Britbike forum

Classic British Spares Klempf British PartsBaxter Cycle BritBike Sponsor SteadfastCyclesSRM Engineering Lucas Classic Motorcycle Industrial tec supply Hepolite Pistons The Bonneville ShopLowbrow Customs

Upgrade your membership to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
MikeG
MikeG
New Hampshier USA
Posts: 3,272
Joined: August 2001
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Top Posters(30 Days)
quinten 91
Rohan 65
Top Likes Received (30 Days)
quinten 13
Newest Members
makrph, vanGinneke, Gearhard, yornocT120R, robert wilby
11,840 Registered Users
Who's Online Now
2 members (Gary Caines, Magnetoman), 21 guests, and 70 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
KC...thanks for helping me out on the other thread, but rather than hijacking more, I thought I'd start a new thread.

Since building my 68 Lightning from boxes, I've always had problems lining up the front end. The wheel always wanted to go East, and the handlebars wanting to go West. Also, whenever putting the front wheel on, I noticed that the slots in the axles didn't line up with the slot for the screws in the lower trees. I can't remember if they are too wide or too narrow, I'll check this afternoon. Finally, I recall a good friend Adam M (and fellow bb.com member) mentioning that my front wheel was a 69 and not correct for my bike.

Now...putting one and one and one together, and what you mentioned in another posting...I believe now I know what my front end problem is. The axle is either 1/4" too short, or 1/4" too long.

Here is a summary of what was posted on the other topic.

Be aware that the TLS brake forks came in 2 widths. Most people mistakenly think the '68 was the 1st year for the wide fork, but it was '69 - '70. Why care? if you have '68 Trees, the axel is 1/4" shorter. Vs / Vs, The '69 & '70 RH lower leg has a bigger brake "key", to make up the distance to the backing plate.


KC...thanks for posting those details. So if I hear you correctly, the 68 trees and a 69 front wheel won't fit well...it will be out 1/4". I guess the easiest way to fix this would be to buy 69 trees. Is that right?


center to center on the trees 6 3/4 wide are wide
center to center 6 1/2" are narrow trees


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
BSA on eBay
Joined: Oct 2003
Posts: 11,294
Likes: 35
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Oct 2003
Posts: 11,294
Likes: 35
Quote
Originally posted by BSACafe:
So if I hear you correctly, the 68 trees and a 69 front wheel won't fit well...it will be out 1/4". I guess the easiest way to fix this would be to buy 69 trees. Is that right?
I have no way to confirm the axle length differences, but if that was the case, it would be much quicker, simpler and far more cost effective to simply swap the front axle.


Don't hide 'em, Ride 'em !!

RF Whatley
NE Georgia, USA
Joined: Sep 2002
Posts: 7,731
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2002
Posts: 7,731
Likes: 1
Quote
Originally posted by RF Whatley:
I have no way to confirm the axle length differences, but if that was the case, it would be much quicker, simpler and far more cost effective to simply swap the front axle.
IF you have an impact wrench and a 1-1/2" deep socket. Otherwise, it would probably be easier to fly to the moon laugh


A smattering:
'53 Gold Flash
'67 Royal Star
'71 Rickman Metisse
'40 Silver Star
'37 Rudge Special
sixtyseventy Lightboltrocket road racer...and many more.
Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
Just back from the garage, and the top trees on the 68 Thunderbolt, 68 Lightning and 69 Royal Star are all 6 3/4 wide center to center. The 68 Lightning and 69 Royal Star both have what seem to be 69 TLS front wheels. The 68 Thunderbolt has a different "hub cap" so I'm thinking it's correct for the year.

I'm not sure if I interpreted the original posting correctly. Is it the trees that are different from 68 to 69, or only the axle lenght of the front wheel?

Also...when fiddling, I noticed the large nut on the front wheel in question is loose. That can't be good....but on the other hand an impact wrench wouldn't be necessary to fit a different axle.


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
Joined: Aug 2001
Posts: 5,433
Likes: 54
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 5,433
Likes: 54
69/70 TLS wheels have top entry for the brake cable and the small knave plate (drum diameter) pressed on.

68 wheels have rear entry brake cable and large diameter knave plate retained by screws. RIII's have a different knave plate.

Early 69's most likely still had BSA forks. Firebird Scramblers all seem to have shuttle valve (Triumph style) forks as do late Lightnings. The seal holder will tell you which forks you are dealing with. BSA seal holders are straight, the taper is part of the fork leg. Triumph seal holders have the taper as part of the seal holder.

There is some differences in triple trees, but I don't remember the details. I have tried to stay with BSA forks, they work better :p .


Never underestimate the human ability to elevate stupid to a whole new level!.
Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
The 68 Lightning has BSA style forks and here's a picture of the wheel, that I believe to be a 69.

[Linked Image]

[Linked Image]

Here is a picture of the Thunderbolt....the brake set up is different...as you described with the rear entry.

[Linked Image]

My Royal Star has Triumph style forks with the correct top entry wheel.

[Linked Image]

So...that said, if I do in fact have a 69 wheel on a set of 68 forks, the axle would be the incorrect lenght. Is that right?


