Hi everyone,
I think the answer to the question of which 'type' of tire, bias or radial, works best on the V7 is that it simply doesn't much matter. The only persistent advantage of bias ply is that they last longer and use tubes. That they handle heavy load better seems irrelevant on a bike that is not really intended as a touring or two-up bike; that some of you do so, and enjoy this advantage, is just lucky for you.
Radials simply aren't necessary because no one is going to ride fast enough or aggressively enough on this bike to justify need of them. Nothing about the frame, suspension, geometry or ride characteristics of this bike will let you ride anywhere close to the limits of modern radial tires, without risking injury due to the inherent limitations of the bike itself.
The simply fact of the matter is that this bike probably has bias ply tires because its cheaper to put the same tire on every bike in the line, and the spoked Racer requires it. There is probably some huge profit incentive that causes factories to continue to employ this outdated construction technology (for bikes that admit their use) despite its general overall inferiority.
I suspect that bias-ply tires would have disappeared long ago had the rubber compounds and tread designs not improved so significantly and sufficiently enough to keep them in the game past any practical purpose. They are still used in competitive auto applications for different reasons.
The only bikes I know of that ship with combinations (bias-ply in front, and radial in back) are Harleys, and they do it only for aesthetic reason, so that they can get a really wide tire on the back without suffering the visual intrusion of a really tall side-wall (bias-ply tires being generally uniform in geometry).
As far as I can discover, no manufacturer of radials recommends running them with tubes (even the ones that manufacture tubes specifically for that purpose), so I don't know why people keep pursuing this as an option. Note: Insurance investigators always check motorcycle tire pressure (if there is a tire left) and tubing, to check if you have been...improvising.
If you have spoked rims, you need tubes, and therefore bias ply tires. If you have alloy rims, you can get radials if you want, but you won't need them. Or, you can get a bike that you don't need, just to get the tires you want. I bought a Panigale just so I could have high-tech radial tires. LOL! You can buy my radials. They they come with a Panigale for $14,000 Canadian.
If those of you who 'want' radial tires do so simply because you 'want' radial tires, you're wanting the wrong thing. Talk to Todd about suspension upgrades instead. As far as I can tell from reading (something I'm very good at), the Sport Demons are, as it turns out, pretty much the best solution for this bike. Point for Guzzi!
I've got my crash bars on, and I'll be setting out to explore the limits of these very tires in a week or so when I finally insure this bike, and start gymkhana on it. Should be a hoot! I'll report back with my initial dry/wet findings soon.
Timothy St. John
