Unravel the mystery that is rim widths and find out what's best for you.
30MM Internal rim width
The XM 481 is labelled as an All Mountain rim in the DT Swiss line-up, however, some confusion often arises as this category can mean different things depending who you talk to, not to mention we will be assessing two different rims from within this category. However, mostly we are looking forward to seeing how the XM 481 handles itself and then compares to the XM 421, both classified as All Mountain yet with 5mm difference in overall rim width. We do expect that these wider rims will prove to be the most sturdy and durable out of our three test wheels and across our three chosen trails, but enough of this chitchat, let’s get setup and get out there!
As this was the first set of wheels and tyres we setup for this test, along with perhaps being the most suited to our 160mm travel test bike, we started with our baselined air pressure (rear pressure of 27psi and a front pressure of 25psi) and suspension setting using a ShockWiz. Out on the trails this setup did offer very low rolling resistance and little to no tyre roll on turns, but was lacking the grip we were chasing equally across the three tracks. This was to the point where out on the Thredbo Flow Track our ShockWiz wanted us to change most of our settings as it searched for enhanced grip. Feeling fast doesn’t always mean faster, especially if you’re fighting the bike for grip and the ability to slow down.
We reduced the air pressure in both front and rear tyres by 2-3psi each. Now, this does not sound like much but we wanted to see if by making minimal changes we are able to determine their sweet sport. For interest, it turns out that these changes to air pressure produced a similar setup used on a set of Stan’s rims and Maxxis tyres.
Having now dropped our pressures to 25psi rear and 22psi front, the changes were surprising and delivered instant improvements across the board with even the ShockWiz showing us green lights again. To be sure however, and with this current setup now looking like it could be the best of both worlds when discussing grip and speed, we took the plunge and dropped even more air out. Now sitting on 23psi in the rear and 20psi in the front it was obvious straight away on our Stromlo Forest Park trail, Little Seymour, that we were now operating in the territory of maximum grip for the front and rear and under hard landings and hitting corners at high speed the amount of movement in the tyres and potential for tyre roll and burping (suddenly losing air as the tyre tread maintains grip but the sidewall gives way under cornering or impact forces) would see us revert back to the previous setup.
Increasing the air pressure to 30psi rear and 27psi front delivered a rough ride and it only took a single run down each of the chosen trails to confirm that this pressure is excessive and certainly not recommended.
As a result of the above testing across our varying trails we confirmed that the sweet spot for our aggressive rider is 25psi rear and 22psi front. This setup results in the best overall performance when it comes to speed, grip and braking for the 30mm internal rim for the XM 481 when using a 27.5x2.4” tyre.
Claimed rim weight: 490g
Internal width: 30mm
External Width: 35mm
Depth: 7mm centre
Tyre: Onza IBEX 27.5x2.4” skinwall
Tyre weight: 885g average
Front wheel weight: 895g
Rear wheel weight: 1010g
Installation pressure: 25psi
Tyre tread edge to edge: 61mm at 25psi
Tyre casing edge to edge: 56mm at 25psi