Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board The A70 Lightning story (rebuild)

I don't usually post progress stories on my rebuilds because I am so slow. When this one arrives I will assess the condition and decide what to do. If the bike cleans up pretty well and looks half decent I will assemble the engine and get the bike on the street for a while. Then maybe do a complete restoration. I am moving the photos over from the garage sale to show the starting point for the build

and a couple more

You got a really good deal there with that bike, I was one of the interested parties and was prepared to offer a lot more for it.

Good luck with the rebuild and probably restoration. Being one of the last A70s ( i think) that left the factory and being so few in the first place of a rare model it would be a real shame not to restore it to its former glory.

Best regards

A total restoration is the goal. I find if I can ride it around for a while it helps me concentrate on completing the restoration.

Bookmarking this thread, can’t wait to see this one come together in whichever form you choose

I agree. I've never come so close to doing something stupid and adding to a collection of planned projects that I would probably never complete in my lifetime as I did in considering buying this bike.

Glad it's going to come back to life. We're not in a hurry, but if the fact that people are watching helps motivate you into working on it, then that's a healthy thing!

Lannis

bsalloyd - Is that the A70's crank?

Mine looks so much different than yours. The flywheel has been seriously lightened. Supposedly factory done.

All a70 and last of the A65 were like that. The width of the scalloping differs between the 650 and 750.

IDK - Something looks different Allan. Mystery...

The width on the late A65s between the scalloping is 40mm. When I converted an A10 crank for my A70, I estimated that the width was 35mm from the attached photo I saw on one of the forums.
A65 on left, A70 on the right.
Good luck with the rebuild, I'll watch your progress with interest.

Nice find! I look forward to seeing it once it's together.
I always had one question about the A70. The pictures I've seen show it as having a triple oil cooler. I never measured over 170 degrees oil temperature on my A65 with a tiny chopper oil cooler. Do these bike really run that hot or was it just that they were only designed for flat track racing?

The OIF was a little low on oil capacity and not the best for oil cooling at constant 6-7500rpm
I don't know how long the flat track races were but when those lumps were/are 'pepped up' they
could produce 70bhp. so a cooler wasn't a bad idea.

Sorry I can not answer many questions about this bike. It is the first unit construction type I have overhauled. I should know more after I complete it.

According to what I have found it was the tenth bike to come off the line in June 1971. I will still send the details to the BSA owner club for dating.

Races were usually 25 laps.Not sure is that applied to all TT, short track, half mile and mile.
Dave Aldana's bike does not have a cooler but Jim Rice's does, from 1971

Trackmaster frames had a smaller backbone than OIF's but the fill was at the headstock.
This is a Tri-C Trackmaster frame which has a sheet metal extension to the top backbone for more oil. Not sure if the original Trackmaster had this.

The bike arrived at my home 4/18/23 at 5:00 AM. I will post pics once I get everthing unboxed

Two photos of the bike after the sun came up

I thought you said you were slow with your rebuilds.

I bet it's an inventory build to see what's missing. But it looks mostly all there.

I like my story better

There don't seem to be many obvious parts missing, so I'm looking forward to the blow by blow rebuild, with lots of pictures.

Could just be bad lighting on those first pics.

It looks like I could just drive away on it, but that is nut the case. So, tear down is coming.

Agreed, No chain, kicker, shifter or spindle, clutch cable and probably no guts in the engine.

It is the small details that cause the issues

Fortunately, most parts are the same as the A65.

It's the unique parts which will cause the most delays if any are missing or worn.

Do you have the A70L pages for the 1972 parts book? I can scan them if you need them.

The seller provided all of the tech information. He sent me the title, parts manual, and over haul manual.

I am beginning to sort out the Fasteners for the rebuild. Are the Fasteners cad plated, zinc plated, or something else?

Cd which you can not get now days unless you know some one who does military / avaition Fasteners and is willing to risk big fines for you
Sand blasted stainess is the closese appearance wise but it will rust so requires a lot of maintanance .

If it is cad, I have a place here in Texas I can use. They do the aviation work in the Dallas area.

Sssshush
You know where you can get a very similar appearing finish to the original done.
We would not like to make people think we are doing anything illegal .

It is just like the original, but, I do not know how they do it. Honest officer

I have not been able to find a law prohibiting cadmium plating for hardware in the U.S.
While OSHA cadmium exposure regulations & environmental disposal regulations affect cost and availability of cadmium plating and some state laws restrict the sale & use of cadmium in specific items such as packaging and jewelry, it does not appear to be illegal in the U.S. for an otherwise compliant plating business to cadmium plate any hardware sent to them or for anyone to use cadmium plated hardware on their motorcycle.
Whether they will do it and what they charge is their choice.

