Drum Brake Arcing

[Voltaire]

My 53 Thunderbird has a very poor 7" SLS front brake.
Its hard to look like Marlon Brando when you can't stop.....:innocent:
Research has led me to getting some self aligning shoes to replace the pivot type.
I was down at the local brake shop and there was a Speed Twin wheel identical waiting for 'Brake Arcing"
I think if it improved the brake its probably worth a punt.
Do they use a machine?

[pete376403]

its going to either be machining the drum back to round or re-curving the shoe surface to match the drum. did they have a lathe big enough to spin a 19" wheel?

[Voltaire]

They don't do the wheel just the shoes.
I'll enquire as its probably worth doing.

[Grumph]

Usually, it's machining the assembled shoes/backplate to around .010in undersize to the drum.
Chamfer the leading edges suitably - and cut water/dust removal grooves.

Done it many times. Always worth doing.

[Ginge09]

Check and tighten spokes first so the hub is under the correct tension. Then get the shoes done.

You can arc the shoes yourself with sandpaper glued to the drum but it’s a pain in the arse.

I did my ‘57 3TA myself when I was young and impoverished. Made a big difference but would send to the brake man next time.

Some truck brake shops can spin a bike wheel. Car brake shops usually can’t.

[husaberg]

My 53 Thunderbird has a very poor 7" SLS front brake.
Its hard to look like Marlon Brando when you can't stop.....:innocent:
Research has led me to getting some self aligning shoes to replace the pivot type.
I was down at the local brake shop and there was a Speed Twin wheel identical waiting for 'Brake Arcing"
I think if it improved the brake its probably worth a punt.
Do they use a machine?
Just extend the lever arm on the drum for more leverage.
or i seen one years ago where they converted a std drum to hydraulic actuation they used mini wheel cylinders if i recall correctly.
there are plenty of discrete levers with remote reservoirs on the market these days.
Failing that stick a 8 inch bsa drum in it only a rivot counter will notice.
Besides Marlon Brando never worried about brakes unless he was going past a burger bar.

[Voltaire]

Just extend the lever arm on the drum for more leverage.
or i seen one years ago where they converted a std drum to hydraulic actuation they used mini wheel cylinders if i recall correctly.
there are plenty of discrete levers with remote reservoirs on the market these days.
Failing that stick a 8 inch bsa drum in it only a rivot counter will notice.
Besides Marlon Brando never worried about brakes unless he was going past a burger bar.

rivet....:laugh:

OMG....8" brake drum...no way. I've got anoraknaphobia.

[husaberg]

rivet....:laugh:

OMG....8" brake drum...no way. I've got anoraknaphobia.
Meh, i am not sure i would care if anyone noticed my R6 monoblock and 320mm Brembo never came out as an official option on a RD350B (i just need a set of TZR250 1KT forks and yokes to make them a bolt on.)

[husaberg]

Meh, i am not sure i would care if anyone noticed my R6 monoblock and 320mm Brembo never came out as an official option on a RD350B (i just need a set of TZR250 1KT forks and yokes to make them a bolt on.)


anyway if you get bore count the Rivets on this
https://www.youtube.com/watch?v=VykzdDTOHmU

[F5 Dave]

Meh, i am not sure i would care if anyone noticed my R6 monoblock and 320mm Brembo never came out as an official option on a RD350B (i just need a set of TZR250 1KT forks and yokes to make them a bolt on.)
How would they ever notice it in your shed?

[husaberg]

How would they ever notice it in your shed?

I could post pics? of the shed on the net.
plus its a big shed room for plenty of people
Got any TZR250 1KT forks?

[Drew]

I could post pics? of the shed on the net.
plus its a big shed room for plenty of people
Got any TZR250 1KT forks?

I gather the picture I sent you of the forks I have were the wrong ones.

[husaberg]

I gather the picture I sent you of the forks I have were the wrong ones.
I cant remember getting a pic but you said they were a different diameter plus they were side mounted mudguard. The TZR250 1KT ones are 39mm and have top mounts and provision for 320mm discs.
I think the ones you described were early FZR ones with 280mm discs
the only ones that i know of that had the 320mm discs were the first TZR250 a couple of Japanese market SRX's the TDR250 and the OW01 and the FZR1000 (early) and i think a japanese model FZR750 and maybe a higher spec TRX850 that we never got. the FZR1000 forks and the rest are 41mm or maybe even bigger.
The early FZR250 2kr has the 320mm disc with 36mm forks as does a couple of other SRX's
plus i think the late FZX250 Zeal has the 38mm forks and the 320mm disc either of these would be okay also.

[Paul in NZ]

The real answer is yes - yes it is worth it...

