I had a Duro and it measured 75mm wide.
You need some clearance, I like at least 5mm. I have done less but you tend to get some rubbing.
75mm minus 5mm each side leaves you enough room for a 65mm wide tire, which would be a 2.5 or possibly a “small” 2.6 if you want to push the boundaries.
If you really want to stuff a Duro in there you could try dimpling the frame to get a few extra mm on each side.
Something like this:
(Not my picture, poached off the internet)
On my 26" the top crown clearance is tighter than the sides (with a 2.35 tyre), so crushing the tubes won’t help. The 24" might be different though.
My 24" club has 73mm clearance.
The Halo 2.6 Ception has been suggested as the largest tyre successfully squeezed into a club frame.
You could give it a go.
I haven’t seen it for myself - but I assume that some light trimming of the knobbles may have been required to make it fit the 24 club.
At the moment I am happy with my 2.35 Schwalbe Crazy Bob tyre (actual width = 2.45)
It has 5mm clearance at the sides, and 4mm at the crown.
If you find a tire which fits width-wise but is too tall, you can make a shim to give you a bit more clearance. I’ve squeezed both a Conti Trail King 2.4 and Big Apple into my LX26 with this method.
It seems like 24 inch off road tires are getting pretty hard to find. I’m searching for a 24x2.5 and in germany the only one that seems readily available is the Maxxis High Roller 24x2.5. As lightbulbjim has pointed out, it sounds like it could be a bit too tall but really hard to tell without having one in hand. Anyone know how tall this tire is from the rim? I have a bout 3 inches to work with. And will this tire likely work ok with a 32 mm rim?
Thanks again for all the help.
I’ve read that a 2.6" tire is the max tire that’ll fit under the crown on the Nimbus II. I saw a pic & the clearance was REALLY tight. I’m sure the tire would rub if got just a tad out of round. I had that exact issue on my 26" Torker LX. Max size 2.5" knobby & I had to shim the bearing caps by a couple of mm.
I have an older 24" Koxx muni with the Duro and although I have enough lateral clearance, I had to use shims to add more vertical clearance as even with the slightest bit of mud it would scrape to bottom of the crown.
I can’t today, as I’m sick in bed, but some day I could measure the width of my Duro. Not sure, but I think my rim is probably around 35-40mm.
From my memory with mountain bikes, I think the width of the Maxxis High Roller 24x2.5 runs lower than the given value (a 2.4" Schwalbe is usually wider than a 2.5" Maxxis). So that might be a good option, but you will probably have to add a vertical shim. I’m not sure what the max vertical is that can safely be added via shims? Off hand, I’d guess that more than 5mm is probably too much.
Well I went ahead and ordered a Maxxis highroller 24x2.5 so will just have to see how it works when it gets here. I’m hoping I don’t have to resort to shims but just in case, does anyone have more information on how that would work? I’m having a hard time picturing how I would use a shim to increase my tire clearance. I’ve tried searching but haven’t really come up with anything that seems relevant.
hmm. didn’t find anything with pictures and only really old posts. I think it only works with older style bearing cup holders (not the CNC milled like the new aluminum frames). Looks like people have used coke cans, rubber or aluminum shims. I honestly can’t remeber which I used as I did it about 6 years ago and haven’t had the wheel off now in at least 3… I’m thinking I probably used rubber strips, but maybe aluminum.
http://www.unicyclist.com/forums/showpost.php?p=139628&postcount=1
Maybe somene else can provide more info?
Oh, I think I remember saskatchewanian having done something with coke cans and he posted above just today, so maybe he knows more? (or maybe I’m rembering wrong)
Yah I used some plastic to shim up my 20" frame to fit a trials wheel. It was from an old water bottle and pretty sturdy stuff. I used tape to hold the pieces of plastic to the top of the bearing.
This was with the old pressed style bearing holders and worked just fine.
You would have to figure something else out for machined bearing holders. I think someone might have made some spacers with a 3D printer…
I found a thread discussing 24 tires choice.
And it contains the image of Saskatchewanian take on extending a frame for more crown clearance (see attached image).
Even with machined bearing cups it would be the same idea:
haha, yah you don’t need to do that ^^^ 
My extended bearing caps were for fitting what was essentially a 31" wheel in a 26" frame before my custom Triton arrived. It worked as a temporary test setup but I would not want to ride like that long term.
Muniham might need mm, not inches. A simple shim should work.
Interesting solution saskatchewanian but as you say, hopefully won’t need to go there. The tire should show up today or tomorrow so once I get it mounted I’ll update with how it fits.
Ok, got the high roller mounted and it fits great with plenty of clearance. For future reference, fully inflated it measures 58 mm wide and 55 mm high when mounted on a 32 mm rim.
Nice! Tons of clearance! Once you get a little experience, would love to ride, as I usually ride by myself.
I try to ride twice a week, weather permitting, usually Wednesday morning and Saturday/Sunday morning on the Isar, south of the Munich Zoo for about 3 hours. Most likely Wednesday doesn’t work for you, but maybe a Saturday/Sunday some time (we are presently in South Tyrol till after Easter - brought 2 unicycles so hopefully will be warm enough to do some muni). But maybe in the spring or summer.
Nice. Just goes to show that you can’t always trust numbers between brands. My Hans Dampf in 2.35 looks wider than your High Roller in 2.5 (on the same rim)!
This is a WTF moment. I can’t believe that Maxxis advertises that tire as a 2.5 when the ETRTO label shows 55mm width. 55mm = 2.16" That’s a huge discrepancy.
Hans Dampf is advertised as a 2.35 and shows 60mm on the ETRTO label. 60mm = 2.36
Many tires don’t quite measure up to their stated size but having two labels so at odds on the same product… I don’t think I have ever seen that before.
I’ve used Highrollers for years on both my DH and aggressive xc MTB and the 26 x 2.7’s mount up to be be about 2.5" and the 26 x 2.5’s are 2.35". These tires are very good at the “real” size so it would be nice if they were labeled correctly.
Matches my experience. But yes, I have always found it annoying that the Maxxis width’s are so off. My guess was they maybe measure from outside knob to outside knob, but even then it’s exagerated. I also had a 2.7" Maxxis that was I think the same as a Schwalbe Big Betty/Muddy Mary 2.4".
