The Bonneville Project

Frame straightened

Alan at Abba Motorcycle Equipment has successfully straightened the frame.

To do this, he fitted the rear wheel into the frame and put it on the jig to see how much out of alignment it was before straightening it back true.

As mentioned before, the main frame was ok but the subframe had been knocked out about an inch out of alignment.

To do this sort of damage, Alan reckons it likely that the bike had done a complete flip and landed on the corner of the subframe.

I hadn't seen a jig before so didn't know what to expect and have included some pictures of what it looks like below.

The bike pictured in the jig isn't mine - it is a 1907 twin cylinder Norton.

Ridden by Rem Fowler, this was the bike that won the first ever Isle of Man TT race. It is so special that it usually resides in the National Motorcycle Museum.

An interesting article about this very bike was recently published in the Daily Telegraph. 

Straightening the frame

I've finally taken the frame to Abba Motorcycle Equipment at Maldon where it will be straightened.

The name of this company has nothing to do with the Swedish pop group Abba.

Rather it stands for Alan Burdett Bike Accessories.

The company was founded in 1982 after Alan - a frustrated motorcycle technician - found the bike lifts and stands he was using totally inadequate for the job.

After extensive testing of new ideas of various ways of lifting a motorcycle, many prototypes later the Abba Superbike Stand was born.

Today, Alan's range of stands and workshop products covers the whole spectrum of motorcycling including race rep, custom, classic and off road bikes.

But he's also a dab hand at straightening classic bike frames.

So far as I know, there aren't many people who do this and I'm fortunate his workshop is less than 10 miles away.

Alan has put my frame in a jig and fitted the rear wheel, so everything can be aligned.

It is already evident that the subframe has taken a hefty wack and is about an inch out of alignment.

However this should be fairly simple to put right - although it will cost £185 plus VAT.

I've also asked Alan to check the front yoke alignment.

I'm hoping the yokes will be ok, but the fact that the stanchions and fork sliders needed replacing suggests I shouldn't be surprised if they aren't.

New sliders and bushes

Closer inspection has revealed one of the fork members (or sliders) has a dent in it.

This is a major blow expensive to rectify.

The dent is stopping the stanchion from sliding up and down properly.

I could bore out the dent, but there would always be a weak spot where the metal was thin.

So far as I can gather, boring out the dent would also mean that stanchion would slide unevenly compared to the other stanchion.

In short, the only way to resolve the problem satisfactorily is to replace the fork member.

I'm beginning to think I'm not really restoring this bike so much as throwing money at it - and I realise some people reading this will probably think so too.

For good measure, I'm replacing both members and the fork bushes too. Then everything on each side will be symmetrical.

The parts have been ordered from Oliver Barnes at Tri-Supply.

Details are below:

Part number	Description	Price/unit	Quantity	Total
97-4170 97-4220	Fork sliders	£132.95	Pair	£132.95
	Bushes	£14.50	Pair	£14.50
			Subtotal	£147.45
			P&P	£13.50
			VAT	£28.17
			TOTAL	£189.12

Fork member problem

I've successfully rebuilt one fork, inserting a brand new stanchion into the right-hand-side fork member.

It fitted perfectly, sliding up and down like a dream.

The left-hand-side fork member is proving troublesome.

My old Triumph workshop manual and Haynes manual say the stanchions are the most likely fork components to be bent in an accident.

But I think the left hand fork member is slightly out of true.

When fitted with the original shuttle valve from the old (slightly bent) left-hand-stanchion, the new (and straight) stanchion gets stuck half way down the fork member.

I've tried all combinations - swapping the old left-hand shuttle valve with the old right-hand shuttle valve, and the other new stanchion and each time it gets stuck in the left hand fork member.

I'm rapidly coming to the conclusion that the left-hand fork member is slightly warped.

I'm not sure what to do - I think I will post a question on the Brit Bike Forum and see if anyone has any suggestions.

Dust excluders - old v. new

At last, here are pictures showing the old and new dust excluders.

The old ones are slightly different - and in two sections.

The new ones, which are going to be fitted to the bike, are in a single section.

Even so, I'll keep the old ones as spares.

One day I might get them rechromed, although this will cost more than their replacements.

Eagle-eyed differences

The replacement stanchions have arrived from Len Craig & Sons.

In fact, they arrived two weeks ago, but I was on holiday.

Together with two dust excluder sleeves, some 40 or so ball-bearings and a couple of cork washers, I now have everything I need to rebuild the forks.

The replacement dust excluders are slightly different to the originals, seemingly with a more rounded taper.

I've probably described this badly, so I will post a photo this evening.

