Having fitted both sliding doors with some near identical sized acetal (plastic) wheels some time ago here is more information on them. They have been fitted for 4 years now and seem to be holding up well. (First fitted in June 2015).
Certainly others have commented on the smooth running of my van doors.
The wheels are supplied by Versatile Marine,(www.versatilemarine.co.uk) based in Penryn, Cornwall. They are now selling on eBay also as supplier 'versatilemarine 2010'.
They supply a number of different sizes. The ones I used are very close to the metal ones fitted originally.
The size I used was: - Diameter = 36mm, Width = 12mm, Hole Size = 10mm
This compares with the original worn metal wheels, I have of : - Diameter = approx. 36mm, Width = approx. 13mm, Hole Size = approx. 10 mm (suspect hole was 3/8 inch (9.525mm) originally but has worn)
The one dimension not quoted is the inner diameter, where the wheel would sit on the bottom runner.
For the metal wheel this is 1.0 inch diameter, (25.4mm) and for the plastic wheel this is 31mm diameter, (1.220 inch).
So in effect there is a radial height of half the wheel inner diameter difference. That is .110 inch (2.80mm). The door wheel holder spring easily accommodates this additional compression and the wheel stays on the runner okay despite it being a shallower profile..
To fit the plastic wheels I opened up the carrier fork holes to 10mm and fitted a piece of 10mm stainless tube as an axle. Flaring the tube at each end to hold it in place.
Additionally I added extra 5/16 ball bearings to the top door rails, filling each spare space.
For those with the means the plastic wheels could be machined to reduce the internal diameter down to 1.00 inch. (25.4mm) and making the profile closer to the original.
Calling these Acetal wheels 'plastic' is probably doing them an injustice. They are for a marine use and are intended for sheaves pulley wheels for blocks, masts, yachts, boats, dinghies etc. So they are intended for a pretty tough environment.
Quote "Acetal provides high strength and stiffness coupled with enhanced dimensional stability and ease of machining. As a semi-crystalline material, acetal is also characterised by a low coefficient of friction and good wear properties, especially in wet environments."
Sounds an idea material for driving in the UK!
See the photos below: -
Acetal wheels fitted to holder
Obviously metal on the left, Acetal on the right
