I've got a question here for motorcycle tires since they have a rounded contact patch and not a big flat contact area.

I'm used to doing the chalk line method on cages and most other types of vehicles that have the large contact areas with the ground to adjust the tire pressure to find out the optimum pressure for the given parameters of my normal load.

Can this method still be used on a motorcycle tire, if so how much of a contact patch should I be looking for on the 140/90 rear tire and the stock 100/90 front tire of the savage?  I'm using the Route 66 tires currently but when those wear out I'll most likely get the Metzeler ME 880 Marathon tires so I have a much longer lasting tire that still has great grip.

BTY I'm down to about 225 and most of my riding is solo, but every now and then I do 2up with my daughter and she weighs in around 140.  If you need to know I also have the progressive shocks 11" model 412-4233C 115/155lb installed as well.  I still need to change out the Fork oil for 20wt from what Lancer has told me,  but I've been avoiding that as I'm not really wanting to tear down my front end just yet. Now if they made a better progressive spring for putting in there it just might give me the nudge to do that, but all I've found is the Ryca one that stiffens it up to much from what I've heard, for every day riding comfort.

Also I may need to add the roads around here SUCK, as I'm sure JOG can verify since we live fairly close to each other.

Any advise is well appreciated.

TIA

R.F.

Serowbot wrote on 03/29/13 at 22:18:45:


I did Serow,  and that's what I was kinda figuring. That's why I asked to just to be sure.  I didn't worry about it much years ago when I was riding because my riding back then was mostly off road.  Now my riding is all on-road, so tire life is very important.  I'll  give the few lbs over the stickers a shot and adjust from there to see how she feels.  Won't be able to find out this week, as we have storms predicted all week long  :'( but hopefully after that we have some good weather again and I can get some good riding in.

Tire makers want you to run the air that will give the best tire life...
Car makers want your luxury car to feel smooth,.. or your economy car to get their estimated mpg's...
Whatever...  everybody has their agenda...
Ride yer' own ride...
... as long as your tire pressure is between 20lbs and 50lbs... it ain't gonna' change yer' life...
Lower than 20lbs,.. you could slip the tire on the rim,.. and cut your valve stem, or pinch the tube...
Higher than 50lbs, you could blow on a pothole or curb...
The rest is up to you... not the tire company or bike maker...
Everyone has an agenda,.. but, it's your bike...

Bike tires wear out so fast,.. nothing else really matters...
The center patch will go before you use up the tread...
... and the sidewalls will rot away,.. before you any damage running low...
The difference in the life of a tire, is a couple of thousand miles either way...
I'd rather get new tires,... than replace bearings, or fork seals, shocks,... even frames can crack, if you hardtail... or limit fork travel...
If the tire pressure is harsh to you,.. it's twice as harsh to your bike...
... but,.. if your tire pressure has you squirrly on the road,.. it's a danger...
Less math,... more gut... ...

JMHO...

PS... semi trivial trivia...
Those nuts on your valve stem,... are for installation purposes only... they aren't supposed to be tightened down after install... (even mechanics tighten them down)...
They should be screwed up, to mate with cap after install... this allows a tiny bit of shift before the valve is decapitated,... in the case of rim slip...
...