Mounting/dismounting tires at home?

[GasSavers_maximilian]

How much clearance is there normally? Ye old Miata tire calculator says .9" difference from your 195-65-15s, but I'm sure you already checked that.

[theholycow]

Actual difference seems to measure a whole inch or more...I guess it could be .9 and just hard to tell. They're also wider too. I'm worried that rolling over a bump while steering sharply, the corner of the tire can catch the front of the fender...it's not like they build in extra clearance on cars like this. Rabid modifiers are expected to go wider but never taller.

[GasSavers_maximilian]

I have often wondered how much to trust that calculator. Do tire sizes change once you mount them? Easiest way to be sure is probably to measure the circumference.

[theholycow]

I suspect they expand a little from inflation, and of course wear reduces their size. Additionally there are differences from one manufacturer to the next. It's all approximate...

[GasSavers_maximilian]

Came across a portable tire balancer in a HFT catalog I got in the mail. Since it just looks like a tilting platform with a bulls eye level, maybe you could whip up something similar.

Something hanging might be easier to build yourself.

[theholycow]

Yeah, I saw that too. No way I'd spend $60 for it, I agree that it just looks like a platform with a level. I don't expect that anyone could do any worthwhile balancing with that (or a home-hacked version), any better than theclencher's free strategy above.

I guess the project is on hold while I chew on the ideas and try to figure out how to approach it as cost-effectively as possible. My budget keeps getting smaller every day.

[GasSavers_maximilian]

In the shower I was considering a home made version of that tool and came up with a couple ideas. Probably not worth it over theclencher's technique, but it's fun to consider.

Take a small piece of plywood and put a bolt in a position corresponding to each hole in the rim and tighten them in place. Then you put a nut and a washer on each bolt followed by a spring. You'd attach the plywood to something heavy to keep it from tipping. You'd calibrate it by placing a pre-balanced tire on the setup, turning the nuts under the washers to adjust the springs slightly until a bulls eye level on the tire (need a small piece of shaped plywood for this) is centered. If you added another nut you could lock them at that setting. One nice bit about horizontal layout is that you may not need to attach the weights to figure out where they go. Just lay them in the same spot and attach them when balanced. I don't think that'd introduce enough difference to matter, but I could be mistaken. Have to be careful the threads weren't hitting the holes in the rim, so smaller bolts would be needed than the hole size. Or just grind the ends down a bit.

An even simpler hanging one could be made. You'd just attached a piece of plywood to the rim and then have an eye bolt in the center, suspended by a thin piece of string. The plywood would go on top of the rim. Just to the side of the eyebolt is the bulls eye level. You adjust things until the tire is horizontal.

[theclencher]

I'm as cheap as they come. I'm as willing to tackle things at home as they come. But sometimes it's just worth it to pay the man. They have the nice tools and they do the job, better, in but a fraction of the time.

[GasSavers_maximilian]

I agree. I just like design problems. In theory one could turn the nuts on the first setup until it balanced, then determine the weights required from how far they moved. So not worth it.

[theholycow]

Bump a few months later...That project fell through the cracks, a victim of my lack of follow through. I just stumbled across something that I think might change things for me:
http://www.walmart.com/catalog/catalog.gsp?cat=495845
WalMart tire services:
Tire Mount (Carry in only) $3.50 per tire
One Time Balance $5.00 per tire
Lifetime Balance $7.50 per tire

At those prices I can afford the experiment. That's a maximum of $11 per tire for permanent mounting and a mere $3.50/each for an experiment where I don't care to get them balanced.

It seems too good to be true. Can I really walk in to WalMart with a wheel and a tire and have the tire mounted for $3.50?