It isn't illegal. Regulations are strict and most companies don't want to deal with the high investment and operating costs for such a limited market. Chrome plating is in the same sinking ship.

We have a platers near us in Sheffield that do plating work mainly for industry like equipment in pharmaceutical. The work isn’t cheap but I basically sent everything on a bike for £150 and could have done about 3 times the amount.

The plating is zinc but it isn’t like the junk a lot of chrome platers use which turns scabby after 12 months and the colour can be matched to pretty much anything. What I got was a little greyer than I would have liked but it still looks good and the quality is second to none.

OK, new subject,paint I have been researching the correct paint color to use for tank and side panels. I have heard that Etruscan bronze was used. However, this color is only shown in the 1972 parts manual. That manual would be use for bikes with vin numbers beginning JG00101. No such bikes were built. Most information I am hearing is they were painted the same colors as the 1971 A65 Lightning. In the 1971 parts manual this color is listed as bronze with white lining. According to the original BSA paint list Etruscan bronze is listed as /322. The bronze for the 1971 A65 is listed as /295 C6712 with Postans 03638 white. I believe BSA would not add a new paint number to the list if they were the same.

Etruscan bronze for 72 was on the thunderbolts, the lightnings were red (I know yours is an A70) conversely the 71 was orange / Etruscan bronze

I have seen 2 shades of this colour on Lightning side panels and another on an original brochure that I have.

I’m a big fan of sourcing NOS panels, mainly for colour matching purposes.

I’ll try and add some photos below….

Ok.. so the first two are off the article, this is 71 Lightning but it will give an idea of the colour.

The 3rd one is of a 71 (with correct scheme for 71 big tank) and the colour on that shows more similar to the article.

Lastly showing the original painted thunderbolt tank of mine and the white of it, some people think it’s ivory or dove grey, but it was just white (and I think the article pictures back that up too)

Though, are we sure that those small few 72 A70s used the previous year colour scheme? Or would they have used the Firebird Red like the Lightning?

I have some more photos I will add also

My '72 t'bolt was that 'excruciating bronze' colour..........well, that and rust anyway.
Or maybe it was 'excreting bronze'.

Alan, Are the A70L’s 1971 or 1972 models. All of the ones I have seen are stamped with second letter code’E’ which is 1971. The 1972 parts manual states it is for bikes coded JG which is 1972. At BSA in Maryland, USA a bulletin was issued in March 1972 which states the A70L was painted Firebird red lined white. Regarding the two colors you have seen BSA the 1971 bronze color is listed as, bronze with white, /295. The 1972 bronze is listed as Etruscan bronze with white, /322. These colors are from the original BSA color list. I believe the two years were painted two different colors. Mine will be painted in the 1971 color scheme which is more orange looking than the1972 color.

There was only about a handful of bikes built in 72 and those of which were all the same month as yours, the rest I believe were all the 71 model year.

It’s hard to know what colour those 5 bikes were, unless someone has images from that time or owned one from that time. It’s possible the tank was all red, much like it is now but maybe a different shade. Or they could have used up some tanks prepared from the previous year.

Not here is an A70 picture somewhere (and it appears on a video) from 72 with a 4 gallon tank of which I think I recall is like the picture above but chrome as the main section and red for the stripe.

I’ll try and find it later.

I think there were either 3 or 5 1972 models made. As Allan said, those seem to have had a variety of styling treatments, so were probably sent out to see which people liked best, or perhaps hated least.

Tthe bike with the red UK tank and white stripe behind the "BSA" decal may have been the Donelson bike. That was covered here earlier, but do you think I can find it?

As far as I know, the 1971 A70Ls were essentially the same as the A65 Lightning, with the possible exception of a fluorescent stripe on the tank. If the fork sliders are ribbed, it'a a 1971, if they're polished and not ribbed, it's a 1972. I'm fairly sure yours is a 1971.

Mick Page of Burton Bike Bits restored an A70L years ago, and BBB has an online A70 register. I'm not sure all the details are correct.
Angus Campbell in the UK is putting together the full 1971 "Power Set" range. He has a number of YouTube posts of the work on his A70, so he might be a useful contact. The so-and-so has a pair of Bandit/Fury 350s as well, which are now running.

