Britbike forum

Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesThe Bonneville ShopLowbrow CustomsGirling Classic MotorcycleLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade Your membership! Premium Membership Gold Membership Vendor Membership

New Sponsor post
5% Off Everything for Brit Bike Users
by The Bonneville Shop - 12/30/21 4:54 pm
New FAQ post
Manuals on DVD - Buy 4 for 3
All 4 DVD Manual
Member Spotlight
Gary Caines
Gary Caines
Hiawassee, Georgia USA
Posts: 109
Joined: October 2014
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Top Posters(30 Days)
Lannis 63
Top Likes Received (30 Days)
Lannis 25
NickL 24
Newest Members
Lil Dave, OWhatAThrill, Mountain Rider, ToddK, JohnS_au
11,995 Registered Users
Who's Online Now
4 members (quinten, Tom A65LR, dandruff, JER.Hill), 23 guests, and 23 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums35
Topics75,326
Posts758,926
Members11,995
Most Online14,755
May 5th, 2019
Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
#847146 04/25/21 11:42 pm
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
There's more info in the modified form....Basics, 61 frame , 60 Super Road Rocket engine , rebuilt but stock...2000 ish Honda CBR 43mm fork assembly, A65 fuel tank reworked to fit A65 front wheel, Triumph rear wheel , this that and the other things......
7 months ago I started with a frame, some engine parts and some junk...Now I got this

CBF3B8CF-5A3A-484E-939B-0EBB1BB430B2.jpeg 3D2BAB8F-828C-442F-A445-BCBAFC7D2CE1.jpeg 0742982B-701B-46D3-BC7D-330A194EE3E8.jpeg 212538D1-ABA9-4921-BA33-F46497CE2558.jpeg 980C8CCA-8C19-465D-A43B-A0F478417A81.jpeg

79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
British motorcycles on eBay
Joined: Jan 2006
Posts: 8,206
Likes: 212
Britbike forum member
Offline
Britbike forum member
Joined: Jan 2006
Posts: 8,206
Likes: 212
Looking sharp!

(the half-width front brake is going to be the only disappointing feature)

Last edited by GrandPaul; 04/26/21 1:32 pm.

GrandPaul (does not use emoticons)
Author of the book "Old Bikes"
Too many bikes to list, mostly Triumph & Norton, a BSA, & some Japanese
"The Iron in your blood should be Vintage"
Joined: Feb 2008
Posts: 5,867
Likes: 352
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,867
Likes: 352
Disagree---the half width front brake is much better than the later full width Ariel or BSA front brakes.
"Back in the day" sidecar racers used to take two of them , machine the hubs and weld them back to back to have a double brake.
They were great on a road race outfit.
I had the half width brake on a 1954 A7 Shooting Star.
Coming down to Cregg-Ny-Baa on the Mountain Course on the Isle of Man in 1967 with friends (we had been energetically riding the course) a friend came alongside me and motioned to stop for a drink.
We pulled into the Cregg-Ny-Baa Hotel at the bottom of the hill, parked up and went inside for a pint (or two----).
We had only been inside for a couple of minutes when a guy came rushing in and said "Whose is the BSA A7 in the car park?-- it is on fire".
I rushed outside to find smoke from the grease in the front hub rising into the air!

Tony--set up the brake properly as I know you will do and I dont think that you will be disappointed in it.
Just my two cents worth of course.

2 members like this: NickL, GrandPaul
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
I riveted NOS Ferodo linings front and rear...We will see how it stops but for sure it won't be the Ducati 320 mm disc and Brembo caliper on my T140D, lol...I like the vintage look of the half width brake drum in contrast to the beefy 43mm fork tubes....I also like an exposed primary drive, but the stock primary enclosure will be used....A series of compromises...pick and choose...


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Dec 2004
Posts: 11,505
Likes: 211
Britbike forum member
Offline
Britbike forum member
Joined: Dec 2004
Posts: 11,505
Likes: 211
If the Ferodo disappoints, or wear out and cannot be replaced, then MZ Gold woven lining is an excellent asbestos free replacement. Made my 8" single sided as good as my 7" TLS but I also made the shoes fully floating.

Joined: Sep 2004
Posts: 1,804
Likes: 174
Britbike forum member
Online Content
Britbike forum member
Joined: Sep 2004
Posts: 1,804
Likes: 174
I had my A65 half-width hub brake 'breathed upon' by a local expert a while ago. He skimmed the drum with the rim on and then fitted modern road/race lining riveted to the shoes, the shoes were then arced to fit the drum exactly.

