woody

Yes I'd agree. you don't need an extensively modded engine to make it run well. Decent airbox and exhaust with a reliable and efficient ignition and it will do all it needs to. Tried one a couple of years ago and it had all the power needed for classic events.

No dedicated twinshock events or classic events that cater specifically for twinshocks in the Midland Centre as there isn't a dedicated following unlike other areas of the country but that doesn't mean there are no trials to ride your bike in. You can ride it in any trial that has sections of a suitable nature, essentially any club trial and you'll always find a few other twinshocks at them. Most ACU or AMCA club events will be suitable and if they don't run a twinshock class it doesn't matter, just enter as a Novice/Clubman/Over 40 - whatever you are and ride it on the course that suits you. Some clubs run 2 routes, some run 3, just pick the one that suits. For a bit more of a challenge, the AMCA do a 50/50 'clubman' route where you ride a mixture of routes, the easiest of the harder sections and the rest on the easy route. As has been mentioned, Stourbridge trials are of a gentle nature and good for pre65 and twinshocks and there is one coming up in a few weeks near Kidderminster so may be a good idea to go and have a look. They are always on Saturday afternoons or Bank Holidays. If you want to venture out a bit there is the Peak Classic club in Derbyshire, Herefordshire Classic, Border Classic (Oswestry area) Wilts and Dorset (but good luck to you in getting an entry there...) Golden Valley Classic (Bath and surrounding area) Bath Classic and maybe a couple more I've forgotten. If your're road legal with it there is the Sammy Miller Classic bike championship that has a twinshock class and all events are single or 2 lap trials and offer a good ride around roads and green lanes rather than 10 sections in a field. It's a national championship so the events are spread out but the sections are generally quite gentle and laid out more for pre65 bikes. All of these clubs advertise their events in TMX so get a copy and look through the regs available at the back although you'll usually have to look on the AMCA's own page for details of their events, they're not always in the regs at the back. There is also the calendar on this site for what's on. Main thing is to get out on your bike and enjoy riding it. Whether it is in a twinshock trial or a twinshock class is not important. Enjoying riding it is and there are plenty of events out there.

Best 2nd 3rd 4th 5th This is a nice one too but there isn't a better photo to see it properly. Built in Spain for Magical's 60th I believe and a bit trick I imagine judging by the slimline ignition cover. Must be a lightweight flywheel in there far starters.

picture now added in earlier post

Don't know if this is any use to you but I've attached a picture of a TY250 twinshock stay (presumably a Miller one) that came off my Majesty. Distance between the mounting holes front to back (ie; on one leg) is 10cm centre to centre. Width of the stay is almost 12cm (measured accross the bolt holes from the outside edge of the bracket that contacts with the lugs on the fork leg) Measured with a ruler and the bracket has pulled a bit but close enough for what you need I would think. Hope this helps Won't let me upload the picture for some reason so I'll add it later when sorted out.

I doubt it even though it was never an issue. Rob Shepherd successful in the 70s on the Honda, Lejeune 3x World Champ in the 80s on the 360. Lejeune and Saunders successful again on the RTL Monos winning world rounds but no championship this time. Dougie winning the first outdoor world round on the 4RT and maybe the title but for injuries. Fujinama winning more rounds than anyone in the world rounds last year. Yep, those 4 strokes really struggle. On the indoor circus, Fuji has always been hit or miss and lacked consistency whereas Doug, at one time the most consistent of them all, ever, is probably now past what it takes to win again indoors, consistently at least (and people seem to forget he lost both titles when on the 2 stroke) So it's hard to guess at whether it is rider or bike - as let's face it, none of us actually know, how can we. Indoors is hardly an even playing field anyway as the Spanish riders get far more exposure and practise on the sections than anyone else so they ought to win. Whether Bou wins again all season on the 4RT indoors doesn't matter, he has proved twice, by a large margin, that it can.

There is an Alta on ebay now link insert doesn't seem to be working so the URL is this: http://cgi.ebay.co.uk/Alta-suzuki-trials-b...1QQcmdZViewItem or item number 140077444064

Full lap was reckoned to be about 5km. For the trials bikes that rock section was the hardest obstacle by far. Impossible to ride feet up or even with a few well placed dabs for any of them. It was just a case of maul it through. There were a couple of steep descents just before the rock section, one of which would have been 'exciting' on a trials bike. The other obstacle that caused the enduro bikes problems, the log section, posed no problems for the trials bikes. Colley was the best on this as he carried his front wheel across the gap between the log platforms whereas everyone else dropped off the first and rode back up onto the second. Really impressive. Even more impressive was that he won with no rear brake which he wiped out early on the first lap. For the steep descents he was killing the engine and going down on the front brake with the bike in gear. Having been down them on an enduro bike in the earlier clubman race, that makes me feel sick just thinking about it......

