PROJECT PART TWO
Heath’s Beta TR34
What a difference a month makes! No sooner had the last edition of Classic Trial
Magazine arrived, I received the delivery for the repaired front exhaust;
I could now finish the Beta TR 34 project. Carlos Galvez is a master of exhaust fabrication. He was the man who produced many of the HRC Racing exhausts in the two-stroke Grand Prix era. He had done a brilliant job of rescuing the flattened and deformed lower curve of my front pipe. This, of course, meant that a rear silencer was needed – with mine being still in many parts after I decided to split it to clean and re-pack. Luckily, my riding buddy, Graham Wignall, had recently taken delivery of a well-used Beta ST model and its rear silencer was at least useable. At last, it would give me a chance to run the machine without annoying all the neighbours!
Much to my surprise, the Beta fired up on the third kick. Given the reputation of the old ignition fitted to these machines and the old carburettor, I was amazed it started at all! At this point, I discovered that the borrowed silencer had obviously blown most of its packing out sometime over the last 30 years — the exhaust was making a great impression of a FS1E with a Micron pipe fitted! Noise aside, it ran and rode okay. I had used a couple of large washers to space the front wheel correctly to at least allow me to hop around my drive for five minutes.
SUPERHERO
Local engineering superhero, Trevor Miles, popped into my garage after work one evening and took away the silencer parts and measurements for wheel spacers. A week later I nipped onto the M5 motorway just one junction down to collect the finished items.
The joint of the front and rear pipe just relied on a single ‘O’ ring inside the silencer entrance, but 30-odd years of movement meant that I wasn’t happy this was going to be enough to make a good seal, so I found a Viton ‘O’ ring. It would not be affected by the heat. I then applied an exhaust jointing paste. The area of the joint was also very close to the seat-tank unit, and if you look under most TR 34 models, you will often notice a melted rubber pad or some heat deformation in the plastic. To help with a better seal, and protect the plastic around it, I used some exhaust heat wrap and kept in place with some nice stainless ties. I also fitted some rubber padding on the frame rail near the seat end. It would help the fuel tank stay a little higher. I then had to find some fittings for the front of the fuel tank — the round slidein bits that fit to the frame. Good-old social media groups came up trumps again; ask in the right place, and someone will know a trick or tip! It appeared that the fuel tank locators from a KTM 85 motocross machine are exactly the same size. On eBay, I bought a pack of four new ones for under a tenner – bargain!
Fitting them completed the Beta rebuild, or as much as
I am going to do for now. It’s now quieter, although many will remember that back in the day they had to fit WES silencers to get it through the FIM noise levels, so it’s not whisper-quiet. The engine is not overly mechanical noisy. I am guessing that I as am so used to the lack of noise you have with a modern water-cooled machine these days, to me it probably sounds worse than it actually is!
ALMOST THERE
Steve Saunders, via his SXS website shop, supplied not only a new branded Braktec lever assembly for the front brake but also a new TRRS front brake pipe; with a quick bleed works a treat.
I was worried about the four-piston rear Grimeca brake. Even when new, they weren’t that reliable. After 30 years, I did expect corrosion on the aluminium main casing or at least pitted seals and pistons. Rather than do the right thing and strip it all down and check it, I just got the syringes out and bled oil through it! Would you believe it, it actually worked — and stayed working for 30 minutes of wheelies and skids on the drive; no doubt time will tell on this one.
I was pleasantly surprised by the riding position. Many twin-shocks and air-cooled mono-shocks seem to have the footrest position so high you feel like you are about to go over the handlebars — all the time. Perhaps because of the newer forks and yokes, and the lovely S3 handlebars, the Beta felt relatively modern. Sure there is a bit of extra weight there, but if you could ignore the louder engine noise, you could be forgiven thinking you were on something much more modern.
