Changing A Tyre. On a Bandsaw

by John

I was frustrated because my bandsaw was not cutting parallel strips in the Huon pine, which were for first layer hull planking on Bellerophon..

Well, it was cutting, but the strips were not parallel, they were wedge shaped.

And Huon pine is a scarce, rare, superb timber, and expensive!

So I adjusted checked the blade tension, adjusted the fence but the problem became worse.

So I opened the wheel enclosures. And discovered bits of rubber floating around. Something was clearly not right.

The problem was that the “tyre” on the upper wheel had broken and come off! The blade was riding on the metal of the aluminium wheel, throwing the carefully set angles and clearances way off.

So I shut everything down and explored options for fixing the problem.

The bandsaw is a Metabo/Elektra Beckum BAS 500 with 17.5″ wheels. Not a bad machine, but frankly not a great machine. I bought it originally because of the Metabo brand, but was disillusioned early by its poor tracking and rather flimsy head. A complaint to Metabo Australia did result in them sending me an improved blade microadjusting mechanism, but I did not install it, because meanwhile I had made my own version of a decent blade guide.

That is the bandsaw with the upper tracking head which I made many years ago. The head has 7 ball bearings. It is probably the most robust component in the machine.

Subsequently it has performed adequately for a decade or two, until 2 weeks ago.

So I measured up the top wheel and searched the Internet for a supplier of new tyres. I could find NO SUPPLIER in Australia. I rang several bandsaw manufacturers who advertised tyre installations but they were not interested in my machine. Well, one said that they would consider it, but suggested that the cost would be in the vicinity of $aud400.

So I checked OS. A UK supplier offered tyres but wanted over $aud120 plus shipping.

AliExpress had several suppliers offering “tires” but nothing for my machine. Eventually I located one with “tires” the right diameter, but they were 32mm wide not the 25mm of my machine. I wondered if I could reduce the width of one of their tires. So I ordered one. Cost including postage $aud25.

It arrived yesterday, but it appeared to be way too small. Bummer. It was for 16-19″ wheels so should have ben OK. And I had the anticipated problem of cutting the width down to 25mm. I had been thinking about possibilities. Not keen to use scissors on the 6mm thick band, but I tried this option…. Nothing to lose.

I cut a piece of wood to length so the tire was tightly stretched as in the pic. with the edge of the tyre aligned with the edge of the wood.

The too wide “tire”, stretched over a piece of sacrificial wood. And the bench saw with 5-6mm of blade protruding. I cut both sides at 25mm width quite easily.

Then adjusted the bench saw so that only 5-6mm of blade was protruding, and cut the rubber and just touched the face of the wood. I was concerned that the rubber might catch and throw the assembly back at me, but it was actually quite straightforward. The cut was slightly wobbly but OK.

I neatened the irregularities with a pair of heavy scissors.

But when I attempted to stretch the tyre over the wheel it would not go on. So I looked up the process on YouTube, and heated up the tube in a sink of hot water resulting in an improvement in the stretchiness, but it still would not fit. So I forcibly stretched it between my feet and hands, several times. And eventually it slipped on! Whew!.

Heating the trimmed rubber tire in the kitchen sink.

Everything needed re-adjustment. Blade tension, Guide bearing positions, fence alignment.

And it worked perfectly!!!!