Drilled rims questions

Newbie in learning phase. I have picked up a used KH trials unicycle to learn on. I have had a few other unicycles, I like this one considerably better. However, do the drilled rims weight savings really justify all the dirt and grit that gets into them? I think those holes just make it harder to clean and keep clean.

Wouldn’t having these holes just invite more dirt and grime to accumulate negating any weight savings?

Once I learn to Unicycle properly / half decently etc. I want to buy brand new, another trials uni, and a mountain uni, probably 24" to start. Once comfortable with those, gradually acquire larger sizes.

As much as I like the KH 20, I don’t like those holes in the rim. So I was thinking about going with another brand that makes good strong unicycles without holes in the rim. QU-AX and Nimbus seem to be pretty good.

I prefer to go for durable products that last logest requiring least and easist maintenance.

However, I am willing to reconsider, depending on what sort of answers I get.

I only have one drilled rim (TryAll), and it’s on my MUni. I haven’t noticed much accumulation of crud inside the rim. My theory is that the gap is pretty shallow, so thick mud doesn’t really get in there, and the more watery runny stuff just flows out. Also, the rim strip bulges out a bit, and closes up a lot of the gap.

My uni has a KH20FL rim. It used to have a KH hub as well, but I had to replace the hub because it was so noisy, as most KH hubs seem to have been for a period of 5 years or so.

If I rinse my tire off after a muddy ride, water does get inside the rim. I splash it out with repeated spinning and bouncing. From this forum, I have also learned that if my tire pressure reaches 80 psi, the innertube will explode through the rim tape at one of the drill-outs. The tire I have could otherwise handle 110 psi. I would probably never want it that hard, and you probably wouldn’t either, since you’re talking about trials and muni, but that is another issue with drilled-out rims.

In my opinion, the drill-outs are not helpful, but if I were a contender for world unicycle high jump champion, I might feel differently. For my purposes, the Nimbus Dominator2 rim seems perfectly good. It’s strong, has no drill-outs, and is 5mm narrower than the KH rim, which means that any fat tire, though slightly less wide, is just a tiny bit thicker.

With drilled rims you cannot use very thin and light tube at high pressure without avoiding puncture. I think this is not optimum from weight and wheel inertia point of view, I prefer undrilled rims

OK, so only a slight benefit in weight reduction. I found the holes to accumulate dirty crud, and like to keep my possesions clean when possible.

What is this about KH hubs being noisy? Is this on the current models? The KH 20 I have is beat up and probably older. Haven’t noticed the hub being noisy. Wouldn’t that be bearings?

I think of the KH 20 as a learner sized Muni.

When I opt for something newer I might have to go with something else to avoid those holes. When I started out I had to replace all my tires with high psi as I was flattening them at 50 psi, and blowing them off the rim going over that. After I lost a few pounds trying to learn unicycling, I no longer need high psi tires, trials 19" hold me up OK now, and I assume 24 x 3 mountain bike tires will also do that sufficiently.

I hope to eventually become a half decent or better mountain unicyclist.

Looks like I will have to look to Nimbus or QU-AX in the future.

Here is a thread I started about this problem. It has links to similar threads from earlier years.

No, it wasn’t a problem with the bearings, it was poor design of the hub itself. KH finally got around to fixing it in about 2015.

KH hubs older than about 2008(?) do not creak, and I don’t think the current ones do either. Their product description says, in two different places, “The Spirit hub is forged from a single piece of CrMo material. This results in a beautifully simple, strong and reliable hub.” Yes, in other words, unlike the one we were selling before!

Some of the older hubs were, I think, made from three parts, pressed together. Eventually, there would develop some play between the parts, and that caused the noise. Some newer hubs are one part, forged.

Another reason to use the forum search function…

Thanks Song.

This KH 20 I have is probably pre 2008.

I get the impression that eventually it may be necessary to learn wheel building, and get on top of the information of various parts that go into them.

If you went for a ride with me on my old Wilder (Profile 48-spline axle), I don’t think you would hear your hub at all. :slight_smile:

As for “holey” rims, the holes do not necessarily make it lighter. When I redid the wheel on my KH Schlumpf 36" in 2011, I upgraded to the new Nimbus Stealth rim with the holes in it. I made my own rim strip from old aluminum window blinds, painted to match my frame, which probably negated the weight of the holes by the time I had them securely taped in there. But I like the way it looks, and it doesn’t bulge at all. However, a year or two later, the following iteration of the Stealth rim had no holes, and apparently was lighter anyway! I like light, but not at the expense of strength; I prefer bombproof for most situations.

I also want bomb proof over slightly lighter weight.

To me those holes are primarily rim weakening crud catchers, making clean up a much bigger job.

Eventually stronger and lighter better deisned parts made with better materials will probably become available over time. I would rather go with what is simple and strong and current.

Quite honestly, I think Munis are WAY overbuilt for what most people use them for. Most Munis you can buy are capable of handling drops over a meter easily, which, let’s face it, 90% of riders don’t do. For the average rider (especially a beginner), I wouldn’t come close to worrying about a KH wheelset. If it lasts Ryan Kremsater, it will last you just fine.

I have a 26" Nimbus oracle, and so far, I haven’t had to true the wheel, even after trying drops bigger than myself.

