OZ rear disc mount

[IMO]

Having been surprised at the relative ease of set up with a Juicy 5 on the front, I am now going to fit the same to the rear. I contatcted RDS but they are ex  stock on the hammerhead, and the A2Z adapter is designed for flat drop outs, which the OZ does not have.

So I purchased over the weekend an off cut of 6mm ally plate , approx 250mm x 450mm.
Hopefully this will give me enough metal to make 2 if the first goes horribly wrong.

My idea is to bolt and epoxy a scalloped plate to the inside of the frame ( wheel side) overlapping the drop out to use the QR as another fixing point. Then drill and tap 3 more holes into the drop out and bolt through into those as well.

The tricky part, which i hope to acheive is to 'recess' the 6mm plate by 2mm so it  interlocks with the oval drop out and QR lug.  So when offered up to the frame the adapter will locate on the drop out stopping any rotation force against a huge surface area , well the  'eye' shaped cut out on both the inside and the outside edges. I think a router might be the only way to do this, but the guys in the next unit have cnc machines etc so will be able to help. 

This should mean a very stiff and well located plate to fix a caliper mount to, somewhere just above and behind the drop outs. I think 6mm plate is overkill , and maybe 4mm would have sufficed, however, by machining down 4mm  to make a channel to 2mm would not leave a lot of metal behind.  a 2mm thick bit of ally is easily bent by hand , with minimal levage. Yu then have to think abut the torque a braking wheel at 25 mph , with 200lbs of lever acting on it is going to create to see why the hollowed out plate and 6mm ally is the route i intend to go down.

Will take pics alng the way, looking at  a 160 rotor fyi.

Any reasons not to do it this way? Other ideas welcomed .

rob  imo

[willem]

Sounds like you have this pretty well scoped out. You may even be "over-fastening" the whole gizmo with three bolts and the QR.

I actually went for a few years with just JB weld and the QR. The notched fit over the dropout will carry a lot of your load.

If you can... clamp it in place and get it welded.

[Old Proflexer]

As i recall, several years ago someone made a unit from carbon to the effect that you describe - can't remember who it was.
Any pictures I saved of it died with my old computer.

You don't have to get too complicated with a plate - they're pretty easy to make.



about all there is to it -

OP

[IMO]

Thanks for the pics OP, maybe it is overkill , and looking at 6mm plate its way thick and will certainly take some abuse. It will also take some machining to relieve a scallop to take the curved drop out. Might have to re - think that  idea, but actually have enough material for 4 so can afford a couple of cock ups, and might have some time on my hands soon .  fecking recesssion

[hyperhank]

Hey OP, Can you email the stencil/template drawing for this plate or know where I can download it?  Thanks Henry 

As i recall, several years ago someone made a unit from carbon to the effect that you describe - can't remember who it was.
Any pictures I saved of it died with my old computer.

You don't have to get too complicated with a plate - they're pretty easy to make.



about all there is to it -

OP

[rapiddescent]

if you're using aluminium - consider the heat transfer problem.  We got some tremendous temperatures being transmitted to the frame during testing so we didn't use Al.  I'm getting some more HH's made up because a few folks have been asking. 

I wouldn't go for anything less than 6mm thick !!

[Colin]

A Hammerhead is 4mm thick, but is made of an exotic Stainless Steel, probably used to make SAAB Jet fighters!

Col.

[Carbon_Angus]

actually they are made from alien elements from a solar system in the spiral arm that we share in our galaxy.

[Old Proflexer]

Henry - I've made and mounted quite a few, handshaped the first one and duplicated it for the others.
Many here have made them from a variety of materials including carbon and aluminum.

My aluminums have functioned just fine over the years and have never had any heat transfer problems whatsoever.
From a time/money standpoint, might just be easier to buy one - Callum's not in this to get rich and they're good units.
That way you'll get all the correct bolts, spacers etc. and won't have to spend all the time to ferret it all out.

Here's an old link that had some pics in it of some carbon units - when we moved, I believe all the old pics were tossed
http://idriders.com/proflex/smf/index.php?topic=1173.0

Hey OP, Can you email the stencil/template drawing for this plate or know where I can download it?  Thanks Henry 

[IMO]

drew a blank with the 6mm plate . it was just too thick to use habd tools on to get the shaping required. The machine shop wanted  ££££££ to cnc the perfect job . The guy asked if i  made  100 could I sell em. I dont thik there are 100 in existance, so no , not really.
So have been playing with 3mm plate. Have a peice cut with the adapter i have one of the bolts fits up in the 'eye' of the drop out oval, with the other mounting 1" outside . This positions the caliper above the QR making removing the wheel easy , and where most  manufacturers now mount the caliper. The upper bolt cannot move as it rests almost touching the dropout. the outer one could 'cut' its way through the ally eventually i suppose.
Snapped an axel on sat, so will have to try what i have made as my rim only wheel is busted.
i have some  permanent temperature marker strips , will stick them on and do some downhilling to see if the plate heats up.