Triumph Twin twinshock trials bike.

The exhaust system fits very tightly to the engine and frame, and as such is a bit of a bugger to get on. You seem to be wrestling with it for ages getting nowhere near, and suddenly it pops into place! Hence why there are no pictures. It had been pointed out to me that the system was designed to not need the finned rose clamps to hold it on, so they have been left off, probably saving a couple of kilos. With everything in place the last job before the tank and seat was to check the valve clearances. Now as I was assembling I had been very careful to put everything back in the same place it had come from, having marked where each pushrod, follower, rocker box etc came from. At each stage I had turned the engine over gently to ensure the bits that should go up and down were actually doing that. So imagine my surprise to find that the right hand inlet rocker had no adjustment. :nenau It was as though I had put a longer pushrod in?
Turning the engine over showed the correct sequence of valves opening and closing, so I put the plugs in, put the tank on and wheeled it outside. Very gingerly leaning on the kickstart and bugger me if it didn't start! Ah well, no horrible noises, so I let it tick over, checking for oil returning from the sump, and cracking the rocker line nuts to see if oil was getting up there. With everything seeming satisfactory, I blipped the throttle to get that glorious twin exhaust note, then wheeled it back into the garage. I was already late for a meal out with Denise, Hannah and my Dad.

DSC_0144-L.jpg


No sump guard on, so that I can check the oil connections, but otherwise good to go (I think) Can anyone spot what else has changed while the engine was being done? Don't tell them Tim! :D
Mark
 
Is it the fact that I've raised the bars?

DSC_0142-L.jpg


Everybody tries each other's bikes out after a trial, unless you're really anal, or your bike is a heap of junk. After 3 people asked if the bars weren't a bit too low, I thought there might be something in it and put some old clamps underneath. They only lift the bars by 20mm, but it did make a huge difference to the feel of the bike.
But no, that isn't it.
Mark
 
Is it the home made folding gear lever?

DSC_0145-L.jpg


The marks on the timing cover show where the extra width of the Twin (or the ineptitude of it's pilot) can cause a problem. With the original, solid gearlever, just after you hit the rock that caused the mark, the bike could get knocked out of gear. At the top of a steep climb, that can be entertaining to say the least.
This is a combination of a Yamaha folding lever and a Triumph splined end. Sadly, the welder didn't quite grasp the concept of right hand gear levers, as it would be far better tilted down, but its an improvement.
But no, that isn't it either.
Mark
 
The following day was one of our local club trials, but as I didn't expect the Twin to be up and running I had opted to ride the Tiger Cub. At the trial there were three Twins, one on a shakedown before the Pre 65 Scottish, one being tested after being built for one of the expert riders, and one that I had heard about but hitherto disbelieved.
The first two were in Drayton frames just like my own, the other a home modified road frame. Fair play to the guy for going his own way, on perhaps a more authentic Pre 65 tack, but he really needs to get a better welder. Pretty it isn't.
I was offered a ride on the two Drayton bikes to see what I thought, and its surprising how very different they all feel despite sharing the same geometry.
Also, I had a chance to run my valve question by other people to see what their opinions were. Most suspected that I hadn't lined a pushrod up properly.
All this meant that as soon as I got home the Tiger Cub was left dirty while I had a look at the Twin! (I was off the next day, so cleaning it then. :thumb)

The valve adjuster now had loads of clearance. :nenau Tim put forward a theory that the pushrod cap might have come away from the rod slightly, thus lengthening it, until a very determined tappet hammered it back down. Whatever it was, I could now adjust it to the correct measurement. With this done I ran the engine for a good fifteen minutes (my neighbours love me!) and the wheeled it into the garage to dump the oil and change the filter.
Mark
 
Anyway, back to the "What else has changed" question.
The wheels, that's what. :D

