Did a search and couldn’t find anything real definite so here goes:
Looking for a road tire to try some road on my 29. Problem is, my rim is a 42mm wide Dominator 2. Sounds like about the only road tire that’ll fit it without blowing off is the 29 x 2.35 Big apple? But those sound like they handle road crown poorly.
So, my question is, is there a road tire that’ll fit a wider 42mm rim but isn’t so sensitive to road crown? Kind of drawing a blank from looking through other threads and looking at tires.
Sorry if this has been asked too many times. Just can’t seem to find anything real concrete.
You should be able to use any tire that is at least as wide as the rim. I don’t have any tire recommendations for you but what you are looking for is something that will have a round profile/cross section on the rim. try to avoid tires with either a squared off profile or a raised centre tread.
The schwalbe marathon seems to get the nod quite often though I have never tried one.
Okay. Just seems like people have had problems with ~2" tires blowing off their 47mm KH rims. Maybe since my rim is only 42mm? If it’d work, I’d just as soon use a 2" big apple or 2" marathon. I did ride a 2.1" SB8 over the summer without issues…
Just don’t wanna get a tire only to blow it off the rim and destroy a tube.
Normally I’d say: just look up what is the minimum recommended width as according to ETRTO, whose table Schwalbe cite on their website, but sadly it doesn’t extend far enough into the realms of special mining applications for rims that wide.
Your inner rim width should be about 36mm or “36c” (42-6, rule of thumb).
The table goes only to 29.
Extrapolating with a quadratical model (and adapting the model to fit all data points), I calculated a minimum width of 75mm or 3". A ridiculous result.
Maybe the original table in the ETRTO standard is more complete. You could buy it for a mere 114 Euros to look up the recommendation, a real bargain.
Or more easily: just make use of nlouis1’s experience and try tyre width=inner rim width+6 -> 42-622, maybe Vittoria Randonneur.
Thanks for the links Vookash! Maybe I could find something with smaller knobbies on it like that Furious Fred that’d be a bit more durable. My SB8 was nice, but very thin and I got puntures in it like none other.
Thought I’d throw this in just to clarify my fears. Top of second page, tire blowing off 42mm rim.
I keep thinking that I got this figured out, then I read another post like in that thread. Ideally, I’d just get the Marathon Supreme or BA 2.0, but don’t want to be blowing off tires.
While that ETRTO rim/tire chart doesn’t go high enough to show their recommended minimum tire size for a 36c rim it does show a maximum recommended rim size, of 27c, for a 50mm tire. ETRTO recommendations are certainly going to be conservative, but we are still talking about a rim that is 9mm, or 33%, wider than recommended for a 50mm tire.
Tire pressure is probably a big part of the equation. They have to consider what is the largest rim a given tire will stay on, reliably, even at maximum (or higher) pressure and under load.
That blow off was at 65psi. At the end of that same thread pstrick says he is now running at 55psi and is doing ok so far. Later, again in that same thread, pcuni says he has put hundreds of miles on a 45c tire, mounted on a 38mm KH XC rim (about 32c), at 45-50psi without issue. This rim/tire combo is a little less out of spec but the rim is still 23% wider than it should be, by ETRTO standards, for a 45mm tire.
Klaas_Bil’s blow off was with the narrower KH XC rim and a 2.0 tire, even closer to spec but still over by about 18%, but that was at 70psi.
Seems like it mostly boils down to tire pressure. Anecdotal evidence on this forum suggests that the combination of a 50mm tire and a 42mm (36c) rim will probably be ok at 45-55psi, and will probably fail at 60-70psi. But, to ensure compatibility, a narrower rim or wider tire would be advisable.
When you were running the SB8 2.1 on that rim what was the tire pressure?
Maybe we should start a thread asking all the experienced 29er commuters to chime in with their rim/tire/psi stats. Especially if they are running on wider rims.
Of course that’s if there are any left that haven’t moved on to 36" commuting.
Okay, totally makes sense. When I was running the SB8 it was only 35-40 psi max. I can’t see any reason I’d want my tire harder than 55 psi anyway.
I think what I’m gonna do, is get the Big apple 2.0 since it sounds like that’s less sensitive to road crown, but won’t break the bank like the Marathon Supreme. I’ll run it at around 45 psi. and see what it does.
I hear ya on 36ers. I’d be getting one myself if I could afford it, but want to try some road riding first before I decide I need to get one.
Thanks Mad. That helped my understanding considerably. Sounds like it’ll never be for sure, but it’s a safe bet if I run lower pressure.
I’ve been doing lots of research the past couple of days on a 29" road uni. I want to move up to a 29" and want to buy a nice one.
Why does UDC’s road unicycle come with a Big Apple 2" tire if the Dominator rim is too wide? Looks like some folks have had problems with blow outs. Should I avoid this set up?
Sorry if you’re all tired of this topic. I’m a newbie and don’t have the bike knowledge that a lot of you have.
I just want to buy a really good stock uni for the road that I might be able to convert to light muni.
I found the D2 and 2.0 Big Apple to be a perfectly good combination. What it does need is lots of playing with the tyre pressure to get good results (my experience of all schwalbe tyres).
IIRC, mine works best around 35-40psi (I use it as a winter tyre).
With modifications (new cranks and tyre), that unicycle can take on anything and is a solid buy.
UDC (US) has just started offering a Nimbus 29" Oracle Road LT". I’d like to add brakes but not sure which ones are better. For cranks, maybe 150mm. I want the 127/150 dual hole cranks but those are out of stock. I can free mount my 24" with 152mm cranks but not always. Hopefully I’ll be able to handle a 29" uni. I’ve been riding about 3-4 miles a day on paved trails and want to work up to 12 - 14 mile rides.
Based on my experience of building a 29 after riding a 24 for a while as a beginner I would say that 150’s are too long unless you are going to do a fair amount of XC with climbing. I ended up giving those 150’s to Jakob F after realizing I would never use them, and I haven’t regretted it once. 125’s are very manageable on a road 29 even for steep hills. 100’s are harder to push, but if you work up to it they really make the 29er a solid road going machine. I haven’t tried 114’s, but I would bet they are a good all around set of cranks for speed with control on a 29. I have to admit that sometimes I feel a bit out of control with the 102’s I have on my 29er. Even as a beginner I never felt out of control with 125’s though.
I’m sure those are great unicycles. I can tell he put a lot of love into them and they’re really tempting, especially the road one, but I think I’d like to have an Oracle frame.