I had a problem with the rear drum on the Trophy. New shoes just made it worse. The brake hardly worked, most of the adjustment was used up, the lever was at the wrong angle etc etc etc. Eventually I realised that the ‘new’ shoes had a metric sized material which was a smidgeon under the originally imperial one. Considering the drums 50 years old and has seen a fair few miles its little wonder it wasn’t flash.

So – took the whole thing in and the brake shop put oversized linings on the shoes and machined them to fit the drum. Now much much better.

Remember though back in the day these bikes used asbestos linings and the modern stuff isn’t quite so good… Originally I could lock up the front on those brakes (with provocation) after fitting proper linings…

ALSO check that you have the correct handlebar lever. There are 2 types with different distances from pivot to cable end to suit Norton or triumph. Get the wrong one and your brakes rubbish…

[F5 Dave]

Probably just had stronger hands back then Paul.

Or 'Provokers':shutup:

[Drew]

I cant remember getting a pic but you said they were a different diameter plus they were side mounted mudguard. The TZR250 1KT ones are 39mm and have top mounts and provision for 320mm discs.
I think the ones you described were early FZR ones with 280mm discs
the only ones that i know of that had the 320mm discs were the first TZR250 a couple of Japanese market SRX's the TDR250 and the OW01 and the FZR1000 (early) and i think a japanese model FZR750 and maybe a higher spec TRX850 that we never got. the FZR1000 forks and the rest are 41mm or maybe even bigger.
The early FZR250 2kr has the 320mm disc with 36mm forks as does a couple of other SRX's
plus i think the late FZX250 Zeal has the 38mm forks and the 320mm disc either of these would be okay also.
My FZR750 had 320mm disks. But 41mm forks.

[Paul in NZ]

Probably just had stronger hands back then Paul.

Or 'Provokers':shutup:

Bigger balls and slippery roads... I remember having a front wheel skid competition with my make coming down Dyers Pass road... Got to the bottom and the paint on the hub caught fire... Hmmm....

[Drew]

... Got to the bottom and the paint on the hub caught fire... Hmmm....

I did that in a rental truck once. Going through national park.

[Grumph]

Bigger balls and slippery roads... I remember having a front wheel skid competition with my make coming down Dyers Pass road... Got to the bottom and the paint on the hub caught fire... Hmmm....

Over a period of about a month, I went through every lining on the market in the front of the Mach 3. The test was - up Dyers Pass to the Sign of the Kiwi and back down to work in Colombo St - hard. If I had a front brake left after that it was suitable for racing.

Only one lining ever managed it - an American Raybestos industrial lining - probably solid asbestos...

[husaberg]

Over a period of about a month, I went through every lining on the market in the front of the Mach 3. The test was - up Dyers Pass to the Sign of the Kiwi and back down to work in Colombo St - hard. If I had a front brake left after that it was suitable for racing.

Only one lining ever managed it - an American Raybestos industrial lining - probably solid asbestos...
I remember you writing about that one as used on the maniporri cableway.


My FZR750 had 320mm disks. But 41mm forks.
Those arent the ones you have though are they? as they would have had top mounted mudguard.
ps they were on the list although only i thought they were only imports
One i did leave off the list was TZ250 only one model though i think, around 86 or so maybe. Also maybe likely a TZ125 or two as well I am not that familar with a lot of Yamaha stuff.

[Voltaire]

The real answer is yes - yes it is worth it...

I had a problem with the rear drum on the Trophy. New shoes just made it worse. The brake hardly worked, most of the adjustment was used up, the lever was at the wrong angle etc etc etc. Eventually I realised that the ‘new’ shoes had a metric sized material which was a smidgeon under the originally imperial one. Considering the drums 50 years old and has seen a fair few miles its little wonder it wasn’t flash.

So – took the whole thing in and the brake shop put oversized linings on the shoes and machined them to fit the drum. Now much much better.

Remember though back in the day these bikes used asbestos linings and the modern stuff isn’t quite so good… Originally I could lock up the front on those brakes (with provocation) after fitting proper linings…

ALSO check that you have the correct handlebar lever. There are 2 types with different distances from pivot to cable end to suit Norton or triumph. Get the wrong one and your brakes rubbish…

I missed this with all the background Jap Yap noise...


I eventually found some new Ferodo ones and took them down to the Brake Shop, he looked at them and dismissed them as "too thin", so after some searching pulled a set of rears off my shelf T110 as the pre unit rears are same as half width 7" ones.
Dropped them off and await the result.
I initially pulled the front apart as I thought the wheels bearings were knackered but turns out the DIY axle spacer is a few thou less than the 20mm wheel bearing. Surprised that Triumph wheel bearings are metric.

