Posted on April 22 2016
Back in November, we started our long term test with Fox's IRD electronic lockout control system, suitably named IRD, standing for Intelligent Ride Dynamics. Although the IRD doesn't do anything that your clever brain can't, it does control the basic suspension functionality that we have all grown to accept as the norm on modern high end mountain bikes. The ability to control the compression damping via the flick of a switch is simply and suitably what it's all about.
In our first outing on the IRD - we setup the fork only on our Yeti ARC hardtail, and enjoyed the benefits of instant and convenient 'lockout' engagement, especially handy for those short pinchy climbs where you may be either racing, or jumping in and out of the saddle chasing strava koms.
BUT, i feel the IRD system was a little bit wasted on my Hardtail, so we decided to step it up a little with a custom setup onto a 2016 Rocky Mountain Vertex. The Rocky Mountain uses a short 6.0x1.25 rear shock, which is not made available in the aftermarket Fox IRD rear shock. But, with a donor IRD shock (6.5x1.5) in the next size up, and using the damper body, air can and shaft from the 6.0x1.25 Rocky Mountain DPS shock, we rebuilt the shock into a custom sized DPS/IRD to suit the bike's shorter stroke and eye-to-eye - of 6.0x1.25.
The IRD setup is not overly complicated thanks to it's use of Shimano Di2 wiring. Initially, under a small time restraint - we setup the IRD into the Rocky Mountain using an external bottle cage mounted battery pack, which was effective enough for the job, but ugly enough to do something about it. With a mix of wires routed interanally, and externally - The setup was generally pretty clean - but not perfect.
The bike was then raced to an elite podium place at the Australian Marathon champs, and the brutal 70 odd km course around Blue Derby was perfectly suited to the bike and setup, with several long climbs, descents and a good variety of technical features to warrant using the DPS / IRD shock/fork in full open mode. Although, a majority of the time during the race was spent in 'half open' medium 'trail' mode - largely thanks to actually being able to easily sit in that setting with the indicator dial showing a sort of 'half moon'.
Following that event, the ugly 'little' battery back on the downtube really had to go, so we stepped it up. Thanks to the guys at Semi Racer here in Brisbane, we got hold of a current Shimano Di2 wiring kit, internal SM-BTR2 battery (looks like a permanent marker), and the appropriate charger kit. This meant we were able to re-wire the system, so that it was fully internal, using the battery mounted with foam in to the 3T Doric seat-tube, and a addtional charge port mounted just below the stem for convenience. (although you don't really have to have this, but it's better than pulling the seatpost out each time.
So that's it for now, we will update the blog if any other changes are made! 2017 IRD units are coming soon too! (no change as far as we're aware - Other than being available in the 'step-cast' 32 100mm fork option. Stay tuned!