Good morning all,

I am looking to convert my 68 VW IRS chassis to rear wide 5 rims keeping the drum brakes.  I am going with wide 5 disc brakes up front on a narrowed and adjustable beam and want to keep the wheels uniform.  A few months ago I saw that CSP had a conversion drum but it is no longer on their website.  Any suggestions.



Original Post

You can use a later IRS drum, but you may need to take them to a machine shop and shorten the center hub/spline area. Or maybe add a spacer to take up the length, I can't remember. All I do remember is the splines are the same for all swing-axle and IRS and only vary in length of stub axle.

To use a 5x205 mm Beetle drum on an irs trailing arm I believe you can keep the wider late shoes, wheel cylinder and backing plate, machine the contact surface ¼" deeper in the drum (to accommodate the wider shoes)  and fabricate a 5/8" spacer for under the axle nut. I'll see if I can find my notes to confirm this for you later in the day. Al

You can use Thing drums on the rear, but they do increase track width by about 1/2" per side.  Depending on wheel offset, this could be an issue.

I have a similar set-up on my car, discs on the front and drums on the rear.  I used wide five drums from a '67 Bug on my IRS rear.  I also used the narrow shoes from an early Bug.  As Al mentioned above, you will have to have a spacer under the axle nut.  Using the narrow, wide five drums will help give a little more clearance between the tire and fender.

Another comment, you may not need a narrowed front beam for your disc brake conversion.  I used the wide five disc brake kit from CB Performance (not dropped). I have an adjustable front beam that allowed me to set the front to the appropriate height.  In my opinion a narrowed beam will push the front wheels too far inboard.

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Last edited by James

Hi all,

Glad Bob Z asked this question.  I'm new here (live north Charlotte, NC area) and have just started a Speedy build.  My dad's had the CMC kit for 35 years and I have managed to find most of the parts in storage.  I'm probably missing some things but I'll deal with that as I find it.   I too have a IRS donor (73pan).  It already has a 4 lug front disc conversion.   I'd like to do the Wide 5's at some point on all 4 corners, so thanks to those that have answered.  It has already helped me...

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