Tech Talk - Measuring Full Travel
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If you own or ride a Bucksaw or Horsethief frame equipped with a RockShox Monarch rear shock, this post is primarily for you.
If your Bucksaw or Horsethief features a Fox rear shock, the following does NOT apply to your rear shock, but you might find it interesting none-the-less.
First things first, if you haven’t figured out how to dial in your rear shock properly for sag, check out our suspension setup guide. Proper setup is key to getting the most out of your Salsa full-suspension frame.
Chances are, after a nice long hard ride, you’ve checked the O-ring on your rear shock to see how much travel you were getting. For most of you, it might look something like this:
Checking the position of the O-ring is good practice and can help indicate if your target air pressure is a little too low or too high. In the case of the later, there is no sense carrying around travel you aren’t using, and lowering your air pressure a few psi might be warranted. In the picture above, the O-ring would indicate there is quite a bit of unused travel.
This is where it gets tricky, so pay attention.
The RockShox Monarch rear shock used on both the Bucksaw and Horsethief features 1.75 inches of stroke fit in a 7.25-inch eye-to-eye package. This 1.75-inch stroke is not custom, but is also not as common as other sizes like 1.5 and 2.0-inch stroke shocks. When Rock Shox developed this size Monarch, they used the 2.0-inch stroke shock body. What this ultimately means is that there is 0.25 inch of shock body that is never used on the 7.25 x 1.75 shock. Look at the picture above again – the O-ring is just about 0.25-inch from end the body.
To the unknowing eye, this O-ring reading might prompt one to run less pressure on the next ride in an effort to use up more of the available travel. DON’T DO THIS! If you let the air out of the shock and compress the suspension at the same time, you will see that the shock bottoms out before the O-ring is pushed of the shock body, about a 0.25-inch from the end. This means the O-ring will NEVER reach the end of the shock body on this shock.
Now if you are like me, you actually like to keep track of your shock settings and how much travel is being used from ride to ride (at least mentally). To achieve this on the 1.75-inch stroke Monarch, add a piece of trimmed electrical tape to a clean shock body, just behind the O-ring with the shock fully compressed. This will give you a positive and accurate bottom-out point to judge the O-ring against. If you take your time, do it right, and start with a clean surface, it’ll stay put. The one pictured hasn’t moved since July.
Also note that the factory sag gradient markings on the shock body are CORRECT for a 1.75-inch stroke. You can still reference these for quick and easy sag checking during initial setup up. It’s just the bottom-out point that gets tricky on this size shock.
For those of you riding other bikes that are just curious where your O-ring should wind up at full travel, you can simply check it by letting all the air out of your rear shock and gently compressing it fully. In most cases, the O-ring should be at the end of the shock body. In some cases, it might even be pushed completely off the shock body.
Now that you’ve got your shock marked with a piece of tape, go hit the trail you most often ride and double-check that you are using all your travel. Enjoy the ride.