I’ve just gone back through the photos the seller of your bike sent me as I too wanted to buy it, the GE bike which yours is was sent to Baltimore and despatched 30-June-71

It it would have had the Lightning orange with fluorescent stripe, though all twin carb bikes had that same florescent stripe. So the article I posted but with a black frame would be correct.

Mick at Burton Bike Bits still had the original sticky stripes from the last time he mentioned it on a Facebook forum not too long ago.

Alan, do you know of anyone who has the paint code or the correct for sale? Thanks, Lloyd L

I know a person in Houston who owns an A70L. His fra is lower in the back than mine. Did BSA revise the frame to lower the seat height?

BSALloyd——I have been struggling with ascertaining the paint specs for a 1971 BSA A75RV that I am restoring.
I have a further complication in that the frame etc should be dove grey rather than the black which the basket case I bought was painted.
The red color of the tank and side covers was apparently used for only a short period of time.
Don Hutchinson of MA is renowned for his knowledge of colors for Triumph bikes and I have used him for Triumph bikes in the past.
On the off chance I called him ref my BSA problem and he was most helpful.
He had the formula for the dove grey and also for the red color and I bought both paints from him.
I recommend that a call might be well worthwhile.
HTH

Thanks Tridentman, He is already been contacted and is checking for the correct color. Lloyd L

And just to add to the general comment.
The tanks were spary painted in batches by different operators so no two would have been the exact same colour
When Steve was busy venting his spleed all over the bike press for BSA destroying his excellent styling he mentioned many times the QC on paint colours was discusing and the only consisant colour was for the frame parts that were dipped and even they there were differences.
If you get your hands on period literature you will see a lot of critism about the quality of the paint which I think Cycle World wrote "appear to have sun faded on the ship coming to Amercia .
So do not beat yourself up over an exact colour match, it does not exist
And finally no matter what colour you paint it at least 1 in 10 people who come across to look at it will tell you in a voice loud enough to hear clearly for 50 yards around that you got the colour wrong .
So unless you are trying for a $ 100,000 austion sale bike, find an orange that knocks your socks off and makes you go WOW every time you take the cover off it .
And apparently the Ivory which the whole tank is painted in before the orange goes on was just as wonky

A70L from Schoenewald's collection

I nearly said that I have the paint code for the dove grey as I had it colour matched.


I will take a photo of the NOS inner side panel that I have, but the colour is more like the 72 variant than the bronze than the 71, but it is a lightning panel as the thunderbolt is cut different for the carb. The lacquer on it seems to have faded too, despite it being in the brown paper for all those years.

Going back to the green, I bought panels for all over the world for it, didn’t quite get a full set but I think it’s safe to assume that they were painted at different times. And whilst the finish does vary slightly they were all the same colour bar one which was the tiniest bit out that I doubt most people would spot the difference and all matched the untarnished lacquer under the tank. But those were in good condition.

The thunderbolt I did a Mercedes Elbait green, when I do a twin carb oif, that will go as either Nissan Katsura orange or Renault Valencia orange.

Some photos and a link…

In the link there are some original panels, the thunderbolt panel is either NOS but definitely original.

The orange panel on the right looks similar to the colour on Dave’s photo and the rear quarter panel looks a little like some of the other “original” bikes I have seen. Personally I would settle for either of those colours. I would have bought the set but the price is a little high for my liking.

EBay link

This was the panel I bought. EBay link 2

And this is the Katsura Orange on a test card. Note that these colours really do “pop” in the sunlight and this was taken on a less than sunny day.



Same colour under light





I would need some clarification here on when they changed from Dove Grey to black frames. I thought it was July 71 for A65’s, but I believe all but a few A70’s were black frames. But for those interested this is the colour match.

The frame painted by me, the bracket original, just had a bit of polish to clean it up. Code EC11195. Whilst I like the dove grey and it was the original colour for my frame… if I was to repaint the frame, I would do it black.




If you have the ribbed forks, the finish was the original cast appearance and only the rib was polished. I taped the rib off on mine, had the sliders vapour blasted and then rubbed the rib with some fine wet and dry.

As far as I know, `the frames were painted black by the May 1971 (EE) bikes.

You could be right, I think by July it was coming towards the summer shut down so May might be more realistic as they were already paying dealers a a good wedge of money to repaint them. My “thunderbolt” (which is really a Lightning dressed up as a thunderbolt) is EE, that was painted black… but the paint underneath is was dove grey, as was seen with all the contact points were exposed (like swing arm removed etc), the thunderbolt frame I have is DE and that is the same.

