hello!
ive been looking at the choices i have for front uprights,as i was gonna use the sierra ones, but they need adapting and theyre already big and heavy enough.. so as im going bec i thought i may use motorbrike disks and calipers. i then looked at different uprights that people are using, and liked the look of rorty's design, but he said the designs he made were copyrighted so i couldnt see them, and im not mechanically minded enough to be able to take the picture and make a working design from it- i also dont have the measurements from cortina (or similar) ones to take them from.
so, does anyone have designs that work well (with bike or car disks/calipers), which have lightweightness(?) as a main
design specification? (or ideas that maybe could work well). i am using sierra running gear so it would need to fit the sierra rack.

For manufacturing them i have access to a lathe, cnc machine, laser cutter, small metal casting foundry (for any metal with a melting point of under 1000*c), and all the general tools.
Any help/ideas would be very welcome!

I'm not sure that bike discs and calipers would be up to the job of stopping a car,
standard bike will use two front and a single rear caliper to stop 200-300Kg (depending on bike and rider of course )

Although maybe if you could use two calipers per wheel/disc it would be possible?

Cheers

Alex
Thinking about it, bike discs are a bit on the thin side as well and mounting them to a car type hub would be difficult

They should work nicely on your trailer/caravan if you're still building it. As said, they might be a bit under powered for a car.

i cartainly am still building it (undergoing models at the moment- will update)!!

i was looking at other posts on the bike caliper thing and others have said they should be up for the job, as long as theyre 4 or 6 pot ones- i think there are a few people on her doing it. (rorty has used them on his buggies although they are quite a bit lighter). i would laser cut my own disks so warping wouldnt be such a big problem, it would just be their stopping power. two calipers on one side would pretty much kill the weight loss that having motorbike calipers would give...

But to do it sensibly/properly, you'd need two discs too. (IMO) Just one might get too hot and if it were that simple Mr Honda/Yamaha etc would do it to. I know the blackbird for example uses a pair of 6 pots at the front, but one to a disc.

4 or 6 pot bike calipers on single discs would be more than up to the job of stopping a 500kg
car, but you would need to split them and add a spacer to allow thicker disks to be used. Bike discs warp even on bikes and IMHO are too thin for car use. Another problem with bike calipers is the mounting lugs, which are usually totally unsuitable for mounting in car applications. So by the time you have faffed around spacing them, mounting them, and making thicker discs, its prolly not worth the effort. Oh and you might have to play around with M/C bore sizes to get them to work, unless you can adapt the bike one.
Al.

[Edited on 3/10/06 by Wadders]

Have you seen these?
http://www.stuart-taylor.co.uk/products.html

no i hadnt ^^^, thats exactly what i wanted to see though, it looks like ill be able to copy them, thing i dont know is where to locate the wheel centre on the upright.

One reason big bikes have a caliper on each side of the wheel is to stop the forks twisting under braking. Some of the old jap bikes I've owned were terrible for this, jam on the brakes and you'd suddenly be veering accross the road.

Buy them, copy them, sell them.