Brake Drum Cracked.

[Vincent Brake]

Vic, they must be of ordinary cast like GG25 for they machine realy easy ( i do a lot of trueing up when installing a 2x2 brake.)
They are also a bad fit, as they lay on everywhere but for the earea under the bolts, so we machine them back, near the spokes, and make the flange fit diameter a 3 mm bigger.
For material I would chose nodulair cast like GGG40 its less britle but harder to machine.(am going to make a small batch of ALU hubs with this as liner schrunk into it.
Vincent Speet

 

[Tom Gaynor]

True, but hellish difficult to obtain. In practice, for me, it's setscrews or nothing, no short bolts available, hence the use of three dowels. Captain Loctite should ensure they don't fall out.

its better the thread doesnt go right up to the shoulder then the sprocket and drum will be driven by the bolts diameter and not relying on the nut to pinch it together and the drive will also be just on the crest of bolt thread.

 

[Tom Gaynor]

Brake drums

Vincent:
Spelling: "nodular", and "shrunk". And "brittle".

i HAVE PICTURES OF MY BROKEN BRAKE DRUM, POSTED LATER. iT IS QUITE CLEARLY not A FINE-GRAIN CAST IRON. (Sorry, caps-lock hit by mistake.)

Keep me posted. My Vincent wheel weighs about 16 kilos with tyre, the wheel with 9" four-shoe brake on my Petty weighs 11 kg.
A friend made a ribbed, cast-on, ally muff for his Rudge brake. I've ridden it. I was VERY impressed. My Rudge brake stops fast, then stops stopping. His stopped and continued stopping. So I am very interested in your new project, for two reasons, weight and fade resistance.
Your four-shoe brake continues to give complete satisfaction.

Vic, they must be of ordinary cast like GG25 for they machine realy easy ( i do a lot of trueing up when installing a 2x2 brake.)
They are also a bad fit, as they lay on everywhere but for the earea under the bolts, so we machine them back, near the spokes, and make the flange fit diameter a 3 mm bigger.
For material I would chose nodulair cast like GGG40 its less britle but harder to machine.(am going to make a small batch of ALU hubs with this as liner schrunk into it.
Vincent Speet

 

[ernie]

Vincent is from the Netherlands and if I could spell Dutch as well as he can English I would be a happy man.

Nevertheless well done Vincent & Tom, excellent thread, I have not suffered a broken drum yet but the driven flange did part from the rear hub once - fortunately at only 25mph cos we was all over the road.

 

[petermb998]

Hi Ernie
As I was following you when your drum gave way I was under the impression at 1st that that was the way you always ride your bike 2 up.
best regards peter

 

[ernie]

Peter Bromberg you were the man who saved our bacon by allowing me to ride your lovely Rapide - with brakes that work - to the port while you trailered my bike there.

But it was the hub that gave way, altogether a mucch more serious occurrence. Tee Hee.

 

[Tom Gaynor]

Cracked drum

Bear in mind that I'm pretty sure that the reason I cracked my drum was that there were NO nuts on the five sprocket bolts.

Peter Bromberg you were the man who saved our bacon by allowing me to ride your lovely Rapide - with brakes that work - to the port while you trailered my bike there.

But it was the hub that gave way, altogether a mucch more serious occurrence. Tee Hee.