The aftermarket fork hop-up business has essentially been non-existent since the days of bolt-on arches and Total Air cartridges, a fact that's surely down to the majority of suspension brands not leaving much room for improvement these days. MRP, however, believe that isn't the case, and they've come up with a clever looking system that replaces your fork's air spring top cap and tokens with a cartridge that does the same thing while offering tool-free external ramp-up control.
Ramp Control Cartridge Details
• Speed-sensitive ending-stroke control / adjustable bottom-out
• External, tool-free adjustment via crown-mounted dial
• Replaces fork top cap and volume spacers
• Weight: 56 grams
• MSRP: $139.95 USD
The appropriately named Ramp Control Cartridge replaces your fork's top cap and volume-adjustment tokens, and the 56-gram unit retails for $139.95 USD. MRP offers a bunch of versions to fit different models ranging from cross-country forks with 32mm stanchions to forks with 34 and 35mm upper tubes, and travel from 90mm to 180mm. MRP is also working on Ramp Control upgrades for downhill forks, which I can see being popular among racers. Check out the compatibility chart below to see which version works with what fork model. The Ramp Control Cartridge weighs 56-grams, which is just 5-grams more than a Pike top cap and two Bottomless Tokens.
How It Works
To best understand how the Ramp Control unit works, remember that air is a mixture of gasses that, while extremely thin, will still put up some resistance when forced through an extremely small hole or port at a high rate of speed. So while air does act differently than oil, you can think of it in kind of the same way in that oil is forced through ports and shims to provide damping. In fact, there have even been dampers that used air rather than oil, although that was many years ago now.
When we think of adjusting air volume to tune ramp-up, we're probably picturing some sort of system where the physical volume of the air chamber is altered by turning a dial to move a piston up or down. And, with a sixteen-position dial on top of the cartridge, it looks like that's the method MRP have gone with... but they haven't. Instead, the anodized orange knob adjusts the preload on a small port at the bottom of the cartridge. More preload means that it requires more force for air to enter the cartridge, and you'll therefore have more bottom-out resistance. Less preload allows air to transfer from the fork's normal air chamber and into the cartridge easier, so you'll have less ramp-up.
Why didn't MRP go with some sort of volume-adjusting system as used on the piggybacks of some shocks? ''One advantage is that the air spring curve is steepened only to the extent required when required,'' says MRP's Noah Sears. ''That's the result of the speed sensitivity. A pure volume adjustment doesn't have that feature.'' Controlling air transit during compression offers another plus, Sears explains, in that it's more independent than altering air spring volume: ''On-the-fly volume adjustment is less attractive than it sounds because a change in volume will change pressure and thus change your sag point.''Installation
Getting the Ramp Control unit into your fork isn't difficult, but you will need a few tools and some common sense. The first thing you'll want to do is write down the air pressure that you're using pre-Ramp Control Cartridge, just as a place to start from once it's installed. Next, let all the air out of your fork so you don't lose an eye when you remove the top cap (with a socket wrench, not an adjustable wrench as I used), and then back it out of the fork. An 11mm aluminum nut hides access to the cassette tool interface under the orange dial.
You need an 11mm socket to back off the aluminum locknut that's hidden under the cartridge's air valve dust cap, and backing the nut off allows you to lift the orange dial up and off of the cartridge to expose the cassette tool interface. A cassette lockring tool is needed to thread the cartridge into the fork to the correct torque spec for whatever fork you have (I'm sure you'll be using a torque wrench, right? Right.).
Next, drop the orange knob back down onto the cartridge and then thread the aluminum locknut back down over it by turning the 11mm socket with your fingers rather than the wrench. Being aluminum and that its only job is to hold the dial on, this nut calls for just 2Nm, which is next to nothing. If you use a wrench, you'll likely damage the nut, never forgive yourself, and live in shame forever. If you didn't bust the nut, you can now pump the fork back up and call it done. The cartridge drops right into the fork. Total installation time: less than ten minutes.Performance
I dropped the Ramp Control Cartridge into a RockShox Pike that, depending on where I was riding and my level of courage, had seen anywhere from one to four Bottomless Tokens installed inside of it. So I was familiar with how the fork felt with a single volume spacer, but also with how it ramped up when crammed nearly full, with me preferring the latter setup for the majority of my riding. It's not that I'm constantly sending my bike and body off of large moves, but I do far prefer more progressive suspension that provides feedback and something to push against.
MRP says that when the cartridge is at maximum progression, it's approximately similar to four tokens, but I wanted to start at the opposite end of the range before going all the way to the other extreme. When the orange dial is backed completely out, the progression is very similar to when the fork had a single token installed, which is to say that it's relatively linear and that I could get full travel (at the same pressure I was running with the stock setup) a bit too often for my liking. If I was on the mountain and the fork had a single token in it that provided a similar feel, I'd likely reach for a shock pump to add 5 - 10 psi, a change that would equal less bottoming but also a less forgiving feel in the early stages of the stroke. Compromises.
Instead, I turned the orange dial all the way in to see what maximum progression felt like. The result was me going from using full travel with a touch of hard bottoming on one particularly nasty landing to not quite using the fork's full stroke when coming down off of the same drop. But, since this move is probably the hardest impact that I'm likely to see on my local mountain, I thought that I should be using all of the travel but that it should be more of a soft bottoming moment than a hard one. Backing the dial out a few turns did exactly that, all without having to use a socket wrench to add volume spacers. Fill the fork's air spring as per normal, and then adjust how it ramps up by turning the orange dial.
After a bunch of tinkering, I actually ended up running 5 psi less in the Pike and had the Ramp Control Cartridge's dial all the way in, a setup that provided more sensitivity at one end of the stroke but just enough progression at the other. In other words, less compromise. MRP's trick cartridge is still inside of my fork after months of use, and I still play with the dial from time to time to adjust the fork's progression. Pinkbike’s Take:
|A big benefit of the MRP Ramp Control unit is that it removes the need for a socket wrench and can be used to alter how a fork feels in mere seconds, making it more likely that riders will adjust their suspension to better suit where and how they ride. But spending $139.95 USD on the upgrade will make zero sense if you're not the kind of rider who thinks about such things. The set-and-forget crew simply won't benefit from MRP's drop-in cartridge, regardless of how effective and clever it is, but those who appreciate being able to tinker with the feel of their fork on the trail will see it as money well spent. - Mike Levy|
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