DSC_0143-L.jpg


DSC_0148-L.jpg


DSC_0146-L.jpg


DSC_0149-L.jpg


Once I had got more in tune with the bike, the more I was enjoying riding it, but the old second hand wheels were letting it down. I should have been collecting them at Telford show, exactly a year after this project started, but the wheelbuilder broke his arm! The hubs are Tiger Cub replicas, but manufactured this year.The brake plates have a self centering pivot, so you can get the shoes contacting the (perfectly round!) drum evenly. Stainless steel spokes laced to alloy rims, and just for good measure, a brand new IRC tubed rear tyre and a Michelin front. I collected them at the end of April from Jim Pickering, "Mr Drayton" himself. I had asked for a brake plate adaptor to fit the REH forks, which dispenses with the need for an anchor arm. He had one, but hadn't fitted it because he couldn't quite remember who it was wanted it. It shows the difference between an engineer and a spanner twiddler though, when he pressed it into place with a fly press, where I would have used the lump hammer next to it. :blast
Mark
 
Looking forward to the next installment....perhaps we'll hear about the timing cover inci'dent' :D
 
Thanks Tim, not much chance of keeping my little indiscretions quiet with you around! :augie :D
Denise's daughter has taken an interest in trials, but so far the ones we had been to had easy sections, but it was difficult to get to some of them. This meant she was leaving some sections out and losing both marks and confidence. One of the other riders suggested we try one of Manchester 17's Dead Easy Trials, the clue being in the name.
Bank Holiday Monday saw weather almost too nice for trials, but as I had promised, away we went. The venue was on the other side of Congleton at a farm that also hosts weddings, with catering and a large flat paddock for parking. The sections were all laid out on the hillside beyond the paddock with stunning views over the Peak district and within easy walking distance for spectators. As there were only a couple of other people there that knew me, there was a lot of interest in the Twin, and a lot of appreciative comments.
There were only two routes, the beginners route, and the clubman. I rode round with Talei and helped her with each section until she got over her nerves and by the end she was doing nearly all of them by herself. I did warn her on the way there that she was likely to get beaten by a five year old on an electric Oset, but to take consolation from the fact that their seven year old sibling would be beating me on a small wheeled Beta 50. And so it came to pass. I lost 11 marks, one safety dab, and two fives for following the white route instead of my own. Concentrating too much on Talei's line and forgetting mine! :blast Talei dropped 41, but was made up at having finished. She now knows more of what she can and can't do so is looking forward to the next trial.
Sadly no photos, as I was too busy, and Denise's phone died.
Towards the end of the day, I noticed oil on my back tyre, from the main breather . What was that all about? Oil was still circulating back to the tank, so it wasn't blocked anywhere. Was it just the heat? Pondering this dilemma , I washed the oil off when I got home. As I was scrubbing the back tyre, I managed to push the bike off the sidestand and buried the throttle in the mud. Cursing and swearing, I cleaned that off and pushed the bike into the garage to start dismantling to investigate the breather issue.
It was then that I noticed this:

DSC_0161-L.jpg


DSC_0162-L.jpg


When the bike had fallen over, the gear lever had punched into the timing cover and split it. How very amusing. Not.

I have access to a very good welder, but he polishes things with a 6" angle grinder. I know it won't leak at least. I also pointed out the issue with the gear lever being at the wrong angle, and perhaps being a few mm too long. He fixed that FOC for me, as it had been his misunderstanding earlier. I took the opportunity to change the folding end for a stubby one too. Will paint it after I've tried it in a trial to make sure it works.

DSC_0172-L.jpg


DSC_0171-L.jpg


The next trial is tomorrow, so some of my questions will soon be answered!
Mark
 
Loved reading the latest updates Mark. Takes me back a long way seeing that engine being worked on :thumb2
 
Having done another practice session where everything worked OK, I had entered for the Reliance Cup trial on 3rd of June. This is one of the NBBC road trial series, and was in the Peak district around Buxton. I have to say the bike performed brilliantly, only let down by the rider! One of the problems with a road trial though, is that you spend a lot of time in a rev range that you aren't used to, and start to hear noises that may or may not be there! Thankfully nothing fell off, or broke so all good. Here's a clip of me in section 3, swiped off Facebook.


