old trials fanatic Posted January 27, 2011 Report Share Posted January 27, 2011 (edited) I've always hated the term Pre65 and welcome the idea of "British Twinshocks" so if you do too what eligability critera would you have? I'll start you off with my ideas. Engine : Obviously must be based on crankcases, barrels and heads as produced by the British Motor Cycle Industry prior to 1970. Copies allowed but must comform at least in exterior appearience to the original item. Internals: free. Ignition system: free. Carburettor: free but no fuel injection. Clutch must be cable operated. Gearbox free. Frame : Must obviously be twin shock and made from steel. Shock position free but shocks minimum 340mm max 360mm. Wheelbase without rider to be minimum 50". Ground clearence without rider to be maximum 14" no minimum. Seat height without rider minimum 28" no maximum. Mudguards free but must provide adequate cover to the tyres. Chainguards must be fitted but material free. Petrol tamk material free but must be mounted above the engine and have a minimum capacity of 5 ltrs. Oil tanks free. Seat optional. Forks : Telescopic : Maximum stantion diameter 35mm. No leading axles the front wheel spindle must be below and in line with the slider. Otherwise any fork legs allowed. Yokes free. Leading link forks also acceptable of any make. Brakes : Drum brakes only cable operated front rear cable or rod operated no hydraulics otherwise free. Tyres : Must be in compliance with ACU handbook. There you go at least something to start us off. Perhaps we might even get the ACU to adopt if we ever get concencus. Be interested in your thoughts. Edited January 27, 2011 by Old trials fanatic 1 Quote Link to comment Share on other sites More sharing options...
02-apr Posted January 27, 2011 Report Share Posted January 27, 2011 (edited) Why rule out certain genuine Enfield fork sliders? I only ask as the twice I took a pretty standard Bullet round the Pre '65 I certainly didn't feel advantaged in having the spindle forward of the centreline. Edited January 27, 2011 by 2/4 Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 27, 2011 Author Report Share Posted January 27, 2011 (edited) Why rule out certain genuine Enfield fork sliders? I only ask as the twice I took a pretty standard Bullet round the Pre '65 I certainly didn't feel advantaged in having the spindle forward of the centreline. Dont have a problem just trying to stop people using TY monoshock or Marzocchi forks out of a Fantic. However see your point. Might need to make an exception for Enfield forks on Enfields. Then again if i remember Tony Calvert did win the scottish "Pre65" on a cub fitted, some may say fiddled, with leading axle sliders which may have been from an Enfield. By having a leading axle you can steepen the head angle considerably giving better steering but i take your point. Edited January 27, 2011 by Old trials fanatic 1 Quote Link to comment Share on other sites More sharing options...
monty_jon Posted January 27, 2011 Report Share Posted January 27, 2011 All seem good common sense rules. The only one I don Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 27, 2011 Author Report Share Posted January 27, 2011 All seem good common sense rules. The only one I don 1 Quote Link to comment Share on other sites More sharing options...
monty_jon Posted January 27, 2011 Report Share Posted January 27, 2011 It would make the sport more accessible to people on a limited budget Like me Quote Link to comment Share on other sites More sharing options...
andy m Posted January 27, 2011 Report Share Posted January 27, 2011 And for those wanting to knock up some forks that work... Look you can still buy the fork bottoms and sensible money. http://cgi.ebay.co.uk/ROYAL-ENFIELD-BULLET-PAIR-FRONT-FORK-END-LEGS-LH-RH-/170423915609?pt=UK_Motorcycle_Parts&hash=item27ae0e9459 Quote Link to comment Share on other sites More sharing options...
tony283 Posted January 27, 2011 Report Share Posted January 27, 2011 Glad we sorted out the Enfield legs ! ..... and the wheelbase, as the Enfield was up there at 55.5" Better make sure you have Greeves and DOT forks as acceptable even if they were never desirable! Tony Quote Link to comment Share on other sites More sharing options...
