Half-width Brake

Singles, twins and fours.
User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3812
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Half-width Brake

Postby simon.holyfield » Wed Nov 18, 2015 1:41 pm

Folks,

I'be been having trouble with my front brake on and off since my SQ4 went back on the road late last year. This year it has had a lot of attention, and is a lot more effective than it was.

Yet it still 'groans' particularly when reversing but also moving forward, which is probably down to the cable being a little tight and the shoes still bedding it in.

However, I wanted to check:

Brake Plate.png


Do your brake plates bend outward (in the direction of the arrow) by a few mm when the brake is applied?
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
http://ariel-square-four.blogspot.com

Knud.Degnbol
Holder of a Waxed Cotton Anorak
Holder of a Waxed Cotton Anorak
Posts: 410
Joined: Fri Mar 25, 2011 12:03 pm
Location: Denmark
Contact:

Re: Half-width Brake

Postby Knud.Degnbol » Wed Nov 18, 2015 6:52 pm

How can you see that?

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3812
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Half-width Brake

Postby simon.holyfield » Wed Nov 18, 2015 7:36 pm

Quite easy in the garage. Never looked on the road!

Seriously, the whole brake plate moves a visible amount. I'm guessing that's not normal.
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
http://ariel-square-four.blogspot.com

roger.fellows
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 751
Joined: Tue Feb 21, 2012 8:32 pm
Location: S.Cumbria UK
Contact:

Re: Half-width Brake

Postby roger.fellows » Wed Nov 18, 2015 10:56 pm

Sounds as though something is not as square as it should be. Brake shoes able to move out of true? Hub slightly conical? Play that should not be available?

Roger

Simon.Gardiner
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 1049
Joined: Tue Aug 02, 2011 11:37 pm
Location: South West (Bristol-ish)
Contact:

Re: Half-width Brake

Postby Simon.Gardiner » Wed Nov 18, 2015 11:42 pm

I've had at least one half-width hub that used to move slightly when the brake was applied hard - not sure any movement was as much as a couple of mm, maybe just the one.
It's something slightly out of line - mine didn't rub and worked fine and as I couldn't spot anything obviously amiss I forgot about it....

SG
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)

nevhunter
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 4065
Joined: Tue May 10, 2011 9:42 am
Location: Victoria.. Australia.
Contact:

Re: Half-width Brake

Postby nevhunter » Thu Nov 19, 2015 12:13 am

The brake shoe linings may have worn lopsided and when force applied the brake plate springs a bit. They are not actually that strong, and normally don't have to resist much force along the line of the axle axis. Check shoes for uneven wear. The springs may be distorting the way they sit, or the plate may be too close to the wheel hub. Something wrong with the bearing installation..Nev

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3812
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Half-width Brake

Postby simon.holyfield » Thu Nov 19, 2015 3:01 pm

How thick is the lining on a typical stock brake shoe?
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
http://ariel-square-four.blogspot.com

User avatar
paul.jameson
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 2088
Joined: Wed Oct 12, 2011 3:04 pm
Location: Herefordshire
Contact:

Re: Half-width Brake

Postby paul.jameson » Thu Nov 19, 2015 8:41 pm

My KH front brake plate moves exactly as you describe when the brake is applied but by about 0.1mm, according to my rough measurements with the vernier calipers. That brake does work, but is not the best of the type I have had. Equally, it is not the worst. It is a sod to set up well and goes out of adjustment in under 1000 miles but it is not bad enough to have made it to the top of the list of priorities for attention.

I replaced the dust cover with a stainless one which I attached with 4BA allen bolts, as is my habit. I have since wondered whether the original spot welds added to the rigidity of what is one of the flimsiest brake plates Ariel made.
Paul Jameson
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.

User avatar
simon.holyfield
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 3812
Joined: Mon Oct 17, 2011 11:16 pm
Location: Norfolk
Contact:

Re: Half-width Brake

Postby simon.holyfield » Fri Nov 20, 2015 7:04 pm

Well, I didn't expect two cracked shoes...

IMAG3757.jpg
cheers

Simes

'51 Square Four,
'58 Huntmaster,
'42 W/NG,
'30 Model A
http://ariel-square-four.blogspot.com

User avatar
paul.jameson
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 2088
Joined: Wed Oct 12, 2011 3:04 pm
Location: Herefordshire
Contact:

Re: Half-width Brake

Postby paul.jameson » Fri Nov 20, 2015 9:00 pm

If you are short of shoes, PM me.
Paul Jameson
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.


Return to “Four stroke”

Who is online

Users browsing this forum: No registered users and 15 guests