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
Joined: Sep 2002
Posts: 7,731
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2002
Posts: 7,731
Likes: 1
All of this sounded kinda fishy to me, so I decided to go out on a limb here and look at the parts book before sticking my neck out. The reason, Jer, why all your triple trees measure the same is because they ARE all the same. Same part number 1967-1970. I suspect the reason for the different axles (there are, in fact, three for the three years in question) is that the axle cap bolts on the Triumph forks are offset inward and the ones on the BSA are centered on the lower. This would mean that the '68 brake used a longer axle, though I can't confirm that 100%. What I can say with certainty is that they all use the same triple tree.


A smattering:
'53 Gold Flash
'67 Royal Star
'71 Rickman Metisse
'40 Silver Star
'37 Rudge Special
sixtyseventy Lightboltrocket road racer...and many more.
Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
Thanks Alex...that makes sense to what I'm seeing. It's been a while since I had the front wheel off the Lightning (69 wheel on 68 forks)...that would mean that I would have had to basically squish the forks together to make the wheel fit.

The good news is, I can take the wheel off the Thunderbolt to see if it lines up correctly on the Lightning....and if it does, then I'd be in the market for a 68 TLS, and I'd have a spare 69 TLS.


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
Joined: Sep 2002
Posts: 7,731
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2002
Posts: 7,731
Likes: 1
Really, as Richard said, all you need is the axle (37-1641). This part number cross-references to Triumph 500,650'65-68.


A smattering:
'53 Gold Flash
'67 Royal Star
'71 Rickman Metisse
'40 Silver Star
'37 Rudge Special
sixtyseventy Lightboltrocket road racer...and many more.
Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
Well that would make things much less expensive. I'll do a little more "garage research" and see if that'll do it.


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
Joined: Sep 2004
Posts: 268
E
Britbike forum member
Offline
Britbike forum member
E
Joined: Sep 2004
Posts: 268
The Triumph axle is the shorter one til 1969 when they made the trees wider like the BSA. Do you know what the two drilled indents on the leg and the cap mean like in your last photo?

Joined: Feb 2006
Posts: 307
BSACafe Offline OP
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2006
Posts: 307
Webster...are you referring to the two dents on the fork seal holder?


Jer

http://www.caferacer.ca

1968 BSA Lightning Cafe
1968 BSA Thunderbolt
1969 BSA Royal Star
1972 BSA Thunderbolt
Joined: Sep 2004
Posts: 268
E
Britbike forum member
Offline
Britbike forum member
E
Joined: Sep 2004
Posts: 268
No, the drilled indents on the leg and the cap. It is a trivia question!

[Linked Image]

Joined: Oct 2006
Posts: 338
Britbike forum member
Offline
Britbike forum member
Joined: Oct 2006
Posts: 338
Hello guy's if I am not mistaken on the 69-70, the dimples are used to denote type of lower leg IE 69-70 TLS.
Also the orrientation of the two caps, the caps are not designed to be ambidextriouse each lower has its own cap due to the corrisponding difference in the two ends of the axle.

Good Night and Good Luck Signed GreenMOnster


Good Night and Good Luck Signed GreenMonster
Joined: Oct 2007
Posts: 1,877
Likes: 39
I
Britbike forum member
Offline
Britbike forum member
I
Joined: Oct 2007
Posts: 1,877
Likes: 39
Alex:
Im glad you said so unequivocally that all the "trees" are the same...I was having a panic attack reading this thread as I have just managed to get a replacment set for My 70 after looking for years.

Wasnt the only difrence in the trees (not the droop top ones) that the earlier ones had 5/16" pinch bolts and latter were 3/8"


"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Joined: Sep 2002
Posts: 7,731
Likes: 1
Britbike forum member
Offline
Britbike forum member
Joined: Sep 2002
Posts: 7,731
Likes: 1
Ig, I think you are right about the pinch bolts. This has all been rattling around in my head and I finally put it all together. Here are some of the facts:

From the parts manuals:
*There three different top yokes installed on dry-frame A65's: The flat type with keylock installed on all '66-'70 bikes(68-5129), the flat type without keylock istalled only on '65 competition models (42-5011) and the drop-yoke (68-5049).
*There were four different bottom yokes: early type all models through '65 (42-5086) also installed on pre-unit models which I'm pretty sure use 5/16 bolts, the '66 only (65-5126), the '67 thru '69 which uses 3/8 pinch bolts (68-5174) and finally the '70 only which looks like a different casting but seems to be functionally identical to the earlier ones.

From trees I have:
All of these triple trees seem to be interchangeable as far as width and spindle length goes and all downtubes can be fitted. Obviously, the drop yoke will raise the front end by about 1", but aside from that can be used just the same. I don't know that I have one of those '66 lower trees, but I suspect the are just as interchangeable.

Hope that helps.


A smattering:
'53 Gold Flash
'67 Royal Star
'71 Rickman Metisse
'40 Silver Star
'37 Rudge Special
sixtyseventy Lightboltrocket road racer...and many more.
Joined: Oct 2007
Posts: 1,877
Likes: 39
I
Britbike forum member
Offline
Britbike forum member
I
Joined: Oct 2007
Posts: 1,877
Likes: 39
Alex:
that sounds right. I started a thread (maybee 6 mounths ago) "were all A65 pre oif stearing yokes (tripple trees) the same" or something like that.

Could be of intrest to some on this thread as it had plenty of good comments and someone down loaded detailed pics.

Cheers

BSACafe;
i found the old thread and bumped it up its quite relevant to your enquiry (see my comment above for title)


"There's the way it ought to be and there's the way it is" (Sgt Barnes)

Moderated by  Allan G, Jon W. Whitley 

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5