Author Topic: Why is my front brake still useless?  (Read 1661 times)

Online RDfella

  • Valued Contributor
  • ****
  • Posts: 313
  • Karma: 4
Re: Why is my front brake still useless?
« Reply #15 on: 27.01. 2019 16:08 »
'why is my front brake still useless'.   Because they are.
In my experience the FW 8" brake is no better than the SS 7" and nowhere near as good as the SS 8"
I fitted a Triumph TLS backplate to my A10 to try to improve matters, and it's still useless. Modern brake lining materials don't help either - can't beat the old woven asbestos ones. On one of my bikes I converted the SS 8" to TLS and it'll bottom the forks. Wish I could say the same on my A10 with the Triumph TLS.
'49 B31, '49 M21, '53 DOT, '58 Flash, '00 Firestorm, Weslake sprint bike.

Offline mikeb

  • Valued Contributor
  • ****
  • Posts: 429
  • Karma: 7
Re: Why is my front brake still useless?
« Reply #16 on: 27.01. 2019 22:11 »
thanks for all your comments guys - super helpful.
RD - some guys race with SLS shoes and claim its all in the setup, so while they'll never match the brembos on my modern they can surely get better than what i have.
Julian - your eagle eye was right - i've got the steel pads at the wrong end... arrg! so i'll fix that. i'm endlessly impressed by your cache of service sheets
GB/swarfy - the drum lever is set about right and the handle bar lever is the narrower 7/8 radius type for leverage. the cable is fairy new and without cracks/breaks etc tho has one slight kink in it.

Kiwi/others - I get the point about the leading shoe needing to make first contact. the bike has the lugs on the brake plate that fits to the forks peg so reversing the drum lever is not trivial (i did that mod on my b33). so whats the wisdom on these two methods: 
1. building up the cam face on the leading shoe side - how to do that?
2. getting out the file or sanding block to shape down the first third of the trailing shoe?

Also - re 'fitting' the linings:
3. is there merit in fixing sandpaper to the drum and ?going for a slow ride? to bed them in? or just let it wear in eventually?

AND
4. there are some suggestion around to leave the pivot slightly lose to allow some self-adjustment, as well as with the floating / steel plates. is this a good idea?

thanks again
New Zealand
'61 Super Rocket  - '47 B33 -  '18 Triumph Street Triple RS

Online KiwiGF

  • Wise & Enlightened
  • *
  • Posts: 1302
  • Karma: 12
Re: Why is my front brake still useless?
« Reply #17 on: 27.01. 2019 22:57 »
thanks for all your comments guys - super helpful.
RD - some guys race with SLS shoes and claim its all in the setup, so while they'll never match the brembos on my modern they can surely get better than what i have.
Julian - your eagle eye was right - i've got the steel pads at the wrong end... arrg! so i'll fix that. i'm endlessly impressed by your cache of service sheets
GB/swarfy - the drum lever is set about right and the handle bar lever is the narrower 7/8 radius type for leverage. the cable is fairy new and without cracks/breaks etc tho has one slight kink in it.

Kiwi/others - I get the point about the leading shoe needing to make first contact. the bike has the lugs on the brake plate that fits to the forks peg so reversing the drum lever is not trivial (i did that mod on my b33). so whats the wisdom on these two methods: 
1. building up the cam face on the leading shoe side - how to do that?
2. getting out the file or sanding block to shape down the first third of the trailing shoe?

Also - re 'fitting' the linings:
3. is there merit in fixing sandpaper to the drum and ?going for a slow ride? to bed them in? or just let it wear in eventually?

AND
4. there are some suggestion around to leave the pivot slightly lose to allow some self-adjustment, as well as with the floating / steel plates. is this a good idea?

thanks again

On point 4 this I think has the effect of evening out the force on each shoe, which is not what you want in my experience.

On point 1 the shoes I have are alloy with a steel cap for the cam face (are they all like that?), I used a mig to build it up then filed it flat. The difference was amazing, but of course as the leading shoe wears i guess it returns back to rubbish. Reversing the drum lever is the permanent solution to that, reducing the trailing shoe contact area may also help keep the brake good, but I’ve not tried that.
New Zealand

Last had an A10 in 1976, in 2011 it was time for my 2nd one.

1956 Flash Frame EA7-168x Eng. CA10 913x, left BSA together for Liverpool, 5th Dec 1955.

B31 “hot rod” (yeah right)

Armstrong Siddeley Whitley for rainy days (with wife).

GL1800 Goldwing not sure why yet

Offline worntorn

  • Valued Contributor
  • ****
  • Posts: 369
  • Karma: 2
Re: Why is my front brake still useless?
« Reply #18 on: 28.01. 2019 02:19 »
thanks for all your comments guys - super helpful.
RD - some guys race with SLS shoes and claim its all in the setup, so while they'll never match the brembos on my modern they can surely get better than what i have.
Julian - your eagle eye was right - i've got the steel pads at the wrong end... arrg! so i'll fix that. i'm endlessly impressed by your cache of service sheets
GB/swarfy - the drum lever is set about right and the handle bar lever is the narrower 7/8 radius type for leverage. the cable is fairy new and without cracks/breaks etc tho has one slight kink in it.

