M3R Rear Shock
I’ve had a few questions about the rear shock plus done some experimenting with different settings, so I thought I’d post an update.
The favoured setting at the moment is for a relatively soft spring but quite firm damping.
The first and most important thing to check is the piston in the damper. The standard Revo pistons are black and there is a little number (1, 2 or 3) on the piston which denotes the hole size (there should be two holes in the piston). Hole sizes are as follows:
1 – 1.1mm
2 – 1.0mm
3 – 0.95mm
At the moment I’m using the 0.95mm piston. If you need one then I have a few spares so just ask trackside. Traxxas also make some nice variable damping pistons – part number 5461. I know Matt uses these, although I’ve tested them and actually gone back to the standard Revo piston now – mainly as I found it more consistent.
Where I think there has been some confusion/variation with sharing settings is that there are also some grey pistons used in the Jato and these have either 1.3mm or 1.4mm holes, i.e. very different from the Revo pistons. Hence you really must check the piston and it’s not enough to check what oil someone is using. I think one way to tell if you likely to have the Jato piston is the shock will be red or blue rather than the gunmetal finish. With the 0.95mm piston, I’m using Schumacher 10 weight oil. I always like a light oil as it seems to vary less with temperature and helps with consistency.
One plus of the Traxxas shocks is the huge range of springs that are available – there really is a spring for everyone. The range is set-out in the table below. I’m currently using the double blue spring (1.6N/mm) for which the part number is TRX-5434A.
One final thing to mention is that if you want a little more drop then you can unwind the plastic balljoint on the end of the shock by a turn or two. I know Simon favours this.
The links below will open up pdf’s for the GTR shock instructions and the instructions for the variable pistons.