heavy, lol. Though there is no reason that later ones could have weight dropped.
That seems to me to defeat the purpose of this hub. The idea is to have a hub that freewheels, yet has some room for tiny adjustments in speed. Backwards pedaling should just be an afterthought, I rarely ride backwards except in a street line anyways(I prefer hopping to idling, though I may idle if I have a heavy backpack or something on)
The system that Ian Smith had brought up, from the looks of things, uses a ratchet / silent ratchet, basicly like a freewheel. Freewheel’s aren’t exactly adjustable. Freecoasters on the other hand, can be adjusted by a few methods. One method would be to put washers in to increase / reduce ‘‘play’’ in steps. Another method would be to get a GBH freecoaster adjuster, which is a washer with two grub screws in it, allowing for a more finetuned freecoaster. Another would be the allen bolt in the hollow axle that I mentioned, I have no experience with this type, so I can only assume that it is similar in effect to the GBH adjuster.
The idea of the hub I have thought about is for it to be able to coast forwards or backwards just as easily, with minimal ‘‘play’’ in the system, yet still be able to engage quick enough when it needs to. The idea is not to just coast forwards on it, with a hint of backwards coasting as an afterthought. I have run freecoasters on my BMX for at least the past six years, I’m fairly familliar with them, how they work, and their potential. If the Idea could be brought to unicycling, it has potential for a lot of fun, among other more technical stuff.
Anyway, anyone spot any potential problems with what I propose to do?
If i’m imagining it correctly, then the cotterless to splined fitment might be a weak spot, as it will esentially be a cotterless hub, but with a thinner than normal axel. I’m sure it will be fine though. It sounds like a great idea, i hope it gets made.
There could be that, I’m going to strip my freecoaster tomorrow and see what can be done. Anyway, there’s only one good way to find out.