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Aluminium brakes


atreyu

New Website User
Non-VOC Member
Can anyone supply alloy brake hubs with iron liners? I've read a bit on the forum in the past but I can't remember if there was ever a supplier?
 

davidd

Well Known and Active Website User
VOC Member
As far as I know, there never has been a supplier of aluminum Vincent brake drums. Several members have made small numbers for themselves or their friends, but nothing that is for retail, as far as I know.

David
 

Albervin

Well Known and Active Website User
VOC Member
The Series A Rapides had alloy drums with iron liners as an option to the terrible spun steel drums. As far as post war bikes the only ones I have seen have been made in the shed by very clever people.
 

timetraveller

Well Known and Active Website User
VOC Member
I tried sending you a private message but it will not go, possibly because you are a non member. Email me on enw07@btinternet.com after the first week in September and I might be able to introduce you to someone who has made some of these.
 

atreyu

New Website User
Non-VOC Member
I will email you timetraveler.

If anyone else knows of anyone that may have some please let me know.

I will make my own set if I have to but I was hoping to save some time as obviously it wouldn't be an evening job!
 

vibrac

Well Known and Active Website User
VOC Member
I pondered making a ribbed alloy muff for another bike with a pressed /Spun steel hub the two points I thought of were there seems a slight taper on the outside of the drum so I would have to replicate that inside the muff (possible) or machine the outside of drum paralel (not a good idea?) the second pont is on a seven inch drum as the alloy expands faster than the steel drum when hot I guess I would need a lot of interference( just how much?) and I guess that would distort the drum so it would need a inner skim and as the spokes also fit to the drum that would have to be done after building. anyone done this and got any figures?
 

Cyborg

Well Known and Active Website User
VOC Member
I owned a Rapide back in the 70’s that had finned alloy muffs on the front brakes. Don’t know any of the details as they were on the bike when purchased.
 

Chris Launders

Well Known and Active Website User
VOC Member
Mine had a set of "home made" finned muffs on, three of the muffs were cracked so fitted new drums all round.
 

stu spalding

Well Known and Active Website User
VOC Member
Some years ago I saw a comet with alloy muffs with a single, very large fin, about 2" deep. No further info I'm afraid. Cheers, Stu.
 

Robert Watson

Well Known and Active Website User
VOC Member
Top Picture
These are Rapide front drums with the OD skimmed to run true and the alloy muffs shrunk and bolted. The A twin front wheel had these in period pictures around WW2 as it also had a black out headlight. They were destroyed in about 1958 when the rider T-boned and Edsel! I remade them from big pieces of alloy plate.

Bottom Picture
These are TTR brakes which were reproduced in the US sometime possibly in the 70's or 80's.
The TTR brakes were cast iron drums bolted to the alloy fronting plate (I call it a fronting plate as it is on the other side of the backing plate!) which had the bearing mounts integral with the plate. A's generally have independent bearing housings which are through bolted with the drums and hubs.



IMG_1221.JPGIMG_1216.JPG
 

atreyu

New Website User
Non-VOC Member
Very interesting Robert but I guess theres no chance of getting the alloy brake plates (front plates) anywhere either?
 

Robert Watson

Well Known and Active Website User
VOC Member
I do have a set of complete "Vancouver" brakes. These were cast locally and comprise of Iron ribbed drums, front and rear with slightly larger dia fins than standard and alloy backing plates. They do not have shoes but are all machined and include the appropriate hardware. I could take pictures if you were interested. I have them on four bikes and they work well but I also have a set of Speet brakes which work extremely well.
 

Black Flash

Well Known and Active Website User
VOC Member
Well I am building a new front brake at the moment.
The prototype is in my Comet for testing. Unfortunately in a weeks time I will be on a longer business trip in Asia so three weeks no testing.
It's a composite drum just over 8 inches tls, but with and internal connecting rod.
I will try include some pics as a teaser but I don't know if it works
 

Attachments

Black Flash

Well Known and Active Website User
VOC Member
Some more pictures
Unfortunately the first mould of the airscoops was the wrong shape. I now had the mold redone and the new scoopes look good, but I need to make a new jig for machining.
 

Attachments

vibrac

Well Known and Active Website User
VOC Member
So basically its a question of working out the interference to retain the finned muff on the drum I suppose the interference suggested for the Vincent barrel and liner is a good guide except I dont suppose the drum gets as hot as a cylinder. so standard interference on a barrel and liner is 6 thou more = distortion so I guess that with the increased diameter 4 thou with a close fit of surfaces would be OK
 
Last edited by a moderator:

Black Flash

Well Known and Active Website User
VOC Member
Hello vibrac,
I would do as follows:heating the alloy housing to 180 C from room temperature will make the 7 inch ID grow about 0.65 mm or about 25 thou. I would use a ring of cast iron of 10 mm wall thickness at room temperature about 0.6 mm oversize, so the ring will easily drop[2 thou clearanc] into the hot alloy housing. During ccooling the alloy will grip the ring. Machine the id afterwards.
Erich Kruse from Germany made his cast iron rings with an outer lip with screws for extra security.
Do not be tempted to fit a finished inner ring with just 1/8 inch to start with, it is likely to break during cooling /shrinking time of the alloy.
Contrary to cast drums with keyed outer ring surface you are solely relying on the shrinking of the alloy.
I will post a picture of the Kruse design tomorrow.
Good night
Bernd
 

timetraveller

Well Known and Active Website User
VOC Member
Tim, the diameter of the drum is much larger than the diameter of the liner so you can't take that as the value. I can't do it for you as I do not have my engineering tables with me but it is not a difficult calculation
 

peter holmes

Well Known and Active Website User
VOC Member
look it up here,
costs a bit get a bit.

www.brakedrum.co.uk
they do a 7 inch
I think Vincent has the answer to this one (no, not Phillip, the other Vincent) the Brake Drum Company use the Alfin process and they do seem to have rough idea what they are doing, but it looks like you would probably spend £400.00 per drum minimum, as the only perceived benefit is weight saving, and as over the years we mostly seem to add to weight of our bikes with added equipment etc. I am not sure for road use that it is actually worth that sort of money.
 

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