Need to get some new shoes for the Xj700 old girl, since the old ones have dry rot. But can't figure out if they are bias or radials. The service manual says nothing and the existing tires do not indicate. I'm thinking they are bias because of the year. Was looking at the Pirelli Sport Demons in a 130/90 -16 and a 100/90-19. Any other recommendations like Metzeler's?


Thanks,
Curt

If you are referring to the original Dunlop qualifiers, those were radial, I believe. The large price disparity even today between bias and radials supports that.

As for other brands, you can't go wrong with either the Metzler 880's or the Avon Venoms. both are great tires, put expect to pay a little more for them. cary.

In the past I have run several different setups - BT45s, Kenda's sportier touring tires and currently GT501s.

Now tire threads usually end up with hand waving, I'm right - no I'm right type posts but I'll post my personal experiences.

The GT501 tire is middle of the road to pricier. I had one last 18,000km. I run my preasures at 32 F -34 Rpsi. That's a bit over 10,000 miles. I'm finding the front tire is lasting about 1.5 rear tires.

They are excellent in the rain - very good tread pattern for throwing off water. They also offer very good traction on pavement. The profile of the tire is flatter than some offering a nice big footprint when leaned over. With this shaped tire I have 1/8" chicken strip without touching hard parts. Hard parts only touch when I hit bumps or bottom the suspension out on high speed sweepers. For anyone who rides as aggressively or less aggressively than me - this is not a problem at all. If you ride more aggressively than me the solution isn't a better tire but a better suspension.

There is much debate over running lower preasure to increase contact patch size (also increasing operating tire heat) Some people have argued that with lower preasure they don't wear out the center as fast and the tire lasts as long if not longer. I can point to one person in particular who has the receipts to prove it. However, that is one person, and they ride differently than I do.

Some people are in the high preasure to reduce heat camp - lower heat - lower tread wear. However, all of the wear is now on a thin footprint in the middle. Does that wear any faster than a wider footprinted hotter tire? I don't know.

For me I run in the middle of the preasure range - taking the traction I can get which is more than enough for me, and getting what I consider reasonable tire life.

I did like the BT45s, however, on my bike with my riding style I don't find that they match the GT501. I found they were rounder in profile and didn't have as large a contact patch. As they aged they got very abrupt turning in over the flat spot because of the sharp profile edge created leading to way more wandering and movement in the line. I also didn't think they were as good a wet tire. However, many people swear by them.

Cheers,
woot.

I should add - I'm mid 20's, ~220 lbs, and used to ride sport bikes. (For perspective on style and suspension problem comment) I ride a 650 maxim with seca bars.

Right now the tires that are on there are Bridgestones and from what you said, the originals were Dunlop qualifiers which are a radial. I was able to use the Dunlopmotorcycle.com site and find that the original tires were bias ply.

Interesting about the tire pressure. It does make sense to run the a little lower on air to get the contact patch a little larger.


Thanks,
Curt

Right - so we're dealing with some strange relationships with tire preasures... but for traction here's how I see it.

The lower the preasure (within reason) the larger the footprint the better the traction.

The higher the preasure (Within reason) the smaller the footprint the worse the traction.

HOWEVER - I'm talking dry roads only with that statement - wet roads you would think you'd be more likely to hydroplain with a flatter profile footprint.

Then we have to decide what happens to tire life when we run low preasure. Most people say lower tire preasure equals short life. In a Car I'm almost certain of that. On a bike - I'm not as sure. Low preasure means big footprint. It also means more heat. So does the extra heat mean that it wears the tire faster - even though the wear is spread over a bigger area?

Also - a tire that starts with low preasure will heat faster and that means it's preasure will shoot up - so will it's operating preasure be the same or just under that of the more inflated tire? If that is the case then a low preasure tire will simply run hotter at the same footprint as the cooler more inflated tire. Meaning certainly you'd get more wear - but better traction from the warmer rubber.

My outright guess? Low tire preasure means better traction from warmer rubber, a marginally larger footprint AND it also means that the tire wears slightly more - HOWEVER - it doesn't wear more than the high preasure in the center strip meaning the tire SHOULD last about the same distance as high preasure tire.

But that is where we get into outright handwaving and within a day I'll get the counter arguement. I don't know this for a fact - it's just how I decide to run my tire preasures - somewhere in the middle. 32 Front, 34 Rear. If I go too much below 30 front then I find the front gets very heavy to steer - meaning that the contact patch is much larger in my mind -- leaning me more towards the low preasure camp.

Cheers,
woot.