To the letter of the law if it is not displayed in the correct place then it is the same as not having one fitted, it's the same offence - although agreed, better to have it there than not attached at all. I've suffered that one too, again years ago. Tax fell off the windscreen and landed face up on the passenger seat in an open top car. Got back just in time to be handed the ticket by some nazi worshipping **** who said 'I know you can see it but it isn't on display'......... I got done. Good On the number plate front would you be allowed to have the licenceplate printed ona shirt for example?? or tape a rubber/cardboard one duct taped to your back?? No, if it doesn't adhere specifically to regulation then again, it is the same offence as not displaying one. As has been said, the SSDT is a compromise.

I feel this is a topic that should never have been aired as it is going to produce all sorts of arguments and opinions but resolve nothing. Lets be realistic. A trials bike is never ever going to be fully compliant with road traffic regulations. The police in this instance acted reasonably in my opinion and could if they had wanted, thrown the book at any rider in the event, wether they had tax, insurance and MOT or not. There are many things they could have booked riders for if they had a mind to but they didn't. I know this from experience as I had 13 summons many years ago from being pulled up on a TY250. Some derserved definitely but others just total nit-picking but once it is taken forward you're not going to get out of it so you end up prosecuted fair or otherwise. I'm assuming the police knew there was a trial taking place as I understood it to be that they had to be informed of such events. There has to be some leeway in the interpretation of traffic regs with trials bikes and in this instance they were just checking for vehicles being taxed and registered - they could have asked for insurance too and issued producers. Some of the items a trials bike requires to be fitted with to comply with traffic regs are a FULL sized number plated, not a YOU HAVE USED WORDS OR A PHRASE WHICH ARE NOT PERMITTED ON THIS WEBSITE. PLEASE DELETE YOUR POST/TOPIC. DO NOT TRY TO CIRCUMVENT THE FILTERS IN PLACE ON THIS WEBSITE sized one, tax disc on proper display, constant sounding horn and working speedo. All of these things will be wiped out at the first big crash down a section. The police generally recognise this and make allowances (such as the White Rose national in 2005) For the tax disc to comply it needs to be visible at all times on the left hand side of the bike. So how many riders would keep it clear of mud and visible each time they went onto the road - None - assuming it wasn't lying in a ditch somewhere. Everything is at the end of a computer these days so they know if you are legal or not. As far as the SSDT and pre65 Scottish is concerned, bikes are not checked for legality. Last year they had to be fitted with rear facing number plates in the SSDT, such as the YOU HAVE USED WORDS OR A PHRASE WHICH ARE NOT PERMITTED ON THIS WEBSITE. PLEASE DELETE YOUR POST/TOPIC. DO NOT TRY TO CIRCUMVENT THE FILTERS IN PLACE ON THIS WEBSITE plates, at the request of the police but no way were they road legal as they were far too small. They were a compromise. NO checks are made regards insurance, MOT or tax. It is all down to the riders responsiblity. Can you imagine the additional admin for organisers in having to check that information and more in order to ensure that each bike and rider comply with traffic regs. Highland Lassie may have a view... They then become responsible for allowing the competitors to take part so what happens if they have misread or misunderstood a document. None of the organisers are qualified legally to determine whether riders have bona-fide documents or not so imagine if there is an incident that results in legal action - that unqualified person is then liable for allowing the rider to take part. Totally unfair. Responsibility should rest with the riders not the club. As regards car rallies, they are navigation events in name only. There are certain tricks pulled with the timing of stages such as unofficial checkpoints in a stage, where cars are halted for a period of time. This reduces the time they have to complete that stage. The original stage time that could be achieved within the speed limit then becomes unattainable and they then go balls out to complete it on time making it a speed event. On a lighter note, many years ago my mate was competing in a road trial on his Bultaco on the Clee Hills, maybe the Vic Brittain, can't remember. His bike had played up and he was trying to bump start it with another mate down the road. He wasn't remotely legal. Along came a police car and stopped. He though bugger, that's me done. The police took an interest in the bike and were only too happy to help him get it going and get back into the trial. They both pushed the bike with him sitting on it to get it bump started. It did and off he rode. The number plate that was staring the police in the face as they pushed the bike along was BUL 325A......

In case you still need it the pushrod measurement is 112mm long and 5.7mm diameter (6mm?) Measured with a digital vernier. That is the length of one pushrod. There are two of them, both the same size. Don't know the diameter of the ball bearing that sits inbetween them as I couldn't find one but obviously 6mm will be the largerst it is.