Kiwi/others - I get the point about the leading shoe needing to make first contact. the bike has the lugs on the brake plate that fits to the forks peg so reversing the drum lever is not trivial (i did that mod on my b33). so whats the wisdom on these two methods: 
1. building up the cam face on the leading shoe side - how to do that?
2. getting out the file or sanding block to shape down the first third of the trailing shoe?

Also - re 'fitting' the linings:
3. is there merit in fixing sandpaper to the drum and ?going for a slow ride? to bed them in? or just let it wear in eventually?

AND
4. there are some suggestion around to leave the pivot slightly lose to allow some self-adjustment, as well as with the floating / steel plates. is this a good idea?

thanks again

I would not put sandpaper on the drum then go for a slow ride. This would likely wear out the shoes completely in one short ride.
Even when manually turning the brake plate with sandpaper stuck to the drum you need to be careful to only take off what is needed, nothing more. The sandpaper or emery does work well for this, however.
I start by sticking it on other way around, that is, stuck to the shoes. Use a clamp to move the brake arm ( wheel off ) to a position where the emery just barely contacts the drum. If , as you rotate the brake plate against drum, you encounter uneven friction ( pulsation) then keep rotating the brake plate against the stationary wheel while gradually and incrementally using the clamp on the brake arm to open the shoes up.
When you have an even drag all the way around, the drum is round. It might take an hour or so and you might have to change the paper a few times.
If you find you have even drag right at the start, then the drum is already round and you can't improve it, move on to arcing the shoes to the drum.
Stick some new emery on other way around, onto the drum this time ( all the way around). Now rotate the brake plate while engaging the shoes as before. This won't take much, 120 grit will remove the high spots on the shoes with very little effort.

After this treatment my 2ls will lock the wheel on pavement and is completely smooth in operation, no pulsation.
Your 1 ls might not be quite that good, but it should be decent.

Glen


Offline mikeb

  • Valued Contributor
  • ****
  • Posts: 429
  • Karma: 7
Re: Why is my front brake still useless?
« Reply #19 on: 28.01. 2019 08:22 »
I located the steel pads at the pivot ends and tightened the pivot once centring the shoes (usual routine). then reversed the brake arm – actually not too hard as I previously had made a longer arm so just made a small extension bracket that then offsets the cable by 1/8" closer to the hub. There’s a similar example on a brtibike thread for an a65. See pics below – the cable just clears the forks by a 1/16" or so. Other than looking ugly can you see any problems arising? So now the leading shoe engages first.

I also took Glens tips on sanding the drum (a little tentatively) and linings (maybe a little too much) using strips cut from stick-on sanding discs.

And guess what? From a quick test ride it’s still rubbish.  *sad2* Well, better than it was but not good. No chance of skidding the front wheel or stoppies.

Only one thing more to try of loosening the pivot to see it some movement there helps.

Any other thoughts?
thanks
New Zealand
'61 Super Rocket  - '47 B33 -  '18 Triumph Street Triple RS

Offline Swarfcut

  • Valued Contributor
  • ****
  • Posts: 415
  • Karma: 8
Re: Why is my front brake still useless?
« Reply #20 on: 28.01. 2019 09:20 »
    OK, it looks a bit strange, but an arrangement like that scares me!!

  I would return it to standard, and make a thin sheet steel packing pad to go between the cam and the leading shoe. This means the trailing shoe will not hit the drum before the leading shoe, so you can get an idea of how effective the brake is with one shoe doing the work. This is easier than building up cams on one side. Treat this as an experiment, ride carefully.  If this appears successful, thin down your pad bit by bit to bring more of the trailing shoe into play.

  As set up the leading shoe is the one on the underside of the drum, towards the rear of the machine. Make sure the shoes are fitted with the linings in the correct orientation, as outlined above.

 Swarfy.

Online RayC10

  • Moving Up
  • **
  • Posts: 51
  • Karma: 0
Re: Why is my front brake still useless?
« Reply #21 on: 28.01. 2019 14:31 »
Thanks for the heads up about the steel shoe against the pivot, been doing it wrong for 45 years...never ever goin' to stop learning! Cheers.

Online JulianS

  • 1962 A10
  • Resident Legend
  • *****
  • Posts: 823
  • Karma: 16
Re: Why is my front brake still useless?
« Reply #22 on: 28.01. 2019 15:02 »
The steel pad on the pivot is for floating shoes only.

The 190mm and half width hubs have a flat steel pad at the cam end.

Online RichardL

  • Outside Chicago, IL
  • Wise & Enlightened
  • *
  • Posts: 4819
  • Karma: 45
Re: Why is my front brake still useless?
« Reply #23 on: 28.01. 2019 15:22 »
If this appears successful, thin down your pad bit by bit to bring more of the trailing shoe into play.

