MB1 Revalved Suspension Fork & Shock

The new Kayaba PSF air fork isn’t for all riders, and some can’t get totally comfortable with it yet, myself included (I don’t like the harsh mid-stroke feel). While searching Craigslist I found some Showa spring forks from a 2011 CRF250R for $500. I “forked” over the cash then sent both sets of forks (air fork and spring fork) and the stock shock to MB1 Suspension to see if they could make magic happen.

Once I got the suspension back (which only took five business days) I immediately went to the roughest track in Southern California: Glen Helen Raceway. Having both a revalved standard and a revalved PSF fork, I was able to see if in fact the spring fork had any advantage. I rode with the MB1 revalved air fork first along with the revalved shock and noticed great balance front to rear, but the fork needed to firm up on the initial part of the stroke. Turning the compression in a few clicks on the fork helped remedy the problem, and I was actually quite pleased with its setting. Mid-stroke harshness that was felt with the stock valving was minimal, and the front end settled better into corners. The shock had better damping than stock and held up better on hard landings. Coming out of corners, the shock squatted nicely and the overall ride feel was improved.

Next up was the Craigslist MB1 revalved spring fork. This fork soaked up smaller bumps better and the mid-stroke feeling was slightly more comfortable when coming into rough corners with big braking bumps. The end stroke felt a little softer and less forgiving than the air fork on big slap-down, flat landings. The overall feel of the fork felt more predictable in corners because it gave more traction on lean in (especially on flat corners). MB1 gave me reasons to be even more indecisive. Going into this I thought the spring fork was far better than the air fork, but the spring fork is only minimally better in the beginning to the middle of the stroke. I was surprised by how nicely MB1 got the air fork to work, as I was not a big fan of the stock feeling. The more jumpy the track, the more I like the air fork. On rough, faster tracks the spring fork has more front-end traction and comfort. Overall, I am happy that MB1 made progress with the PSF, and now I have a choice of which fork I want to use on different types of tracks. —Kris Keefer