IRS into 54 oval.... Track width problems

[Plipton]

Hi All,

First post on here so hello to everyone

I am converting the rear of my oval to IRS but have found the rear wheels stick out too far so I need to narrow the trailing arms or buy some custom ones so that they tuck in under the arches.

So my questions for the forum....

• What is the width of a stock early swing axle rear end ? (I don't have the original gearbox or axles etc to measure).
  
• What is the width of a stock IRS rear?

Measurements (if possible) in mm and from drum to drum (wheel mounting face) please.

Nearest I have found on here is this post which gives me everything else I need to know.

Thanks
Plipton

[NO_H2O]

If you use a 6 inch wide wheel with amore inset (ie and 52mm vs a 23mm inset) would that clear things up?

[Plipton]

Yeah it would........ but (at the risk of horrifying everyone on here) I want to stick to wide 5 stud pattern - I have a set of CSP disks which cost the fat end of £2000 and (horror of horrors) a set of original Empis so I can't really afford to replace them for quite a while.

Unfortunately all the wide 5s I've seen have next to no offset so I need to narrow the diagonal arms but it's a bit hit and miss without knowing the original measurements.

Cheers
Plipton

[Steve C]

Hi

I had Type 3, 4 stud rear brakes on a 1303, it was 1405 mm drum face to drum face.

I think the Type 3 brakes might add a few mm.

Steve

[Plipton]

Thanks Steve,

I have a pair of Type 3 drums to use as a comparison so should be able to use that as a starting point

Anyone out there got the same measurement for an early Type 1??

Ta
Rick

[NO_H2O]

You could have Boulton Wheels make up a set of wheels. They take wide 5 centers and weld them to a GM steel wheel hoop and can do any offset. So you could do a 15x6 with 55mm inset.

[Plipton]

Boutlon Wheels sounds like a possible plan. Do they have a website? I can't find them on Google.

Thanks

[NO_H2O]

I can find you some info.

[Plipton]

Thanks

[NO_H2O]

Here is a link to the place I ws thinking of. It is Stockton Wheel not Boulton.
http://www.stocktonwheel.com/

[Plipton]

Thanks for that. I'll give them a call and see what they can do. Looks like they may be able to make 15s into 16s which would look a whole lot better

Meanwhile, if anyone could measure their early SA bug rear end it would be much appreciated.

[oasis]

While you are waiting for your answer, I'm curious ... besides wanting to maintain the wide-five pattern, was putting an oval on an IRS chassis otherwise difficult?

[Plipton]

No, not at all. Only the rear body mounts had to be lifted to accommodate the later shock mounts. I used a '69 semi-auto IRS chassis with a clutch tube welded into the tunnel.

However, that was the '56. Many years after being "restored" I found that it had been done badly with non-original parts. That's not to say it is beyond use but that the heater channels and valances are wrong for the year. I was tempted to get it all redone and then at the VolksWorld show last year I was offered a near-perfect 54 shell and chassis for 1/2 the cost of the repairs so I grabbed it.

The chassis I am now using is the '54 but with IRS diagonal arm mounts welded into the rear forks.

Here's some pics of the 56 on the 69 chassis....







Edited to say - oops just noticed the first pic is of the SA chassis

[Plipton]

The trouble is the offset on wide 5s is much less than the later 4 stud wheels so they don't fit under the arches without some work. I like the arches to look full so I need to get this spot on!