[F5 Dave]

They were probably supposed to be imperial,but with 3rd world production tolerances:innocent:

[Grumph]

They were probably supposed to be imperial,but with 3rd world production tolerances:innocent:

Nah - it's supply side economics. The continental bearing factories were cheaper than UK made. I found the same in a 1920's Douglas gearbox - metric bearings.

[husaberg]

I missed this with all the background Jap Yap noise...


I eventually found some new Ferodo ones and took them down to the Brake Shop, he looked at them and dismissed them as "too thin", so after some searching pulled a set of rears off my shelf T110 as the pre unit rears are same as half width 7" ones.
Dropped them off and await the result.
I initially pulled the front apart as I thought the wheels bearings were knackered but turns out the DIY axle spacer is a few thou less than the 20mm wheel bearing. Surprised that Triumph wheel bearings are metric.


They were probably supposed to be imperial,but with 3rd world production tolerances:innocent:


Nah - it's supply side economics. The continental bearing factories were cheaper than UK made. I found the same in a 1920's Douglas gearbox - metric bearings.
Interesting i had a countershaft seal fail when my son had a CRF50
I ordered the seal twice the second time I confirmed the fiche number myself neither seal fitted as they were clearly to small on the od
Afterwards on the third fail i went to the local spares shop it turns out the seal was imperial rather than the metric size the parts fiche said.
I wondered at the time if Honda had subcontracted the CRF engines out to the Chinese?

[Voltaire]

I recall many years ago when I was an apprentice and for 6 months I was working with a guy who was big into vintage cars.
He told me a story about early Ford bearings only being available from Ford as they were a special size.
Turns out they were metric.
Did a Google search today whilst on the train into Auckland that you helped pay for, and turns out a lot of bearings were metric even 100 years ago.
Nice relaxed trip from Penrose to Britomart, one less vehicle on the road and I can text, read, update to my hearts content and only $3.50.
Probably have a beer on way home so can drink and ride and text.

[husaberg]

I recall many years ago when I was an apprentice and for 6 months I was working with a guy who was big into vintage cars.
He told me a story about early Ford bearings only being available from Ford as they were a special size.
Turns out they were metric.
Did a Google search today whilst on the train into Auckland that you helped pay for, and turns out a lot of bearings were metric even 100 years ago.
Nice relaxed trip from Penrose to Britomart, one less vehicle on the road and I can text, read, update to my hearts content and only $3.50.
Probably have a beer on way home so can drink and ride and text.
From what I understand most of the bearings were made in Germany and Zee Germans are metric from long long ago.
The French have been using it since 1795.....
Germany 1872.
The poms were meant to be in the early 70's but progress was a little slow.

[malcy25]

I remember you writing about that one as used on the maniporri cableway.


Those arent the ones you have though are they? as they would have had top mounted mudguard.
ps they were on the list although only i thought they were only imports
One i did leave off the list was TZ250 only one model though i think, around 86 or so maybe. Also maybe likely a TZ125 or two as well I am not that familar with a lot of Yamaha stuff.

TZ250 84/85 were mounts for 300mm disc side mount mudguard, and 40mm. 86-88 were same but 320mm disc mount (mounts both sides, 86-87 had one 320mm disc, the 88 had twin282mm discs and adaptor plates to make the calipers fit). 89 stayed 40mm, went to new sliders for 282mm discs an cartridge dampening internals. ALL are incredibly short only about 695mm long. They are also bloody expensive to buy and only two other bikes I know have 40mm forks. Vmax and GPZ1000RX!!!

[husaberg]

TZ250 84/85 were mounts for 300mm disc side mount mudguard, and 40mm. 86-88 were same but 320mm disc mount (mounts both sides, 86-87 had one 320mm disc, the 88 had twin282mm discs and adaptor plates to make the calipers fit). 89 stayed 40mm, went to new sliders for 282mm discs an cartridge dampening internals. ALL are incredibly short only about 695mm long. They are also bloody expensive to buy and only two other bikes I know have 40mm forks. Vmax and GPZ1000RX!!!
40mm forks
40 Kawasaki KZ-1000E1/E2 "ST/Shaft" (79-80)
40 Kawasaki ZX-1000A1/A2 "Ninja" (86-87)
40 Yamaha VMX-12 N/NC/S/SC/U/UC/W/WC/A/AC/B/BC/D/DC (85-92)
40 Yamaha XVZ-12 DL/DKC2 "Venture Royale" (84)
40 Yamaha XVZ-12 DN "Venture Royale" (85)
40 Yamaha XVZ-13 T/TC/U/UC "Venture" (87-88),
40 Yamaha XVZ-13 DS/DSC/DT/DTC/DU/DUC/DW/DWC "Venture Royale" (86-89)
40 Yamaha XVZ-13 DA/DAC/DB/DBC/DD/DDCDE/DEC "Venture Royale" (90-93)

I missed the Seca 2 and the diversion that had 320mm discs as well

[malcy25]

