What sets the Momsen apart from the standard Arisun is the development and use of a 120tpi (threads per inch) casing. Higher thread-count casings are lighter, more flexible and supple, and (usually) more expensive. The supple casing means that there should be more grip and traction, but does tend to sacrifice on tyre wear.
The dual compound design features a harder 68A centre for slower wear and a softer 60A on the shoulder for better grip. At this stage it is only available in 29x2.20, but there are whispers of more sizes to follow. Weighing in at a very respectable 621 grams, actual weight (on my digital kitchen scale), it compares well with the competition of similar specification.
The squarish, slotted block tread design features short, relatively close-spaced centre knobs with wider spaced knobs on the sides and shoulder. The sidewalls feature a 40TPI x 40TPI reinforcement which is visible when holding the tyre in hand - compared to a tyre with a thinner, weaker sidewall, the Momsen Mount Graham stays remarkably round with very little sag.
On the Trail:
I mounted the tyres to a set of American Classic Tubeless 29 wheels and converted them to tubeless using Stan's No Tubes sealant. They mounted easily and sealed first time using a Topeak JoeBlow Mountain floor pump. The 120TPI casing and tread pattern delivers a good combination of traction and speed. My first impression on the trail was of instant acceleration, coupled with low drag thanks to the supple casing and shallow tread pattern.
The rounded profile means that you have to use your weight to get grip going around corners. The tyres also struggle to offer enough grip in muddy conditions, but this is true of most fast rolling, low profile XC tyres.
A big positive is the stronger, sturdier sidewalls - especially at this weight. I could easily run pressures I wouldn't dream of on other race tyres without suffering from sidewall "collapse" out on the trail. It also makes for a puncture resistant design when combined with a tubeless sealant. Multi-day stage racers will appreciate this.
After six months of use, I haven't suffered a single puncture or sidewall cut. I am more than happy to sacrifice ultimate weight weenie bragging rights for this reliability. Wear has been good and, more importantly, as the tyre has worn the performance and feel has stayed consistent and predictable.
As a tyre, regardless of price, the Mount Grahams performed well and manages to impress with it's blend of speed and traction in a fast rolling, low profile tyre. As a XC / Marathon tyre it is highly recommend and can even do duty as a rear trail tyre for all but the rainy season. Considering that it retails for under R500, it's "worth" shoots up even further.
Momsen have given us a tyre that is light, durable and inexpensive - a rare find in an industry where one would usually have to settle for 2 out of 3 of those attributes.
Suggested retail: R450
Size: 29 x 2.20
From the Manufacturer:
- High Performance Tubeless Tyre
- Developed for XC & Marathon Conditions
- 120TPI carcass for less weight and a more supple ride
- Tubeless bead for tubeless compatibility and excellent sealing
- Dual compound tread surface