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monday's silly question - using bike disc brakes
02GF74 - 6/10/08 at 11:15 AM

Here is the idea. Fit motorcycle discs and calipers to cortina uprights.

Looking at ebay, calipers are about 1/3 rd price of willwoods but discs are alsmnot same price.

It will save a fair bit of weight over the cortina discs, look really bling but...

a) will they be man enough? (westfield do sell thinner cortina discs)
b) can they be made to fit at reasoable costs?
c) will having floating disc be a problem
d) will there be problem with getting matching master cylinder?

anyone tried this or consdiered dfoing this?

Richard Quinn - 6/10/08 at 11:24 AM

Yes, being an ex-Autograss racer, I have considered it. They may well be up to it as you can now get nice Tokico 6 pots etc. Most of the newer ones are radial mount which could cause a few issues with mounting. Lug mount may be an issue with having to make up adaptors for the Cortina uprights. One thing I would say is have a look at the price of pads (they're not cheap) and bank on replacing pads and discs more often. I've gone with Wilwoods!

MikeRJ - 6/10/08 at 11:28 AM

I supposed you'd have to look at how heavy your car is in relation to a superbike. Most (all?) modern superbikes are well under 200kg, even a lightweight locost is going to be double that.

Mr Whippy - 6/10/08 at 11:34 AM

quote:
Originally posted by MikeRJ
I supposed you'd have to look at how heavy your car is in relation to a superbike. Most (all?) modern superbikes are well under 200kg, even a lightweight locost is going to be double that.


then again I remember quite clearly just how bad my cortina brakes were

will121 - 6/10/08 at 11:49 AM

the use of motorbike 4 and 6 pot calipers has been done as some can be split and respaced to suit various disk thickness, but would think using motorbike disks a non starter on the basis of braked weight diferance

Peteff - 6/10/08 at 11:52 AM

quote:
Originally posted by Mr Whippythen again I remember quite clearly just how bad my cortina brakes were


That was on something twice as heavy as a Locost, they are perfectly adequate even without the servo and will lock the fronts easily if you get carried away.

loggyboy - 6/10/08 at 12:27 PM

quote:
Originally posted by MikeRJ
I supposed you'd have to look at how heavy your car is in relation to a superbike. Most (all?) modern superbikes are well under 200kg, even a lightweight locost is going to be double that.


But bikes have 1 disc and a car would have 2.

However despite that, IMO i wouldnt want to risk it for a few hungreds of grams maybe a 1kg or 2 of weight saving, coupled with some cost saving too.

Budget remould tyres are cheaper, but as with tyres, brakes are somewhere i wouldnt want to scrimp n save.

[Edited on 6/10/08 by loggyboy]

rayward - 6/10/08 at 01:01 PM

But bikes have 1 disc and a car would have 2.



most (prob all?)sportsbikes have 2 discs anyway

Ray

r1_pete - 6/10/08 at 01:04 PM

quote:
Originally posted by rayward
But bikes have 1 disc and a car would have 2.



most (prob all?)sportsbikes have 2 discs anyway

Ray

They sure do, I think the big problem would be the speed of pad wear, compared to cars there is very little meat on bike pads.


[Edited on 6/10/08 by r1_pete]

Richard Quinn - 6/10/08 at 01:15 PM

... and as I said before, the pads are tiny but very expensive!
I think that the thinner discs would also get a little warm so warpage could be an issue

02GF74 - 6/10/08 at 01:23 PM

quote:
Originally posted by Richard Quinn
... and as I said before, the pads are tiny but very expensive!
I think that the thinner discs would also get a little warm so warpage could be an issue


warpage - that is why they are floating.

I reckon they are more than big enough to halt a locost but the thinness means there is less mass so they will heat up if used under lost of heavy braking. As they will not be in open air as on a bike, this is probalby the main drawback.

I also wonder if the large disc will fit inside a car wheel.

oh well, back to the drawing board....

tomgregory2000 - 6/10/08 at 02:34 PM

motorbike discs do warp as mine have on my VTR1000 and it gets quite intresting braking at a ton plus, also the brakes on a bike dont get used that much because there is so much engine braking and the heat build up if used on a car would be extreme

Richard Quinn - 6/10/08 at 03:02 PM

quote:
Originally posted by tomgregory2000
also the brakes on a bike dont get used that much because there is so much engine braking
Get a slipper clutch and see how good your brakes really are(n't)??

dinosaurjuice - 6/10/08 at 03:24 PM

I was hoping somebody would start a topic about this. Ive got a Mev Rocket, and being mid engined i was thinking some 6, or even 4, pot big-bike brakes would be ample on the front.

Aftermarket wavey discs might be an answer to heat build up, not sure how much difference they make though.

Richard Quinn - 6/10/08 at 03:32 PM

The other thing to bear in mind is that getting bike calipers etc under a 13" rim is going to be a no goer. I think you would need 15" as a minimum.

dinosaurjuice - 6/10/08 at 03:39 PM

my rocket runs 17's...im getting really tempted by this now. i should have taken up the offer of a student loan afterall

for wheels 14" and under....what about quad bike discs?

MikeRJ - 6/10/08 at 03:53 PM

quote:
Originally posted by dinosaurjuice
Aftermarket wavey discs might be an answer to heat build up, not sure how much difference they make though.


None, wavey discs are a fashion accessory!