At the same time, I built a new brake cable using a Venhill kit which uses a heavy-duty cable and Teflon lined cable. Additionally, I used a new brake lever with a 7/8th ratio.

The result is superb and I now have a great front brake which is nearly as good as a single disc brake.

The engineer mentioned that the brake performance would tail off since it wasn't a fully floating arrangement, but that this could be fixed by making a slot in the brake plate together with a modified pivot so that the pivot could move thus making it a floating shoe.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
I haven't ridden a Brit Bike with a single leading shoe front brake in at least 35 years...My expectations are just adequate.....I could have put a disc on the front but thought the drum brake will add some bad road thrills...
I had a disc front brake Trident many years ago. A good friend was a huge man, like a bear..He was also the best street biker I came in contact with. So he takes my Trident out for a ride, I can hear him shifting like a pro drag racer...After a bit he pulls back , the front brake is actually smoking hot...He says " Man, this thing flies..and the front brake needs new pads...."


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Dec 2004
Posts: 11,505
Likes: 211
Britbike forum member
Offline
Britbike forum member
Joined: Dec 2004
Posts: 11,505
Likes: 211
I widened out the 1/2 circle end on the shoe using a milling cutter the same diameter as the pivot, just needs 1/4" so the shoe can float itself.

1 member likes this: NickL
Joined: Jan 2014
Posts: 1,847
Likes: 245
N
Britbike forum member
Offline
Britbike forum member
N
Joined: Jan 2014
Posts: 1,847
Likes: 245
Or file the end of the shoes flat and fit a couple of steel feet.

Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
Got more work done. As always I cut the friction discs on the lathe for more effective average mean radius and more grip.

F7F281DC-2EDF-4C46-99EA-B6D49301D861.jpeg 08F24294-B0B7-4BA5-9187-0B7E8039EBA6.jpeg

79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
2 members like this: GrandPaul, johnu
Joined: Sep 2008
Posts: 868
Likes: 12
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2008
Posts: 868
Likes: 12
Looking good Tony!


1955 BSA Bantam D1 Plunger
1956 BSA A10RR Street and LSR Bike
1961 BSA C15S
1966 BSA spitfire
1969 Triumph T100C
1970 Triumph TR6R
1970 Triumph TR6C
1972 BSA Lightning LSR Bike
1974 Triumph T150V
Joined: Jan 2006
Posts: 8,206
Likes: 212
Britbike forum member
Offline
Britbike forum member
Joined: Jan 2006
Posts: 8,206
Likes: 212
Originally Posted by Hillbilly bike
I cut the friction discs on the lathe for more effective average mean radius and more grip.
So, you reduce the total area of friction material by removing some from the inside edge around the centre?


GrandPaul (does not use emoticons)
Author of the book "Old Bikes"
Too many bikes to list, mostly Triumph & Norton, a BSA, & some Japanese
"The Iron in your blood should be Vintage"
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
Yes, it's explained here... Mean effective radius

It does make a difference....and it can make a 6 plate plate grip quite well...The pre unit has only 5 discs..


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
More, Mikuni TM 32mm flatslide, my go to carburetion. A mismatched Siamese exhaust required a bit of fabrication and my usual mixture of old and new parts
I began with the parts on the lift....I had to get another better set of crankcases...lot of 650 A 10 parts on Ebay for reasonable money

50219212176_322dab255e_c.jpg 9BED039C-45FF-465C-BBB6-959447993E8F.jpeg B06A4C73-E7D8-4D81-AE5A-BB6ECA670DC5.jpeg

79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
It's off the work lift...a few minor details, probably start it tomorrow

769959E9-9C29-4CF8-9B8F-2E242281C74C.jpeg

79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
2 members like this: chainreaction, D.Bachtel
Joined: Aug 2001
Posts: 497
Likes: 2
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Aug 2001
Posts: 497
Likes: 2
Looking good. Going to be fun to ride !


1968 BSA Firebird
1200 Sportster
XS 1100
1972 Rickman 125
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
Thanks..... The damn new old stock tank badges cost a small fortune... Normally I don't care about cosmetic details but they look spiffy...


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Nov 2011
Posts: 7,691
Likes: 639
Britbike forum member
Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,691
Likes: 639
Originally Posted by Hillbilly bike
Yes, it's explained here....
The "analysis" on that web site is nuts. The analysis says that if you cut away even more of the material until the inner radius and outer radius are nearly the same, so the mean radius would be even larger, the plate would transmit even more torque. Except it won't, because it will slip.

