Mini-Review: Feeling A Little Fat

On June 30, Bow Cycle hosted a fairly huge demo day for a wide variety of bike lines. I saw that they had a Specialized Stumpjumper FSR Comp 6Fattie available in my size, so I took it for a ride.

The Bike

Stumpjumper FSR Comp 6Fattie mid-fat

The 6Fattie before it got dirty.


The parts spec is fairly basic on this bike, which retails for $4309.99 in Canada. No carbon to speak of, but decent, serviceable parts. Brakes were Deore, shifting by SRAM. The low gear was a 28×42, about what I run on my fat bike. Tires are 3″ wide at both ends, mounted to 29mm rims. This provided a very round tire profile – more on this later. The fork was a 150mm travel Fox 34 with a 3-position compression damper and adjustable rebound, and the rear shock a Fox Float with adjustable rebound – both set to about 25% sag. I am used to a Fox 36 and a CCDBAir – more on this later.

The Ride

I was out kind of [very] late the night before, so I decided to try the bike on a short section of Ridgeback, one of my favourite trails. Pedaling out from Station Flats, I immediately noticed that the front end felt super light compared to my Mojo HD. Any effort to pop the front wheel sent it a foot higher than I thought it would go. The 34 was nowhere near as heavily damped as my 36, so I reduced my inputs accordingly. Even after making that correction, the ride felt bouncy. I dialed in a whole bunch of rebound damping front and back, which helped a lot. I also had to reduce the tire pressure. The bike was set up with about 18 psi in the front and 20 in the back. I dropped that down to ~16 and ~18 psi, which calmed things down a bit. I would have gone lower for sure if the bike was set up tubeless. Geometry-wise, the 6Fattie is pretty close to my Ibis, so no major adjustments there. All those changes made, I felt more comfortable tackling the turns and roots as I rolled into Ridgeback.

Climbing up moderate pitches felt fine – no weirdness there. On steeper bits with roots, the tires hooked up okay and didn’t need much body English to get the job done. Things still felt bouncy – I didn’t get a “planted” feel from the bike. The shock and fork probably needed to be tuned more to my preferences. Regardless, not bad. Small roots and mini-chunder were swallowed up by the fat tires – a very smooth ride when just cruising along. Compared to my Mojo HD, it wasn’t a huge difference, but it had more traction over smooth roots. The amount of effort to spin the big tires up was about the same. I’d need to spend more time on the bike to see if there was a major difference.

When I turned the bike downhill even a little – that’s when things got crazy. Crazy fast, that is! Despite the fact that the tires and suspension had me feeling like a superball, I clocked my fastest time on that trail by almost 2 minutes. Sections that I usually didn’t bother to brake for, now required speed checks. The bike carried speed everywhere. Corners were the only place where things got sort of sketchy. I didn’t trust the tires very much, given the very rounded profile and lack of side knobs. I had to do some panic moves here and there to stay out of the rhubarb when I drifted off line. Still, that didn’t seem to matter. Fasterness. Lots of it.

The Verdict

Would I buy this bike as-is? Probably not – I’m a build-it-from-the-frame-up kind of guy. I’d want wider rims, tires with some edge knobs, different drivetrain, different suspension, etc. That said, the 650B+ category has my full attention now. I need to ride some other bikes to see if this was just a fluke, but if it wasn’t, my next bike will definitely be a little fat.