Ask an Engineer

[Ocean1]

yes i realise an MMC material would be probably better but does anyone have any ideas?

No.

Other than to suggest the 7000 series cast tooling grade alloys are most stable both mechanicaly and thermally.

Guess annodising would add wear resistance, but it's not very thick. Wonder if the ceramic coating used on zorsts would stay bonded to alloy.

With enough cash you could play with explosive clad composites like toolsteel/alloy/toolsteel. Even then I'd think you'd have trouble keeping them bonded.


PS: if you've got plenty of cash let me know.

PPS: Have talked to NZ cylinders about chrome alloy disks?

[husaberg]

No.

Other than to suggest the 7000 series cast tooling grade alloys are most stable both mechanicaly and thermally.

Guess annodising would add wear resistance, but it's not very thick. Wonder if the ceramic coating used on zorsts would stay bonded to alloy.

With enough cash you could play with explosive clad composites like toolsteel/alloy/toolsteel. Even then I'd think you'd have trouble keeping them bonded.


PS: if you've got plenty of cash let me know.

PPS: Have talked to NZ cylinders about chrome alloy disks?

Hello Thanks

I guess MV being in the business of building aeronautics would have had some pretty exotic alloys and coating available as well as a large pot of cash. but any idea on a pad material for a aluminum disk?

all the stuff i have seen has said all the coating were not that successful i know Triumph tried plating with plasma and some other metal sprays. anodizing i think would too soon abraide off.
Def no to ther nicosil the plating. As already will be gifting them about $500 i guess for the cylinder so not relaly an option.

ps if i had plenty of cash i would be off to Monacco .......

Actually how big are some of those diesel pistons say a 140mm cat piston....... they would be full of silicon be heat resistant and i guess that is what burt would have used (if he had of believed in brakes that is) and second hand free......

[Ocean1]

but any idea on a pad material for a aluminum disk?

No mate, outside my experience. Guess whatever it is you'de want to make a good radius on the leading edge to help prevent it machining the disk for you.

Actually how big are some of those diesel pistons .

Fucking big. My old tutor used to tell us about standing on his ship's piston to clean up the ring step on the cylinder, with a disk grinder.


As for Burt, dunno if he made Indian pistons out of them but he definitely had a few Cat pistons donated.

[husaberg]

From memory (out of George Beggs book)the rod were Cat Grader axles hammered flat with a power hammer after been reheated in a forge
Initially he used Ford Truck axels but they were not up to the job.
The pistons were initially a mix of ford and chev pistons (as in the movie) but the gudgeon's were always ford
The later Pistons were die cast from diesel pistons as he assumed they would have to be better quality than the petrol ones due to the higher pressures.
He however always used genuine Indian roller due to the radius edges which he reckon were les likely to shed there hadending.
these were heavily worked as it was very late in the piece that he actually converted to a pressure fed big end.He said it was to hard (which is funny considering the other modifications he made which were far more involved)
The majority of the time the crankpin he used was only 20mm which to me is is amazing.


The piston idea may be worth a crack....
but i suspect there with be a bit of steel reinforcing within i might have a peek in the scrap bins a Goffs.

But the material to use i guess will have to be softer than the disks so maybe a softish copper alloy.

At the end of the day its only for a rear brake for bucket so i guess basically anything could work for a while anyway.........

[Grumph]

[QUOTE=husaberg;1130445667]From memory (out of George Beggs book)the rod were Cat Grader axles hammered flat with a power hammer after been reheated in a forge
Initially he used Ford Truck axels but they were not up to the job.
The pistons were initially a mix of ford and chev pistons (as in the movie) but the gudgeon's were always ford
The later Pistons were die cast from diesel pistons as he assumed they would have to be better quality than the petrol ones due to the higher pressures.
He however always used genuine Indian roller due to the radius edges which he reckon were les likely to shed there hadending.
these were heavily worked as it was very late in the piece that he actually converted to a pressure fed big end.He said it was to hard (which is funny considering the other modifications he made which were far more involved)
The majority of the time the crankpin he used was only 20mm which to me is is amazing.


The piston idea may be worth a crack....
but i suspect there with be a bit of steel reinforcing within i might have a peek in the scrap bins a Goffs.

I've come late to this but I've used alloy discs, anodised and non anodised. They only last if your rider doesn't use the back brake....

Just make up a disc in mild steel - the weight penalty is grammes only and it will see out a couple of seasons.
For rears, use as soft a pad as you can find.
Remember, during the 1960's Ferrari used mild steel discs.....
Till they learned about nodular cast iron anyway.

[husaberg]

From memory (out of George Beggs book)the rod were Cat Grader axles hammered flat with a power hammer after been reheated in a forge
Initially he used Ford Truck axels but they were not up to the job.
The pistons were initially a mix of ford and chev pistons (as in the movie) but the gudgeon's were always ford
The later Pistons were die cast from diesel pistons as he assumed they would have to be better quality than the petrol ones due to the higher pressures.
He however always used genuine Indian roller due to the radius edges which he reckon were les likely to shed there hadending.
these were heavily worked as it was very late in the piece that he actually converted to a pressure fed big end.He said it was to hard (which is funny considering the other modifications he made which were far more involved)
The majority of the time the crankpin he used was only 20mm which to me is is amazing.


The piston idea may be worth a crack....
but i suspect there with be a bit of steel reinforcing within i might have a peek in the scrap bins a Goffs.

I've come late to this but I've used alloy discs, anodised and non anodised. They only last if your rider doesn't use the back brake....

