Originally Posted by
Bazooka
As for air pressure there is no exact "must be this" number, but a range of between 20-25 lbs in the rear tires is what I recommend, some recommend more but you will sacrifice ride quality if you go higher than 25lbs, 20-22 is the sweet spot for me.
Your sweet spot will depend on your style of riding, the terrain, one or two up, etc. Dont be afraid to experiment with your rear tire pressure as this is the single biggest variable in ride quality, assuming all else is in proper working order with your trike's suspension system. As for front tire air pressure, always run max recommended pressure as stated on your front tire.
Also, the Motor Trike solid axle conversions run a ladder bar rear suspension, with heim joints located on either side of the front of the ladder bars. These need to be inspected periodically as some have been known to strip their attachment threads out of the heim couplers, which is something you dont want to happen. Further, it is recommended that the heim knuckle be lubricated with a silicone based spray-on lubricant every couple of thousand miles to prevent them from binding.
Whether not lubricating the knuckels is causing the heim joint failures I cannot say for sure but these are two areas that I would pay attention to, particularly if the trike has some age/miles on it. It might be worth emailing Motor Trike with your vin number in order to ensure yours are the newer ones.
Lastly, Motor Trike uses a small air bag type of rear shock so adjusting the air pressure is pretty straightforward with these shocks. If they leak down frequently and most do, a good short to mid term fix is to air them up to 90lbs and let them sit overnight then lower back down to your preferred air pressure the next day. This balloons the air lines slightly and helps seal the o-rings at the shocks and T fittings and is a well known fix for this problem.
I hope this helps and if you have any more questions, give me a shout.
P.S.- I edited my first post and this one a bit for clarification.