40mm forks
40 Kawasaki KZ-1000E1/E2 "ST/Shaft" (79-80)
40 Kawasaki ZX-1000A1/A2 "Ninja" (86-87)
40 Yamaha VMX-12 N/NC/S/SC/U/UC/W/WC/A/AC/B/BC/D/DC (85-92)
40 Yamaha XVZ-12 DL/DKC2 "Venture Royale" (84)
40 Yamaha XVZ-12 DN "Venture Royale" (85)
40 Yamaha XVZ-13 T/TC/U/UC "Venture" (87-88),
40 Yamaha XVZ-13 DS/DSC/DT/DTC/DU/DUC/DW/DWC "Venture Royale" (86-89)
40 Yamaha XVZ-13 DA/DAC/DB/DBC/DD/DDCDE/DEC "Venture Royale" (90-93)

I missed the Seca 2 and the diversion that had 320mm discs as well

I have a pair of brand new Vmax chrome legs if any one wants them. New aftermarket ones. !

[husaberg]

I have a pair of brand new Vmax chrome legs if any one wants them. New aftermarket ones. !
I thought the max legs would be far thicker walled than the TZ ones?
Actually all of them would be i guess.

[Banditbandit]

My 53 Thunderbird has a very poor 7" SLS front brake.
Its hard to look like Marlon Brando when you can't stop.....:innocent:
Research has led me to getting some self aligning shoes to replace the pivot type.
I was down at the local brake shop and there was a Speed Twin wheel identical waiting for 'Brake Arcing"
I think if it improved the brake its probably worth a punt.
Do they use a machine?

If you want to keep it stock - there's plenty of suggestion beem made .. and you just have to learn to ride with shit brakes.

Back then we all tried to replace the front wheel with one of these .. Triumph Conical Hub ..

338817

338818

Twin leading shoe - instead of single, air cooled. From an early 70s Bonnie

Or this variant - from a '68

338819

[malcy25]

I thought the max legs would be far thicker walled than the TZ ones?
Actually all of them would be i guess.

Not massively, but I needed longer legs to get rake and trail back (I needed extra 30mm or so) and I was fitting cartridge conversion anyway so they existing damper rod spring etc was being ditched so didn't matter.

[Banditbandit]

My 53 Thunderbird has a very poor 7" SLS front brake.
Its hard to look like Marlon Brando when you can't stop.....:innocent:
Research has led me to getting some self aligning shoes to replace the pivot type.
I was down at the local brake shop and there was a Speed Twin wheel identical waiting for 'Brake Arcing"
I think if it improved the brake its probably worth a punt.
Do they use a machine?

One quick question ... do you use the rear brake much or only/mostly the front one?

When I rode older British bikes I used the rear and front together .. and possibly relied more on the rear than the front. The bike stopped OK - and I survived a few occasions when I needed to stop rapidly .. The rear is still a 7"SLS ... but it does increase the stopping power.

When I got modern Japanese bikes, it took me a long time to stop using the rear brake all the time.

It was braking that caught me out riding a Japper during the week and the classics on the weekend. Swapping feet for brakes and gears never caught me out - but riding an older British bike I would go flying into a corner - then suddenly remember the brakes didn't work ..

A few adrenaline moments banging down the gears for maximum engine braking, standing on the brakes, then letting them go to lean it over .. they never lean on brakes .. holding on praying .. had a couple of trips on the grass strips as a result .. but fortunately never dumped it ..

[Kickaha]

I gather the picture I sent you of the forks I have were the wrong ones.

What have you got? I am after something for my XJ550

[F5 Dave]

What have you got? I am after something for my XJ550

The last rites?

[Kickaha]

The last rites?

Don't be like that Dave, I have a bit of a soft spot for them, first road bike I ever rode back when they were fairly new, first bike I did 100mph + on as well

[Drew]

What have you got? I am after something for my XJ550

Forks only, 41mm FZR. Got no wheels, brakes, or triples.

[F5 Dave]

Don't be like that Dave, I have a bit of a soft spot for them, first road bike I ever rode back when they were fairly new, first bike I did 100mph + on as well
A mate had one with a Saga? pipe. It sounded ethereal given the beans.

[husaberg]

Forks only, 41mm FZR. Got no wheels, brakes, or triples.
Now i am confused i thought you said they were 38mm?
Whats the spacing on the Caliper bolts 100mm? because thats the ones i am after?

[Drew]

Now i am confused i thought you said they were 38mm?
Whats the spacing on the Caliper bolts 100mm? because thats the ones i am after?

Yep, I'm measuring the wrong forks. The FZR ones are gone already it seems.

[husaberg]

Yep, I'm measuring the wrong forks. The FZR ones are gone already it seems.
No worries