Do we talk about motorcycle tires here?

Status
Not open for further replies.
Joined
Dec 18, 2004
Messages
475
Location
Greenville SC
Tire question ONLY ...

There is much on the bike forums on tires and pressures, but there seems to be little (or none) on relative advantages of pressure in the tires except that too low causes overheating and too high breaks things.

Given a street only requirement, OEM sizes, and easy riding (ALWAYS under 80 mph, usually under 60), what are the advantages and disadvantages of lower and higher pressures. I'll assume here that we are talking between 20 and 40 psi.
 
Just from my own experience.I always stay with the manufacturers specs,To low can cause terrible handling problems and to high can cause blow outs and a harsh ride.If you only drove twisty roads at mid speeds then slightly higher may give the tire a slightly more "rounded profile" making for quicker handling but overall its a waste of time.A tire with a different profile would be the better solution.
 
IMO... A few more psi than spec will help the tire last a tiny bit longer and dropping a few out will help grip. My bike has different specs for riding 2 people as well so with a fully loaded bike you should up the pressure a bit. Check with the tire maker and in your owners manual so they can point you in the right direction.

Just an example......the spec calls for 36 psi cold without a passenger....maybe 40-42 with a passenger...in the twisties without a passenger you may try around 32 for a bit more grip when pushing it hard.
 
If the tire isn't an OE tire, then ask the tire manufacturer what pressure that they recommend that you use with their tire on the bike that you own.

It may be slightly different than what the motorcycle manufacturer recommends.
 
On my cars I run near the max sidewall pressure instead of the lower door placard, so the sidewalls fold less during cornering.

On the bike, of course, this is not an issue. I stay with the stock PSI recommendations. Like sven, I have various manufacturer recommendations based on load. I don't have the riding skillset to experiment in a vain effort to improve on the manufacturer, and don't need to be sitting in traction while the state police examine my wrecked "modified" bike.

In the MSF class they pointed out there's only about a postage stamp sized contact patch. At least bike rubber is very sticky, though wear suffers. Pretty much anyone in the USA selling a bike tire doesn't want you to lose traction and fall off, IMO. Impressed with even my inexpensive shinkyo (?) I got to replace a bridgestone with 3-digit (1990s) date code. Mounted both the bike tire and my car tires myself and they put more care/ precision/ rubberyness into the bike one.
 
Thanks folks! It looks like the bike manufacturer's numbers are not a bad place to be, perhaps a little more for better life (of the tires). Like eljifino's "I don't have the riding skillset to experiment", nor do I ... I don't even have the skillset to know better vs worse.

I purposefully didn't give details first because I was after general answers, which I got, but one comment, from mrsilv04, "If the tire isn't an OE tire, then ask the tire manufacturer ..." sounds smart, but I doubt much in my situation.

I'm a big guy, 6-4, 35" inseam, and have found the "adventure tourer" (SORTA a dirt bike) KLR650 to be the only thing comfortable. But I ride strictly on the street. I put similar construction (bias), same size, street tires as the dual-sport Dunlop 750's that are OEM. What tire ... well this is a TIRE forum ... Bridgestone BT045.

Kawasaki says 21 front, 21-28 load dependent rear. They don't differentiate between dirt and road. SOME suggest lower in dirt, higher on the road.

My riding position is further to the rear than normal, so I suspect the front load is SLIGHTLY lower than usual ... so probably stay with the 21. Sitting where I do, I probably have their high load on the rear, so the 28 rear is probably pretty good. Whatever else, I'd guess than 5-6 higher in the rear than front is better balanced, so if I harden up for better life, I'll do it with that in mind.

THANKS AGAIN!
 
I mostly ride adventure bikes,and usually run 20/25 front rear regardless of what the manufacturer says...going higher feels ''greasy'' to me.Lower pressures put down a bigger footprint.I ride mostly in very twisty hilly country and seldom go on straight roads.

My current bike is a road bike set up as a streettracker for the same roads and gravel.I have two sets of wheels,and on my road wheels with standard tyres I run manufacturers pressures,and my back road wheels I'm back to my 20/25 - and the bike handles much better,feels glued to the road.
 
I think the wider tires allow for more wiggle room to an extent. My honda had 3" tires so I stuck with factory pressures. If they were low I could feel the back in slosh around. Two high and it felt too... like it would be more likely to "snap free" if pushed, less warning. Me likes the factory numbers. But I was a conservative rider that really didn't push things.
 
George

Check the tire pressure when cold and after a normal spirited ride. If you have more than 10% increase in pressure, start with a higher pressure next time.

As said above, within limits, more pressure gives longer tire wear and lower pressure gives more traction. And, as said, if the tire maker recommends a specific pressure for their tire on your bike, start with that pressure.

Try radial tires--you'll like them on the street. And if you get the chance, take a close look at the Suzuki V-Strom DL650. Better on the street than the KLR, not as good in the dirt. A higher DL1000 seat on the DL650 would give the tall rider a better position--easy to find the seat on fleaBay and it fits right on.
 
Originally Posted By: XCELERATIONRULES
I'm a dark sider.

http://darkside.nwff.info/

http://darkside.nwff.info/database.php


All I have to say is "Wow"!

Xcel: I would be very careful listening to what these guys say. They don't seem to have enough sense to avoid obvious danger areas. I'll give you 2:

1) It is a rule in mounting tires not to exceed 40 psi. Not only don't they specifically say to do this, they specifically mention using 80 psi. People have been killed using this kind of pressure. If the tire doesn't seat by the time 40 psi is reached - THERE IS SOMETHING WRONG!

2) On the sidewall of passenger car tires, there is a maximum inflation pressure listed. Typically it will be 35, 44, or 51 psi. I see references to over 100 psi. This is very dangerous and shows a profound lack of understanding as to how tires are designed.
 
On my old BMW R100GS the solo spec is 31F/36R. Going up to 34F and 40R transforms the street handling. It has a much better road feel throught the bars, and the rear gets on its sidewall better in fast cornering. After owning this bike for 19 years it handles better than ever, thanks to tires that keep getting better every few years.
 
Originally Posted By: Ken2
And if you get the chance, take a close look at the Suzuki V-Strom DL650. Better on the street than the KLR, not as good in the dirt. A higher DL1000 seat on the DL650 would give the tall rider a better position--easy to find the seat on fleaBay and it fits right on.
The Wee was my first choice until I tried one. I'm NOT a spirited rider, and with my long legs put my rear end too far to the rear wheel to ride with the "forced" seating position of that otherwise wonderful Wee. I tried a 1000, and while different, it wasn't better. Up but not back.

One of the guys with whom I ride has the Wee with an aftermarket saddle ... he loves that bike. He is 5-10 with 30" inseam ... I'm 6-4 with a 36" inseam.

The Suzuki dealer said they can do a custom seat if I buy a new bike ... but I'm content, a good place to be when jobs and money are tight. I have a hard time finding things to fit, and that is too much to gamble on. Boots that fit my 14EE are another issue ... and shifting in them ... don't ask.
 
Status
Not open for further replies.
Back
Top Bottom