I’ve killed the KOM i25 on the back of my Soul – split it at the seam so it no longer holds air tubelessly. It’s not really been man enough for the job – I’m a bit over 10 stone, very rarely pinch flat but ride a lot of rocky peaks trails and have dinged the hell out of the back, and to a lesser extent the front. I rarely bend wheels, its just dings and these have been spectacularly bad. Generally happy with 2.3ish Maxxis/Spesh tyres. I like the feel of light wheels and I quite like climbing, but prefer descending.

Probably going to go for DT rims – an XM on the front with an EX on the back.

…but whether to stick with 25mm internal or go 30mm? Sticking with 25mm will add on 60g to the rear, which I can live with (plus swapping to brass nips from ally). Going for 30mm will be nearly 3 times that. I did notice a benefit in edge grip when cornering when I started using 25mm internal rims, but at what point do things start getting too square in terms of tyre shape, or are only beneficial with nearer 2.5 tyres when increasing rim width further?

I went from dt e1900’s with 25mm internal to dt Swiss xm481’s with a 30mm rim earlier in the year. I can’t saynive massively noticed a difference – other than the Hope hubs I built the xm’s to are noisier then the dt 370 hubs. Plus the xm’s look nicer! Running a 2.5wt dhf on the front and a 2.3 aggressor on the rear. I tried a 2.4wt dhr2 on the back and it was so draggy it sucked the life out of the bike.

An XM481 is quite a lot stronger than a KOM i25 which is quite a fragile rim.

Up to 2.4″ tyres, stick to 25mm. I’ve noticed tyres squaring up and steering strangely on Flow rims, which are 27mm I think. Maxxis have specific WT tyres now for 30mm + rims, but the tyres are 2.5/2.6″. There are DH racers still running 25mm.

I tried a 2.4wt dhr2 on the back and it was so draggy it sucked the life out of the bike.

Possibly because the wide rim flattened the tyre profile?

EDIT – Maxxis do standard and WT tyre profiles from 2.4″ upwards

One of the benefits I can see is that the foam inserts only seem to work properly on rims over 25mm wide  AFAIK so (especially on  a hardtail) you’ll potentially miss out on being able to use one and run lower pressures whilst still protecting you wheel rim? I’m on Hope wheels which aren’t really suitable at 25mm (according to Rimpact etc)

If you prefer light then stick with 25mm. I had similar concerns, but now I’m running 30mm with 2.35″/2.4″ and they’re absolutely fine.

I’d stick with 25. Since swapping to 30s I’ve found I get a lot more pinch punctures and I think it’s because of where the bead sits in relation to the tread. Other than this inconvenience I’ve not noticed any difference over narrower rims.

I went from i23mm KOM to DT481 i30mm using 2.35″ tyres, probably should have gone for 25mm for less weight & more tyre height.

wider on the front, for me; 35mm front, 25/30mm rear works well.

I went with 25mm ex471 rims for my recent build.

30mm any day for Trail/AM, easy to fit Panzer plus less tyre roll at lower pressures. Run 25 for XC/Trail still though as I run higher pressures and skinner tyres

I would be surprised if the difference between 25mm and 30mm rims was 120g, or is that for the pair?