Wow, Swarfy, that's a lot of assembly/disassembly you've described  in this iterative process. I suppose ultimate safety is the justification, but I'm guessing most of us would say, "that'll have to be good enough" after a couple of rounds of testing. Maybe I'm just old, lazy and busy.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Offline RogerSB

  • 1960 Golden Flash, Plymouth, Devon, England
  • Valued Contributor
  • ****
  • Posts: 498
  • Karma: 5
Re: Why is my front brake still useless?
« Reply #24 on: 28.01. 2019 17:28 »
The steel pad on the pivot is for floating shoes only.

Here's a diagram I captured from somewhere at sometime showing floating shoes correctly fitted and a good explanation of how they work.

And also a photo of my non floating front brake on my 1960 Golden Flash (no steel pads).

(Edit): I can say I don't have a problem with my GF's brakes so I can't complain about their lack of efficiency. Seems it could all be down to lining material.

1960 Golden Flash

Offline Swarfcut

  • Valued Contributor
  • ****
  • Posts: 415
  • Karma: 8
Re: Why is my front brake still useless?
« Reply #25 on: 28.01. 2019 18:24 »
 Apologies to those who may have misunderstood the finer detail of my earlier post.

  By returning to standard, I meant assembling the shoes with the concave pads on the pivot end, as outlined by Julian. Then fabricating an additional thin flat steel  pad to go between the cam and the leading shoe, to move the leading shoe nearer the drum so that it contacts the drum first. Then experimenting with the thickness of this pad to try to improve the performance of the trailing shoe.

  Maybe just easier to source a late A65 TLS  front wheel.

  Swarfy.

 Additional....RogerSB has an ideal front brake testing facility on the southern approach road to the charming village of Widecombe in the Moor, South Devon...... the incline featured in a popular song, back in the day.

Offline RogerSB

  • 1960 Golden Flash, Plymouth, Devon, England
  • Valued Contributor
  • ****
  • Posts: 498
  • Karma: 5
Re: Why is my front brake still useless?
« Reply #26 on: 28.01. 2019 22:45 »
RogerSB has an ideal front brake testing facility on the southern approach road to the charming village of Widecombe in the Moor, South Devon...... the incline featured in a popular song, back in the day.

Yes, we have lots of narrow, steep windy roads here in the South West of England. I live on the top of one, which gives me a good view of Dartmoor, just 10 minute ride away, that's where I usually head for when out for a ride.  There are some places to avoid but on the whole its a great place for motorcycling.

1960 Golden Flash

Offline worntorn

  • Valued Contributor
  • ****
  • Posts: 369
  • Karma: 2
Re: Why is my front brake still useless?
« Reply #27 on: 28.01. 2019 23:22 »
 I recall stopping at the top of a steep descent on a B road in the Dales. There was a sign at the top the read " Steep hill, 25% grade"
I thought that had to be a misprint but soon realized it was correct. We were two-up with luggage.
To make matters worse, there was a T intersection at the bottom with the stop sign on the B road, the other road a busy through road. If unable to stop at the sign, the next stop was the side of a stone house directly across from the stop sign!

Glen

Offline Swarfcut

  • Valued Contributor
  • ****
  • Posts: 415
  • Karma: 8
Re: Why is my front brake still useless?
« Reply #28 on: 29.01. 2019 09:21 »
Time for a laugh and learn moment.....

 In a time when the old bike movement was starting to stir, there was a well respected (according to the Mags ) restorer in Leominster, in the fine county of Herefordshire, UK.

 So that's where I sent my front wheel hub with its  early single sided brake drum.  Weeks passed and I eventually collected a nicely restored wheel, fitted it to the bike and all was good.

 Some weeks later, on a Club Run to Shropshire, we descended the long steep hill known as the Long Myndd. Got to the bottom, brake working fine, drum smoking as the powder coated or stove enamelled finish (as we thought) bubbled and popped. From the smell we reckoned it had been painted with oil based house exterior paint.  The invoice said "Restore Front Wheel" so I suppose that's what I got. Alas, assuming the finish would be heat proof.


   Then we realised the spoke pattern was wrong. So, not feeling that the Man in Leominster would be too inclined to put things right, we sent the wheel to a builder in Coleshill,  Birmingham,  who refinished the hub with heat proof paint and respoked the wheel, all in a matter of days.

  I cannot believe the original restorer actually did the work, but that it was farmed out elsewhere......so it looks as if we both got conned.

  So, always specify exactly what you want doing as regards materials and their suitability for intended use.  As a choice of finish, powder coating is a relatively thin, quick and durable industrial finish, works very well on new clean smooth metal. But it will show up the slightest imperfection.  As it is cured by heat, is it capable of withstanding the heat from a hard used brake?

 Swarfy.

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Posts: 4963
  • Karma: 27
Re: Why is my front brake still useless?
« Reply #29 on: 29.01. 2019 09:47 »
... As it is cured by heat, is it capable of withstanding the heat from a hard used brake?...
I've never been aware of the powder coating on my brake drums suffering from braking heat.

I ask again, are there different powder coating finishes available?