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Posted: Wed Jul 27, 2005 6:30 am
by mattf
Sev wrote:A bike under heavy cornering has the contact points of it's tires reduced to the point where they are about the same size as a postage stamp.
Might want to fact-check that one. A postage stamp is about one square inch. Don't think so.
But that has nothing to do with the original question - which bike to buy and/or avoid. I second the recommendation for a Honda Shadow, but only because I like the way they look. I've heard that the "ACE" is the worst of the bunch but I have no first hand knowledge of this.
Lots of folks love V-Stars too. Also, the V-star precursor, the Yamaha Virago, was a pretty popular bike if you like the looks of it. Personally, I think the Virago was a GREAT bike - I had an 82 Virago 920.
Posted: Wed Jul 27, 2005 7:40 am
by Sev
As one can imagine, there is quite a bit of force coming into play when your bike makes a turn. You are probably not a light weight (how about a generous 200lbs with gear?). Your bike likely weighs in at several hundred itself (A loaded Valkyrie goes near 800 or more). Add to that half ton, the actual acceleration of your vehicle (about 45mph in a typical casual turn). So you are running fine up the road until the road presents you with a curve. You pitch your bike into a typical lean, that half ton at 45 wants to go straight and you need it to go around the bend. The only thing preventing a crash is about a 2 inch contact patch between your tires and the pavement where the forces involved in a simple casual turn exceed 1 G in space age parlance. The scuffing where your tire meets the pavement is what causes the "side wear" bands to appear sooner or later and this scuffing is the only "force" that is capable of producing the wear that eventually becomes evident. If one looks at the pictures of the worn front tire and the worn rear tire, the squared off side band wear is evident at the typical lean angle for casual riding on typical roads.
Taken from:
Motorcycle Tire Wear
Additional information to be found in NAIT institute motorcycle training manual written by: James Mcarthy Retired Kawasaki Racer.
The further you lean, the less of your tire comes into contact with the pavement. Like I said, a bike under heavy cornering has its footprint reduced to about the size of two postage stamps. Then again, I'm not talking about an 800 lbs hunk of steel like a mean streak.
Posted: Wed Jul 27, 2005 7:51 am
by ronboskz650sr
2 inches wide. Also 6-7 inches long. Big bang engine firing is based on this fact, and allows the tire to regain traction due to a lapse in the firing pattern (power let up). The next power stroke then has the advantage of the full contact patch. That's what Motogp bike manufacturers are playing around with, and the contact patch is simply one part of it. Nevertheless, Multiple reliable sources will confirm a contact patch of a few square inches, on each tire.
Posted: Wed Jul 27, 2005 8:28 am
by Joe Mc
I think you guys are focusing on the wrong part of Sevulturus' comment and taken this thread to a whole new topic.
Regardless of the exact size of your contact patch, what he said is true and relevant to the conversation.
"Sometimes things add up quickly is all that we're saying. That's 400 lbs of steel balance on two postage stamp sized peices of rubber (contact surface) all it takes it a little oil at the stop light for you to put your foot down onto, or a little sand in a turn and the bike is out from under you."
Posted: Wed Jul 27, 2005 8:33 am
by ronboskz650sr
ronboskz650sr wrote:...The oil is a real hazard, like Sev said. ....
Sorry, just trying to keep all of the information accurate, while confirming the sound advice.
Posted: Wed Jul 27, 2005 8:39 am
by cb360
Yep. Regardless of the actual # of square inches - which will vary - it's a good point.
Posted: Wed Jul 27, 2005 8:56 am
by ZooTech
Which is why we should all end this nonsense, scrap our bikes, and only drive cars from now on.
Posted: Wed Jul 27, 2005 9:13 am
by cb360
I'm gonna go ahead and stay on the bike. But I'll keep a sharp eye out for oil and sand
Posted: Wed Jul 27, 2005 10:54 am
by ZooTech
cb360 wrote:I'm gonna go ahead and stay on the bike. But I'll keep a sharp eye out for oil and sand
And don't forget oily sand!
Posted: Wed Jul 27, 2005 12:10 pm
by ronboskz650sr
Or sandy oil!