Fixed! Bent Navigator Frame

Thanks for your kind words Anna, the hospital did a great job screwing my wrist back together again and it is healing fast.  I am hoping they will give me the green light to start driving again when I have my review next week! 

Sadly it happened so fast I didn't get the car's number and the front frame tube in the NOC shop is for the Jubilee and is different from the Navigator so wont fit.   Like you I am not keen on having frames straightened unless there is no other option.   To be honest I'm not sure they could straighten a Lightweight frame and particularly the front frame tube given its design and the way it is bent. 

Perhaps one of our members has had a frame straightened and can advise accordingly.  I hope your rebuild is going well!

Nick

Thanks for the sage advice Robert, I've loosened the stanchions in both yokes and wheel spindle and re-centred them and they are properly aligned and the sliders are running smooth and free on their bushes so I am confident the forks aren't bent and it is the Frame Front member.    I know 1 deg doesn't sound much but using the 1 in 60 rule that equates to about 0.72" over 42" - the approximate length of the forks and wheel to the ground (I will measure it tomorrow to be sure).   Just looking at how much that is on my bike it is too much to be safe unfortunately.   If I cant find a replacement I might have to resort to brute force as you suggest!!!

Nick     

Bare with Dan, I will pop out and check!   Nick

Hi again Dan, I think yours is a Navigator Front Frame member, its got the higher and slightly different Head Steady compared to the Jubilee one.   It looks is the same mine as the attached photos show.    The only difference is I suspect it is the earlier one than mine which had the 7" Road Holders because it lacks the later / stronger steering lock stop at the bottom and probably the steering lock lug at the top - although can I see that just on the edge of your photo?   The NOC shop still has the earlier bolt on steering lock stop plate in stock which is encouraging - do you know if that will work with my wider 7.375" forks?   Bless, nothing is ever simple with a Lightweight Norton!   If you are interested in selling it please PM me!

Cheers   Nick

Dan, further to my last and for your info the later front frame member has a simple sheet metal plate welded on the top, right hand side of the steering head for the steering lock (Later frame 1) and a thick, wide plate welded to the back of the bottom of the steering head (Later frame 2).   I'm guessing that second hand late Navigator front frame members may be rather thin on the ground so I might have to adapt a later one!    

I hope this information is helpful to others who might have a twisted or bent frame!

Nick

Hi Dan,

Thanks for getting back to me so quickly and spending time trawling through your spares.  Good suggestion to check with Andy about the earlier bolt on steering lock stop, he's already helped tremendously and he is always spot on with his advice.     Fully understand and thanks for even considering it - a swap for the club Jub one would be incredibly kind, I will get back to you once I have spoken to Andy and done some more research.    I might even try Russell's, you never know your luck with their Alladdin' s cave of a store room!

I've just finished stripping the whole front end off the bike - I am surprised it only took three hours, including stripping the forks and for once I didn't encounter any problems!   I bet it doesn't go back together that easily!   A real positive is with the front down tube off I have been able to prove that my diagnosis was correct.  The 'goose neck' above where the top tube bolt on is bent 1 deg laterally in the direction I thought.   I will look in to whether it can be straightened as a last resort - not ideal but useful to have in my back pocket as an option.

Enjoy the weekend.

Nick

Thanks for your kind words Peter, luckily I managed to miss the car but in doing so I had to lay it down and I parted company - uncomfortable but much better for me and the bike than hitting it head on!   As for the broken wrist it's mending nicely so hopefully back to driving soon.

Thanks also for all the advice and back ground information above, I will add those checks to the ones that Andy has given me to check the rest of the frame - I'm keeping my fingers crossed because the top tubes seem correctly aligned in all planes so far!

As for where my Front Frame member / Downtube a check with a steel rule confirms it is bent from where the top tubes bolt on.  Thinking it through logically below that joint the Downtube is pretty rigidly attached and supported by the thick bottom tubes, two quite closely spaced engine mounting bolts clamping it to the crank cases and the cylinder head steadys.    Above the top tubes there is no bracing and a long 'Goose Neck' up to the steering head where all the front forks forces apply.

Therefore, any lateral force applied to the steering head, via the bike landing on the end of the handle bars and dragging them along the road at circa 30 mph in my case, slamming the forks to full deflection will apply considerable lateral leverage on that unsupported top section.   No wonder it bent sideways - I'm just surprised it wasn't more than 1 degree!   

Thanks for the really useful photos.  I used a steel rule alone that upper section and it shows a similar but much smaller bend.   I am going to explore straightening options with our local engineering companies just in case I can't find a decent replacement and if Dan finds he can't sell his spare.   I have posted an add in the club Classified Wanted section and I am trawling Ebay but no joy yet.

