I’ve often wondered whether the demise of the KH Spirit line in favor of the Boundary line was a design idea championed by Kris or if it was more forced upon him by the industry.
By discontinuing the Spirit line of cranks, that effectively obsolesces every KH frame produced up to that point for riders that want a disc brake when no Spirits are available. Once the supply of Spirit cranks are gone (and that could be years from now) there’s no effective way to run a disc brake on a pre-Boundary KH frame. Hmmm, unless the frame and inboard disc wheel are run “backwards” with the rotor in front on the left side but then the braking force is pulling away from the frame when the frame was designed to have braking force going into it. Plus it would just look weird.
Sure there are advantages and disadvantages of both systems (my personal opinion is Spirit has advantages over Boundary, for me).
It just seems to me like Spirit cranks were truly something that was born in the unicycle world rather than something the b*ke industry flows (forces) down upon us one wheeled folks. I would really like to hear Kris’ @danger_uni story about this. Or perhaps @rogeratunicycledotcom may have some insight.
I have a KH frame with rim brakes tabs only. Using your words, this frame is obsolete, but KH brand is still going strong. KH successfully survived the switch from rim brakes to disc brakes. Not a big deal for the company I guess.
The KH spirit design looks like a great example of clever adoption of bike industry technology. It is a slightly modified bike crankset with brake disc bolted instead of a cog. Other people experimented with this design too — you can find some images on this site.
The existing supply of Spirit cranks is lower than you may think seeing how many shops no longer list them and the few that do, don’t have all the references (so until stock is depleted).
Do not discount ingenuity. Before Spirit cranks arrived, some riders were using Mountainuni disks that were basically disks that can be attached on a crank’s ring spider. We may end up with something similar in the long-run to keep some isis unis without spirit cranks but with a disk frame complete
It seems to me it is simply a cost-effective solution. As far as I know, KH doesn’t sell lots of unicycles nowadays. 10 years ago, these unis were considered as the best unicycles you could get. However, they haven’t evolved a lot since then. I guess this is due to the fact this is not Kris’ primary job. He hasn’t that much time and money to invest. Switching from a standard only KH unis were using to a more common interface (Shimano Hollowtech/Qaxle) probably makes it easier to produce, sharing manufacturing time and skills with Qu-ax.
I’ve also read that ISIS is a nightmare to manufacture. Maybe Qaxle is easier?
Although I prefer the Qaxle interface, I am also quite sad about this Spirit thing. I don’t like when something becomes obsolete and is not produced anymore, because it may lead to elements being not usable at all. Ecologically speaking, this is bad. But we’re practicing a niche sport, so it’s hard to maintain everything.
It looks like D’Brake adaptors are no longer being sold on their own (maybe coming with some older Nimbus frames) so definitely feels that way.
I’d be interested to try Boundary/Q-Axle at some point in the future to directly compare the two and see if the change is worth it.
I’m not sure how much evolution there is available for “mass market” high end unicycles (Qu-Ax/Nimbus/KH) without increasing the cost too much. The work has been done to get really good, reliable unicycles down to a reasonable price point.
That’s a good point. Due to Covid, prices have sky rocketed and I’m not sure either how much evolution is available without increasing the costs even more. We may have reached the point where every new evolution costs a lot (Pareto law: 80% of the job takes 20% of time/money, and 20% of the job takes 80% of time/money). Maybe we’ve done 80% of the evolution and we won’t see anything new for this segment of market.
Plus it would just look weird.
