studio208 Posted December 2, 2017 Report Share Posted December 2, 2017 On 4/30/2004 at 6:07 PM, t-shock 250 said: 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! Heyyy.... I'm 62 and still tinkering with my my vauxhaul.... (actually it's really a megane rs265 8:08 or was until I sold it to buy another Trials bike) Quote Link to comment Share on other sites More sharing options...
turbofurball Posted December 2, 2017 Report Share Posted December 2, 2017 On 3/5/2004 at 11:15 PM, eric23 said: I miss the disk brakes, hydraulic clutch and ergos of the modern bikes ... Well, can't speak for the brakes, but certainly my clutch and ergos are fine thanks to throwing the right parts at it ... in fact, I'm getting to the point where it's not very far from the TXTPro for my level of riding, lol As to the subject at hand, perhaps instead of trying to define a slippery fish there could be a standardised set of handicaps, so you can enter on anything but the more fancy features your ride has the less likely you are to win? So, say, unit construction engine adds 5 points, disk brakes another 5, etc, so that people not being competitive can ride an aircooled monoshock with disks, and super hardcore types can ride an old Ariel 500 and really fight for their position? 1 Quote Link to comment Share on other sites More sharing options...
still trying Posted October 16, 2018 Report Share Posted October 16, 2018 I'm not directly affected by this discussion as I'm not in the UK. However we also have "Twinshock trials". As a bucket list project I designed and built a bike, using the motor, wheels(drum breaks) and front forks/ triple clamps from a KT250. It is a very modified / modern looking bike. (this causes much debate at trials, but as I don't take points, no hassels,... sofar). I laid the shocks over and moved them up and in. (Mass nearer the C of G and narrowed the swing arm 40mm, frame 50mm at bottom and 80mm at seat (motor is still fat as ever) . Saved 15kg from original bike The shock position has no progression and the travel is10mm more than a stock honda tlr250 My interpretation of Twinshock is; The technology must be of the period, (exception being motor spark system). Air cooled motor Drum breaks Cable operated breaks & clutch unless proof of use in period Rear shocks MUST bolt directly to both frame and swing arm, with little or no progression from the mounting points / layout. Anyway these are my thoughts on the subject You can see my bike in the projects section on this site. The end result really only gave me a bike that rides like a well sorted twin shock. Funny that!! Quote Link to comment Share on other sites More sharing options...
feetupfun Posted October 16, 2018 Report Share Posted October 16, 2018 2 hours ago, still trying said: I'm not directly affected by this discussion as I'm not in the UK. However we also have "Twinshock trials". As a bucket list project I designed and built a bike, using the motor, wheels(drum breaks) and front forks/ triple clamps from a KT250. It is a very modified / modern looking bike. (this causes much debate at trials, but as I don't take points, no hassels,... sofar). I laid the shocks over and moved them up and in. (Mass nearer the C of G and narrowed the swing arm 40mm, frame 50mm at bottom and 80mm at seat (motor is still fat as ever) . Saved 15kg from original bike The shock position has no progression and the travel is10mm more than a stock honda tlr250 My interpretation of Twinshock is; The technology must be of the period, (exception being motor spark system). Air cooled motor Drum breaks Cable operated breaks & clutch unless proof of use in period Rear shocks MUST bolt directly to both frame and swing arm, with little or no progression from the mounting points / layout. Anyway these are my thoughts on the subject You can see my bike in the projects section on this site. The end result really only gave me a bike that rides like a well sorted twin shock. Funny that!! I love experimenting with twinshocks too so know where you are coming from. I'm currently making (probably less drastic) changes to a KT and would love to see photos of your "KT". I'll go looking in the "projects" section About your specifying non-progressive rear suspension, if that was an actual rule then the early 1980s OSSA gripper would be excluded, because it has positive rate rear suspension geometry. Also the Godden Majesty 250/320 has negative rate rear suspension geometry so not having progressive geometry is probably not something that could be used in any rules without excluding some completely standard twinshocks. With the brakes there are lots of standard twinshocks including the KT that have a rod actuation for the rear brake so probably shouldn't make cables compulsory for brakes. 1 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted October 16, 2018 Report Share Posted October 16, 2018 First thing I noticed when I found your KT, still trying, was that it only has one shock!! Hard to be a twinshock without two shocks, or maybe it's just an optical illusion there is another one on the other side of the muffler (out of view) Very interesting design and yes it sure makes the motor look big Quote Link to comment Share on other sites More sharing options...
