34 replies to this topic

[Duffy]

Thanks, Dale, I'm happy to hear it's as frustrating for you as it is for me! I worried I was the only guy who thinks this crazy--now the world's secure in knowing there's only two.

Actually, when I first got my truer I read that adjustment thing in my instructions and kinda cringed when I looked at the mount...then I went to work with gages and found no measurable misalignment. Huh? What's he worried about, he nailed it at the factory--no mandrel run-out, didn't bother checking the abrasive drum (see Dale's comments above), tested a couple tyres and--forgot about it after that. Either I was lucky, or you do good work, or you're lucky.

I'm by no means qualified to say what I'm about to and invite review by my peers (or, better, SU-peers):I'm betting, you still gotta get the tires out on the track and run 'em in.
A cylindrical tyre in free state is one thing; sitting on the track with it's load, another. --Now add side loads, aero, banking, number of rights and lefts and their cambers and and and...Any condition of cylindricity or coniferrissness will work itself out, as the physics of driving laps with that car--on that track, under raceday conditions--all these things play into how & where the loads affect the rubber, & what the rubber's gonna do about it.

And that's the part that's not up to us to control. We just gotta roll with it.
--Yah, I heard it after I typed. it. I'm leaving it right there.

Duffy

[Jim Webb]

Permit just a tiny drift? John, what's that 3rd dial all the way to the right? I can guess what it is for (precise placement of the needle for super-accurate removal of the waste part of the donut) but would like to know who came up with that? Looks useful.

Jim

[John Miller]

Hey Jim,

Exactly. . .

I lifted that pic from http://www.proforman...&products_id=62

That is called the "Screw Job" and it precisely allows you to trim the width of the to tire dial out traction.

Although, Terry "Mr. Big Shot" Watson has a much simpler and effective method to take away traction. Maybe he'll grace us with his presence and explain. What say you Terry?

[Phil Irvin]

My 2 bits worth....Different tire compounds cut differently. The NOB JOB gets you close. If you cut them at 5V. They get hot and expand. You cut them to .765 and they are hot. Measure them hot off the cutter and again after they sit for 10 min.....Difference.....Even after a cut. They still need running in...Just takes less time.
Measure a set of tires that are very good after a race. You will find they are a slight cone shape. Untreated on a small hub will cone a bunch and Wonder rubber on a big hub will still cone but not as much. The donut on a KING will really tell you if the tire is flat or has a slight cone, run in, shape to it

OLPHRT
PHIL I.

[Mike Patterson]

Maybe I should have stated that I would like a tool that would make sure the drum axle and the wheel axle are parallel. I realize the difficulties in measuring to a granulated surface, that's why I was trying to get the drum out of the equation.

[Duffy]

Mike, I officially accuse you of moving the target.

Even if there was such a tool: How y' gonna get the drum out of the way so you can do the measurement, get those axes parallel, and then get the drum back on and assembled--the same?

My suggestion: go with the easy, slow way; because you don't want/need to pay someone to come up with a tool that'll do this, that you'll use once. This looks like a "Pay the Two Dollars, Abbot" moment.

Sorry.

Duffy

[Mike Patterson]

Even if there was such a tool: How y' gonna get the drum out of the way so you can do the measurement, get those axes parallel, and then get the drum back on and assembled--the same?

Duffy,
I don't know, I haven't disassembled the machine to see how it's constructed. I just assumed (yeah, I've heard that joke) that the drum axle was supported on both ends by bearings, and that the drum is removeable for replacement. That's why I asked the question on alignment: I KNOW there are people in this hobby who are smarted than me, and I was hoping one of them (or you) would come up with an easy answer.

[Phil Hackett]

[Duffy]

Okay, now, that's just nasty.

[Rick]

But practical way to get what you want.....................