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What Is A Twinshock ?


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Hi

One question, i know this might sound a bit daft, but what actually constitutes a "twinshock" ?

Let me explain. Just look at the Cotswold Majesty for example or choose your own. Here is a bike which undeniably is a "twinshock" (it has two rear shock absorbers) but it was made this century.

So are twinshocks anything with two rear shocks? Do they have to be manufacturered before a certain date? Must they be aircooled? When we say manufactured which bits do we actually mean?

After all there are many aftermarket frame kits around. Some replicas of the originals, some of works frames, some just very light and tidy.

You see where i am going with this is why couldnt you modify a TY250 mono and fit two rear shocks? or any other bike for that matter?

I am currently building a B40 and have fitted an Otter frame from Faber marketing. I have some Bultaco forks in perfect nick so they are going in the front. The wheels are conical hub ones i think off an old SWM i used to have and they are fitted because they were in my garage were in good nick and were in effect free.

So is this still a "twinshock"? Well i think so as all the bits came off a twinshock and in the late 60's and early 70's the bikes were modified with whatever came to hand that was lighter and better.

I have tried to find out a ruling re pre 65 and thats almost impossible never mind a classification of a twinshock. It all seems to depend on the club. One club secretary commented "We dont really bother. As long as i looks like one thats good enough". OK but from how far away and what does a twinshock look like anyway?

Early monoshock Yams, Fantics, Armstrongs etc etc are now cheap so what if you converted one ?

Anybody tried it. B)

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Whenthe Falcon twinshock series started (the present classic series evolved from this) one guy did conert either a RTL or a ty Mono to a twinshock, the loophole was soon stopped by stating that the machine must have originally been fitted with 2 shocks mounted on the swinging arm I think.

It all depends at what level you wish to ride, I guess, if its just for club trials who cares if you want to make a monoshock a twinshock sounds woftam to me though.

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To some extent i agree. It was just the discussion on "Which is the best twinshock" that made me think.

In some respects its an arguement for a National regulation for what is a twinshock.

This all came about because i decided, mistakenly probably will wait and see in two weeks time when i do my first event for 20 years, to take up trialling again and couldnt see myself hopping about and leaping up sheer rock faces. Ahh i thought twinshock or pre 65 thats for me.

So whilst rebuilding an OSSA i found out the bits are like hens teeth, the Cota isnt much better so i bought a Bultaco based on the fact that Bultaco UK seemed to have a good range of bits. Then it dawned on me that believe it or not B40 stuff seems plentiful so here i am with a B40 in bits but getting there. But what bits do you fit and what dont you?

Received a brochure from Majesty moto the other day and though the stuff looks great i started to think are disc brakes and

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I don't think that Sherco forks or discs are in "the spirit" of a twinshock at all, and why anyone would want to spend that amount Of Time And Money is byond me.

If you are thinkining of getting back into trials buy a modern bike and forget the prep and maintainence hassles. A pal has a montesa hardly used for 1600 ready to go, enjoy the riding. there are quite a few bikes like this and parts are easier to get than a twinshock.

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It's easy to see why people spend time and money on old bikes, it's their interest, their hobby and they want to make their pride and joy look a bit different to the others. It's exactly the same as thousands of spotty youths up and down the country "modifying" their vauxhaul novas!

At the end of the day, modifying old trials bikes any amount won't make you a better rider, but people ENJOY tinkering with things, especially motorcycles!

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Our club rules state that a twinshock bike be a 1975 or later model, have twin shocks, drum brakes and air cooling. We've had some debate and disagreements over this rule, particularly as to the division between twinshock bikes and vintage bikes. I'm of the opinion that the 1975 date is a couple of years too early. There were a number of Japanesse bikes coming onto the market in that era that really are vintage bikes (my TY175 for example). There needs to be a distinction between the first generation Japanesse bikes, the earlier Bultacos, Montesas ,and MAR's, compared to the SWM's and Fantics of the 80's. I'm looking forward to reading the opinions of this post, the leadership of our club might find them enlightening.

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If you are thinkining of getting back into trials buy a modern bike and forget the prep and maintainence hassles.

I am also going down the Twinshock road. I could buy any modern Bike and win Trials every other week, but it's not about awards. I have an attic full of plastic trophys already.

I have a family now and can't afford to travel all over the coutry riding nationals, I want to pull a bike out the garage every now and then and have a laugh.

If I turn up to a Trial on a modern bike people will expect me to win - myself included, after a while the enjoyment fades and it starts becoming a chore. Hopefully with the Twinshock there won't be any expections to win, especially if I ride the expert route.

I don't know why Eric and others want to ride Twinshocks - hey perhaps they enjoy it!

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I'm with you on that one Steve. One of the reason i havent gone out and bought a modern bike, goodness knows i would have probably been cheaper, is also that there wouldnt be anything of me in it. Well probably the odd skinned knuckle. Rebuilding a twinshock and modifying it IS a major part of the attraction. To me anyway. Along with the enjoyment, hopefully, when you ride. Like you i would feel under much more pressure, mostly from myself, to try to win which is not what i am looking for anymore.

