1968 Commando frames

I am starting to restore a 1968 Commando and am not sure if the frame has been fixed as I understand they were dangerously poorly made in the first year of the bike. Does anyone have a link to photos of what an original frame and a modified/fixed frame look like so that I will be able to tell? The bike only has 5300 miles and is completely original. I bought it off the original owner and it has sat in a garage since 1973 (still had gas in the fibreglas tank). From what he told me and what I can tell, it is complete but he is in his 80's and can't recall getting the frame fixed or changed. It's definitley the original frame as all the numbers match (unless replacement frames had matching numbers)

Anyway, any advice or help would be much appreciated.

darmah said:

I am starting to restore a 1968 Commando and am not sure if the frame has been fixed as I understand they were dangerously poorly made in the first year of the bike.

Click to expand...

It wasn't the case that they were poorly made, but that the design was inadequte in that the headstock area was not sufficiently braced.

Look for a 1 inch diameter tube running back from the headstock directly underneath the main 2-1/4 inch spine tube? If there isn't one, and the front fuel tank brackets are welded onto the down tubes, then the frame is the very early type which broke.

I think the early frames were usually replaced under warranty wherever possible rather than strengthened.

Early '68 frame: http://www.nortonproject.org/1968.htm
Later improved frame: http://www.nortonproject.org/1969.htm

You'll want to compare against the photo's LAB provided to know for sure. I'm the second owner of a 68 as well, the factory replacement frame on my bike was stamped with the matching numbers directly on the headstock neck so numbers alone wont necessarily mean it's the original. I've heard that dealers had a "repair" for the frames as well which I can only assume mean adding an additional support but I've never actually seen one first hand or seen any legitimate (Norton) documentation on it.

The frame was adequae for the crappy front rake the early bikes had. It wasn't until they got a decent disk brake on it that they discovered the weakness. Initially, I believe they inserted the brace between the downtubes in the belief they were spreading apart under heavy braking forces.

It would have looked a lot more elegant if they'd used the tapered tube design we developed for the Stormer, but I guess it was the best they could do with the downward spiral the company was in by about 73.

In the original configuration of the Stormer, the top tube was welded to the headstock tube down near the bottom instead of near the top like the Commando. A bracing "wrap" that reachd down to the centerline on the outside of the top tube connected to top of the headstock into the top tube, maybe 4 inches aft. The stresses were passed into the top tube at the aft end of the brace and caused it to "oil can", resulting in a cicumferential crack around the top of the main tube. Eventually, it fatigued through all the way.

The redesign was to split the top tube into two halves, line them up with the top and bottom of the headstock at the front and ending up in s circular tube at the seat. A triangular piece of steel was then welded into the gap, crating a continuously varying cross section.

As far as I know (I left just as the works team started using it), it worked fine and there were no more top tube failures in the M-X team bikes, which was the harshest service environment. I'm pretty sure Bombardier (KTM?) used the same design whan they started using that frame.

frankdamp said:

The frame was adequae for the crappy front rake the early bikes had. It wasn't until they got a decent disk brake on it that they discovered the weakness. Initially, I believe they inserted the brace between the downtubes in the belief they were spreading apart under heavy braking forces.

Click to expand...

I really can't see how that can be right Frank?

As I believe the weakness was apparent from fairly early on, subsequently the frames were strengthened with the extra tube for '69. A front disc brake was not fitted as standard to any production Commando until 3 years later (1972).

I have a 1968 Commando that was very early production. The dealer replaced the 1968 frame for the original owner with a 1969 frame within a few months of his purchase of the bike. He took the bike in for service and the dealer told him that the frame needed to be replaced with a newer frame due to insubstantial strength at the headstock. Apparently the 1968 frame was not damaged, but the dealer had been told to replace it by Berliner/Norton.

Thanks for the replies. I checked the photos provided and I definitely have an original frame that has not been changed. That leaves me in the quandry of what to do; restore it as is and don't ride it (trailer queen); find a frame somewhere to replace the one I have; or find out if the current frame can be modified. If anyone has any further advice or thoughts that way, I'd be more than happy to hear them.
Cheers.

a welder could put a brace in there

IMHO if you are planning to ride it -at all- you need to source a new '69 and upwards frame. I would not take the chance.