Yes, as far as I know the pistons are the same, just need to add the window for the Gripper. I was also told that you had to turn the MAR piston back to front if used in the Gripper otherwise the ring gap would foul the ports but I don't think this is right. I rebuilt a Gripper a few years ago and used the MAR piston and from memory didn't turn it. The skirt height is the sme back and front, unlike the 250. When I bought the bike it rattled really badly from big end and piston but still had good power and pulled very well. I rebult it with the MAR piston but I also used a rebuilt MAR crank that I had as at the time I had no idea they were different. Something was definitely different though as the bike just wouldn't run right at all. It was better before I rebuilt it. It wouldn't pick up cleanly and it used to spit back. Couldn't do anything with carb or timing to cure it and evetnually sold it. Perhaps it was down to the ignition flywheel keyway in the crank being in a different position from the MAR meaning I was never going to get the timing right. Only way to tell would have been to put them side by side and compare but don't know what happened to the Gripper crank. Similarly it would have been interesting to have compared the original piston that came out of the Gripper to the MAR one, but I threw it away before the new MAR one arrived. Be really interested to know if anyone knows for sure (none of the dealers/specialists did that I asked at the time) as I will surely aquire another one one day and I'd like to know how to rebuild it properly next time.... Look forward to seeing pictures of your finished Gripper

What is the difference, dimensionally, between a Gripper 350 piston and a MAR 350 piston. I don't mean the window in the back of the Gripper, just the measurements. Some say they are the same, some say they are different. I remember having one of each and they both appeared to be the same. Also, are the 350 Gripper and 350 MAR crankshafts the same. Again, opinion differs on this. There is supposed to be some sort of difference between them, maybe the flywheel key is in a different position? Both bikes have the same bore and stroke Do you know Roberto?

Sitting in queues at sections

Imagine, if you slide the yokes all the way down the stanchions as far as they will go, the front of the bike will drop and the front wheel will be pulled in towards the frame. The angle of the forks in relation to vertical will be reduced making the steering respond quicker. This also has the effect of making the bike a little more unstable in a straight line as the steering will deflect more easily of rocks or bumps etc. If the yokes are slid all the way up to the top of the stanchions the steering angle is increased as it raises the front of the bike, pushing the front wheel away from the frame, therefore the steering responds slower - imagine a chopper. This means the bike is more stable in a straight line as when the front wheel hits rocks or bumps it responds slower and doesn't deflect so easily. Look at an old Bulto and Ossa for a comparison, the Bulto has the front wheel pushed out and has good straight line stability up rocky streams, but steers a bit slow for tight nadgery stuff. The Ossa has the wheel pulled back more with a steeper steering angle and is quicker steering in nadgery setions (but obviously is still bloody brilliant up rocky streams due to a superb chassis - an unashamedly unbiased view) Reducing rear spring preload has the same effect of sliding the yoke to the top of the stanchions, it drops the rear of the bike, raising the front making the bike more stable in a straight line and slowing down the steering - more applicable to racing disciplines rather than trials though. Go too far at the back though and the bike will just float at the front which will be too light and stable won't be the expression you're looking for....

The Bulto forks take a bit less oil than the Ossa (maybe due to the shorter legs?) Book recommends 200cc I think in MK1 or MK2 Ossa forks (as per bike pictured) I use 180cc generally with 10W as this gives a relatively soft action but as with most things it is all down to personal preference so you could use that as a starting point. The MK3 and onwards had longer forks so usually 200cc as a starting point for them.

Come on, somebody must have some pictures and I'm gagging to see them

I'll have a look for one and measure it next time I'm out in the shed, sometime during the week probably Alternatively, you could try Ellastone Offroad, A&B Autos, Mainly Spanish or Sammy Miller, as all have used Ossa parts and would most likely have pushrods

Well if everything works ok, you've a good useable twinshock for a pretty good price there. In case you didn't know, the engine number means it is a 250. I noticed there was a question mark over the engine size in the ebay questions. Good luck in the greybeards, I'll look for the Gripper in the results.

Honda UK possibly, as they were Honda commissioned bikes and sold through the dealer network. Or try the Vintage Motorcycle Club who are able to date off-road bikes and their certificate of dating is accepted by DVLA for age related plates. Worth phoning them and asking the question. http://www.vmcc.net/ For shocks I'd use either Falcon or the new Rockshocks for good quality and action

There are 3 rear wheel bearings as standard, 2 on the sprocket side and 1 on the brake. This is with the original dished sprocket fitted. If you have the flat sprocket and carrier conversion then there is an extra bearing in the carrier itself, so you have 3 on the sprocket side and 1 on the brake side. No Ossa MAR wheel I have seen has had 2 bearings on the brake side. 6201 is the right bearing size. Length of the spacer depends on whether you have the original dished sprocket or the flat conversion, with the dished sprocket the spacer is obviously longer. As there is no spacer on the brake side, it is just a case of measuring the gap on the other for the length of spacer required. Clutch push rod is actually 2 rods with a ball bearing in between. Don't know the sizes off hand but if I can find one I'll measure it. Both rods are the same size. Original style skid plate you'll have to hunt around for as no-one stocks them but Steve Goode has a new old stock Renthal which is just as good, the only difference being it doesn't have the raised sides like the original but that means that it is possible to remove the side casings without dropping the bashplate like you have to with the original type. It is probably just the plate itself and you would need the front mounting brackets from the original plate.

