on my BM R80 i run 35psi in rear 30 in the front & 25 in chair so when i put chair on my shovel i started with the same numbers but having dug out an old clymer manual it recomends 22 front 26 rear & 20 chair this seems very low to me any one have a definitive answer i am running conti tours at the moment but intend to change them soon possibly for dunlop touring, unless you have a better sugestion
I run 36# front and 34# rear and hack on all my HD rigs.
With a different sidecar than HD I run between 28# & 34# depending on sidecar weight. If the sidecar has an auto tire usually they will take even less PSI since they are designed to support a much heavier vehicle than a sidehack.
Lonnie
Thanks lonnie i thought i wasnt being stupid where on earth do they get the figures from. any advice on choice of tyre its an HD rig CLE clasic already has dunlop on chair.
Because bikes, rigs, drivers, load and tires vary a lot I opt for adjusting tire presure taking in account the form under load and the behaviour in bends.... Had once a very bad experience withg my MZ where the tire tried to flip off the rim.
Too high pressure and contact area to the ground goes away and you wear your tire in cero point nothing. Breaking becomes uneffective too.
Too little pressure and the bike becomes spoungy and the tire may come off in a hard ridden bend with a lot of load....
And on dirt you should lower pressure for to gain grip. (in trial you might go down to 7 PSI)
The pure PSI numbers will not help you much with a poor tire (low number of layers) you will have to go up in pressure and still feel unconfortable. With a heavy wall tire like car tire or tcheck Mitas back and sidecar tire you can go down quite a bit.
Get to "Your" numbers checking and observing for to find out the right combination. The original numbers given by the factory didn't help me much until I made some tests with the portable compressor and 2 cement sacks on a parking lot observing a neffew making circles. => And still on the front I do not feel confortable appearantly because the front tire seems to have few layers and is pretty round, so with high pressure I feel little grip in hard left handers, but if I go down with pressure direction becomes inaccurate..."spoungy"
On my rig Jawa 350, Velorex 562, which is very light and original Mitas tires, driving alone: front 30, back 32, sidecar 29PSI
with heavy passenger and load: front 34, back 37, sidecar 35PSI.
Observe people on solo bikes, you'll get pretty fast an idea of how a tire should look like. Then when You observe somebody else making circles you see how the tires get obligated or rubb away, so that you can make your conclusions and correct the presure accourdingly.
Best regards
Sven Peter
33psi front and hack 36 psi on the rear tire has been good for me.
Avon MkII square profile front, standard Ural tire hack and just now replacing the Avon MkIII with a metzler block k
*might have them avon's mixed up, I dunno...
Note:
The poster was referring to a Harley shovelhead motorcycle with a sidecar.
Lonnie
