Thread: Disc Brake Conversion.

Originally Posted by Sideroad

Just having a look at other discs.
The ford bronco has a 5 stud with a PCD of 139.7 and has a disc with a 108mm center hole.

http://www.dba.com.au/products/dba579
or even better,
http://www.dba.com.au/products/dba510

Hilux as posted by TJWA.
http://www.dba.com.au/products/dba154

This could also get the caliper further away from the swivel hub and the disc more protected by the wheel. It is much more expensive though.

At this stage, I'm thinking the best solution could be to combine Sideroad's idea for a disc/ring/plate and one I have had.

If we built a thick spacer, say 20mm thick or more to mount to the back of the hub, we could have 5 holes in it corresponding to the stud holes in the hub. If we then got longer studs, they could go through the spacer ring then through the hub to the other side. This would securely hold the spacer ring against the hub and not reduce the hub's strength in any way.

We could then have another 5 threaded holes in the spacer ring evenly spaced between the stud holes for the disc to attach to.

Then, by simply choosing a 5 hole disc which has less height than the one we have now the spacer would be made the right thickness to compensate.

Sideroad has already found a disc which may be suitable.

http://www.dba.com.au/products/dba579

We need a total height of 49mm, the plate above is 29mm high so we would make the spacer ring between the hub and the disc 20mm thick.

Was just wondering if LRO has had a chance to pull his apart aswell so we can see what those are to..Mite be able to combine with them aswell ?

This path could work. How critical is the disc thickness?
If we change the disc thinkness we may need to change the caliper, which changes the mounting plate, which puts back to square one.
Here is a disc with 5 holes, similar disc dia and height but is much thicker. http://www.dba.com.au/products/dba770 it is off a Toyota dyna, so the rating would never be an issue.
What are our critical dimensions?

If we were to go with what has worked and has been done, we are far more likely to do this project. So I would suggest we work with a 49mm height(be it disc or disc and spacer), similar thickness and dia, same calipers, and regardless of the no. of stud holes use what fits and make a ring/disc/plate to bolt it to the hub (as a spacer or internal). I do like the idea of the spacer between the hub and disc as it gives room to deal with the hub webs and different no. of disc stud holes.
I still don't think the no.of holes is the biggest issue.It can be worked around.

Originally Posted by TJWA

At this stage, I'm thinking the best solution could be to combine Sideroad's idea for a disc/ring/plate and one I have had.

If we built a thick spacer, say 20mm thick or more to mount to the back of the hub, we could have 5 holes in it corresponding to the stud holes in the hub. If we then got longer studs, they could go through the spacer ring then through the hub to the other side. This would securely hold the spacer ring against the hub and not reduce the hub's strength in any way.

We could then have another 5 threaded holes in the spacer ring evenly spaced between the stud holes for the disc to attach to.

Then, by simply choosing a 5 hole disc which has less height than the one we have now the spacer would be made the right thickness to compensate.

Sideroad has already found a disc which may be suitable.

http://www.dba.com.au/products/dba579

We need a total height of 49mm, the plate above is 29mm high so we would make the spacer ring between the hub and the disc 20mm thick.

OK my Daft time again .. If we use a spacer between the disc & hub isn't that going to cause all sorts of trouble with the bracket & caliper as it will now sit further back & when the hub is on it would hit the bracket & not go on properly...

Hey Banjo,

easy mistake to make. If you look at the link you will find it is to a disc with 29mm height as opposed to 49. And that is the 20mm mentioned as a spacer. So no change of caliper location. I have been thinking of the spacer idea(between hub and disc with stud for wheel going from spacer through hub for wheel). I think it is just adding another potential problem point re: stud holes in hub, tolerance issues and other rust surfaces. I do think a spacer sandwiched between hub and disc with the hub tapped and socket head bolts from the disc side would work.

Originally Posted by banjo

OK my Daft time again .. If we use a spacer between the disc & hub isn't that going to cause all sorts of trouble with the bracket & caliper as it will now sit further back & when the hub is on it would hit the bracket & not go on properly...

Originally Posted by Sideroad

Hey Banjo,

easy mistake to make. If you look at the link you will find it is to a disc with 29mm height as opposed to 49. And that is the 20mm mentioned as a spacer. So no change of caliper location. I have been thinking of the spacer idea(between hub and disc with stud for wheel going from spacer through hub for wheel). I think it is just adding another potential problem point re: stud holes in hub, tolerance issues and other rust surfaces. I do think a spacer sandwiched between hub and disc with the hub tapped and socket head bolts from the disc side would work.

I knew that. I just wanted to make sure you guys new what use where going on about ..

I dont think an engineer would go for the bolts Studs being so long as to go through the spacer & hub for wheel studs..
I once asked about wheel spacers & was told by an engineer that yes i could legaly use them but the spacer had to bolt to the hub & then the wheel bolted to the spacer as the spacer has the wheel studs in it...
So the spacer had holes & studs in it ....

Hi
Have not had a chance to take the disk apart yet. Will get to it Tonight and take the mesurments, been to busy with work

It does seem as though we have hit a snag. Every conversion kit I can find uses a custom built hub to get around the problem of mounting the disc without weakening the hub. Really trying to think outside the square on this one.

I'm guessing the bearing size or something would be different on the Defender / Disco hubs and we couldn't use one of them?