By the time I have done rebuilt the forks, I am hoping the wheels I ordered will have been built and returned from the Devon Rim Company.

Then I will take the frame, forks, engine and wheels to Abba Stands to be checked for alignment.

Once correct, I will dismantle everything and arrange for the frame to be painted.

The 6000rpm Bonnie

A family holiday means I'm unable to work on the bike for a few days.

Rather than not update The Bonneville Project weblog, I've decided to post a link to a short video.

It's a 24-second film of a 1968 T120 Bonneville accelerating to 6000rpm.

To play the video, click the photo (above left).

It's a 4MB file, so may take a while to download on slower connections, but is well worth the wait.

I suggest setting the volume on your computer to ABSOLUTE MAXIMUM while it loads.

The sound this machine makes is awesome.

I watch - and more especially listen - to this film whenever I need inspiration to work on my bike.

The video is from The Bike Shed website. It belongs to Hugh Brown, one of Britain's best Bonneville restorers.

I'll be well impressed if I can turn my "Just To Show It Goes" bike into something that sounds like Hugh's.

Circlip pliers - how handy?

I wonder how many times I'll use many of the tools purchased as part of this restoration.

My latest purchase is a set of circlip pliers, bought in readiness for dismantling and reassembling the forks.

So far as I know, I only need them for one job.

Shuttle valves are fastened in the bottom end of each stanchion by means of a retaining nut.

Circlips prevent these shuttle valves recessing into each of the stanchions.

I purchased the circlip pliers them while waiting for the replacement stanchions ordered from Len Craig & Sons.

I’m going to take the shuttle valves from the old stanchions and fit them to the new ones.

The circlip pliers cost £6.50 - cheaper than new shuttle valves which retail at £11.00 each.

There's nothing wrong with the old valves anyway.

But whether I'll use the circlip pliers again, who knows.

Len wins another order

While the wheels are being built, I am busy sorting out the forks.

Both forks show signs of age - and one of the stanchions is bent.

I'm replacing both stanchions, both main springs, the rubber gaiters and various other bits and bobs.

I was going to keep the original dust excluder sleeve nuts, and just replace the oil seals.

But as I can buy new sleeve nuts complete with oil seals for £45 I've decided to replace them too.

I've ordered the parts from Len Craig & Sons (top left).

I purchased some stainless steel mudguards from Len last autumn and he gave me a good deal.

This time, he offered me a choice of stanchions - one pair made from Japanese steel (£40) or a pair made from British steel (£56).

I went for the British steel which is better quality.

The plan is to rebuild the forks, reattach them to the frame, slot in the wheels and engine, and then check everything is aligned correctly.

If not, any necessary tweaks can then be made to the frame before it is painted.

Once I'm happy everything is true, I'll disassemble the frame and forks, get them painted and then start rebuilding the bike proper.

New fork parts are:

Part number	Description	Price/unit	Quantity	Total
82-4047	Cork washer	2.00	Pair	£4.00
97-1891	Solo main spring	10.00	Pair	£20.00
97-3633	Dust excluder sleeve nut c/w oil seal	n/a	Pair	£45.00
97-2119	"O" ring	2.00	Pair	£4.00
97-2092	Stanchion	n/a	Pair	£56.00
97-0430	Fibre washer	unknown	Pair	unknown
97-1062	Aluminium washer	unknown	Pair	unknown
S70-3	Steel ball (1/4 in diam)	unknown	40	unknown
			Subtotal	£
			VAT	£included
			P&P	£
			TOTAL	£

I will fill in the total once I know it - it's in the region of £156 delivered.

Tyres: the Dunlop TT100

Shaun from the Devon Rim Company called to say my hubs arrived safely.

He praised their condition and my paintwork, which was pleasing, and then talked me through the entire wheel-building process and what it involves.

I've gone for the stainless steel rims and spokes without a tyre safety bolt.

I originally wanted an Avon Speedmaster tyre on the front, with a 4.10 Avon GP on the back.

They don't make the GP any more - the equivalent is an Avon Safety Mileage but this doesn't come in a 4.10.

Instead, Shaun advised me to go for Dunlop TT100 tyres front and back because they come in the width I want.

This is the second time somebody has urged me to go for Dunlops - the first was Geoff, on this blog - and I'm going to take their advice.

The Dunlop TT100 was the first production tyre to do the Isle of Man TT circuit at 100mph+.

It's a softer compound tyre than the Avon and has a more rounded shoulder, so should give more grip and better lean into corners.

The wheels should be completed and delivered towards the end of August. In the meantime, I am going to source some parts for the forks.