Ohlin’s expert shock-service man, Andy Dawson, had warned me that the rear shock spring could be a little soft for my … erm, more ‘modern’ bodyweight! But, I had set the slightly longer front forks a bit softer, so the machine seemed well-balanced front and rear.
After a small amount of hammer modification, the rear brake pedal sat at the right height. I made a rear shock mud flap to fit the lower rear mudguard filler plate. I struggled like mad to get the air filter box screw holes to line up with the sub-frame brackets. If I had an aluminium version, it would have at least been easier to bend to fit. So, with new wheel bearings fitted and the front wheel finally spaced correctly, it was time to go and ride it actually off-road.
ACTION
In truth, I had managed one quick ride in the woods. I fitted the borrowed silencer and badly spaced front wheel. Even then, I was surprised by how nice it felt. Everything worked. The engine was good once it was off the bottom end. The noise from the silencer was very off-putting though! The suspension worked well, and front and rear brakes worked as well as modern ones – of course the front would, it is a
modern one!
There was a strange feeling when approaching full lock that something was moving on the front, but as, at the time I didn’t have the correct spacers, it wasn’t totally unexpected.
Fast forward a couple of weekends, and I had the chance to get out again; this time in the pouring rain. It was also up near Cirencester, so the mud did at least contain some Cotswold stone, which offered a little bit of abrasive grip. Once again, I had my crash test dummy, Francisco, with me to give his views on the Beta. He grabbed my camera to try and make my riding look presentable. After a quick ride around, he said it felt great and not old at all. And I have to say I agree with this detailed technical view!
One thing I had completely forgotten to do was take the carb off and strip it for a good clean. Steve Goode once again came up with the technical details as far as jetting and settings go, so I will give it a nice soak in the ultrasonic cleaner and check all the numbers are right.
The engine was a bit hesitant off the bottom end, but I am hoping this is carburettor related as I still don’t trust the ignition system fitted to these machines.
You may see from a photo or two included here, we decided to see what the Beta was like in flight. Well, it jumps very well and – even better – it lands well! The rear suspension unweights nicely for hopping over things, and the clutch lever is very light in use helping to ride in the more modern style. I still had a bit of a weird feeling with the steering on lock and need to investigate that, but everything is tight and as it should be.
It gripped fairly well in the conditions and rode the roots and leaf-covered stones nicely. It wasn’t short of power on the climbs and, for some reason, seemed really easy to complete nice floater turns on. Not only was the clutch surprisingly light to use, but the gearbox was smooth and accurate. I
didn’t suffer any false neutrals – Fantic riders will know what I mean! I think perhaps it may be slightly high-geared, but once again I need to ride it more to confirm that.
IT ALL WORKS
Nothing fell off, and everything worked, so you can’t ask for more really! I’d even like to ride a few competitions on it eventually. The red air-filter box side-cover has a crack in it that could allow water to pass in but a friend of Trial Magazine, Trevor Bennett, has had some 3D printed copies made and one is in the post as I write this.
At the time of writing, we are entering another lockdown here in England, so no riding for at least a month. It will give me time to check out the front end and sort the carburettor problems; other than that, I don’t feel the need to do anything else to the Beta. I want to ride it more before deciding on whether to smarten it up with paint and new graphics.
My desire to ride mud all winter long is low, so I think this could be it now until summer. I am looking forward to seeing how it rides in the rocky streams over in Wales. I seem to remember a certain Mr Tarres being fairly good in those conditions!
THANK YOU
Once again, I would like to mention and thank a few people who have made this project possible. Michel Kaufman at S3 and John Shirt at Trial Enduro Direct, where you will find the lovely S3 parts catalogue; Steve Goode, who not only supplied parts at great prices but was my go-to person for technical information; Carlos Galvez over in Spain who rebuilt the front pipe whilst under various Spanish Covid restrictions; and the two Trevors, Miles and Bennett, for items and engineering work. I will have forgotten to mention more, but really must give a namecheck to riding mate Francisco Ramniel, who not only helped with some photos and riding