2011 Moots MootoX RSL — Tire Choice
See also the general riding notes.
I evaluated the Moots MootoX RSL with three different tires:
- Schwalbe 'Furious Fred', about 380g;
- Schwalbe 'Rocket Ron', about 543g;
- Schwalbe 'Racing Ralph', about 684g.
The choice of tire has a HUGE influence on how quick the MootoX feels.
The MootoX RSL frame is exceptionally responsive to power and steering inputs, but heavy tires with high rolling resistance will mask the inherent responsiveness of the RSL.
Grip is always an issue, so in this discussion, one must understand that an ultra light weight tire is not going to grip as well— but it also might be the very best way to teach oneself finesse when riding, eking out every last drop of performance by smooth application of brake and steering input, just as in a race car on a track.
On trails with loose material over hard-pack, I prefer the heavier Schwalbe 'Racing Ralph'.
On clean hard-pack fire road and single-track packed dirt, the ultralight Furious Fred tires offer awesome responsiveness in a 29er.
Legal disclaimer: Since we are not financial advisors or divorce attornies, never, ever test ride a Moots MootoX RSL with Furious Fred tires unless your bank account is flush.
Grip and feel on the beefier tires
I began testing the MootoX RSL with the Schwalbe 'Rocket Ron' tires. The Rocket Ron tires are a moderately light tire with very good grip, and they roll fairly efficiently, but definitely do not feel speedy in terms of effort to sustain speed or accelerate on pavement or similar hard pack conditions.
Switching to the heavier and beefier Schwalbe 'Racing Ralph', grip increases noticeably. On hard pack and paved roads the Racing Ralph tires feel similar to the Rocket Ron tires; neither of those two tires feels particularly efficient in terms of rolling resistance and both seem unresponsive to spin up to speed. Stick with the Racing Ralph tires for all-around versatile tires with excellent grip.
The Schwalbe Furious Fred tires 29 X 2.00"
I knew that the Furious Fred tires were light, but I was shocked at the dramatic improvement in responsiveness of the bike, both in terms of acceleration, but also quickness of handling and steering. The stunning difference that 2/3 of a pound of rotating weigh on each wheel makes must be experienced to be appreciated.
Of course, a light tire on a heavy wheel is only a half-win, which is why I’m using the Easton EC90 XC 29er wheels, which are about as light as they come.
Almost, it was as if the MootoX RSL 29er had been transformed into a 26er— the race-bred behavior of the MootoX RSL was revealed, with the acceleration dramatically improved, the steering showing markedly quicker feel, and speed picking up awesomely fast on pavement and hard pack dirt. A remarkable transformation.
Were I racing, I’d use the Furious Fred tires, giving up some traction for the quicker acceleration. So long as there were not jagged rocks or similar terrain that could shred a tire sidewall.
The Furious Freds can (and must) also be run at higher tire pressures for even lower rolling resistance— yet the tire carcass is especially compliant, so that the higher tire pressure feels less harsh than one might assume. Almost like using a tubular (sew-up) tire on a road bike instead of a clincher.
My experience proves to me that a 29er bike need not feel sluggish; the RSL practically leaps forward when applying power with the Furious Fred tires. With the Furious Fred tires, the MootoX RSL feels very much like a 26er, except that it rolls over stuff and handles bumps better, retaining those very useful characteristics.
Downsides of the Furious Freds
On the downside, too-hard braking can overtax the grip of the Furious Freds. Riders with modest technical skills are likely to lock up the brakes and skid. These are tires for those with finesse, or for those looking to learn finesse, not for 'bangers'. Years ago, I trained myself to ride with minimal grip by riding smooth (no knobs) tires for a summer. That training (with a few “teaching moments”) paid off with a lifelong ability to sense just how much is there for grip and braking.
Local reference rides and surface conditions
For those who live in the Palo Alto area, I tested the tires on Alpine Road (dirt), Monte Bello to White Oak Trail to Black Mountain, Russian Ridge and Windy Hill (up and down), as well as various adjoining trails.
The descent from Black Mountain entails various off-camber curves, often with a thin layer of loose soil over hard pack. On such surfaces, some care is required, but the one time I nearly “lost it” I was able to save it by steering wide for a moment. That sort of surface on turns definitely requires strict attention: tires can brake and turn, but there is a limit to friction. So brake first and then turn with smooth steering input (avoid jerky sudden steering inputs).
Also problematic are washing out in sand or gravel; here the 2.00" rounded profile washes-out much more readily than a less rounded 2.25" Rocket Ron or Racing Ralph.
Fun with road cyclists
A gratifying use for the Furious Fred tires is on the road, whenever it just feels like a good day to give road cyclists an inferiority complex; the Freds sprint so well (put 45 psi into 'em) that translation of power to speed on the MootoX RSL is surprisingly high— and I bring a road cyclist perspective (most of my riding).
By comparison, I tried such games with the Racing Ralph tires, and I had to run myself ragged to pass road cyclists with the RR’s— way too much rolling resistance.
One word of caution— don’t even think of using the Furious Fred tires in a tubeless setup without two bottles (4 oz total) of Stan’s sealant. The Furious Fred tires are “tubeless ready” for UST rims, but they are not UST tubeless, and thus need sealant to fill pinholes!
The Furious Fred tires have very thin sidewalls full of pinholes, and it took me an hour of pumping and riding around the neighborhood to get the sealant to plug up all the holes, which sealed the pinholes pretty well, with occasional hisses and small geysers of white sealant erupting momentarily. This subsided over the course of an hour.
A subsequent ride showed modest pressure loss in one tire, so I just pumped it up; the Stan’s sealant continued to seek out the holes and over the course of a 90 minute ride the pressure loss was minimal in one tire, and modest in the other. Bang around during initial setup, as the flex tends to stretch the rubber and open up weakly sealed areas, then the sealant goes to work.
If nothing else, this is a testimonial to just how good the Stan’s sealant really is, and why the nasty thorns this time of year have not caused a flat even once— I’m sold on Stan’s sealant.