My new G310GS came with Metzeler Tourance tyres.When I picked it up from the dealers I asked what tyre pressure they'd put in, 38-42 psi he replied, thats what we put in all the GS's. That sounded about right for a 1200GS but a bit high for a light weight like the 310GS. Then we checked the 310 manual and BMW recommends 1.7-1.9 bar or 25-28 psi, which seemed a bit soft to me and the dealer. I decided to go for 34-38 psi until I did more research.
After a bit of googling it turns out that BMW's 25-28 psi is what the adventure boys are recommending on the dirt, and 38-42 psi on the tar. These are the figures for the big adventure bikes and Im still thinking that a light weight bike like the 310 would be more in the mid 30's. Oil threads and Tyre pressure threads are notorious for a huge variation of opinions but Id like to ask what pressures other GS riders are using.
Today I rode 80ks on dirt and sand and another 100ks on tar. I still had 34-38psi in the tyres and on the tar they felt fine, (i really like the tourance tyres btw)
I rode the Plomers Point Rd from Crescent Head to Port Macquarie. The first section of the 30k trip was in reasonable conditions, the road had been graded for the camping areas, and didnt present any difficulties. After that a 4X4 only sign and the road quickly descended into deep mud holes resembling hippo baths and long stretches of soft sand which quickly brought me to a 1st gear crawl. In the sand the rear wheel sunk in quite deep, but I kept the bike moving slowly. If I went too slow i stalled, too fast the front wheel would sometimes take on a will of its own. In retrospect I had too much pressure in the tyres for such soft ground, and I didnt have a tyre gauge or pump. They have to be in my kit next time. After a real hard hot slog without water, I came out the other side and back onto graded gravel at Port Macquarie. Water also needs to be in the kit. Plus a *** and a lighter.
I took the Maria River Rd back to Crescent. This is a graded, gravel, well used back route to Kempsey which I imagine would be a bit of a race track. I felt comfortable at 60-70 kph, and the GS could have gone much faster. Once the road got into Kempsey Shire it became corrugated with lots of hidden pot holes but the GS didnt seem fazed by that. The tyre pressures were ok but might have been softer on the fast gravel.
When I got back on the 100kph hotmix the 310 just took off, handling beautifully, for a fast freeway stretch then home. The 310GS pulled up well, nothing had fallen off, Sometimes it was challenged by the conditions, other times sailed through and I was the one holding things up, Afraid the 310GS aint that shiney anymore but this is why I bought it.