Just make up a disc in mild steel - the weight penalty is grammes only and it will see out a couple of seasons.
For rears, use as soft a pad as you can find.
Remember, during the 1960's Ferrari used mild steel discs.....
Till they learned about nodular cast iron anyway.

I know your right but where the fun in that Greg
I have a couple of disks here to play with but the wheel i are using is the STD front Honda pattern with a 57mm center and a 74mm pcd(on the Rear)
It need as great amount of offsett as the hub is narrow so trying to kill two birds with one stone.
I initally planed to modify a chinese rotor of a pitbike or similar but finding a suitable one has not been easy

[Ocean1]

From memory (out of George Beggs book)the rod were Cat Grader axles hammered flat with a power hammer after been reheated in a forge

Sounds right. Although I know he was given a Cat dozer (D7?) halfshaft to make rods from which was big enough to have taken a rod sized slice from.

it was very late in the piece that he actually converted to a pressure fed big end.He said it was to hard (which is funny considering the other modifications he made which were far more involved)
The majority of the time the crankpin he used was only 20mm which to me is is amazing.

Well, a dipper on the big end is a fairly reliable bit of kit for those revs, if the oil stays put in the sump. And I guess the small crankpin also means much lower surface speed eh?

The piston idea may be worth a crack....
but i suspect there with be a bit of steel reinforcing within i might have a peek in the scrap bins a Goffs.

But the material to use i guess will have to be softer than the disks so maybe a softish copper alloy.

At the end of the day its only for a rear brake for bucket so i guess basically anything could work for a while anyway.........

Bucket rear? Can you find a pushbike caliper to reach around the rim?

As for pads... one material used in't oldentimes was cork. Was compressed and encapsulated with (silica?) resin. Very high coeficient of grippything, wouldn't need much calliper force.

[husaberg]

Bucket rear? Can you find a pushbike caliper to reach around the rim?

As for pads... one material used in't oldentimes was cork. Was compressed and encapsulated with (silica?) resin. Very high coeficient of grippything, wouldn't need much calliper force.

The caliper is sorted and is a tiny one of a KTM 50 its is still attached to the bike otherwise a gentle breeze may blow it away.
Today I saw an interesting caliper set up from a Rokon i will ad it here as its quite quirky as the disk is solid yet the caliper with float effortlessly.

[Grumph]

i'd have thought you'd recognise a copy of early Honda.....

If you need a big offset on the disc, do an alloy carrier and float a mild steel disc on shouldered capscrews.

[husaberg]

i'd have thought you'd recognise a copy of early Honda.....

If you need a big offset on the disc, do an alloy carrier and float a mild steel disc on shouldered capscrews.

You would think so but no...
i looked at the pic and of a CR750 and still no

Then kept google and by jove your tight Greg.....

it fairness they do predate me by more than a few years... Actually i have never seen a K0 or K1 or K2.
The old mans got a 350 four so i hope that's not the same set up as it does have a large bracket like that......

Yeah re the adapter spacer i have a criminal dislike verging on hatred of bolting on one piece only to bolt on another piece to it.
It doubles up the fastners ( as well as my chances of over tightening or loosing or leaving out etc)and the time to change the wheels, and the beer i will need to provide to the guy that will have to make it plus its all unsprung. I know it is OTT...

[speights_bud]

Yeah re the adapter spacer i have a criminal dislike verging on hatred of bolting on one piece only to bolt on another piece to it.
It doubles up the fastners ( as well as my chances of over tightening or loosing or leaving out etc)and the time to change the wheels, and the beer i will need to provide to the guy that will have to make it plus its all unsprung. I know it is OTT...

But how are guys who can supposed to get beer in their fridges?


C'mon get a pushie brake!, much lighter on un sprung weight, a little imagination can get you a quite cool adapter spacer too. (mines a bit average)

[husaberg]

Same way i do beg the mrs for it......
The ktm 50 is made by Formula who also do MTB brakes they are tiny actually as small as my thumb designed to work with a 140mm disk.

[husaberg]

OK bit the bullet and coughed up $10 on one of these.
I was hopining the would be enough meat in the spokes to allow a direct bolt straight adapter on, but its only 8mm wide at the correct PCD



its going on my CBR400 NC23 front wheel (rear wheel on my bucket)
the adaptor at this stake will possibly resemble this as i are no artist with a mill.



I already have a collection of RS125 sprockets. So i have to fab a mount for this as well most people think that i can get by without a cush drive but will be alright. (6mm bolts i think) 58mm center 78mm pcd 6 hole.

if i went cush i was thinking along the lines of a old Honda single set up with the tab dowels bolted on the sprocket.
The sprocket is then retained with the circlip to the hub so it would be QD with the rubbers in the adapter plate.

Along the lines of below to save space i guess i can go to Nolathane for the bushes.. rather than metalastic


The adapter would end up looking like this only with the sprocket rather than the bearing retained by a circlip


Input from the panel??????????????????

[Ocean1]

Circlips go inside the bushes? How do you fit them?

Could use pins with a head inside the bush and a thread to retain the sprocket?

[husaberg]

Circlips go inside the bushes? How do you fit them?

Could use pins with a head inside the bush and a thread to retain the sprocket?

I will try and find a better pic the circlip only retains the sprocket which sandwiches the whole assembly.
the little xl and xr Honda's ran the system 70-80's
the pins bolt to the sprocket on on side pin on the other and the bushes are retained in the adaptor or in the little Hondas case the hub