Just wondering is anybody has tried any of the new breed of bicycle rims? It seems the mountain biking world is catching up with the idea that there’s an advantage to wider rims that allow you to run much lower pressures. So all of a sudden lots of new wide rims on the market - several 40mm wide ones, which is close to a Nimbus Dominator or a KH XC (and given the modern hookless shorter sidewall design probably results in a wider tyre profile). Then there’s this 50mm wide one - wider than a KH Freeride, but a LOT lighter.
Would such a rim stand up to use on a unicycle? With a 135kg bike rider limit, it should be strong enough for a 75kg uni rider, given we don’t stress our rims twice as much, shouldn’t it? I was thinking about maybe going for one of the 35mm ones, as I wasn’t so bothered about having a super-wide rim, and wanted something a bit lighter, but then if I can get 50mm wide for the same weight…
They’re all a bit pricy. I’ve not found a single one that is around 50mm wide, has 36 holes and a nearly as good value for money ration than the KH rims. (The few which exist, seem not to be available here in central europe)
Thats why many fatbikers use KH rims for their builds.
Fun to see that this time its the muni world that is useful for a part of the MTB world
More on topic, all these carbon rims looks very good and are really interesting if they provide the same strength as current alloy rims with the huge weight drop. It is not yet there price wise (still over 2x more). Another itch to scratch…
Here is a 29" 27mm wide, cyclocross carbon rim. It works wery well on a uni, regarding stiffness and light-weight. We havent used it for hard off-road riding, so it would be difficult to say anything about drops…
Here is the second, a 26", 90mm wide, 36-hole carbon rim. I buildt this wheel last september, but have not tested it yet… (…was actually waiting for the new Schlumpf-hub). Anyway, when having such a rim in your hands, and bulding a wheel, you get high expectations…
This rim looks very nice on a uni (+1 for the colorful ones).
I stumbled upon them when doing research for my fat unicycle and it would have been in my parts list for the ultimate build (it is just twice the price of the Surly Clown Shoe – not bad for a carbon rim).
However, budget and 125mm hub requirements lead me to go safe and settle for only 82mm aluminim
Can’t wait to read for review on how it feels riding on the snow and/or in technical trails
When I got into the bike biz the transition had already moved away from true “clincher” rims, but the discussion was still alive. This is from what I remember about it.
Originally “Clincher” Rims had straight sides that would hold the tire by “clinching” it between the sides of the rim. Later a newer rim that held the tire more securely was called a “hook bead” rim since it had a hook that would hook the bead of the tire. For a while there were Clincher rims, and Hook Bead rims available and they were differentiated as such. Some tires still have a warning on them to be used only with Hook Bead rims.
As for the beadless question:
Beadless is probably a modern misunderstanding of the origins of the term. In practical terms all “clincher” rims at this point are either straight sided, or hook bead type. The bead being a part of the tire, not the rim. So, I would understand “beadless” to be synonymous with straight sides. Some rims are called “crochet” rims, but that is just another term for a rim with a hook (like a crochet hook:) ).
Now I’m wondering if “Crochet” was originally to differentiate from “Clincher,” but the latter term survived? It could be. hmm.
How much rim flex do you need with that tyre? Personally I’m not convinced there’s any advantage to rim flex even with smaller tyres - just makes control more difficult, and it’s only ever going to be a fraction of the amount of “travel” you get from the tyre. Even normal “flexy” alu rims don’t actually result in wheels with much vertical flex - checking the calcs in Brandt’s “The Bicycle Wheel”, a load of 500N results in a deflection of 0.15mm at the rim for a normal alu rim.
Thanks Killian and jtrops for the comments on beadless and hookless. I wondered mainly because I looked at this page:
Some are “hookless” and others are “beadless” but it looks like they’re all called “tubeless compatible” which I know just a little from threads here about “Stan’s,” and “ghetto,” etc.
Once upon a time I tried to put some take-off folding Michelin road tires on a friend’s 80s Centurion bike, and when we tried to pump them up they lifted right off the rims. I guessed that was from lacking hooks on the beads, and the Kevlar beads kept on stretching with nothing to grab onto–i.e., the “clincher” vs “hook” thing jtrops mentions, and that bike was probably from around the time of the switch. I’m still a little foggy on “beadless” though by which I’d guess they imply something beyond lacking hooks, not that it matters a huge amount to me right now.
I really think that it’s just bad proof reading, and that they are using the terms alternately to describe the same thing. What I have seen in the past is reference to hooks, and hook beads on rims. The first term is accurate, and the second is probably due to the awkward name “hook bead rim” as if the extra metal is a bead that hooks. In this context hookless would be referring to the first, and beadless would refer to the second.
The issue is spoke holes. In mountain biking the standard is 32 holes, so unless you run a 32 hole hub, you are SOL. This is where unicycling needs to catch up with mtb. I believe it’s a proprietary issue, ie it keeps from folks from buying rims not provided by unicycling mfgs.
I am running 32h on all my unis except the 36er, I run Velocity P35’s on the 650b and 29". which worked great, though they are only 35mm. On my fat bikes I run anywhere from 45mm to 80mm, all 32h.
I use the Nimbus 32h one piece chromoly hubs and Sprit cranks.
I have some WTB Scrapers on order, they have an ID of 45mm which is a little wider than the Nimbus muni rim, probably close to the same width as the KH, but they weigh far less and are probably stronger by design. The WTB rims have a very good bead lock design, with “hooks” on the bead shelf and on the rim edge.
I have some Velocity Duallys unmounted, they are 39mm ID, about the same as a Nimbus muni rim. I like Velocity, because they are made domestically. but I don’t find the quality to be great, also they don’t have a secure bead lock for tubeless.
The carbon rims are pretty cool, I have played with them, they are showing promise, no failures that I have heard about. Carbon is probably the future for high end wheel builds. They are not always significantly lighter than a quality aluminum rim, though they are probably stronger when designed correctly, and they could have more longevity.
Be cautious when picking lightweight rims, some rims like the Stans Hugo aluminum single wall design are having problems with denting.
OK, thanks again. That makes sense. Good help is hard to find.
A few days ago I was musing over the idea of a Kickstarter campaign or group buy or whatever for some piece of gear, something a bunch of us would like to have but can’t get, and I wondered about a 32 hole version of some model of hub. But we’ve got the Nimbus 32h one piece chromoly hub. Is there something else you need or would rather have? Or should there be a campaign for a 36 hole version of some rim?
(Actually I have the machined sidewall version. Too lazy to look but it’s out there too.)
Worst thing I can say is that people who know will know that you didn’t pay very much. Also, only a couple of mm wider than a Dyad. But that’s what’s on my main road uni, plus I have a 26" pair on my most ridden bike. They’ve stayed true and all still look brand new.