I’m looking for a rim to move my Schlumpf hub into my 29" uni. I’d rather build a new wheel and go narrower than the KH rim as it’ll be for road/town use.
It would have to be compatible with Magura brakes and have 36 holes to match the hub.
After some research, I came across this rim: Mavic A319
It has what I’m looking for and a great price, and it would work with a set of spokes I already have. Also it’s got good reviews especially from tourers and tandem users. So that’s looking good for a one wheel machine.
Now it’s a 19C with a total width of 25mm. Mavic says tire shouldn’t be wider than 50mm but the one I have and wanted to use is a Schwalbe Big One, 2.35" wide (i.e. about 60mm).
Is that really too big for this rim? I read a lot about rims lately and with the wave of fatter tires on MTB, it seems acceptable to go that wide on such a rim. But real life - and unicycling - has different rules.
Do you think this rim would work? What would be another choice?
schwalbe super moto + kh 47mm rim at 44PSI = BANG!
Good question and I will follow this thread with interest.
As you know, yesterday I tried to put a schwalbe super moto 29x2,35 + a foss tube on the kh 47mm freeride rim of my g29, inflated it at 44PSI/3 Bars only (to prevent the famous “BANG”) but the tire exploded 30min later anyway, preventing me from knowing how it feels to ride a road tire on a geared unicycle (I only rode 26x3 and 29x3 knard so far)
Anyway, one issue I may see with the narrow rim you’re talking about (25mm) is : will the magura rim brake pads even reach the rim once installed on the frame?
I’d also like to find a light 29er rim (around 500gm) that would be compatible with the schwalbe road tires (supermoto, big one, marathon suprem etc…) but also my knard, AND rim brake compatible, so I think 35mm internal distance would be the minimum, but I’m even not sure brake pads could reach the rim walls.
For the Magura pads contact, if there is not enough adjustment with the default bracket, the Tensile offset bracket may provide slightly more adjustment (with a reasonable rim).
As for the rim, it will depend on the hook profile and the pressure you are planning to put in your tire.
The only Mavic rim I had was a replacement on my learner and it was about 23-25mm inside and I ran it with a Michelin tire 26x2.0.
For road use, I have been able to use a KH XC rim (38mm inside) with a Schwalbe Big Apple 29x2.35, a Maxxis Hookworm 26x2.5 and a Schwalbe Big One 26x2.35 at 4 bars (in all of them) without any trouble of the tire jumping off the rim (seems to be a problem only with tires too narrow for the rim width).
And as a side note, I was able to use some V’Brakes with the 2005 KH frame & this rim (and I am guessing Maguras would have worked too).
In my experience I like my rim to be 2/3 to 1/2 the width of my tire. If you are running higher pressures you can get away with wider tires on skinnier rims.
Getting a wider tire then running higher pressures never made sense to me, but plenty of people do it.
I believe that the Magura mounts on unicycle frames are spaced for a minimum 38mm wide rim. The tensile offset bracket is primarily designed to allow for wider rims, I am not sure if they are useful for going skinnier, or if the outside vertical section of the brake would prevent them from going further inboard. I think it would be easier to make an adapter to use V brakes with the post mounts further in.
I’m still very happy on my 700c Rhyno Lite, 27.5 mm and 36 holes…That’s been my go-to wheel for three years now, since my first summer of riding.
Edit: But yes, pretty good chance that any rim like this will need some funky Magura adapters. Didn’t UniGezer come up with something for that? (Vague memory, too lazy to search right now…)
Thanks for all the input, I didn’t think about the Magura mount placement, but it makes total sense. I’ll have a look into what could be done to change the pads’ position, and see if I can find the mod made by Terry.
I guess I could just go ahead and do it and see what happens - the rim is pretty inexpensive and I have all the other parts. Safer option is to get a Nimbus as it’s known territory, but it involves getting spokes too and all would add up to much more.
Looks like four holes in each piece, two plain ones for the mounting screws that thread into the frame’s Magura mounts and two threaded holes that serve as the offset brake mounts.
Thanks LE! Nice thread! Terry build a neat machine, and pretty light. My 29" at the moment (Big One tire and Foss tube, oh and disc brake) only weights 12lbs. Close to Terry’s, though I don’t have handlebars.