still trying Posted October 17, 2018 Report Share Posted October 17, 2018 Oops, forgot about rod actuators, Cables and rods, maybe it should be equipment that was available at the time. So you could use a disc system off a period road bike, That would be heavy, huge, and in the way Yes my KT is a twin shock. If there was only one shock it would be way too soft (couldn't fit a big enough one in), and the top shock mounting bolts also connect the bottom / back frame (the box section bit) to the backbone. The twinshock guys said you could build your own frame (I think they envisaged a replica), so I sketched and doodled at work during breaks, (didn't intend to actually build it) until I thought, "I've got to build this". I learnt a lot, picked up a new skill (beating panels into petrol tanks), and gained a lot of respect for the guys back then who developed bikes. 2 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted October 17, 2018 Report Share Posted October 17, 2018 I must say I'm impressed with your workmanship, especially the fuel tank. Making stuff yourself is very satisfying. I've wanted to try making an aluminium trials bike tank for a while and seeing yours is motivational. Back on the rules. Over the ditch, we've got a manufacturing date cutoff for "twinshock" bikes (1 Jan 1987) which would be a problem if you wanted to ride that bike competitively over here. Apart from the rules there is always the "pub test". Not sure if this happens in other countries but it definitely is a thing here. Years ago TV reporters doing an opinion piece would posit "what would the man in the street think?" The official legal term is "what would a reasonable person think or do under the circumstances?" But the "pub test" sounds lots better to me because with any luck, she or he will have had a few drinks and be quite prepared to share their thoughts about any topic. I haven't had a drink tonight so I'm probably not the right person to be sprouting off one way or the other. 1 Quote Link to comment Share on other sites More sharing options...
b40rt Posted October 17, 2018 Report Share Posted October 17, 2018 Rule of thumb :- any modifications I make are ok, anything that goes one step further is cheating. ??? 4 1 4 Quote Link to comment Share on other sites More sharing options...
section swept Posted October 24, 2018 Report Share Posted October 24, 2018 On 30/04/2004 at 11:54 PM, old trials fanatic said: 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. Well for me you hit the nail squarely on the head....each bike is as different as it’s owner. Every modification made by the owner gives their bike a bit of character, I don’t mean bought online mods, but those modifications the owner has made to improve...for them....the bike. These mods could be the exhaust or different fuel tank, frame mods to the original one and engine and drive line mods. As you say “ there’s a bit of me in the bike”. The latest bikes would only have the bling trick bits that everyone can obtain, unlike the mostly unique mods actually made by the owner. I contacted a club secretary to seek advice about removal of the lower frame rails under the engine on a twinshock of 1972 manufacture. Their reply was that it was a common mod in the day so would not affect legitimacy when the rule book was reasched for. I also think that when all the bikes look similar just as they do from about 97-98 onwards it’s just the riding gear that different. Even the engines nearly all sound the same, both 2 and 4T. Thats something else that provides character with twinshocks and pre 65’s, you know that there is going to be many different engine notes crackling around a course. With reference to your second from last paragraph, I just wonder how some of the ‘old’ talents eg Miller, Smith, Andrews, Peplow etc would get on with the latest bikes and the hopping about and how the Toni Bou’s etc might fare on the old irons! 1 Quote Link to comment Share on other sites More sharing options...
section swept Posted October 24, 2018 Report Share Posted October 24, 2018 On 03/05/2004 at 11:02 AM, j@mes said: thanks nigel didn't spot that one. there just not teaching us well enough in school now Maybe the words should be ‘They are just not paying attention well enough in school nowadays’! Quote Link to comment Share on other sites More sharing options...
turbofurball Posted October 24, 2018 Report Share Posted October 24, 2018 51 minutes ago, section swept said: ... and how the Toni Bou’s etc might fare on the old irons! Something LIKE THIS, perhaps? 1 Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted October 24, 2018 Report Share Posted October 24, 2018 Good to see that the youngsters can still do on a twinshock what Bernie was doing all those years ago. Quote Link to comment Share on other sites More sharing options...
section swept Posted October 24, 2018 Report Share Posted October 24, 2018 3 hours ago, 2stroke4stroke said: Good to see that the youngsters can still do on a twinshock what Bernie was doing all those years ago. That move had to be developed from somewhere....the schriber flip. 8 hours ago, turbofurball said: Something LIKE THIS, perhaps? To do that on that bike and then to repeat with the latest machinery would be like riding a feather. Quote Link to comment Share on other sites More sharing options...
scifi Posted October 29, 2018 Report Share Posted October 29, 2018 Quote... Rule of thumb :- any modifications I make are ok, anything that goes one step further is cheating. Showing my age a bit, but I remember a time when if you raised the ground-clearance, it was frowned upon. It should be worth stating in the rules that a seat of 1 inch or more thickness is required... But who needs more rules... . Quote Link to comment Share on other sites More sharing options...
turbofurball Posted October 29, 2018 Report Share Posted October 29, 2018 1 hour ago, scifi said: It should be worth stating in the rules that a seat of 1 inch or more thickness is required... But who needs more rules... Some of the last twinshocks had seats less thick than that! Quote Link to comment Share on other sites More sharing options...
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