I now, since my birthday, have a lovely Nimbus II 20" unicycle. Because I do most of my practice away from home, it tends to live in my car boot after my morning practice so that I can take advantage of finding myself somewhere rideable at lunchtime or the end of the working day. I still have the cheap Indy 20" I bought to begin with, and in theory I use that on the patio if I can’t be bothered to get the good one from the car, but in fact either it or the Nimbus eats up my tiny patio so quickly it is hardly worth it now that I am actually able to string more than a few pedalstrokes together. I tend to use the 16" instead. The Indy 20" has a very smooth tyre on it which is already a bit worn - I am wondering if there might be some usefulness in putting a thicker knobblier, tyre on it and planning to use it more on the grass as a sort of ‘mini-muni’ trainer. Or am I just trying to make a silk purse out of a sow’s ear?
Interesting question. For you, I think the issue with riding on grass involves volume, rather than tread. If the Indy tire is a high-pressure/low volume tire, then it may be more of a challenge on uneven surfaces. If there’s significant volume in the Indy tire, you can try lowering the tire (tyre) pressure, and that will help you roll over bumps. Some tires aren’t suitable for low pressure, and they will start folding or bottoming out when the pressure is dropped. I suggest, as a first step, lowering the tire pressure and seeing what happens. Good luck!
Have you tried the cheapo’ lately? I bet that if you do, you’ll wonder how on earth could you ride it… Having tasted what a proper uni is!
I’d say… Gumtree?
The 20" will stick in the ruts a bit too easily and tip you off.
I can not see it working very well for Muni on grass or rough surfaces, but it should be OK on uneven footpaths and hard packed tracks with a 20x2.5 knobbly tyre on.
Add up what you might need to upgrade, and cost it out against putting the money off a new 24" or 26" later-on.
I am in the same situation with my practice Uni, a cheap Chinese Ebay special I bought second hand for £16.
Saddle upgrade, longer seatpost, cranks, pedals, tyre = appx £50 worth of extras so far.
Even now I am considering the £20 Quax 20x2.5 tyre for mine, taking the price parts plus the Uni up to £86 - I must be mad.
http://www.unicycle.uk.com/unicycle-parts/tyres/qu-ax-cross-20-x-2-5-tyre-6607.html
I bought the 24" Club Freestyle for £79 on special offer from UDC UK.
Their weekly offers are hard to beat.
Sometimes it is cheaper to buy a whole package, than try to build a new Uni from parts.
PS - the knobbly tyre for the 16" is only £9 if you want to do Mini trials in the back yard.
The additional grip is amazing - hence the desire to upgrade the 20 to a similar 2.5 wider stickier tyre for wet winter practice (e.g. iding, free mount, stop/start, and maybe riding backwards if I get that far).
Even though the 20" is likely to be too small for off-road riding, it should open up the possibility for easier learning when riding outside.
Note: my patio has rubber tyre marks all over it from the 16" knobbly - so don’t use a trails 16" or 20" tyre indoors.
In summary to the gibberish above - go for it.
The Quax 20x 2.5 is the only 20" knobly tyre available, the rest advertised as 20-inch are really 19-inch trials tyres.
Also consider a £9 16-inch tyre for the mini Uni at the same time if you are paying UDC £10 postage for shipping.
I don’t believe a 20-inch wheel will work very well for off road muni - but it should be an absolute laugh practising with loads of grip, and no spin-out on wet winter pavements and skate parks.
I almost forgot - Specialized do a 20x2.8 tyre.
http://www.tredz.co.uk/.Specialized-Big-Roller-Tyre_94238.htm
I wanted one of these for the Bounce Factor - but the contact patch of the rubber knobbles looks to be smaller than the Quax tyre.
Only on the grass - so I’ve no idea whether my inability to ride it is down to that or to the unicycle.
I may update my old bike like this guy…
In my case the comparison would probably need to include the cost of a divorce in the case of buying another unicycle in anything like the nearish future - whereas a new tyre and pedals for one I’ve already got is just running costs, really, isn’t it?
This is a very convincing sentence, thank you!
While I have a muni, I ride two of my 20" unis “off-road” (unpaved surfaces) all the time. (Actually, I ride all my unicycles off road at times, even the 36er.) One is a plain 20" I put a BMX tire on, and the other is my trials uni that has a big, knobby tire. For light trails and light off-road use, they both do fine. I’d likely use my muni on anything challenging and technical, but I certainly don’t restrict myself to paved surfaces when riding these two 20" unis.
Please correct me if I’m wrong, spinningwoman, but I don’t think you’re considering riding difficult or technical off-road trails, and I think upgrading the tire is a great idea. For about £13 GPB ($16 USD), I bought a 20" BMX tire at Wal-Mart that looks cool and is great for mixed terrain on my little generic 20". I think you have a good idea there, and I say go for it.
I tried a cheap 20x2.25 Kenda Kutlass bmx tyre and it fails to provide the grip or volume required to ride over uneven paving slabs in my back yard. The 16 UDC club trials uni I bought last week works so much better for bouncy shock absorbsion and grip to prevent spin out when pedaling.
I guess the Kenda has a hard rubber tread compound, or harder side walls compared to the 16 tyre.
In the UK we have two problems.
- No wallmart.
- And wet winters.
The grass and off road tracks will be wet and muddy now for the next 6-months.
Even the concrete will be slippery when wet, so a grippy contact patch is essential.
It is good to know the 20’s can handle off road. When I tried grass on my 24 the hidden bumps needed a committed amount of speed to be successful, and longish cranks to overcome the slight gradients on soft ground with a soft tyre.
The £20 Quax tyre from udc uk will fit no problem, but incur postage costs.
The £20 Specialised needs 70mm plus between the forks to allow the tyre to fit width ways, and 70mm between the rim and frame crown for height.
These are the two tyres I am considering to upgrade my 20" into a wet weather winter practice uni.
So - the tyre has arrived (qu-ax) so now all I have to do is work out how to change it. I may be back for advice…
I just thought - I’m going up from a 1.75 tyre - do I need a different tube? And assuming I do, can I just buy one from a local bike shop?
Did you get the 2.5" tire? If yes, it’s a good idea to get a larger tube to fit. I’ve used a 1.75" tube in a 2.7" tire “in a pinch,” (rubber does stretch, after all), but only until I could get the larger size. It wouldn’t take much abuse.
Your local bike shop may have the larger tube, or you can get them on-line (which is what I usually do – my local shops don’t tend to carry much that fits my needs).
Cheers!
Don’t forget to wait for the tyre to “scrub-in” and take the shine off before making a final verdict on the new levels of grip.
I found that new tyres needed a few rides to wear in and get rid of the mould release left over from the manufacture process.
Also - I am itching to get hold of a Quax myself, a glowing report will make the wait seem even longer.
I did it! My first uni now thinks it is a baby muni, with an awesome looking Qu-ax tyre on it, (plus I had already given it a ‘seconds’ Nimbus gel seat and Nimbus pedals to replace the ultra-slippy ones it came with). 
I am really pleased - I’ve already gone further on grass with it than I have before, andit seemed to handle OK on the tarmac too.