scottishsteve Posted January 27, 2011 Report Share Posted January 27, 2011 my honda tlr is fitted with a fantic front end disc brake i think its worse than a drum brake.i would love to put a honda front end back on but its the price that puts me off. Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 27, 2011 Author Report Share Posted January 27, 2011 Glad we sorted out the Enfield legs ! ..... and the wheelbase, as the Enfield was up there at 55.5" Better make sure you have Greeves and DOT forks as acceptable even if they were never desirable! Tony Good point i wrongly assumed that nobody would want to ride with leading link forks but i take your point and have amended the post. Again thanks for pointing out my omission. 1 Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted January 27, 2011 Report Share Posted January 27, 2011 Hi Guy's Hi OTF. Nice one, at least I have someone on my side at last. It Should be "British Twin-Shocks", from now on then, and roughly the formula that you have started. I only included 38mm fork legs as Max in my rules, as If you need a cheap pair of forks for a bike classed as, before that dreaded date, you can pop 38mm fork tubes straight into Norton sliders. did'nt you realise that?? Regards Charlie. Quote Link to comment Share on other sites More sharing options...
broony Posted January 27, 2011 Report Share Posted January 27, 2011 Spot on OTF ,lets hope it catches on,then riders will be able to ride anywhere without the threat of the Pre '65 Police . cheers the noo Brian Quote Link to comment Share on other sites More sharing options...
totalshell Posted January 27, 2011 Report Share Posted January 27, 2011 whats wrong with the scottish p65 rules for rigids... original frame no mods original engine etc etc.. too much 'free; in your vision otf for me. all you you'll end up with is new frames new hubs new forks and an engine that resembles something made before 1970.. not pre 65 as i'd want it.. and a lot more expensive than it is today a specials builders paradise.. back to basics withe the scottish rigid rules followed on by pre unit then unit then two strokes in 5 - 10 years everyone would be riding brit bikes again.. Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 27, 2011 Author Report Share Posted January 27, 2011 whats wrong with the scottish p65 rules for rigids... original frame no mods original engine etc etc.. too much 'free; in your vision otf for me. all you you'll end up with is new frames new hubs new forks and an engine that resembles something made before 1970.. not pre 65 as i'd want it.. and a lot more expensive than it is today a specials builders paradise.. back to basics withe the scottish rigid rules followed on by pre unit then unit then two strokes in 5 - 10 years everyone would be riding brit bikes again.. Hardly anybody rides rigids round here so didnt really take them into account as there are so few of them. Perhaps i should have? How many of those in the scottish have "original frame with no mods" seen a few exact copies made in T45. "all you'll end up with is new frames new hubs new forks and an engine that resembles something made before 1970.. not pre 65 as i'd want it..." and you think we dont have that now??? Err "and a lot more expensive than it is today a specials builders paradise" sounds like you are describing the current scottish Pre 65 to me. My proposals would allow people to use freely available components and then build a competitive bike without resorting to all the "fiddle" stuff then trying to make out it's something it's not as is currently rife at the scottish. Give you a perfect example of whats wrong with the ridiculous term Pre65. A mate turned up at our last trial on an AJS 37A which is most definately NOT Pre65 so wouldnt be allowed to ride if we all adopted the scottish debacle. But why ? the bikes a rubbish example of why the British bike industry went down the toilet and is no way any advantage over a Pre65 legal James. At least if we got real and adopted British Twinshocks then there would be no question of legality the same was that Cheetahs are also illegal in the Pre65 world but why should they be? theyre in the spirit far more than all the "specials" allowed to enter the scottish event. 1 Quote Link to comment Share on other sites More sharing options...
old trials fanatic Posted January 27, 2011 Author Report Share Posted January 27, 2011 (edited) Hi Guy's Hi OTF. Nice one, at least I have someone on my side at last. It Should be "British Twin-Shocks", from now on then, and roughly the formula that you have started. I only included 38mm fork legs as Max in my rules, as If you need a cheap pair of forks for a bike classed as, before that dreaded date, you can pop 38mm fork tubes straight into Norton sliders. did'nt you realise that?? Regards Charlie. hi Charlie didnt know you could but if you go above 35mm then you open it up to Sherco, Gas Gas, Beta whatever forks. Is that really where you wanted to go. Cartridge forks. 8" of fork travel etc? As for Norton sliders you could use them if you wanted but the formula i was looking at would allow you to use forks freely available from motor cycle breakers countrywide for half the cost of a pair of Norton sliders alone which have only been used to legitimise fiddle forks so far. Plus 38mm stiffens the torsional strength of the forks which i feel takes us into a whole new ball park. The crux of my proposals was to try to make British Twinshocks more affordable by eliminating the need to hide modern components making them look sort of period which is where most of the exorbitant cost of pre65 comes from. Edited January 27, 2011 by Old trials fanatic 1 Quote Link to comment Share on other sites More sharing options...
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