first evaliution on my TD Yam 260mm front drum

Bernhard · Sep 14, 2016

[quote

I wil keep the original liners from the Hungarian,
they same to be very good for streer use, some racing riders says to change it for racing ones, but they need to warm up to be usefull an that will never happens on the normal road[/quote]

I suggest 50/50 green race and brown linings, with the leading edge of the brake shoes filed at a 30 degree shallow lead in angle .
BTW, whit such a big drum wait until you encounter a strong side/cross wind –you are going to find that the bike wants to steer itself

yves norton seeley · Sep 14, 2016

Bernhard said:
[quote

I wil keep the original liners from the Hungarian,
they same to be very good for streer use, some racing riders says to change it for racing ones, but they need to warm up to be usefull an that will never happens on the normal road

I suggest 50/50 green race and brown linings, with the leading edge of the brake shoes filed at a 30 degree shallow lead in angle .
BTW, whit such a big drum wait until you encounter a strong side/cross wind –you are going to find that the bike wants to steer itself[/quote]

Thanks for the suggestion about the linnings, I did already the leading edge a 30 degrees, I have a bit of experience with drums, at the end of the 60's I was a Side Car rider, using a BMW rensport with 16 inches weels with giant drums on it with hydrolic like on a car.
I was working years for the belgiam kawasaki distributor, and at the end of the 60's I owned a 500 3 cylinder, first generetion and I remember that I put a Grimeca 4LS on the bike, it was a bit dangerous wit the Dunlop K81 from the late 60's
But I manage to cross the city of Brussel on fresh snow to go to my work, a real circus act believe me
yves

yves norton seeley · Sep 14, 2016

Fast Eddie said:
The drum brake looks fantastic sir, well done!

Before you splash your cash on Ceriani forks, you might want to check out Maxton. They make Ceriani replica forks, but of FAR superior quality and performance.

Hi fast eddie
I already contact Maxton, of course they are top, but so expensive, maybe if I go tothe bank with my riotgun....
Thanks
Yves

yves norton seeley · Sep 14, 2016

Fullauto said:
Yves, that is a beautiful bike. It is a real achievement on your part. May you be riding it in twenty years.

I hope to ritch 86 years, I am a smoker and here in Belgium they put on the cigarette box: "smoking kill slowly" Ok to me I am not hurry

acotrel · Sep 14, 2016

Smoking tyres is better than smoking cigarettes as long as it is not the tyre on the front wheel of your bike.

SteveBorland · Sep 19, 2016

Great looking bike & brake there Yves!
I have an original TR3 brake sitting under my bench, sourced from a long gone racer project. I was using this on my 1969 T150 Trident as a replacement for the rather feeble standard TLS drum, but took it off due to problems getting it work properly.

Basically, there was a lot of lost motion due to wear in the various pins and bushes in the levers, but the main issue was that I could not get full contact with the brake shoes and the drum. I had the shoes redone locally, but they would not turn down the linings to achieve full contact, saying that this would produce a tapering lining thickness across the length of the shoe - something they were not prepared or willing to do.

Either the shoe pivot points are wrong (not very likely) or the drum liner has been turned down rather a lot by a previous owner or the brake shop did not know their job....

Would it be possible to ask you to measure the thickness of t he iron liner inside the drum the next time you have it apart? This would help in determining what I can do to get my 4LS working again.

Thanks,
Steve in Denmark

madass140 · Sep 19, 2016

Steve, I manufacture this brake, I disected a genuine one to see the details on the cast in liner. the cast in liner is very thick , you could increase the diameter from 260mm to 264mm without issues, you would save a lot of weight also. Since about a year or so ago I have been fitting bronze bushings for the 4 camshaft holes, and also arcing the shoes to get maximum shoe to drum contact, set up right they really do work well.
Sorry Yves for jumping in there, your bike is a real gem good onya.
Don

yves norton seeley · Sep 19, 2016

SteveBorland said:
Great looking bike & brake there Yves!
I have an original TR3 brake sitting under my bench, sourced from a long gone racer project. I was using this on my 1969 T150 Trident as a replacement for the rather feeble standard TLS drum, but took it off due to problems getting it work properly.

Basically, there was a lot of lost motion due to wear in the various pins and bushes in the levers, but the main issue was that I could not get full contact with the brake shoes and the drum. I had the shoes redone locally, but they would not turn down the linings to achieve full contact, saying that this would produce a tapering lining thickness across the length of the shoe - something they were not prepared or willing to do.

Either the shoe pivot points are wrong (not very likely) or the drum liner has been turned down rather a lot by a previous owner or the brake shop did not know their job....

Would it be possible to ask you to measure the thickness of t he iron liner inside the drum the next time you have it apart? This would help in determining what I can do to get my 4LS working again.

