Tuesday 24 May 2016

That Moment When You Realize The Difference Between Road Tires & Multi-purpose Tires

I went out for a blast on Saturday of the long weekend.  It wasn't a long ride, just up and down the few windy roads near where I live that follow the Grand River before heading home for an oil change.

The Tiger was frisky and I was enjoying exploring its limits.  After a run up and down the north shore I crossed the river on a road I don't usually take.  Coming up the south river bank hill, I think I'm still a few hundred yards from the stop sign when I finally pick it out of the growth on the side of the road and realize it's only about forty yards ahead of me; I'm doing 80km/hr and the Tiger doesn't stop that quickly from 80km/hr.

Ahead on the right you can see the stop sign, but this spring it's in long grass and the trees have filled out around it.

Between smaller tires in general and a curved profile to
manage cornering on half as many contact patches,
motorcycle tires do an amazingly good job.
Motorcycle tires do an astonishing job of gripping the pavement with barely any contact patch.  I've had to dig deep into braking at various times and have always come away surprised at how well they grip with so little contact to the pavement.  Of course, I've only ever ridden road bikes with road biased tires until this spring (the KLX doesn't count, I barely road it and besides, those big, knobby tires slapping on the pavement were a constant reminder that it wasn't a road bike).

Finding myself astride an athletic Tiger coming in too hot to a stop sign with through traffic doing the better part of 100km/hr had me realizing I'm in a bit of bother.  You can feel remarkably naked on a motorcycle in that moment.  If I can't stop in time I'll end up in the intersection, possibly side swiped by a two ton box.

As the adrenaline begins to course through me I'm happy to note that my right foot is already deep into the rear brake and my right hand is squeezing the front brake hard.  Meanwhile my clutch hand has me in neutral already.  The rear has locked up and is snaking about back there.  I've never had a rear lock up that quickly before.  The bike is shedding heaps of momentum but I'm not going to stop in time.  I go deeper into the front brake where all the bike's weight is concentrated and it starts to skittle as it too locks up.  You can slide down the street in a car all day, but staying vertical on a bike with two locked wheels seldom happens.  All of this is flashing through my mind while my body is doing its own thing, I'm not consciously doing anything at this point.  My foot remains locked on the rear brake, but to my surprise my hand immediately eases off and reapplies brake over and over whenever the front starts to wobble; I didn't know it would do that.  Even with all that adrenaline I'm happy to learn that I didn't freeze up or lock up and drop the bike; I'm glad I have smart hands and feet.  Maybe all that reading about motorcycle dynamics has paid off.


The big Tiger is crouched down on its long front suspension, trying to shed all that forward momentum into the ground.  I would have stopped already on the Ninja with its sticky Avon road tires and hard suspension, but this isn't a purpose built road bike with pavement biased tires, it's a tall trail bike with multipurpose tires - tires that are evidently very easy to lock up, though I didn't know that until now.


These are wicked all rounders - they handle the road well
and are magical on loose stuff, but there is compromise in that
I've shed the majority of my velocity but I'm still not going to stop in time.  Things have slowed enough, and my hands and feet seem to know what they're doing without me telling them, so I glance up and down the road as I near the intersection; it's all clear in both directions.  I immediately release the brakes and roll over the painted white line marking where to stop - impending lock up on that wouldn't have gone well.  I glide through the intersection, release the clutch and continue down the country road in front of me in too high a gear.

"Get your head on straight!" I say to myself as I gear down and move off down the road.  You don't miss stop signs until it's too late on a motorcycle, especially when you're going to be entering a through way with high speed traffic.  Getting t-boned in a car there would probably have been fatal, getting t-boned on a bike would have been a certainty.

There are two take aways from this little incident.  Firstly, pay better attention and approach unfamiliar, overgrown intersections in a more circumspect manner.  The Tiger's big triple gets you going quickly so easily that it's easy to forget how fast you're moving - keep that in mind too.  Secondly, those Metzelers may feel fantastic on gravel and loose dirt (and they do, the bike is astonishingly stable), but they aren't grippy like road tires and they'll lock up early on you in an emergency.

I was remarkably calm afterwards and enjoyed the rest of the ride.  Even during the emergency braking and immediately after I didn't get the shakes or anything like that.  This turned into a good learning opportunity about a few key items.  I now know how I handle emergency braking (better than I could have hoped), and I've learned the dynamic limitations of multipurpose tires, all with no penalty.

If it happens again I might give myself a smack in the head, but it won't.

A picture perfect day for a ride along the Grand River...


Back home and all cleaned up - that engine will get you going faster than you think you are, and the bike's athleticism
will encourage you to push it, but those tires aren't up to 10/10ths road riding, so keep that in mind ya big git.