The restorer's dilemma

I had a very welcome envelope from the DVLA last week, containing the long awaited V5 registration document (the "log book"), finally making Bagheera road legal. This was followed two days later by another DVLA letter kindly informing me that my registration application had been successful and to expect my V5 soon. 

A bit more bureaucratic faffing is now required to secure a actual number plate, which these days seems to need a lot of paperwork. I send off for a nice tidy 'classic' black-and-silver plate to put on the back of Bagheera.

The Smiths 3003 series instruments may look
the part, but it's best if they actually work too.

While waiting for it to arrive, I decide to take the rev counter apart to see if I can fix it. The manufacturer, Smiths, clearly did want you to do this — why else did they seal the glass permanently on by crimping the metal bezel onto the case all the way around instead of screwing it on? 

Some very patient encouragment with a variety of screwdrivers mean I am able to slowly bend up the lip of the bezel all the way around and remove it and the glass with minimal destruction. The case is full of fine brass shavings like glitter. Not good.

Before I can take the face off the tacho, I need to remove the needle. But before that, it's important to hop the needle over the peg at the bottom end of the dial and see where it comes to rest. It eventually needs to go back in this exact position. I remove the needle by levering off with two small screwdrivers, while protecting the face with some card and trying not to launch the needle across the workshop. Then face is removed by releasing two reusable plastic rivets.

Now I can see the guts of the mechanism, it's clear what is wrong. 

Speedos and tachos work in the same way; a cable with a rotating core comes from the engine or one of the wheels into the back of the unit, where it turns a magnetised drive disk. This disk is set close to, but not quite touching, another disk this time made of aluminium. Although aluminium is not magnetic, when the drive disk spins it induces electrical eddy currents in the aluminium, and these interact with the magnetic field of the drive disk. The upshot is there is a small torque induced between them and the aluminium disk gets dragged around too, which is why it's called the drag disk.

The drag disk winds up a light spiral spring which is connected to the pointer. As the drive disk spins faster, the drag increases, the drag disk turns and winds up the spring until the forces balance and hey presto, you have a reading on the pointer. 

A final refinement is a steel plate located on the other side of the drag disk. This inhibits the magnetic field in the drag disk, so by adjusting the exact position of the plate you can calibrate the instrument.

That's the theory. On mine, the two disks are actually touching. They turn together, winding up the spring until it is tight and max revs are indicated, then suddenly it slips back to zero. Several times per second. 

The cause seems to be wear on a large brass rotor, which in the speedo is used to drive the mile counter, but in the tacho is basically just a spacer. It has lost whatever bearing or lubrication it once had, and ground itself into dust against its metal bracket.

Unfortunately, spare parts don't seem to be available to the public, and anyway the job looks incredibly fiddly, with various tiny rivets to drill out and then replace. So it's off to the experts for a quote. I've saved myself some cash by dealing with the case, glass and face myself but I am still apprehensive.

The answer? £25 for a good second-hand drive mechanism, £10 to repair the needle spindle, £20 to do the work and calibrate, £10 return postage. £65 in total. 

That's an awkward kind of number. And herein lies the restorer's dilemma.

Because I could simply jump on ebay and buy a Indian-made reproduction unit for about £20, which looks pretty similar and probably works just fine. On the other hand, properly rebuilt and refurbished original units are fetching £150-£200 these days, which makes £65 look reasonable. Do I buy a cheapie? Have it fixed? Or just leave it as it is, original but broken?

I suppose the question is what am I trying to achieve with this restoration. Something I should probably have thought through before I started, rather than now on this blog. 

I reckon there are two considerations for restoration — finish and originality.

Look at the finish of this concours winner.
This bike looks better in 2018 than it ever did when
brand new in 1968. But was it worth it?

For some people, finish does not matter. It is enough to simply rescue an beaten-up or damaged classic and do just enough to get it back on the road so they can enjoy riding it. There is even a name for tatty, rusty, bodged-together bikes that nevertheless ride well. They are called rat bikes.