The more I look at rims and the less options I find. I’ve been looking at something slightly wider than the Mavic (19C) but it looks like there is no such thing! I looked at LE’s suggestion, the Rhyno, but the ERD is too off. I looked at all the other models they offer, and the wide ones (23 to 25mm inside width) only come in 32 holes and disc only. Seems like MTB only go for 32 these days. Google found me a Salsa Gordo (very creative name, guys) which looked perfect: ERD spot on, double walled, 600-ish grams, rim brake, 33mm wide. But it’s no longer produced. And yes, I looked on eBay. A guy is selling a pair for $300… A competitor is the ZRT from No Tube (or something similar), but it’s disc only -though the profile looks like pads might work-, but no shop in Europe sells the 29".
No rush, so I’ll look at the downhill stuff a bit more, there might be a lead in that direction - having said that, a lot of MTB forum messages are raving about… the KH rims! But I don’t think it a model that exists anymore, it’s the one with no holes.
It is the version I am running: KH XC rim 38mm. And you are right, it got discontinued a while ago for the KH freeride rim 47mm.
If you are looking at 36 holes & rim capable, it already makes for an interesting search in a 32H / disc brake world. However, adding a specific ERD in the mix to re-use spokes is what makes it epic
Usually, lightweight will be 32H only (like the Velocity rims) or the 36H / brakes may prove to be on the heavy side (Alexrims, Weinmann…).
You may get lucky on the second hand market with a bike rim or maybe an old KH XC rim !
If you are really getting desperate, it may be my cue to let my KH rim go for a lighter one as I do not use brakes on my 29er (but the KH rim is still about 660g…)
Didn’t know that one, it seems they work with several shops here in Europe, so it might be possible to find one. But at the end of the day, it’s not much wider than the easy-to-find rims - it’s 21mm inside, where the most common size is 19mm.
Sidd, if you’re serious about your KH rim… we should talk!
I ran the Rhyno Lite on my 29er muni for about a year. A good rim for the price. and avail. in 36h. In the end I found it to be too narrow for optimal muni though - I had too much tire fold (using a Hans Dampf Super G 29x2.35) when carving really tight turns and during small side hops under lower pressure. That being said the rim was good enough for me to use for a year without going crazy. I think the Ryno Lite would probably make a great road / light muni rim. You’d be running higher pressure and probably not hopping much - so the narrower width would be OK.
If you’re interested in buying a used 36h rhyno lite rim, PM me. Not sure if it would be worth the shipping, but maybe.
Forgot to mention - I was able to run maggies with my Rhyno Lite on a nimbus drak 29er frame (a bit narrower than the current KH frame but maybe on par with older ones). I used standard mounts (not the offset tensile ones mentioned above).
The Rhyno Lites have a great sidewall designed for rim brakes. They are quite strong too. I’ve used them on my mountain bikes for the last 10 - 15 years and they’ve done very well.
That sounds about right. I’ve never had a tire wider than 2.1" on mine and I can see that happening. On pavement and easy trails, unpaved roads really, it’s been great for me.
I used my Magura HS11 brakset and measured:
~30mm between the mounting bolt and the brake pad at max extension + 27mm Rhyno Lite rim width + ~30mm (other pad to bolt) = 87mm (maybe 90mm) max width between your Magura mounting bolts for this rim to work on your frame.
It would be easy enough to test for yourself - just mount up your maggie brakes, adjust them to max inward position/reach, and measure the gap between them.
I sold my drak frame so I couldn’t measure the mount width on it, but the unis I do have (nimbus 24, 26, and older KH 24) all had almost 100mm between the mounting bolts. I know the Drak had a narrower profile than these unis, but I’m starting to wonder if maybe I didn’t actually run the Rhyno with the maggies.
It was bothering me to the point of distraction, so I mounted my Magura HS11 onto my nimbus steel 26 frame and they do fit the Rhyno Lite (plenty for grab). Whew! - I’m not crazy.
I did have to mount them as far in as they would go though.
Thanks for taking the time to do this!
That’s good news, what I would save on the brake extenders (reducers?), I would spend on the rim. Why not hey!
This rim is at a decent price, even new. Now I need to figure a way to bring it back in Europe as I don’t know if it would fit my regular suitcase…
(but the KH rim is still about 660g…)