Can I ask all on this forum to pass the word word I am looking for a straight and serviceable Navigator or Electra Front Frame Member / Downtube ?   Preferably a late one with the Steering Lock Stop on the top of the steering head and the later, solid Steering Lock Limiter on the bottom of the steering head for the 7.375" Roadholders, shown on the Photos attached below.

Thanks again - in hope!   Nick       

Thanks George,

I spotted Motorliner in Maidstone on the internet, sadly 150 miles from me which is an issue!  Have you had dealings with them and if so do you think they could straighten just the front frame member rather than having to ship the whole frame up there?

 Sadly a comprehensive search of the internet doesn't show any frame specialists in the South West.   I have started putting my feelers out amongst local engineering companies I know to see if anyone can help but would appreciate any advice from someone who has used a specific frame straightening company - particularly if they have successfully straightened a Lightweight frame!

Regards

Nick    

Thanks for the helpful feedback about Motorliner & Parralel Engineering George, I will give them a call and get their advice - it will be interesting to hear what they say about the challenges of straightening a bolt up frame like the Navigator's.   I will also send them an email with photos of the frame front member and ask if they can straighten it off the bike - if they can then it will be a huge saving in transport, time and labour!

I spent a lot of time measuring the frame over the weekend and I am almost certain that it is only the front frame member (down tube) that is bent.   Both top tubes and the rest of the frame seem straight in all four planes.    

My plan now is to dual track sourcing a serviceable front member and straightening my bent one.  Once I have a serviceable part I can mount it in the frame - the proof of the pudding will then be carefully measuring to prove if it is true before I put the forks back on!    .........and resisting the temptation to do a total restoration!!!  

Onwards and upwards!

Nick   

Al, George & Michael,

Thanks for the feedback & suggestions, all very helpful as always!   I have taken all that into account and the fact that the FB and early Navigator and Jubilee front frame members are different from the late Navigator (circa 64 onwards) and difficult to modify for the wider Roadholder forks and the late Navigator frame members are few and far between.    On balance I have decided to go with Andy's sage advice and have stripped the Navigator down to bare frame, engine, swinging arm, rear shocks and rear wheel and will be taking it to either Motorliner in Maidstone or Abba Motorcycle engineering in South Woodham Ferrers - both highly recomended frame straightening specialists.  I have spoken at length with Abba and they  have straightened Jubilee's before and spoke knowledgeably about Norton Lightweights which gives me confidence - I will speak to Motorliner tomorrow and report back which seems the better bet.    Both are quoting between £200 and £300 depending on the work required.   Onwards and upwards!   Nick      

Hi all,

Yesterday I drove up to Abba Engineering in South Woodham Ferrers, near Chelmsford in Essex (01245 322331) and picked up my Navigator which their frame expert Allen had straightened in their hydraulic jig for a very reasonable £285.   Only down side was two 800 mile trips to drop it off and pick it up two weeks later - it was ready earlier but I had to fit it in with work.   

It was a pleasure doing business with a friendly and efficient engineer who knew exactly what he was doing and understood Norton Lightweights.   He requires the frame stripped with only the engine, swinging arm, rear wheel and shocks in place.   Even though the head stock was 'well bent' he managed to straighten it without even marking the paint. 

A happy find was that a Lightweight Norton stripped that way will fit comfortably into the back of a Discovery TD5  so I didn't have the expense of hiring a van or trailer!   Abba Engineering will also lift it in and out safely with a fork lift truck (photos attached) - I can't recommend them more!   

All of that said I hope no one else will be unlucky enough to need their services but of course if you don't know the history of your project bike and have any doubts about the frame it might well be money well spent to have the frame checked for straightness before you spend a fortune on having the frame repainted!

Off to start the rebuild.....the perfect project for the 2nd lockdown! 

Stay safe and well. Nick     

Thanks for the sage advice and kind words Andy, frankly I could have spent years trying to source a replacement late Navigator front frame member or even more money trying to modify an early one - having mine straightened was the quickest, cost effective solution!   I've got my local spray shop lined up to do the painting - it's not my forte!   I'm whipping the engine out of the frame this week and agonising over whether to strip it down for a thorough check and replace anything showing serious signs of wear.   I have a reasonable stock of spares but note that the NOC shop is out of cam followers and the team say they are still trying to source someone to manufacture another batch.   Do you have any idea where else might have them such as Russell's?    As for meeting up on the road in spring - definitely!

Take care and thanks for the fantastic job you do as the Lightweight Tech Expert!   Nick 

Hi Michael,

Thanks for the offer, that would be great if you would.   The Norton part number is:   Tappet Assembly - 20871 and I require 4.   If your local sources have web sites where I can order them passing on that information that would probably the easiest way for me to order them.

Best wishes.   Nick