Steve Lythgoe" <steve@sharples.com>,
of Sharples Tyres in the UK offers this explanation:
"In countries where you drive on the
right, motorcycle tyres will wear more on the left side
because of the camber of the road. On a typical straight
road, the front tyre is continually turned very slightly
to the left in order to keep the bike from dropping down
the camber into the kerb/gutter/sidewalk/whatever. This
shifts the contact patch to the left of the centre line,
and significantly accelerates wear as the tyre is not rolling
freely but scrubbing slightly sideways. In contrast, the
rear wheel is not steering the bike, and as the rear tyre
deforms more readily than the front, the slight inclination
of the rear wheel in relation to the plane of the road surface
actually has much less effect than at the front."
You might also want to read Paul Glaves,
Technical Editor of the BMW Owner's News, take on this issue
by clicking here.
Erik Miner <axeis@pluto.njcc.com>
had this to say about tire pressure: "Only run the
stock pressures if you want bent wheels and quick wearing
tires! But seriously there was a service bulletin last year
recommending that pressures be set 3-5 lbs. over what’s
in the manual. I run my K12 at 38 front/42 rear . I’d
recommend 36 front 40 rear for your R11RT"
Other people have commented:
"Several posts have promoted the use
of tire pressures about 5 or so pounds above that recommended
in the owners manual, mainly to protect the rims. My manual
says 31/36 psi (front/rear)."
"I’ve noticed that the two times
I’ve gotten my bike from the dealer (at delivery and
after the 600 mile service) the pressures were in the same
range, i.e. about 5 psi above the recommended values."
"Supposedly the downside is poorer
handling. I don’t know that I’ve noticed it (I
don’t run my R11RT around the corners at 10/10ths;
maybe 9/10ths with the little experimentation I’ve
done with tire pressures. Basically my experience through
4 sets of tires on my RT is that the dealer will inflate
to rated pressure, the tire will start to wear (especially
scalloping on the front) and inflating to 39/41 or so will
stop the problem. I’ve not dented a rim at higher or
lower pressures but about 80% of my total miles on the RT
(35K) have been at 40 psi or so. Go with the higher pressure,
you’ll get much longer life from your skins."
One rider, Bill, considered going even higher
for two-up riding:
"I’ve been running 36/42 (front/rear)
for 15Kmiles now, but only because I do most of my riding
two-up and that’s what the manual recommended. If those
pressures are approximately what most of the knowledgeable
folks are recommending one-up, should the two-up pressures
be upped (to, say, 40/46, for example)?"
Rob Lentini of Tucson, AZ replied: "I’d
stick with owner’s manual pressures, Bill. NEVER exceed
the maximum pressure listed on the sidewall. In the case
of your tires, that’s 42 psi. Exceeding this cold inflation
pressure invites tire failure. FWIW, I run the stock 32/36
solo pressure, sometimes even less in the front tire since
my weight is 140 or so."
"More pressure is not necessarily better
with tire inflation. Neither is less. The objective is to
get the tire up to its designed operating temperature for
best traction and mileage. Low pressure invites overheating
and can make the rims more prone to impact damage. High
pressure reduces the contact patch, does not allow correct
heating of the carcass, and reduces sidewall compliance.
Bottom line: Read and follow the owner manual recommendations."
Nick Neuhaus <nanco@IDT.NET>
of New York City replied "I am sorry, but I have to
disagree with Rob. I have BT50’s front and rear and
run 38 front and 42 rear, all the time, whether riding solo,
with luggage or two-up. I weigh 235 naked. With leathers,
boots, helmet and all the junk in my pockets the riding
weight must be at least 250. I bent two front rims in potholes
when I was using factory pressure and it cost me about $850
to replace the front wheel/tire. Since I upped the pressure
I have had no more problems. The ride is a little harsher
but I can live with it. Maybe in the well-maintained AZ
roads the recommended pressures are good for Rob. But here
in Pot Hole City, I feel safer maxing out the pressures.
Furthermore if what Rob says about the effects of under/over
inflation is true, and I believe it is, then I would wager
that if I could readily measure the tire surface making
contact with the road at his 32/36 at 140 and my 38/42 at
250, we would be pretty close in total source area."
Barry ('95 K75S) noted: "Many people
on the "big list" speak well of Tim Bond"
Charlie Morrison <cmorrison@peganet.com>
of Ft Myers, Fl said: " I just had a front wheel straightened
by Tim Bond, WireWheels MC Service. The work was excellent
and he was very cooperative with a quick turn around because
I had an upcoming trip. He was highly recommended when I
asked the same question on the list and I also recommend
him. His web page is http://ourworld.compuserve.com/homepages/WireWheels
and His phone number is 606-873-6686"
People on the West Coast have spoken highly
of David Moore Wheel Service in Rosemead California. He
does not have a web page, but his phone number is 818-280-9815.