The reason i started this thread was i have found it almost impossible to find what exists in almost ALL other forms of motorsport a regulation or concise discription of what does and what does not constitute an elegible machine in this case a twinshock.

Loads of differing classifications, almost as many as there are clubs. Some dont even allow plastic mudguards.

It needs clarification as otherwise things will get out of hand and the chance to just have a relaxing ride without ending up bankrupt or off work injured will be gone. Just as it did in the 80's when i packed up trials. OK due to a lack of talent and the ability to hop skip and jump. Then again if i wanted to go trick cycling i would have bought a BMX bike.

Some interesting comments coming though. Keep it up guys after all thats what a discussion forum is for after all. B)

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In terms of twinshock regulations, the only ones that exist from the ACU as far as I know are for the National championship. As Dabster has mentioned these just state that the machine must have been manufactured orginally using twin shocks. Not sure about their positioning. There is no mention of disc brakes as far as I know but I wish they would state they aren't allowed as they give an enormous advantage on sections where brakes are an asset (Phil King for example with huge drops down steep slippery banks with little run off at the bottom. No brakes = 5) It just enables people with engineering skills or money to fit them and gain an advantage. Twinshocks didn't have discs and for the National championship I don't think they should be allowed. Club trials is a different matter and it is down to individual clubs what they allow. Most modern clubs won't care as they just want people to ride and enjoy themselves but if it is a classic club and they have a championship then I think again - no discs.

I'm not actually sure how much further the last/youngest twinshocks can be modified or improved in anyway other than what you would call minor tweaks to footrest position, shock angle/position, steering angles, exhausts etc. Engines on most have more than enough performance, front suspension units all worked very well by then so there's not that much to do. I don't think there is a problem swapping period components over, eg; 300 engine into 240 Fantic, fitting front forks and wheels from other makes, as it could all be done at the time but where do you then draw the line. An engine from a 305 into a 240. Engine from an air-cooled mono beta into a t/s 240. Yes or no? Neither was available in the twinshock period ie; pre '85. I have a spare Majesty frame and a TY Mono engine. I was going to build a Majesty using that engine as the last works Majesties were 6 speed and a different engine entirely from the Majesty lump, and different frame too I think (Peter Salt rode one in the early Sebac days) It would be a sort of copy of one of those but I'm not sure if it would be 'cheating' or not although it is again something that could have been done at the time as Yam monos were out in '83.

As regards the Cotswold Majesty and the ER, my own view is that it is nice to see another variety of bike out there which is at least within the spirit of the game. They're different, as they're new and it adds interest. OK, they can be fitted with modern Paoili forks but I don't think they give that much of an advantage. However, they don't have discs and it is still something that could have been done at the time with any fourstroke engine in a mini Majesty frame.

This is an interesting debate which could provoke all sorts of argument/thoughts but for me the biggest issue to address is no discs in the National championship before they creep in. The next issue for me is to address the routes and classes in that championship before it turns turtle again but that is for another thread.

PS Dabster, that Yam mono with the twinshocks grafted onto it is alive and well and still being ridden down in the Wilts area in Bath Classic and Golden Valley events. Yes it's ridden in the t/s class and as you'd imagine is oh so slightly superior to the more legitimate tackle...

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I am also going down the Twinshock road. I could buy any modern Bike and win Trials every other week, but it's not about awards. I have an attic full of plastic trophys already.

I have a family now and can't afford to travel all over the coutry riding nationals, I want to pull a bike out the garage every now and then and have a laugh.

If I turn up to a Trial on a modern bike people will expect me to win - myself included, after a while the enjoyment fades and it starts becoming a chore. Hopefully with the Twinshock there won't be any expections to win, especially if I ride the expert route.

I don't know why Eric and others want to ride Twinshocks - hey perhaps they enjoy it!

well said Steve, I'm not really into the T/Shock thing myself, but I have just bought myself a Scorpa 125 for much the same reason as you mentioned in you last post.

It's different form the norm and it's a bit more of a challenge to ride than the latest 290 Sherbetamonta all singing dancing bike.

I've been riding a few of the ACU Classic rounds recently and it's great to see the boys out on the T/Shocks and riding them hard as they were meant to be ridden :D

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some one in my club has built up a bike which looks like a mono with no seat etc but has a tl 200 engine in it or something. it also has to falcon shocks on the rear. rides twinshock category on it.

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I don't know why Eric and others want to ride Twinshocks - hey perhaps they enjoy it!

I initially bought the TY as an inexpensive way to get back into the sport. The bike never ran that well and needed a complete overhaul. A good deal on a modern bike came along at the same time as some money came my way. I loved my modern bike until it got stolen. The thieves wanted nothing to do with the stack of TY parts, leaving me with no option at this time other than to get on with the rebuild. So now I'm back in the game with the TY175. I miss the disk brakes, hydraulic clutch and ergos of the modern bikes, and will buy one when the time is right. Meanwhile the TY is just going to have to do, and you know, being out there riding with your buddies beats the hell out of the alternatives :D

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