bassboy

Hi everyone, I have searched the forums and some others and get different results, some people say it cant be done (usually older posts), while other posts say it can be done...

What I'm looking for are answers if the ST170 discs and Mondeo Mk3 calipers fit inside the S1 RST wheel? I read somewhere that they do but they require a small amount of trimming somewhere on the caliper

Can any one confirm?

I'm was holding out putting my brakes on until my new wheels go on, but considering I am changing the MC and Servo setup, I may as well do it now but will be running the 15's on the car for a good few months yet

Thanks for any help

Carlitos

I'm in the same situation by the sounds of it. I have S1 alloys fitted and wanting to do the 300mm conversion but read somewhere I cannot unless I have s2's, and even then the calipers need grinding. I've been holding off until I get the new alloys refurbed. Would be interesting to know if that is correct or not.

Rowe

you'd be better off just running a complete 170 setup for starters - sack the mondingo callipers off........ loads of different pad choices then.
ST150 and ST170 are the same callipers (just the carrier bracket which gives the extra disc size on the 170)
i run 15" wheels on mine, but they're aftermarket. There's quite alot of meat in the callipers - you literally just need to shave the outside edge down a little. I've a few friends who've had to do it to fit 15" team dynamics wheels

bassboy

The Mondeo and ST170 calipers are the same though I thought? I'm sure the same pad fits both?

Anyway, yes the brakes do fit under S1 wheels...you just need to trim the calipers as mentioned above

dojj

iTrader: (3)

the st170 calipers are smaller than the mondeo ones physically but they are also much harder to source

glen has done the shaving of the caliper in one of his threads

Carlitos

Would the ST calipers need shaving to fit as well? I already have Mondeo calipers sat in a box. If the ST ones need shaving as well then I might as well stock with the ones I have, saves me buying more calipers.

Rowe

like dojj says, they're a larger calliper........ but the same size piston IIRC
plenty of lads about breaking ST170's. Steve (1-PD) on here probably has a set somewhere.
I have a set in the garage you can have for free if you cover postage. I'll just have to double check they're in ok condition.


Carltios, it's difficult to say. But there's definitely more room with the ST calipers. It's quite often dependant on wheel offset.

Carlitos

Might be worth a shot then on the ST callipers. If anything it just means less metal needs shaving, which I'm not keen on. Do you know if spacers are needed? I didn't find much info on this setup when searching the forums.

bassboy

Even with the Mondeo calipers, the shaving needed isn't enough to cause any worry IMO

Ill update my build thread and this thread also with pics when I get to that part

Micky

I fitted the 300mm ST 170 disc's and Mondeo Mk 3 calipers to my RS Turbo last weekend.I had ground the 4 ridges off the caliper and the top and bottom edges of the caliper carrier as in Glenn's topic from 2013.I then went to fit my S2 alloys and they did'nt fit over the brakes.From looking in I seen 2 problem area's.1st the top and bottom edge's of the carrier need more grinding.I had no electric in the shed,but I feel I can safely remove more without too much trouble.2nd place is a different matter!!! The back off the spoke's are hitting the outside edge of the carrier big time,and to me it looks like at least 5mm needs to be removed.This I feel would be unsafe and leave too little metal on the carrier.I could fit 3mm wheel spacers and remove about 2mm off the carriers,but this would result in it being a right pig to sit the wheel up on the little bit of hub sticking out,while at the same time trying to line up the wheel bolts with the hole in the hub.
Lastly,the spacer I needed to center the caliper on the disc was not 12mm,as reported widely on the web,I needed 15mm.
More grinding of calipers/carriers for me in the next week or 2.

bassboy

My carriers were shaved slightly too, but not 5mm as you said...

My calipers don't touch the inside spokes...I have S1 RST wheels but I have spaced them out either 10 or 15mm just for looks before I carried out the conversion

polle90

I also used spacers of 15mm.

Micky

@ polle90.Are those 15mm spacers between the carrier and the hub,or between the disc and the wheel?? Thanks

polle90

@Micky.They are between the carrier and the hub.

Carlitos

Wondering if bassboy had any success as yet?



For me I now have ST170 Brembo discs and ST170 calipers ready for fitting, just need hoses. I took the S1 alloy and discs off to size up without yet drilling the hub holes larger and it was difficult to align up for an idea of how much needs to come off as I couldn't securely fit the caliper without drilling the holes, but it looked quite a bit would need removing still. I measured the inside of both s1 and s2 alloys, difficult to measure but s2 definitely had more space.


I'll have another sizing session in the next week or two and might drill the holes outs.



Originally I was thinking of getting these s2 alloys powder coated & new tyres fitting, now I'm thinking the cost I might as well look at larger alloys as the cost wouldn't be much more. Which is kind of annoying because I really wanted s2's - I love the look of them.

bassboy

Yep they are on the car and the wheels turn...which helps lol! Mine are S1 wheels too so the smaller of the 2 sets according to your research

Carlitos

Ah cool. Thanks for responding. Did you have to grind much off in the end?

bassboy

Not overly alot to be honest...it was more the outer edges and the carriers that needed trimming...ill try and get some pics for you

simonmcf

iTrader: (1)

Carlitos

I just bought some 16" Mondeo cossie look-a-like alloys on ebay. So probably I wont need to grind my ST calipers any more. Still would be great to see those pics though.


Although I was a bit silly and thought 205/55/16 was the right size which are already fit to these alloys. Anybody know if that size tyre will fit, at least until I have a bit more cash to replace them with 40 or 45's?

dojj

iTrader: (3)

Depends on what car they are going on
Way too big on a Sierra or fiesta mk5

bassboy

Depending how low you go and if they are spaced...my 15s scrape on 195/45 on the S1 wheels, but the car is very low and wheels are spaced out pretty far lol

Carlitos

Some feedback on my experience if it helps anybody else.

I have in my possession both ST170 calipers & Mondeo calipers. Mondeo definitely have larger piston size (and physical size). I measured and thought I'd remember - I didn't. I think Mondeo was 5-10mm wider. I could be wrong here but I'd think brake pad size & disc size is probably more important than piston size for a non-performance brake setup. I've gone with the ST caliper myself, mainly because it's in much better condition than the mondeo.

I fit 16" alloys in the end so didn't need to grind. So cannot comment on that (went for 195 tyres in the end)

Spacers for caliper. I used some steel rods with M12 hole and cut down to lengths of 12mm. This is too short as Micky said. 12mm length just about cleared the disc but I wouldn't want to drive continuously like that. I'll be trying 15mm once they arrive.

I didn't replace the brake hoses so running with the standard ones. Although they aren't in the best state so will probably replace with longer ones. They seem to be a bit stretched for my liking but so far functioning ok.

Brake fluid was well overdue a change too. It was not a good colour! Should really bleed the rear too.