I’m posting here to get some help with crown issues.
I’ve read several topics about, but it doesn t solve my problem, I saw everywhere that round tires and high pressure would help, and big apple 2.0 tire wasn t sensitive, but with me it s the opposite.
I’m riding the 29" with a dominator 2 rim, big apple 2.0 tire inflated at about 60 psi, any small crown is very sensitive, and when crown is more than about 15% I can’t control the unicycle anymore
At same time, I also have a 24" muni with a 3" fat tire (duro) that I ride with low pressure (about 18 psi), and with 15% crown I don t feel anything, even with 30% I don t have any problem, so I don t understand anything.
Very strange! I ride exactly the same setup and don’t have any trouble with road crown at all. I have experienced this trouble before, but only on my 20" with a Hookworm tire. In that case, I found that higher tire pressure was helpful.
I tried different pressures on the 29 but didn’t noticed any difference, from 20 psi up to 60", but I noticed on the 24", the higher is pressure, the more sensitive it is (at 18 psi it s not sensitive at all, but since 30 it becoming much more).
I guess the deformation of the tire on the road compensates for the crown instead of affecting the whole unicycle when pressure is too high to allow the tire deformation, but it doesn’t work on the big apple, only on fat tires.
I also noticed that it s much more sensitive on left side crown more than on right, don’t know why (never got such a behaviour on my other unicycles).
I tried different pressures on the 29 but didn’t noticed any difference, from 20 psi up to 60", but I noticed on the 24", the higher is pressure, the more sensitive it is (at 18 psi it s not sensitive at all, but since 30 it becoming much more).
I guess the deformation of the tire on the road compensates for the crown instead of affecting the whole unicycle when pressure is too high to allow the tire deformation, but it doesn’t work on the big apple, only on fat tires.
I also noticed that it s much more sensitive on left side crown more than on right, don’t know why (never got such a behaviour on my other unicycles).
Eventually you learn to deal with camber through technique. It is hard to say exactly what it is.
One way that might help learn is to take on short sections of exaggerated camber. Once you can routinely deal with them, ordinary cambers will no longer be an issue.
I ride a lot on footpaths (sidewalks) that are sometimes crossed by steep driveways. There are a couple of very steep ones made worse by nasty steep approaches that flummoxed me for a long time. Now ride straight across them.
As far as I can tell there is some part of the pedalling cycle where I somehow reorient the unicycle back onto the correct line. When I first learnt to cope, the reorientation was almost a momentary still stand but it eventually morphed into something more subtle that I can no longer pinpoint.
However I do ride with tyres that have very flexible carcasses which I believe help reduce the effect. My 36 has a handlebar which also helps.
I’ve learned to deal with on my 20" muni, it’s ok with short passages (100m or less), but the whole road is cambered on 20 miles, it gives me knee pain to correct all time long.
I just noticed that my rim (Nimbus dominator 2) seems to be smaller than 29", the actual tire is 28" and not 29", I am supposed to use 29 tire or better 27.5 ? or 28 only.
A 29 is only called a 29 for advertising reasons, I think. It is actually more like a 28, unless you put some sort of huge fat tire on it. 27.5 is a different, smaller size that was only invented recently, as far as I know, though they are always ridden with a fat tire, so maybe in real life they are usually not smaller in diameter than a 29. I have heard that a 29 is actually the same diameter as what we usually call a 27, which is the standard size for road bikes, but a 29 is built to hold a much fatter tire.
Once you go non-metric, why bother with annoying things like exact measurements? I think that’s how the reasoning goes, at least. Since World War Two, as every American carpenter knows, the board called a “two-by-four” has ceased to be 2" x 4" and has now shrunk to 1.25" by 3.25."
It is possible that some of these facts are not quite right, in which case someone will hopefully correct me, but I guess getting it wrong is half the fun of this system! Enjoy!
Bike wheel sizing is even sillier than you think. The old fractional 27" size used on some road bikes is actually a BIGGER rim than what is now commonly called 29" in north america. the 27" size had a bead seat diameter (BSD) of 630mm while 29" has a BSD of 622mm, which is the same as the modern 700C roadbike and european 28" cross bikes.
If you really want to get into the weeds I would suggest Sheldon Brown’s article: Tire Sizing Systems
As to the original complaint of the road crown affecting the 29 more than the 24 I don’t have much useful advice. Maybe try turning your wheel around in your frame to see if the wheel is dished and the fame is bent (but don’t ride like that unless you also swap the cranks over, you will wreck your pedal threads). If it’s not a mechanical problem perhaps try riding on the other side of the street for a while to balance things out.
no, the opposite, I turn smoother left than right.
about the crown more on left than right side it’s only on my 29. On my 20" I don’t feel difference between left/right.
Sounds like it is time for a new non-camber sensitive tire. The problem may be that it may be hard to get a consensus of what tire would be best.
In my case I only ride a 36er and currently have two. One with a Nightrider tire that is quite sensitive to road camber and a Coker non-skid that is not affected at all by road camber. That does not help you much with a 29er but there must be a tire for the 29" that is not camber sensitive.
Yes, I think so.
Do you have specificities of your both tires and rim width please? To help me guessing what makes one sensitive and not the other one.
Probably would do little good to compare the tires on my 36ers because none are available in a 29" size. There seems to be no hard and fast rule on what tires are better. Some say more rounded is better and others talk of rounded tires that are bad on camber. In a quick search of past treads I found:
“For me, road crown (that’s what I call it…) was a big issue when I was using my BA 2.35 on my 29. I switched to my kenda nevegal (a knobbly offroad tyre), and it’s fine. I have no issues whatsoever.”
“I have a Big Apple tire on my 29” and never noticed any problems."
“Another vote for ‘Big Apple’ from me as well”
“I had a Big Apple for a while, but the 2.5” version - bigger volume. I eventually sold it because I didn’t like how it was prone to road camber. I replaced it with a Maxxis Hookworm, also a 2.5. It’s a bit better, but it’s a heavier tire."
“I read here that one of the best is the Marathon Supreme 2.0” - which I think is listed as a 28" tire. There’s several pages about 29" tires in the “Product Review” section of this forum."
“In my experience the Big Apple 2.35” is quite sensitive to road camber. I’ve heard that the 2.0" is better in that respect but I haven’t tried it. I liked the ride with the Marathon Supreme 2.0" but it blew off my rim a while ago while being at 95% of rated pressure. Not sure if that is incidental. "
“For example, the Maxxis Hookworm in any size larger than 20 inch is terrible. The Maxxis DTH (24 and 26 inch) is far less susceptible. Maxxis Torch (29 inch) is also quite good.”
Some of the worst offending tyres are round profile, whereas many square tyres with solid side knobs reduce deformation and keep you going where you want it to go.
The Big Apple 2.35 is bad camber, but not terrible if you use high pressure. I have not tried the Big Apple 2.0, but it would seem likely that the smaller volume results in less squish and tyre deformation, resulting in better camber performance.
