Yet another rear disc conversion....

[EuropaTC]

(part quote)
. I'm very interested to know how the residual pressure valve works out. Will this result in accelerated pad wear, and will it pose any problems with pushing the piston back into the caliper during brake service? Just thinking out loud here...

Hi Trevor,

Thanks for the comments, again I'll say that I'm only following a path created by others but even so, I'm pleased with the results. 

On the valve thing, apparently you can get 2 settings for the back pressure. If you have drum brakes it's 10psi, (a lot ?) but for discs it's 2psi. Apparently they're used on rally cars as well to give instant braking so I'm looking forward to trying them.  The theory says there's not enough pressure to cause any significant drag on the discs and I can understand that because it would be an MoT test fail over here as the mechanic would assume a sticking caliper and it would register on the rolling road as a fail. Having read up about them, I think they would be a great addition for a standard Europa because as you say, the reservoir is quite low.

I'll post how I get on with them.

Brian

[StrawberryCheesecake]

This thread is proving very useful for me. I'm sort of following it, but adapting for standard studs, 13" wheels, and different calipers. I have a choice of Honda rears and VW Golf Mk4 ally ones, which I have lying around.

For anyone looking at this on standard studs, I've found that the shoulder on the standard studs needs the stud hole in the disc relieving slightly to allow the disc to sit flush against the flange. A little tickle with a die grinder or a pillar drill will do it.

[EuropaTC]

Hi there,

The VW calipers sound interesting if they're alloy, lighter always sounds better with Lotus.  I've never had a Golf so it would be interesting to see a photo of what they look like.

Are you using the MGF disc ?  It's convenient for the same PCD but I know that other discs have been used and re-drilled to suit.

The only reason I had 12mm studs is because of the move to MGF wheels, otherwise I can't see why the smaller studs wouldn't work equally well. The clearance problems with the Cosmic alloys I think was down to their design. There's plenty of radial clearance, it was the way the alloy wheel was cast that caused the interference, it came inboard and just clipped the outboard edges of the caliper itself. A steel wheel is fine, which is as well considering my spare is a steelie.

It's 2 years on now since the conversion and not much has changed. A few "doh" moments not documented here, I replaced the final connection to the caliper with a flexible because I tried a couple of pad materials and it made it easier to swap them around.  This is what it looks like now...

http://www.martley.plus.com/lotusland2016/europa/16europa12d.html

The most marked improvement that still impresses me is the handbrake though, it really is a cracker. Almost like a proper car....   

Brian

[StrawberryCheesecake]

Yes, MGF discs.

I've got revolution wheels which use sleeve nuts, which I've now bought, but perhaps should have waited. If I went to bigger sleeve nuts, I'd need new wheels, or to redrill the Revolutions to a bigger sleeve nut bore, buy new sleeve nuts, new studs, etc. I'm hoping to stick with the existing studs for now, for that reason, although I don't yet have a solution to fit the 7" revolutions on the rear. However, I have 2 sets of revolutions, any only one pair is 7", so I still have wheels which will actually fit the stud/nut combination that I've got.

I might need to modify the body to fit the 7" rims anyway, and I'm not really sure I need the width... it's certainly not top priority for now.