Mark
 
The weekend of the 1st and 2nd of September is the Isle of Man classic 2 day trial, another big event in the Pre 65 calendar. I had been invited to join a group of riders, mainly from the Aqueduct club, who had been over in previous years. All ferry and hotel rooms booked, but I was the only one who didn't get through the "ballot" for an entry. I emailed the secretary to tell them that I would still be coming over with bike and gear ready to take any late cancellation place. One of our group, Neil, twisted his knee a couple of weeks before, so I was given his place.
Here we are, at the start of the event


DSC_0472-L.jpg


But unfortunately, unpleasant noises meant this is where we finished. 4 sections from the end of day one.

DSC_0479-L.jpg


It solved a slight problem for the group, who was to be "pit bitch" for the 2nd day as Neil was observing. I managed to spectate at a couple of the sections, between my refuelling duties.

DSC_0502-L.jpg


Lots of sympathy, and loads of opinions on what it could be from the rest of the competitors. I didn't investigate any further while we were there, not really having the time or inclination. As soon as I got home though it was quick wash off and get out the spanners. Part of me hoped it was something silly (and inexpensive) like a loose bolt somewhere. This photo is from the sump oil screen, which both vindicates my decision to stop, and confirms that it isn't something silly (and likely to be very expensive!)
Bugger.

DSC_0510-L.jpg


Mark
 
So after a few phone calls I decided to hand the job over to someone with more experience of these motors. If it is as bad as everyone thinks, then there will be some engineering work needed anyway, so it might as well be with them from the start. As luck would have it, he is passing my office on Friday and will pick it up. I asked how far he wanted me to dismantle first and he said he would prefer the whole engine, so he can check everything over.

DSC_0511-L.jpg


So here is the liberated lump, ready for collection.
I have had a couple of offers of second hand motors from the Pre 65 trials lot, and a couple of people asking if I want to sell the rolling chassis! Hopefully sometime next week I'll have a better idea.
Mark
 
I’ve just caught up with this very enlightening an entertaining thread.
Thanks for taking the time and trouble to post Mark, it’s been a great read and has given me my first insight of pre 65 trials.

Fingers crossed that the repair goes smoothly and not too expensive either.

Did I read right? After all your time and effort it would be a shame to sell the rolling chassis
 
Hi Oldrat, thanks for your kind words. I do ramble on a bit. :D
No, my intention is to have it back up and running asap (depending on how much it costs!), I was quite surprised at the requests for the chassis, but will be keeping it. Watch this space!
Mark
 
I really enjoy reading these kind of threads and Im intruiged why people put so much time and effort into such unreliable equipment.
I twirl spanners for a living and as a hobby,I like older stuff ,but it has to be reliable to maintain my interest.

I ride a couple of twinshock ty's which are modified from standard but I do wonder at how much of a pre 65 is actually pre 65.
I think ive worked it out, the unreliable bits are the pre 65 bits.:D
 
I too have just found this thread, coincidentally after watching bits of both days trials at the Manx. Thoroughly enjoyed watching it and as you do...started googling 'classic trials bikes'.
 
I really enjoy reading these kind of threads and Im intruiged why people put so much time and effort into such unreliable equipment.
I twirl spanners for a living and as a hobby,I like older stuff ,but it has to be reliable to maintain my interest.

I ride a couple of twinshock ty's which are modified from standard but I do wonder at how much of a pre 65 is actually pre 65.
I think ive worked it out, the unreliable bits are the pre 65 bits.:D

I still have a Whitehawk 175, which will be pressed into service this weekend. The Pre 65 bit of the Twin is just the engine, and bits of that are brand new! One of the engine specialists whom I was discussing my plight with claims that modern piston rings (made for classics) are made of cheese, and he replaces them after six months/when it starts smoking, whichever is sooner. My engine is being collected today, so hopefully will know more soon.
Mark
 


Back
Top Bottom