Unicycle Unstable after Tube Replacement...?

Hi all,

I’m sorry I only seem to find time for this forum these days when I have a problem. (Don’t feel bad, it’s not just you!). As you may know I’m approaching half-way on a 5,000km road trip across Canada on a 29" w/ custom aluminum cases (unityfortheclimate.ca).

So, while I’m pretty new to unicycling (and in many regards, it shows) I’ve done gravel, slush, cross-winds, headwinds and all manner of hills and generally was feeling pretty comfortable…until today.

I replaced a flat tube and now I can’t seem to ride more than a few meters. I’m extra wobbly and the uni feels ‘skittish’ and unstable. Even straight lines are a problem. I basically had to walk all day.

The wheel looks straight and isn’t rubbing on the brakes (tried re-mounting it twice just in case). I checked the spokes and made some adjustments and they seem to have even tension. I also tried reversing and rotating the tire. Anything I might be overlooking?

The tire tread looks somewhat uneven along the circumference (ie., more warn on the left than right). It’s possible the wheel wasn’t perfectly straight before and now the tire is putting the uni at a slight slant. However, I wouldn’t expect it to be such a dramatic problem, and changes in PSI don’t make much of a difference either. I also tried sanding/cutting down the uneven knobbies and it didn’t have the effect I was hoping for.

I’m going to get a new tire tomorrrow and maybe a sanity-check at a bike shop, but since I’m in small-town Saskatchewan it will take a full day including rides to/from. And I’m unlikely to find anyone who knows unis. So, I want to make the most of my time there and eliminate any other potential culprits. IE., is there an easy way to check the rim or frame? Anyone experience something similar? Any good uni mechanics in Regina?

Thanks for any help!

I’m not an expert, but I have a couple questions.
Why did you replace the tube? Did you have a puncture that could not be repaired, or did it blow out following a tire failure?
More wear on the left than the right can probably be expected, given the nature of your ride – many continuous miles, on the right side of the road. Constantly correcting for the road crown will probably tend to wear the left side somewhat faster than the right. Turning the tire around may not help, since you will no longer be riding on a “level” surface, but angled slightly the opposite way.
You mention cutting off knobs, which give one the impression of an off-road tire. I would recommend a tire geared more towards road riding than cross-country (just my opinion).
Hopefully, some of the experts will chime in right about now!

Good luck!

There is a good chance that it is in your head. Since you seem to be near the Queen City you should be able to walk into any bar and ask for “two-zners-please”. While there is nothing particularly magic about Pilsner the second one might be enough to knock free whatever mental block you seem to have.

If you still find yourself near the old pile o bones on the weekend I emplore you to wander over to mosaic stadium to watch the first ever (preseason) Red Blacks game. If I can convince a few other people to come down with me I would even buy you a ticket.

I’m sure this is a dumb question, but in the spirit of thoroughness… Are you sure you have your tire inflated to the proper PSI - matching what you rode before? I only propose that because I had that issue the first time I had a flat. To my casual “squeeze” test, it felt fine, but as soon as I got on, I was riding a bucking bronco. It was the second (and last) time I picked up my uni and hucked it in the bushes in frustration.

When I got back to where I had a tire gauge, I was surprised to find that I was a couple PSI below where I wanted to be (after years of MTB, I’m pretty good at feeling/guessing, but the wide rim threw me off?). I also was not yet dialed in to how much difference a couple PSI can make in control and ride quality. I now carry a small digital gauge for just that reason. (I know you said this doesn’t make a lot of difference to you, but you could be further off than you think?)

I hope it’s something this simple, but if you are way ahead of me, ignore everything I wrote.

Good luck on the rest of your trip!

Thanks for the replies. Haha, good idea about the Pilsner. In a way the idea that it may be all in my head is my greatest fear (although I guess it could save me many bigger headaches). I find it pretty frightening how much of a mental game unicycling can be. Trying to figure it out on a narrow shoulder w/ crosswinds and headwinds didn’t help so I will give it another shot tomorrow before swapping tires.

The PSI is a good point, too; I don’t have a guage so I’m pretty sure it’s not the same as it was. However, I experimented with many different pressures to no avail.

The tube was replaced for a sizeable puncture, not a blowout. It was patchable and I’ve kept it as a spare but I opted to use a new tube to play it safe. It is a slightly knobby tire that I probably could/should have replaced after the gravel shoulders of the Crowsnest. However, all the backroads in SK are gravel and many of the shoulders in Manitoba, so I’m reluctant to go back to a street tire now.

Another very basic question just to cover all the bases -

Have you checked the bearing clamps for the correct tightness?
They need checking even after just a few meters when the clamps have been off, as your weight can settle them allowing wheel movement.

I discovered this in my early learning days.
I was doing quite well until one day I was all over the place, as if I had forgotten everything I’d learned.
I found that there was visible movement in the wheel.
Tightened it up … problem solved.

Another simple question - did you bang the tyre as you reinflated? Sometimes tyres can inflate in a funny shape after re mounting on the rim. Banging it as you pump it up can sort this and give the tyre the correct profile. Also check for a twisted inner tube :smiley:

Been following you on twitter, keep up the great work!

Large tubes can inadvertently be installed with a small fold in them that is essentially invisible from the outside of the tire. This comes from having to stuff the tube into the tire when installing it and overlooking the fold or not noticing it when the last part of the tire goes on the rim. I would imagine that you have already taken off the tire and inspected the tube so you may have already eliminated this as a possibility.