Always happy to help - for info. I've had these wheels* on my CRF300L for over two years now, and for general 'adventure' style riding - that is a mix of paved and unpaved roads/trails and a lot of miles, would suggest the 17/19" combo is the way to go if outright 'off-road' riding is not your priority.

*my own wheels were built on a set of new OEM hubs, laced to Excel rims by Dubya here in the USA - the rear is a 2.50 x 17" with a tubeless bead-seat, while the front is a 2.15 x 19" - which as I mentioned above is suitable for 90/100, 100/90 or 110/80 profile front tyres as desired - for info. I run a 90/100x19 tube-type Bridgestone AX41 up front as this particular 2.15x19 rim is not technically a tubeless anyway, but their 110/80x19 size tyre is.

If you were on a real budget, then I'd suggest simply getting a 17" x 2.50 tubeless rim laced to your existing rear hub, and 'ghetto tubeless' it yourself - as I did - link: here.

As long as you use proper marine grade sealant on the spokes, and good quality rim tape, you ought to have many thousands of mies of trouble-free tubeless tyre running - and note that the 130/80 x 17" rear AX41 tyre is the same diameter as the 120/80 x 18" profile stock size tyre according to the Bridgestone literature, so you're not giving any top speed/ground clearance away nor having your speedo read incorrectly either.

As for the front, as I say, personally I don't consider it essential to have a tubeless front tyre - as long as you run a decent pressure you ought to avoid pinch-flats anyway, while a penetration puncture is more likely to occur when the front tyre flicks up something sharp which is then run over by the rear.

This size 17/19" rim combo also offers a far wider choice of longer lasting all-terrain 50/50 style tread tyres, compared to more skinny 18/21" knobblies.

For info. this is a Rally with the 17/19" wheel combo Rally Raid Products in the UK sell:


photo. Rally Raid demo CRF300L Rally, with their 17" rear and 19" front wheels/tyres fitted.

...very much based on my [size] recommendation after building my own wheels, although be aware their wheels are not technically tubeless rims - so you'd be on your own regarding doing the ghetto tubeless conversion on those, since they don't have a double-lip bead seat as far as I'm aware.

Hope that helps!

Jenny x