White Brothers Fluid 130 650B

By Eric McKeegan

Travel: 130mm
Weight: 4.5lbs. with cut steerer
Stanchion Diameter: 32mm
Steerer: 1 1/8"
Spring Type: Air
Damping: Oil
External Adjustments: Air spring, Rebound, Compression
Disc mount: IS
Price: $950
Country of Origin: USA

When looking for a long-travel fork for either of the alternative wheels sizes, 29" or 650B, there is only one choice. White Brothers has these niches covered with their Fluid series of forks. The 130mm 650B fork got the nod for front suspension duties aboard the 650B Heckler project (see issue #135). Over the course of the test, I've seen varied terrain pass beneath the fork from a 12-hour duo race to a few runs down the slopes at a bike park. Here's the skinny.

Installation was quick, but dialing in the suspension setting would prove troublesome. The left leg is the air spring and the right houses both the compression and rebound damping. Rebound is controlled by a knob at the bottom of the leg, and compression is adjusted by adding or removing air from the top of the fork. More air = more compression damping. The problems surfaced when I was unable to get any sag even using the minimum recommended 50psi in each side. I tinkered around with various settings in both air cambers, lubed the fork legs and waited out the 10-hour break-in period. None of it worked. The fork either felt incredibly harsh or wouldn't extend completely and never got more than 100mm of travel.

It took a few calls and emails, but it was eventually discovered that the air pressure ranges in the manual were not correct. The compression damper side should have between 0-50psi, not the 50-150psi listed. The manual also had a warning that the internals could be damaged by running the fork with no pressure in the damper, which turned out not to be the case.

At this point I dropped the damper pressure to zero and bumped the spring side up to 70psi. The proper pressure made all the difference. There is still a bit of initial stiction, which is helped by frequent lubrication of the stanchions, but overall the suspension action was much, much improved. Overall the fork never felt quite as plush as I would have liked from a 5" fork, but it worked quite well on midsize and larger hits.

From a stiffness standpoint, the Fluid acquits itself quite well for a four-and-a-half-pound fork. Pointing the front end of the bike at the chunk and blasting over it at speed was the way to go. In fact, I would aim for the rougher stuff as it seemed to get the fork moving better into the meat of the travel.

I wished at times for a dial to ramp up the compression damping while climbing, or even just a lockout. As it was I added air to the compression damper for smoother rides and ran it at 0psi for plushness on the bumpy stuff.

The fork would top out if rebound damping was set too fast, and I ended up with a slightly slower return that I would have run otherwise to combat this. Other than that, the rebound damping worked well handling big hits and multiple small ones. The compression damping worked well to prevent brake dive, even when set to minimum. This may have something to do with the initials stiction the fork still exhibits. There also seems to be about 10-15mm of negative travel that is only noticed if I pull up on the bar while holding the wheel in place. There was still 130mm of travel available, so I ignored it and ran about 25mm of sag without taking this extra travel into account.

Compared to 5" travel forks form other makers, this fork matches up well with both weight and stiffness. Solving the stiction issue and adding adjustability for compression damping would put this fork on equal footing with the best out there. As it stands it is the only dedicated 650B long-travel fork available, and once set up properly and broken in, it worked quite well. www.whitebrotherscycling.com