there was a discussion thread about these a while back, and I promised a how-to on a pair of rims I need to do for the budget hotrod pickup. well here it is!!
heres the thread for those who don't know what reverse rims are, or why you'd need them.
so, here's the victim. its some sort of american OEM wheel from the GM stable, in 15x6" size, and 5x5" bolt pattern. judging by the thickness of the steel in it, its a truck rim, or off a heavy-chassis car. the centre are rim sections are both 3mm thick, thats twice what your average uk car rim is!!
its in good, straight, uncorroded condition, and the set of 4 only set me back 50 notes. suffice to say, make sure the rims youre doing this to are in good nick before you start!!
but, the issue with them is the offset. as can be seen here, its too close to my pickup bed for me to even be able to fit it on the axle with a tyre on. it needs to go out about 3/4"- 1" to clear it by enough for it to be usable. measuring up, flipping the rim will give me 1.5", which will be perfect. I could probably squeeze another half inch out of it by tapping the centre back a bit in the rim, but it isnt necessary.
now, this type of rim is the more difficult type to do. the ones that have visible bands of weld on the backside as quite straightforward and self explanitory, simply cut long inside the weld, knock centre out, grind off old weld, refit, job done. this is the type that is spotwelded together, which makes them more difficult to get apart. most wheels are held together like this these days, very very few have seam welds as it costs so much more to do. this technique I'm using here also works on the old type rivveted rims as well though so covers lots of bases.
this is one of the offending spot welds. theres 8 in total, 2 on each of the 4 sections of the centre that make contact with the rim.
(ive drawn round it in tippex so it shows up better)
now, the weld measures about 3/4" by 1", but in my experience they're still stuck together a bit beyond the edge of the spotweld, so you want to go a bit bigger than that- I went 1-1/4" on these, giving me an extra 1/8" each end removed just to make sure. they're nothing worse that drilling the welds out only to find you've done it too small, as you're pretty buggered then, and you'll end up having to resort to a file to widen them out!!
first I put a decent centre punch in the centre of each weld-
then, I moved the wheel over to my pillar drill. I realise a pillar drill with a bed that can drop this low is a bit of a luxury to most people, I imagine if most of you have one itll be a bench mounted jobby, but you could do this freehand with a cordless with a bit of care, itll just be a lot harder work!
as you can see I dropped the bed right down and set up a 1-1/4" hole cutter above the wheel.
you know the little spotweld drills you get for removing spotwelded body panels? envisage what were doing as a rather manned up version of that, and you wont be far wrong!!
heres the first two cut. you need to go straight through both layers as you need to completely remove the bit of steel or you cant get the rim off of the centre, thats what makes this style of rim more difficult and more work.
and heres whats come out- as you can see, very thick steel in these rims!!
with all of em cut, itll look something like this-
guess whats gunna happen next-
one swift clout with the tickling stick (wooden block to stop damage to centre of rim) and the centre is out.
heres the thread for those who don't know what reverse rims are, or why you'd need them.
so, here's the victim. its some sort of american OEM wheel from the GM stable, in 15x6" size, and 5x5" bolt pattern. judging by the thickness of the steel in it, its a truck rim, or off a heavy-chassis car. the centre are rim sections are both 3mm thick, thats twice what your average uk car rim is!!
its in good, straight, uncorroded condition, and the set of 4 only set me back 50 notes. suffice to say, make sure the rims youre doing this to are in good nick before you start!!
but, the issue with them is the offset. as can be seen here, its too close to my pickup bed for me to even be able to fit it on the axle with a tyre on. it needs to go out about 3/4"- 1" to clear it by enough for it to be usable. measuring up, flipping the rim will give me 1.5", which will be perfect. I could probably squeeze another half inch out of it by tapping the centre back a bit in the rim, but it isnt necessary.
now, this type of rim is the more difficult type to do. the ones that have visible bands of weld on the backside as quite straightforward and self explanitory, simply cut long inside the weld, knock centre out, grind off old weld, refit, job done. this is the type that is spotwelded together, which makes them more difficult to get apart. most wheels are held together like this these days, very very few have seam welds as it costs so much more to do. this technique I'm using here also works on the old type rivveted rims as well though so covers lots of bases.
this is one of the offending spot welds. theres 8 in total, 2 on each of the 4 sections of the centre that make contact with the rim.
(ive drawn round it in tippex so it shows up better)
now, the weld measures about 3/4" by 1", but in my experience they're still stuck together a bit beyond the edge of the spotweld, so you want to go a bit bigger than that- I went 1-1/4" on these, giving me an extra 1/8" each end removed just to make sure. they're nothing worse that drilling the welds out only to find you've done it too small, as you're pretty buggered then, and you'll end up having to resort to a file to widen them out!!
first I put a decent centre punch in the centre of each weld-
then, I moved the wheel over to my pillar drill. I realise a pillar drill with a bed that can drop this low is a bit of a luxury to most people, I imagine if most of you have one itll be a bench mounted jobby, but you could do this freehand with a cordless with a bit of care, itll just be a lot harder work!
as you can see I dropped the bed right down and set up a 1-1/4" hole cutter above the wheel.
you know the little spotweld drills you get for removing spotwelded body panels? envisage what were doing as a rather manned up version of that, and you wont be far wrong!!
heres the first two cut. you need to go straight through both layers as you need to completely remove the bit of steel or you cant get the rim off of the centre, thats what makes this style of rim more difficult and more work.
and heres whats come out- as you can see, very thick steel in these rims!!
with all of em cut, itll look something like this-
guess whats gunna happen next-
one swift clout with the tickling stick (wooden block to stop damage to centre of rim) and the centre is out.