off road tyre for 29" nimbus road unicycle

Hi folks

I’m planning on riding my 29er off road

Just wondering what’s the best off road tyre for my nimbus 29" road unicycle.

What is it’s wheel rim width and what’s the widest/narrowest tyre I can fit without the tyre popping off the rim. :thinking:


Bicycles and unicycles have a lot in common when it comes to tires and a lot of information is known about all sorts of bicycle tires. For instance, 29er or 29" is actually a marketing term for 700c wheels, also known as 28" wheels, having a rim Bead Seat Diameter (BSD) of 622mm, but the 29ers use a fatter tire which makes the overall wheel diameter bigger. Anyway, here is some useful information Search on “ETRTO ISO bicycle rim and tire standards” for more information.

Thanks Go Uni :slight_smile:

The widest you can use depends on several things: what the width of the rim? And how much space under the frame. I’m not sure the Nimbus Road uni has a lot of clearance. What’s your current tire? And how much space between its top and the frame?

It’s a little complicated but most of the data can be found on the web (I forgot the link but there’s a site with a pretty comprehensive listing).


  1. your lateral frame width around the widest part of the tire
  2. vertical clearance (rim to frame or extra over your current tire)
  3. your rim width

Then you should be able to find some basic numbers for how tires build up, e.g. 29x2.3 on 32mm rim, 29x2.4 on 47mm rim, etc.

Of course each tire is different and some tire widths vary (i.e. Maxxis always narrower than specified, Schwalbe always wider such that a Maxxis 2.4 tire is usually narrower than a Schwalbe 2.3 tire).

I’m just guessing but unless it’s an ultra-narrow rim I don’t think you should have any problem exceeding the max tire width as you probably can’t fit a huge tire in there anyway (wait, maybe you do have a really narrow 700c
rim – if it’s a typical MTB rim then should be no problem, anything say >30mm)

Thanks guys.

I gather from the UDC site that the rim width is 42mm.

There is plenty of fork clearance above the current big apple 2" tyre

The lateral space between the forks is 3" at it’s widest point.

So I think I’ll go for a 2" knobbly tyre. I’m not doing any thing heavy, just some grassy trails. :slight_smile:

There are good 2.4" wide tires out there, check out the “review” section of the website!

A 2.0" offroad tyre makes you feel ever little bump and regret your decision by shaking you off more often. Quite possibly you’ll have more fun with one of those great tyres in the 2.4" to 2.6" range.

'@ pierrox

@ SteivO

Ok. I’ll consider buying a 2.4 knobbly :slight_smile:

If the rim says 42mm on it, like the poster’s Nimbus Road probably has. Is that the inside dimensional width to correspond with the chart in the link?