Two new/old tires for old prices.

[John Park]

I just picked up a Duro 3.50X18 rear for my 400. It's a copy [or they picked up the old moulds] of a Pirelli MT53 which was a widely used tire in the 50s and 60s. I'm old enough to have used the originals before they totally fossilized. They were also a common dirt track tire as they had an open enough tread to work on loose surfaces. The 'knobs' were low and stable enough to not walk about too much, but had enough give to give smooth slide and hookup action on varied surfaces.



In the center, the blocks are staggered which gives smooth running. Leaned, you get both lateral and longitudinal edges for traction on loose surfaces. At 45 degrees lean - a practical limit - the profile is a bit steep, but there's still something to work with. The originals were pretty hard compound, but these are modern softer rubber, and lots of it. The tread depth is 8mm in the center and 6mm at the edge.

The price is in the $50 - $55 range, which is hard to argue with. The quality of construction seems just fine; round, balanced, and beaded up easily. I think they make a 4.00 as well. There is also a front which looks like the moulds for the Conti rib went to Taiwan as well. It's even less money.

Another option is the IRC GS11 rear, which will need a reply to include the pic…..because, well, because….

[John Park]

Here's the IRC GS11:



This doesn't remind me of anything classic but just may be an old IRC tire that never went away. I just finished one off at the rear of my 400 and was a bit underwhelmed by the longevity. Considering that it's often pretty hot here and the riding style is often 'spirited' I guess 3000 miles isn't awful, and the Conti twin it replaced didn't do any better. The tread depth is 6mm middle and 4mm at the edge.

The tire is touted as an all weather tire which means that there's lots of rain grooving, I guess. It says 'Grand High Speed' on the sidewall, which probably means it was an upgrade from the sort of tire used for delivering noodles in Yokohama. In its defence, I never had it slide except on sand patches and it raised the eyebrows of a few riders on fancier newer bikes trying to keep up with me.

I have another one which I'm planning to try out as a front. The specs call for a 3.00X18 which is pretty much just a 90/90X18 dimensionally, but I've always preferred a 3.50 front because you can run a bit less pressure. IRC makes a matching front, but it's really minimal in rubber quantity [ you replaced them as a pair, I guess] and seems a bit spindly for what I would do to it. The GS11 rear looks like my idea of what a front should be, so I'm going to have a go. I have a spare front wheel with an Avon 90/90 on it to compare with so I'm curious to see what happens.

These are running about $60, which is about right, as another $20 would put them in some stiff competition with tires that look a lot more modern/better, even if they might not actually work better. The nice thing about old inch size tube type tires is how easy they are to lever on and bead up. Just slide onto the old chrome rims like in the old days, with no lube or fiddling.

[bwringer]

Unless you're building a museum display, I guess I don't see the point of mucking around with reproductions of tires from ye olden dayes.

Modern tires do in fact work a LOT better and last a LOT longer.