My friend just sent me this… but it’s a good example of the original paintwork, you can still see the halo from where the original stripe was
EBay Lightning

My bike came off the line the same year and month, its also GE, the frame was black, AFAIK, the change from Dove Grey to Black started in May 71.

FWIW my 1971 A75RV certainly was dove grey overpainted (badly) with black.
I could hear the dealer in US saying to the most junior fitter "Heres a tin pf black paint----paint all the grey on that BSA so that we stand a chance of selling it"!
The bike is matching numbers PE (November 1970).

Thanks for everyone that chimed in on the paint selection. I am not sure any of the participants have a copy of the 1972 parts correction put out by BSA in Maryland. It give the colors for the 1972 model and correct all of the part numbers for the USA bikes. You will see that Etruscan Bronze is only mentioned for the A65T model. The A65L is shown as solid Firebird Red and the A70L chrome Firebird Red with white lining. I believe that is the scheme of the Donaldson bike. The bulletin will not load in a format accepted by the forum. If you would like to see it send me your email with the private message feature. Lloyd L

Hi Lloyd.

As its a fine day in the UK today, I grabbed the side panel I bought from the garage and took it into the sunlight to take a photo of it, as you can see the lacquer is poor but I was amazed by the change in the colour especially from something with poor lacquer.

I have attached the photo from ebay as when I bought it, in poor lighting it looked not far different from that, but in the sun it really shines. At some point I will get this panel colourmatched properly, Im still trying to get my workshop setup but will be getting some proper spraying equipment, which will get me away from the base coat and 2k lacquer aerosols.

When I purchased the bike the PO gave the cart he made to do the engine, thanks Ron. Before I got started I decided it was time to give it a redo. I am attaching the before and after pics. All that is left is to get started with the engine rebuild. Lloyd L

Thanks to the link given on the other A70 thread, I have found the image of the UK styles (4 gallon tank) I was referring to


BritBike link

Gee, Allan. That thread is a blast from the past.
One of the posts on the thread has a link to the Triples Online A70 thread. That TOL thread is a real gold mine.

Today I removed the engine from the frame and cracked it open. Next I will be cleaning all the parts and checking the threads. I will also be checking all of the critical dimensions.

I just found that the sludge tube and plug are missing. Does anyone have a spare or know of a source to purchase?

That's a bummer. Those are some of the special unobtainium A70 parts.

I need to read that. I whip through the attached thread and found the A70 image I referenced earlier (which I was kinda pleased about as I did have it on my phone… but like a lot of images, the phone fairies must not have transferred them to the new one lol)





Aren’t they (isn’t it rather) smaller like the A10 plugs on an A70?

Lloyd, would it be possible to share the casting number off the back of the cylinder head (between the splayed ports?) there was two different twin carb heads for oif, different part numbers though I “think” only one is ever refrenced. One of the differences being, 5/16 UNC threads for the outer rocker box studs on one and 5/16 UNF helicoiled bolts (or studs may have been original) on the other, the casting around the pushrod tunnel was different.

On the two I have the port size was slightly bigger on the higher numbered one (30mm if I remember rightly) and 29mm on the other (with the UNC threads)

Allan, The casting number is 71-2202 There are no helicoils in the rocker bolt holes.

Another question, what is the thread size for the sludge trap plug?

5/8" UNF (19 tipi)

Would you check again, 5/8 UNF is 18 tpi. Thanks Lloyd L

The 19 must have been a typo. It's definitely UNF. Grab a bolt next time you're at the hardware store to check.

Are you sure about that? I thought it was 5/8 20 UNS

I am positive, the designation UNS stands for Unified National Special, which is rarely used.


Buying a bolt tomorrow!

Beezer used some strange threads over the years.

Unified special (or unified constant) was one of them.

BSA did use quite a few 20 tpi threads, but I think they were 20 tpi Cycle.

Morgo has a good range of hex socket crankshaft plugs Morgo Plugs
It could well be a BSF thread as BSA?Triumph were smoking some weird stuff back then, from memory the new for 73 disc fork legs were tapped 3/8 BSF and fitted with a stud with 3/8" UNF on the opposite end for calliper locknut.

Morgo's HB11 looks like a possibility, might be worth asking them what one fits an A70?

These look identical to the ones SRM are selling and use the same ID numbers on the plugs... I think if they didn't taper the plug at each end they wouldn't sit so deep in the crank web.

The HB11 is much shorter than the ones they list for the A10/A65 cranks (6.5mm compared to 11.5mm).