You don't say what bike you're competing on and this changes the perception of how difficult the series is. If you're on a modern bike I'd suggest that any of the sidecar rounds, with the exception of the Peak you will find a bit on the soft side as they don't offer much of a challenge to the better twinshock/pre65 riders. Personally I wish they'd drop them as it seems they are only classic rounds to bolster entries and make the sidecar trials viable (I've nothing against sidecars but the sections in those events aren't set for the solos) Of the remainder:- Newquay Cornwall - long way to go and one of the easier rounds. I rode it in its first year and it was too easy, didn't go last year and I was told it was better. I'll go again this year. It's only just outside Newquay so you could make a weekend of it. Lancs County and Bootle - two of the best rounds and both on the same weekend this year so an overnight stop up in Lancs or Cumbria necessary. Well worth it though. Both are hard but not in the bike or limb mashing way. They are technical sections and mainly rocks (streams, outcrops, gulleys) and can be energy sapping. You have to be line perfect or lose marks, that's where the difficulty factor lies. Once you start centipeding they can be energy sapping and that is when the scores can rise. Welsh Trohy - If Rhayader club run it then it's not to be missed as even though it is a sidecar trial it is perfect for the solos too. Good mix of sections. If Mid Wales run it then it is generally too easy but if they do, it is still at Rhayader this year so who knows. When they run it it is normally at a different venue. Phil King - Colchester. This has been a cracking trial in the past but often criticised as being too hard. It was always held in February so copped the worst of the weather. Big banks with big climbs and descents which are hard if wet - and they were. Personally I loved it even though the Ossa was lacking in the brakes department - some exciting descents. Now in April so should be drier like last year. Still good sections, mainly muddy streams and big banks (but drier in April - maybe...) Alscott Cup - Tavistock in Devon and another of the best rounds with a very good mix of sections from rock outcrops, streams, big banks, roots, mud. Worth the trip definitely. Hillsborough - Sheffield - Another of the best and most difficult, again not because it is intimidating, just due to the sections being technical and requiring precision. If you're on it you save energy. Mainly rock streams but one or two bits of muddy banking. If you're not and you're legging with the bike you get tired - as per Bootle. Peak - North (very) Derbyshire - Not one of my favourites as it all comes down to the last group but others love it - just a personal thing really. Not as hard as Bootle/Hillsborough but hard enough for most I think. Just going back to the severity of the sections, Twinshocks will cope with the sections no problem with competent riders aboard, the Lancs County round was won by a handy bloke on a 175 Yam last year and Phil Wiffen, twinshock champion, generally beat most of the modern bikes on his 300 Fantic. Unless you're anything other than pretty handy, as far as a pre65 bike goes you need a well fettled one. On a standard bike most will struggle. Obviously modern bikes will have no problem with the sections but the riders have to be 'on it' to beat the better twinshocks and that bugger Thorpey. I'd say give the series a go as it will be something new and gets you out of the usual routine. If as Dabster says, you are the same standard as Phil then you'll cope no problem.

Thanks for that I've just found the details of last year's trial on the website. Entries came out on 16 Jan and could be downloaded from the site. Closed 3 Feb. Maximum 180 but twinshocks capped at 40 so I think I'll enter on the C15 in Pre65 as more favourable odds in the ballot

Has anyone got any idea when the regs for the Manx Classic come out and where to get them from. In previous years, by the time I've found out they are out the trial is already full.... I'd really like to do it this year along with the Manx National and make a week's holiday out of it as I've never done either. I e-mailed the club yesterday so waiting for their reply but just wondered if anyone on here knew - or even has a set already....

It's a Gripper, all they've done is modify the swingarm and shock mounts. Frame is nothing like a MAR. This along with the colour, missing tail pipe, seat and seat/unit, probably makes it look worse than it is as besides that, the rest of it looks in sound condition. Good forks and wheels, exhaust, engine cases etc. Obviously the mechanical state of it is unknown but if it sells for around that price it would be a good basis for a rebuild. Any more and it becomes too expensive and too much effort to put back to original as finding the missing parts will be hard. However, it's also a good basis for a special. After all, bikes did have mods carried out to them at the time they were current and it's nice to see modified bikes as well as standard ones. All this one needs is the shock mounts and positioning tidied up and it would be something different. Not sure about it being a common mod though.... Never seen another one like it. Beautiful Gripper Roberto.