That being said, I also think weight on a uni is pretty irrelevant, and that with unicycles you usually get the best price to performance at relatively little money.

On a side note, I don’t recommend 24". It’s not much faster than a 20", a 26" or 27.5" in my opinion makes you noticable enough faster than walking, while a 24" doesn’t.

For strength, you would want more material where the spokes are, and less between them. But that’s not practical for an extruded aluminum rim.

So drilling holes between spokes is a cheap way to get the same effect. I would say that a drilled rim is using the material better, and would be stronger than a same-weight undrilled rim (since the drilled rim started heavier everywhere, and removed unnecessary weight to end up in the same place).

And beginners can be just as hard on wheels as experts, since beginners tend to have lots of bad landings. But I agree with Finnspinn that muni wheels are plenty strong enough. It’s always the other stuff that breaks for me.

Hi there, I’ve got a couple of KH Munis (24 and 26) and couldn’t be happier. I don’t see the drilled rims as anything to worry about (as far as I can see the mud is not a problem). Where I live the weather is very wet all year round so most of my Muni rides are in extremely wet conditions with plenty of mud and puddles. I’ve never bothered to clean the Municycles afterwards as I think you might do more damage than good and I think is a waste of time anyway (next ride they will get muddy again!). I bought these two particular KH unis because of the wider rim (compared to Nimbus and Quax) and love them. I also have Nimbuss and Quax Unis and both are also great Brands. If I was you I would base my choice of purchase on whatever spec you are after at the time (sometimes might be a good price, others might be crank choice/rim width/tyre etc…). I wouldn’t give much thought to the mud/dirt in combination with the rims being drilled.


From what I know so far, Kris Holm has the best seats and cranks. The wider rim is a great plus. The drilled rims and outside of frame baloney slicer disc brake might be minuses. Disc brakes, especially outside the frame, are potential safety hazards: https://cyclingtips.com/2016/04/ventoso-confirms-disc-brakes-sliced-his-leg-open-calls-for-action-on-giant-knives/ http://www.unicyclist.it/forum_forum.asp?forum=11&section=65&post=16589

Too bad rim brakes don’t work as well. Would keep things simpler, lighter, and safer. Is a safety shield available? (more weight cost, etc.) It also seems that you cannot buy ready made the best unicycle hardware without a disk brake installed. I see this on Nimbus and QU AX, no option to not have brakes in the KH Muni. I don’t know about other brands.

On KH products it would have been nice to have an option of ordering them without drilled rims and without disk brakes. It would save a few dollars, some weight, etc. I am thinking of going without any brake when I buy a Muni in the future.

Is there is a good strong long set of cranks full of holes (more than 2) available? Then I could just set the pedals long for downhill, short for speed, etc. I have seen some quick change pedals available. Don’t know how good they are. That would be simpler and safer.

The safety concerns have been discussed before but I think they’re blown out of proportion. I’m not going to comment on the peloton issue except to point out that the situation couldn’t be repeated with unicycles because our rotors are mounted behind cranks.

As for that Qu-Ax rotor - using a rotor that looks like a saw blade is asking for trouble. There was a thread on this forum when it happened.

Honestly, a crank-mounted rotor does not feel unsafe to ride. There’s no way you can contact it while pedalling and during most UPDs you’re not falling directly on top of the uni. I would be more worried about injuries from pedal pins than brake rotors.

I’ve seen pictures of similarily bad cuts done by pedals, brake levers punched through hands, and much more on the internet, I don’t think disk brakes are particularily bad. You 100x more likely to brake an ankle on an UPD then to get any of these more spectacular injuries.

If you want to save a few dollars, you don’t buy KH, it’s as simple as that. Kris Holm aims only at the high end market. I’m pretty sure if you ask Unicycle dot com for a KH without a brake, they’ll offer it too, but for a high end Muni, a disk brake is really appropriate. Disk brakes are really expanding the capabilities of a unicycle more than any other part ever could.

Whether you need a brake or not really depends on what you are doing. Most people probably don’t need it, if you ride mostly flat trails and have no intention of going down long or very steep hills, you are fine without. But with Downhill, nowadays it’s unthinkable to ride at a high level without a disk brake. It offers more control than your legs on steep and slippery trails, relief for your legs on long downhills and takes some of the forces when landing big drops.

I sure do not like that Saw blade disk design. One notch against QU AX.

Kris Holm’s Unicycles seem to be the best of the best, built the way he likes them, specific for Mountain and Trials. I view his Unicycles as the design pushes performance to the limit. Drilling holes in rims represents doing everything possible for performance and weight reduction.

Drilled rims might be an extra unnecessary expense, does not mean I do not want the best parts I can afford. I would rather have less nooks and crannies for easier cleaning. If the cost is the same for a rim without holes drilled into it and otherwise identical I would choose the undrilled one, or even pay more to get it the way that I want it to be.

I see your points on brakes and control. However, I still think some folks might want a unicycle without a brake, still made with the best parts available. If it is not needed, it saves weight and keeps things simpler.

Just in time to make this discussion slightly confusing, KH as announced new rims wider and tubeless ready that are not drilled. :smiley:

Now, you can focus on which shape and color you prefer for your uni :wink: