Abergavenny Christmas Trial December 27 2006

Abergavenny Auto Club Christmas Trial

27th December 2006

A good entry of 45 riders forced themselves away from watching Steve McQueen once again failing to jump fences on the Swiss border, to have a go themselves in the mud and streams near the Welsh border at Park Farm, Llangattock Lingoed.

The 8 sections were set-out in the main streamway through the farmland, with steep and slippery slopes , a couple of waterfalls, tree roots and rock steps for all. Section 1proved to be the hardest for the Sportsman, running on the easiest of the three routes, with a very slippery exit that got worse as the trial went on. Only Bob Griffiths, on his way to a convincing win, managed to get through the end cards on each lap. The Clubman had a tight turn, but a longer run up to the slippery slope, with a number of cleans. Sections 2 to 5 continued up the stream, with the steep drop at the start of Section 2 proving interesting for the drum brakes of the twinshock contingent. Sections 6 to 8 were on the other side of the stream, with section 7 having a long muddy exit which got easier once a deep furrow had been ploughed though it.

There was little difference between a clean and a 5 on most sections and maybe it was because of this that experience won through from the Clubman route, with Merthyr’s Martin Jones taking the win by three marks from fellow club member Nick Morgan. Course Plotter, Matthew Johnson and Alistair Bedford were the only pair to tackle the Expert route, both riding well on a demanding route.
The ever enthusiastic twinshock contingent were out to beat current Wye Valley champion Alan Gould, who put down his below-par performance on the day for being on the ‘wrong’ Honda TL250. Paul Mahoney on his Yamaha came out in front, narrowly ahead of Brian Johnson on his Fantic 200, who was making a welcome return to riding.

Abergavenny AC would like to thank the landowner for letting us use the land again, and to the Landlord of the Hunter’s Moon, Llangattock Lingoed for putting on the food after the trial. He wasn’t expecting so many, but neither was the club The club will be running a 6 round championship in 2007, at some excellent venues in Monmouthshire.


Matthew Johnson 35

Youth Expert
Alistair Bedford 78

Martin Jones 12 , Nick Morgan 15, Nibbs Adams 15, Shane Carless 22, Dai Bedford 23

Robert Griffiths 17, Alan Thomas 32, Steven Andrews 36, Justin Fowler Bishop 51, P J Griffiths 53

Paul Mahoney 46, Brian Johnson 48, Kevin Petit 52

Youth Sportsman
Gavin Griffiths 61


Modifying the Rear Shocks

The standard rear shocks on the Honda are a little longer than normal, around 14.5″. However, most replacements are 13.4 – 14″ long. The bike had already been modified but needed some more work to get the balance of the bike right.

After Gavin rode the TL at the Rhayader Experts it did same that the bike was nose-diving into the rocks, and there was little Gavin could do about it (accept trying to hold on). Taking a side-on look at the bike, the rear-end of the bike was sitting up in the air.

Existing rear shocks

The original shocks on the Honda TL125’s are quite long in comparison to most other trials bikes. The previous owner of the bike had welded on a plate on each side of the swingarm to fit a pair of short 13″ shocks. After having the bike for a while, in a rare Zen moment on the art of setting up trials bikes, I realised that the rear shocks were basically, rubbish.

Being the thrifty rider, I ordered a pair of “Clubman Trials” from NJB Shocks which were about 14″, which I then fitted onto the top of the plates. The new shocks were a lot better, but the bike didn’t look right and the front did seem to be tucking under.

Removed the welded top bolt on the plate and drilled another hole in the plate on each side of the swingarm about 15mm lower. Then fitted a 10mm bolt, with a rubber spacer between the swingarm and the shock; having the bolt not attached to the plate means that it could adjusted depending on the size of the shock.

Next stage is testing, but the bike looks to be more balanced and seems to turn ok.

The 3rd SWM

A couple of weeks ago I went to look at a 1982 SWM TL320 in Wiltshire that Martin Matthews had put me on to. It was original going to be something for a friend, but after a couple of weeks deliberation I decided that I’d get the bike. Its a couple of years later than my other 280cc and the work of restoring it had already been started by the current owner.

Its a 1982 TL320 which has the Pernod blue frame, to reflect the factory sponsors at that time. Its got the Rotax 280cc disk valve two-stroke motor that these bikes had been using since 1978.

I guess my reasons for buying the bike were:
– its a complete, nice example
– that some of the restoration work had already been done
– that though the Jumbo’s not finished, it would be soon
– that I would like to overhaul my existing TL320 in the first few months of 2007

Anyway drove down to pick the bike up, most of which was in boxes and crates. The good things about the bike are that the frame has been powder coated and the wheels rebuilt. The blue of the frame isn’t as good as the Jumbo frame that Redditch Shotblasting did, as its slightly too light and non-metallic. The wheels have been done by Central Wheels and have new rims and spokes and the hubs have been powder coated.

On the Shelf

The front forks and yorks have been overhauled by an Ohlins repair specialist and do seem to be in excellent condition and work well. The engine was checked out by Martin Matthews a couple of years ago and shouldn’t need a strip down.

There is also a spare frame, in the original paint, the has a couple of dings in it. The plastics are all ok, including the tank, which is in better condition that the other one I have. The seat is a solid rubber item, which had changed from the cover padded seats on the earlier bikes.

No rush to start work on the bike, as there is a Jumbo restoration to finish off first, but hopefully it will not be as much work (or expense).

In the beginning…

It has begun….

Having just got married this summer it seems appropriate to use the following phrase:

“My affair with all things trials, Honda and twin shock has begun”

Lets get the pleasantries out of the way:

My wife would like to thank my good friend for introducing me to my new aquisition
and the focus of my attention for not some considerable time I think…
I also would like to thank my good friend for the new collection of bent metal parts currently residing in my shed, that in the early seventies resembled an attractive little machine to say the least.

The project:

Fettled from the Honda stable and rising from the enthusiasm for trials in an era when the Carpenters and John Denver ruled the airwaves and chain guards were a necessity for those who preferred bell bottoms. The little Honda with its small simplistic four stroke engine and with parts still reasonably available seemed a perfect place to start my introduction to observed twin shock trials.
I have to admit though, that I have more than a little enthusiasm for the lovely little Honda. Currently awaiting a thorough going over, piece by piece it sits in all its original glory.. if only bikes could talk…

So what happens next ?

A fan of maintaining as much originality as is practical on a small budget I am going to attempt to illustrate the restoration of my Honda TL125 K. With my mechanical roots in classic car restoration, mostly early Triumphs, I have not set my sites on a bike project until now…. Make no mistake I am very very new to the trials scene and so I apologise in advance for any errors and rest assured that I am seeking guidance from those around me in the know and the mine of information that is the internet… which brings me to this site where I will be posting as many articles on my project as I can… I hope that this will provide an entertaining read and a bit of enthusiasm for those who want to give it a go.. I am hoping that piece by piece the little bike will come together and finally give me an insight into the trials and tribulations of a Honda tl125… (yes well I had hoped to slip that one in earlier..)

The first thing to do is put the kettle on make a nice cup of tea, walk around the bike a bit and then put the kettle on again… all of the important bits are there bar a few of the rarer bits and the engine turns over with a kick on the kickstart….

So the first thing to do in any project is to assess… the assessment in this case is mainly focused on the engine.. the plug is new and a bit sooty, there is compression and the engine oil looks surprisingly clean so someone has obviously tried to revive it at some point. Plug cap off, spark plug out and we have a healthy looking spark with a couple of kicks with the plug earthed on the cylinder head… good. I have decided that it is safe to fire up the engine as it does not appear to be seized and the oil looks good, no severe leaks or obvious ingress of water/filth either so it should be a good test for noise/smoke and other symptoms. There is no throttle cable and the carb looks a bit antiqued.. So this means that its off with the carb, a Keihin 20mm, a simplistic little thing it seems at first but after gaining the necessary access to it by removing the seat, air box and the two securing nuts it seems that its just not budging… in the end I removed it with a couple of very light taps from a rubber mallet and some gentle wiggling… The cause of the tricky removal is clearly seen to be distortion of the mounting plate caused, as I would later be expertly informed: by the carburettor mounting nuts being over tightened. After removing the screw top of the carb it is easy to tell that the carb slide is well and truly seized in its barrel and I am slightly worried that the overtightening of the mounting nuts and distortion have extended to the carb body and thus wedging the slide.. apparently this is a common fate for this type of carb on the early TL’s the basic fix for which is a replacement item!. After a generous soak in a suitable penetrating oil to my glee the slide moves freely up the carb body and reveals the needle and main jet below… a further strip of the carb involving removal of the bowl reveals a mass of gunk and gloop not entirely unexpected on a machine of this age and condition. As I am writing this the carb is stripped and sitting in a bath of petrol where all the sticky residue is slowly but surely being removed… once this has been done I can start to assess the condition of the individual components.. more to follow soon including some pictures……

SWM TL350 Jumbo: Wheels and Brakes

The wheels on the bike were a little scruffy, as where the hubs. The brake pads themselves useless, so should a case of just cleaning them up.

The wheels on the bike have stainless Akront rims, with steel spokes. The spokes all seem tight and didn’t really need much in the way of work, though they are a little rusty in places. Swapping them for some stainless ones at somepoint in the future may be desirable. The rims, the front especially, were well marked, so looked to clean them up and get out the Autosol for an hour or so of cleaning to see how they came up.

I ordered new break pads from MotoSWM and cleaned out the hubs. Removed the glaze using some wire wool and just general tidied up the wheels. I also replaced the front and rear wheel bearings and as the front in particular seemed a bit worn. The bearings are standard sizes, but got those from Martin Matthews.

I also replaced the front and rear tyre clamps, as the original one in the rear (the front didn’t have one) had little rubber on it. They are WM-2 1.85 sized clamps and I got them from LG Racing in Pontrilas, who are a local Motorcross / Enduro supplier who travel out to lots of events and run a mail order business.

I also got the tyres from LG Racing and went for a Pirelli MT-42 front and a Michelin Trials Competition rear. This is a cheap combination (£30 and £49 each) and I like the Pirelli fronts. They are a stiffer tyre and having used them on the Honda in the past know that the rears are not as good as some modern tyres. Michelin X11 Trials Comp’s or IRC’s are probably better on the rear, but are an extra £20 and may not make a real difference except in the long run.

SWM TL350 Jumbo: Top End Overhaul

The initial run of the bike was dominated by a noisy top end. Whats going on ?

During the initial fire-up of the Jumbo, I didn’t have the mid and rear box of the bike attached; just the front pipe. Though it was a little loud, as Gavin my not too near neighbour heard me fire it up from inside his house and it had my ears ringing after, you could tell there was some noise from the top end.

The first run around the garden confirmed that there was a bit too much noise and Gavin confirmed the diagnosis as piston slap. So, 24 hours after getting it all running, the engine came out of the bike for a top end strip, which took me around 45 minutes. Don’t think you can get the piston out with the engine in the frame, as you wouldn’t get the barrel off.

Confirmation that the little end bearing and the gudgeon pin were worn, but I’d seen this during the rebuild. More seriously was the gap between piston and barrel was way to large and more and the 0.08mm tolerance. Now, I’d looked at this on reassembly and both piston and barrel looked good ok, with no wear marks on either, though confess to not checking the ring end gaps, nor the piston to barrel clearance.

Out with the vernier; with the barrel at around 84.10mm. The piston is marked at 84,17mm (note continental decimal point) and is an Eckoh piston, made in Austria. The piston is in good condition, but not the right size.

An email to Peter Knight later, Rotax man in the UK and it seems that the original piston size is 82mm (?), with 4 possible overbores. These are 82.25mm, 84mm, 84.25mm and 84.50mm. There for this barrel was somewhere between 3rd – 4th rebores.

Therefore decided to go for a new piston and 84.25mm piston, with rings, new
gudgeon pin and small end bearing all ordered from Peter Knight. So waiting
for delivery of these before reboring the piston and putting the bike