If, instead, you leave the inner material in place, the outer material is still there to transmit whatever torque it is capable of transmitting. Having the inner material present in no way reduces what the outer material is capable of transmitting, and only adds to it.

What the "analysis" leaves out is the clamping pressure, which is the force/area. For the same force applied by the clutch springs (which directly translates into the force required to operate the clutch lever), the pressure that clamps the plates will be greater if the area is made smaller. So, reducing the area of friction material will help in this regard, but only if the remaining material is sufficient to withstand the torque applied to it.

Although the "analysis" on that site points to a way of improving performance, it does so with an analysis that leaves out an essential consideration that easily could make things worse.

Joined: Sep 2004
Posts: 1,804
Likes: 174
Britbike forum member
Online Content
Britbike forum member
Joined: Sep 2004
Posts: 1,804
Likes: 174
The issue of improved clutch performance by removing material from the inner friction area has come up on numerous occasions, often on the B50 unit singles website where clutch slippage is a notable problem.

In my view, the clutches on most British Bikes are adequate and don't usually slip unless the wrong oil is used and/or the adjustment is wrong. Most often its the wrong oil where a 'modern' oil with friction modifiers has been used, contaminating the friction plates and causing slippage.

I have no idea on whether removing material from the inner friction area would result in a better clutch, and I've yet to see any evidence that it does, so my advice is to keep it standard and use Surflex clutch plates which use a modern compound and have a higher friction coefficient.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
I have practical experience on several Triumphs that is in contrast to both comments above..I'm not the sharpest knife here, I do dumb stuff sometimes and sometimes ring the bell for the Kewpie doll ....I will not second guess Raybestos who designs and makes clutch plates for a variety of applications.
Regardless of spring pressure, all modern bikes have plates with a narrow friction area..
Many here can't get a non slipping clutch with 40 hp at the rear wheel. My land speed race 650 Triumph has 57 hp at the rear wheel at 7000 rpm and 46 ft lbs of torque at 5100 rpm...6 Taiwan friction plates that I cut away like on the BSA... Zero slip.
We shall see how the A10 functions in a few days.....


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Sep 2004
Posts: 1,804
Likes: 174
Britbike forum member
Online Content
Britbike forum member
Joined: Sep 2004
Posts: 1,804
Likes: 174
Hope it works out OK for you and the result is a good non slipping clutch.

One thing I seem to remember is that adding extra clutch plates is generally recommended where ever practical, presumably because the extra plates add more surface area, thereby distributing the spring pressure over a larger area.

There is probably a formula for this equasion which I don't have available or even know how to calculate if I did, but in general it seems to make sense that a larger clutch surface area would help distribute the forces over a bigger area thereby preventing slip.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Joined: Oct 2012
Posts: 6,156
Likes: 213
knuckle head
OP Offline
knuckle head
Joined: Oct 2012
Posts: 6,156
Likes: 213
Gunner, you mentioned Surflex. I have no idea what material the plates are made from other than they are orange. The primary has Motul gear box oil that's a 10/30 designed for wet clutches with or without gearboxes ..


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
Joined: Sep 2004
Posts: 1,804
Likes: 174
Britbike forum member
Online Content
Britbike forum member
Joined: Sep 2004
Posts: 1,804
Likes: 174
The Surflex plates I have used previously have always used a black rubberized compound so I can't comment on the orange plates you have fitted. Hopefully they will be similar and work well and the Motul oil sounds like a good choice as its designed for wet clutches.

Great progress on the bike so far, keep us posted on how it works out smile


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Joined: Feb 2008
Posts: 5,867
Likes: 352
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,867
Likes: 352
MMan,
The clever bit is to get the best balance of increased mean radius---giving increased torque transmission capability with the force from the clutch springs giving increased pressure on the plates---all subject to overall required torque transmissibility and lining life.
IMHO Triumph and BSA did not get the balance correct and the later 7 plate clutches with increased inner lining radius are a lot better than the original designs.
Just my two cents worth of course.

Joined: Feb 2008
Posts: 5,867
Likes: 352
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,867
Likes: 352
Tony--looking good--- and good looking.
Will be a breeze on the country roads.

Page 1 of 2 1 2

Moderated by  Richrd 

Link Copied to Clipboard
British Cycle SupplyMorries PlaceKlempf British PartsBSA Unit SinglesPodtronicVintage MagazineBritBike SponsorBritish Tools & FastenersBritBike Sponsor






© 1996-2022 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5