Others hobbists spend countless hours and vast sums obessing over every detail until they have a bike that actually looks better and shinier than new, and can then be entered into "concours" competitions and compete for rosettes. These people, it must be said, probably ride their bikes rarely as they don't want them to get wet or dirty. And spend a LOT of money. So not a long of bang for your buck.

In between there are the hobbists like me. I want to get the bike into good mechanical condition so that it can be enjoyed for another 50 years, and I want it to look good. But I'm not interested in making it look like it just rolled of the assembly line, after all who am I trying to kid? The "patina" of a classic bike is part of the story and the charm. To me, "patina" means the visible signs of wear and age on a well-loved but well-used machine. It does not mean mechanical faults, unrepaired crash damage or horrible rusty bits.

Then there is originality. This is a tricky one. Some restorers insist that everything on a bike should be correct, by which they mean exactly how the manufacturer fitted them. These people will spend days trawling the internet and going to auto-jumbles to track down those hard-to-find original parts they need. They will pay silly money for those elusive "new old stock" (NOS) bits, things that have been languishing forgotton on dusty shop shelves for decades but never actually been fitted. 

The problem with this approach is that original parts are sometimes impossible to find, not worth the money, or simply not as good as their modern replacements. Triumph themselves sourced parts from lots of companies, few of which still exist, and kept poor records thus blurring the line between original and aftermarket manufacturers. And  anyway, where do you draw the line? No one is daft enough to waste time hunting down unusued engine oil from 1968 (are they?), so why quibble about who makes the spark plugs and footpeg rubbers?

Allan Millyard's bonkers shed-built V10 Viper

At the other end of the scale you have people deliberately modifying their bikes, a little or a lot, and to varying degrees of success. Some people have made customisation an art form, creating incredible two-wheeled sculptures, which others have achieved amazing engineering feats. 

Check out the incredible creations of Allen Millyard for example. Like me, Allen works on bikes as a hobby, in his spare time, in his shed. But there the similarity ends. His latest project somehow fitted an 8-litre V-10 Viper engine into a motorbike. Or rather, he designed and built a motorbike around the engine (it has no frame). It handles, looks amazing and does 200mph. 200mph! Build in a shed!

Or what about his "Flying Millyard" that takes two cylinders from a massive vintage radial aircraft engine and fits it to a classic 1920s frame that looks like it should have been in Chitty Chitty Bang Bang?

Of course, Allen has more engineering talent in his little finger than a dozen ordinary hobbyists put together. Most people's attempt at a custom ends up with something that is probably less ridable, less valuable and to most people's eyes less attractive than the original. 

The Brough Superior. The ultimate classic?

And there is another problem. If you customise a bike according to the latest fashion — be that bobbers, cafe racers, streetfighters or whatever — when fashion changes your creation may be worthless, whereas a classic will always be a classic. Just look at the Brough Superior — a really well-built and very handsome motorcycle from the 20s and 30s. They cost £100-£180 at the time which was certaintly not cheap, but good original ones are now changing hands at up to £300,000 a go.

Bagheera is never going to fetch big money, as the single-carb Tigers are generally worth less than the more desirable twin-carb Bonnevilles, and also the 60s models are generally more sought-after than th later models. It just might, if really well-sorted, fetch £7500-£8000. But to get there would cost me at about the same. So it's a good job I'm doing it for fun and not for profit.

So, after all that ruminating, this is what I am setting out to achieve

• The bike should look as original and undamaged as possible...
• ... but it does not need to look shiney and new, because it's not.
  
• If there is a modern part that works better or is more reliable than the original — use it 
• Mechanically it should be as sound and reliable as possible...
• ...so it gets ridden as much as possible.
• And finally I must remember, I'm not doing it for the money!

Next time... first ride!!!

TOTALS TO DATE: Hours: 120. Cost: £6100 

PS: Yes I did pay the £65 to have the rev counter repaired.