Rear Brakes Question

[robd]

Hi All, I'm just wondering... I'm planning on upgrading my front brakes to ST205 calipers with Mercedes Vito discs(custom jobby) & then using the standard Mk1 discs on the rear with the Mk2 22V rear calipers.

My question, if I do the rear brake upgrade & still have the stock brake setup on the front how would it affect braking & would it be a bad idea? I'm already running the Mk2 brake master cylinder & that made a massive difference to the braking on my std brakes, the calipers don't seem so sticky anymore & it brakes a lot better.

I'm a little way off completing the front brake upgrade & just wondered what it would be like if I just did the rear brake upgrade for now? Main reason being I need to clear some space in my kitchen!! lol :)

Any advice would be great.

Cheers
Rob :)

[Jim-SR]

the 22V upgrade doesnt make a massive difference to the balance, its more about having vented rear discs. hence why people who want to make a large difference go for the Corrado disc upgrade as well.

if you stick 22V calipers on with stock fronts youre going to shift the brake bias rearward by about 7%, so its not going to be dangerous, it might be an improvement over stock, and youll still have considerably more front braking force than rear, the fronts should still lock first provided youve got the stock proportioning valve still attached.

[robd]

Thanks for the advice Jim, think I might change them over now then & see what its like, at least it gets them out of my kitchen then!! :)

Also I haven't done any research into this but was another thought I had, when doing this rear brake conversion you need to spacer the disc 6mm on the rear, I'm guessing this is to move it inline with the caliper so the disc is central to the caliper(if that makes any sense).
Could I not just spacer the caliper back 6mm instead so I wouldn't have to buy spacers & longer wheels studs, I know I would need hefty 6mm washers for the calipers & 6mm longer bolts to hold the calipers on but surely this would be easier & cheaper than spacering the discs & getting longer wheel studs?

I haven't actually looked at the 22V calipers against the rear of the car so not sure if there is enough room to move them inwards 6mm, but was just a thought to make my life easier.

Any comments or thoughts on this?

Cheers
Rob :)

[Jim-SR]

you cant because the calipers sit in front of the upright. to space them back 6mm youd have to remove material from the caliper or the upright. if it was that easy then everyone would be doing it!

there is one easier way that i possibly found that i still havent tested (and no longer will as im doing something different). looking at the dimensions, the front brake discs from a 2001- Renault Clio 1.2 16v (the same discs as used on the old shape Clio Williams too) look like they should be extremely close, if not perfect. i cant account for them physically fitting over the hub though. they are the correct PCD, correct diameter, and correct thickness. and look like they should be near enough spot on for offset.

if you can borrow a pair from a motor factors to try them then its worth a go. the annoying thing is that we had a Clio 1.2 16v sat outside, its now sat at my sisters, so i was going to test it out. i just havent had a chance to go and steal a disc for a few hours yet, and with the weather as it is im not too inclined to do it now lol. im going to be running 22V calipers with some fairly different discs i think, more to come on that in the near future.

P.S. the Clio discs should be about 1mm closer to fitting than the mk3 MR2 fronts. so they will probably still need spacing 2mm (but std wheel studs will allow that difference). the other issue is that they are 60.1mm centre bore, but thats actually better as the mk3 discs require something silly like 0.5mm of spigot, whereas these need 3mm, so can have a proper one machined.

[robd]

Hi Jim, thanks for the info, I did wonder if there would be other issues with spacering the caliper but thought it was worth asking. :)

I'll have a look into the Clio disc & see what I can find out & see if I can find any other discs that could possibly allow you to not have to spacer the disc at all. :)

Look forward to reading more about your brake conversion. :)