You can find a competent frame builder and have him check the present welds for cracks and then weld a tube in similar to the later frames. The frame is just mild steel so no special treatment is needed for welding. There are lots of guys around that build tube frames for race cars and bikes who could repair it. It may be cheaper to just buy a used 69 frame however. Jim

Actually, we started testing disk brakes just before I left N-V in June 68. They didn't make prduction until sometime later because of the insistence by senior management on a sliding disk. They didn't like the odd look of the wheel offset necessary to fit a double-sided fixed caliper. I suspect that the sliding caliper hadn't appeared on the market at that time.

Jim, I thought the frame was Reynolds 531 alloy.

frankdamp said:

Actually, we started testing disk brakes just before I left N-V in June 68. They didn't make prduction until sometime later because of the insistence by senior management on a sliding disk. They didn't like the odd look of the wheel offset necessary to fit a double-sided fixed caliper. I suspect that the sliding caliper hadn't appeared on the market at that time.

Jim, I thought the frame was Reynolds 531 alloy.

Click to expand...

Only on the race bikes. Jim

frankdamp said:

Actually, we started testing disk brakes just before I left N-V in June 68.

Click to expand...

Maybe so, but that still doesn't account for the fact that the early Commando frames broke even though they didn't have disc brakes?

frankdamp said:

They didn't make prduction until sometime later because of the insistence by senior management on a sliding disk.

Click to expand...

However, standard production Commandos were not fitted with sliding (floating) discs.

I had one of my frames welded at a race shop and it has stood the test of time - wasn't inexpensive though. Sourcing a later frame might also be better for when you decide to sell it. Sometimes a frame that has been welded causes a bit of a stir.

Recalls - Search Results


I had same dilema, I found a newer frame. And I did find the recall info from NHTSA, check out the cause of the problem, and unusual sonditions of use, block long 2 up wheelie?

Dan


NHTSA Campaign ID number : 74V239000





Vehicle Make / Model: Model Year(s):
NORTON / COMMANDO 1968-1969

Manufacturer: NORTON/TRIUMPH CORP. Mfr's Report Date: DEC 02, 1974
NHTSA CAMPAIGN ID Number: 74V239000 N/A
NHTSA Action Number: N/A

Component: STRUCTURE:FRAME AND MEMBERS
Potential Number of Units Affected: 1400
Summary:

Consequence:

Remedy:

Notes:
NORTON CAMPAIGN NO N/A. POSSIBILITY THAT THE LARGE DIAMETER TOP TUBE OF THEMAIN FRAME,MAY FRACTURE IN SERVICE DUE TO UNUSUAL CONDITIONS OF USE FOLLOWINGAN INDUCED WEAKNESS INITIATED BY UNSATISFACTORY CRATING AND WAREHOUSINGPROCEDURES. (CORRECTIVE ACTION, ON MACHINES AFFECTED, WITHIN THE SERIES OFENGINE NUMBERS 126125 TO 128634, THE FRAME SHOULD BE CHANGED IN ACCORDANCE WITHTHE INSTRUCTIONS GIVEN IN THE 750CC MODEL WORKSHOP MANUAL (PART NO. 063419). )

Check to Request Research. Submit below.

It looks like you can get a used 750 frame from OB for $500. You might try that route, it might even be an early one, I'm sure Ella would tell you.

Dave
69S

My brother picked up a couple frames in Denver for 50 bucks from Craigslist. He even gave one of them to me. I see them pretty regularly on e-bay. Just don't pay too much unless you can confirm they're straight. Jim

There is a frame on ebay currently for $150.00. Don't know what year or what condition.

Thanks to everyone who took the time to respond. Here's where I'm currently at mindset wise on this problem;

I think I'll go ahead and modify the existing frame, welding it somehow to reinforce the head area. At least this way I can still say that the bike is 'original' as far as the parts on it are concerned even if some are modified. Afterall, I still have to decide if I'll upgrade the Isolastics, ignition, suspension, etc. or not. Ultimately, I want to make it a fun and safe riding bike not a trailer queen that only gets carried to shows.

I see a couple of posts suggesting that buying another frame is the way to go. If you go that route, keep in mind that you will not be able to use your 68 centre stand or the sidestand, and the cradle will need to be drilled to take a later stand. I am not sure sure if you can use the stock triple trees. Also there is some uncertainty as to whether you can mount the early fastback tail on a later frame. The jury is out on this one, but some folks will tell you that the rear loop on later frames is too wide to fit the early tailpiece over it.
A 1969 frame would allow you to transfer your stock bits, and it has the reinforcing strut under the main spine. The 1969 frame was the factory recall fix, so you can still make the case that it is "stock".

Stephen