Thanks,
Steve in Denmark

I will do it one of this days and keep you posted
Yves

yves norton seeley · Sep 19, 2016

madass140 said:
Steve, I manufacture this brake, I disected a genuine one to see the details on the cast in liner. the cast in liner is very thick , you could increase the diameter from 260mm to 264mm without issues, you would save a lot of weight also. Since about a year or so ago I have been fitting bronze bushings for the 4 camshaft holes, and also arcing the shoes to get maximum shoe to drum contact, set up right they really do work well.
Sorry Yves for jumping in there, your bike is a real gem good onya.
Don

HI Don,, On the replica I have, the levers are going over square shafts, on the original Yam there are a shafts whit spindels, I wish to find this one to have the original look.
Are you manufacture this kind of stuff? can I buy it from you?
Thanks
Yves

SteveBorland · Sep 19, 2016

madass140 said:
Steve, I manufacture this brake, I disected a genuine one to see the details on the cast in liner. the cast in liner is very thick , you could increase the diameter from 260mm to 264mm without issues, you would save a lot of weight also. Since about a year or so ago I have been fitting bronze bushings for the 4 camshaft holes, and also arcing the shoes to get maximum shoe to drum contact, set up right they really do work well.
Sorry Yves for jumping in there, your bike is a real gem good onya.
Don

Thanks very much for the reply Don, much appreciated. I've been considering whether to try eccentric bushes on the shoe pivot shafts to try to correct the geometry of t he shoes. If i understand you correctly, you simply arc the shoes to match the drum and accept the tapered lining thickness? This would be much simpler to do, but the brake relining people were very clear in their refusal...

madass140 · Sep 19, 2016

Yves, yes I notice those brakes from Hungary are not real good replicas with the incorrect camshafts and levers Yes I can supply the proper camshafts and bronze bushings, and also the proper splined levers, I recommend that if you us my camshafts that you machine your brake plates to accept my bronze bushings.
Steve, I have oversize linings bonded to the shoes, then assemble the brake complete with shoes, camshfts and levers etc then fit a 1mm shim under the foot of each shoe, then size the shoe assembly to exactly 260mm, then remove the shims dress up the linings with a small taper on the leading edge
and thats it, no adjustment needed, its ready to go.
Don

yves norton seeley · Sep 19, 2016

madass140 said:
Yves, yes I notice those brakes from Hungary are not real good replicas with the incorrect camshafts and levers Yes I can supply the proper camshafts and bronze bushings, and also the proper splined levers, I recommend that if you us my camshafts that you machine your brake plates to accept my bronze bushings.
Steve, I have oversize linings bonded to the shoes, then assemble the brake complete with shoes, camshfts and levers etc then fit a 1mm shim under the foot of each shoe, then size the shoe assembly to exactly 260mm, then remove the shims dress up the linings with a small taper on the leading edge
and thats it, no adjustment needed, its ready to go.
Don

Hi Don, thanks for your replay, very intresting.
I PM you to order
Yves

acotrel · Sep 19, 2016

Sounds good in theory. Wear a decent helmet.

cjandme · Sep 19, 2016

acotrel said:
In this photo...........

........there is a picture of a front drum brake that is very different & antiquated compared to the one Yves is discussing in this thread. Night and Day really, like apples and oranges, so the ominous warning of wear a decent helmet-(because the brake will fail and you will crash) is misguided, IMHO of course.

SteveBorland · Sep 20, 2016

Thanks Don, I'll have to dig t he brake out and try that.

Regarding the helmet comment, I would be more worried about t he opposite - i.e. the tyre loosing traction due to the sudden "self servo" effect of t he 4LS setup. Apparently it's quite a large difference to the linear effect of a disc brake. Since my 4 shoes have never really worked as intended, this is not something I've noticed in the past.

/Steve.

yves norton seeley · Sep 20, 2016

SteveBorland said:
Great looking bike & brake there Yves!
I have an original TR3 brake sitting under my bench, sourced from a long gone racer project. I was using this on my 1969 T150 Trident as a replacement for the rather feeble standard TLS drum, but took it off due to problems getting it work properly.

Basically, there was a lot of lost motion due to wear in the various pins and bushes in the levers, but the main issue was that I could not get full contact with the brake shoes and the drum. I had the shoes redone locally, but they would not turn down the linings to achieve full contact, saying that this would produce a tapering lining thickness across the length of the shoe - something they were not prepared or willing to do.

Either the shoe pivot points are wrong (not very likely) or the drum liner has been turned down rather a lot by a previous owner or the brake shop did not know their job....

Would it be possible to ask you to measure the thickness of t he iron liner inside the drum the next time you have it apart? This would help in determining what I can do to get my 4LS working again.

Thanks,
Steve in Denmark

Here you go:
The thickness of the iron liner is 5mm
Yves

splatt · Sep 20, 2016

yves norton seeley said:
: "smoking kill slowly" Ok to me I am not hurry

Funniest thing I've seen today still laughing , nice bike

SteveBorland · Sep 20, 2016

Here you go: The thickness of the iron liner is 5mm Yves[/quote said:
Thanks very much Yves, that's perfect.

/Steve.

acotrel · Sep 21, 2016

when the brake locks and the front tyre skids, you end up with the big lock to lock tank slapper. If you don'tlet go of the bars and grab the tank, you get launched. - always wear a good helmet.

madass140 · Sep 22, 2016

I'd imagine the experience and consequences would be similar when a disc brake locks?

first evaliution on my TD Yam 260mm front drum

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