What’s the general consensus here, a hardtail mtb, suspension forks and a 1.9 and a 2.1 tyre, both front and rear compatible, which way round do you fit the tyres? Why?

Wider on the front for grip and comfort. Narrower on rear to dig in for climbing grip.

Wider on the front for grip and comfort

Wouldn’t wider on the rear give more ‘comfort’, if he’s using suspension forks?

I run 2.35 on the front and 2.2 at the back. So in your case the 2.1 on the front.

The reasoning is that the tyres do a different job: This http://www.bike198.com/right-tire-setup-trail-bike/ explains why.

Wider on the front for more grip.

Personally I wouldn’t go narrower than 2.1 on the rear but that’s me riding mostly in the Lake District.

Mahoosive grippy one up front and a big fast one out rear..

Wider on the front.

For cornering you’re more dependent on front end grip for turning in. Once you’re in the corner a bit of rear end slide can be advantageous, front end slide often means you’re eating dirt.

For braking due to the way your weight shifts forward your front brake is more effective than your rear, hnce more front wheel grip will be advantageous.

For rolling resistance, when sat on your bike pedalling more of your weight is carried through the rear wheel. A tyre which gives less rolling resistance will be more noticeable here on the rear.

Conventional wisdom used to be a narrow bity tyre on the rear for muddy/wet conditions, but i had a go with a 2.4 on the rear on a steep wet climb recently and it was great.

Ok, cheers guys

I’m running wider minion front and slightly narrower HR2 rear, although the ‘smaller’ HR2 comes up similar to the minion.

Minion grips great for me anyway, but I like the HR2 for grip but I am finding it quite draggy. It does power through crud and over roots though, but flat pedal and it’s hard going sometimes. I do wonder if I don’t need so much grip at the back. I used to run regular HR which rolled better.

Volume aside you want to steer with the front, drive with the rear. Imagine a slick on the front, and a soft mud spike on the rear. You’d wash out everywhere and it’d be a pig to peddle. Swap them around and things make more sense.

As above, you want more grip on the front.

2.1″ both ends … can’t say I’ve noticed any difference at all !

motorcycles go the other way around …..

Size doesn’t mean more grip though, it could be a 1.9 grippomatic and a 2.1 deathslick

I’m rolling 2.1 both ends on a ht, the difference as mentioned above is in what each does. Front is a nobby nic and on the back is an old wtb tyre with a low profile. Trails around me are dry so the nn helps if I encounter looser bits and the lighter tread on the back spins fast.
Weirdly my tyres appear to max out at 2.1 even ones I use alpine riding (actually in the Alps not the alpine style out-&-back stuff)