spud Posted July 3, 2005 Report Share Posted July 3, 2005 This may have already been covered.... does anyone has an opinion on an optimum CC (capacity) for a modern 4t and why? Quote Link to comment Share on other sites More sharing options...
spud Posted July 3, 2005 Author Report Share Posted July 3, 2005 Thank HondaRS. i do have a slight different take on this and considering the lastest Montesa, Sherco and Scorpa only the Sherco is the right size,why?...... A rider called Eddie Lejune (before my time) rode a 360cc Honda against the then Yamaha 250cc. The extra capacity of this Honda gave the machine a winning edge - does this 'winning edge' theory still play true today? Quote Link to comment Share on other sites More sharing options...
woody Posted July 3, 2005 Report Share Posted July 3, 2005 There was more to Eddy Lejeune winning 3 titles on the trot than just the 360 motor in his twinshock bike. That bike was the culmination of a good few years development starting with Rob Shepherd in the late 70s and it was a very special bike right through, not just the motor. And of course Eddy was a pretty good rider... When they went to the mono RTL Honda built Eddy a one-off 360 version but it wasn't successful and was only used for one year. The next year he switched to the 270 works RTL with Steve Saunders. The 360 mono wasn't at all pretty and looked a mess as well. I'm not an engineer so have no idea what the optimum size is but don't see why it has to be 250. The enduro/motocross bikes have no problem with overheating on 400 - 550cc engines so I can't see why a modern watercooled trials engine couldn't be up to 350cc if the manufacturer thought it needed that capacity. There is a lot said about the 4RT being underpowered but I don't think it is personally. I've got one and it will do far more than I am capable of making it do. More than enough power for club riders, enough to finish 2nd, 3rd in the SSDT and enough for Dougie and co. to throw a standard one up some pretty fearsome indoor sections before they got their works versions. A bit more than any national event rider would have to do. Trials isn't all about socket wrenching power unless you're at the sharp end of British Championship or WTC level when a bit extra helps... Incidentally, Lejeune never had to compete against 250 Yams as they didn't have a world Championship rider after Mick Andrews, who was the oldest rider to win a world round in '81 or '82 on the Majesty. Apart from a one-off (fluke..? home bias?) win by Thierry Girard on a mono in late 80s they haven't campaigned at world level since twinshock days. Didn't stop the TY mono being one of the best ever clubman bikes for 10 years or so and it was by no means the most powerful. And I think they sold every one. I would guess that the reason Honda went for a rideable 250 is that there are far more clubman riders out there than experts and a user friendly 250 will sell more than something with too much power. Sales in numbers is what it is all about for Honda. They provide step-up kits for hose that want more power. Yamaha probably opted for 250 as it was an exercise in economics, being cheaper to adapt an existing 250 motor than build an all new one. Obviously I don't know, just my opinion. Quote Link to comment Share on other sites More sharing options...
bikespace Posted July 4, 2005 Report Share Posted July 4, 2005 250 is the capacity favoured by both of the Japanese manufacturers, both of which have been making 4stroke motorcycles for many years, and I would think this is probably the optimum size. If 250 is the optimum size, why's the works bike bigger than optimum size? And if you can specify an optimum size, what's the definition of optimum? The Sherco motor seems to be performing fairly well too, and with carburettor. Is there perhaps a hint of uncharacteristic bias in there HONDArs? Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted July 4, 2005 Report Share Posted July 4, 2005 Woody is pretty much spot on there the 4rt is definately aimed at a larger market, but worringly (for honda/mont/Sandifords) the trials that I have attended are not beginning to get flooded like when the TY mono was about, and after the initial burst they seems not that many new ones about at all, I personally think that it is a 4 stroke thing, alot of riders are happy with a 2 stroke, whatever make. On the hop ups, watching and listening to Laia Sanz's bike this last weekend with every nut and bolt Ti including rear spindle(?), the noise and performance is quite different to a normal 4rt so maybe they will produce an HRC kit foro next year, but they have certainly got the ability to get more pwer out of it, and I would think cc's are the easiest way to do it, which they have probably done already. Quote Link to comment Share on other sites More sharing options...
atomant Posted July 4, 2005 Report Share Posted July 4, 2005 (edited) Theres a variety of questions to be asked before you can arrive at what is the 'optimum' engine size for a 4 stroke trial bike but it goes without saying that adding more HP for a given weight will give more power output. So the question here should really be power to weight ratio. At the moment, the bike with the highest performance for this criteria is the Sherco 4t. Mainly depends on what weight you are and what you want to do with the bike! if your'e 8 stone fully wet and you ride the beginners route.. get a beta 80 Edited July 4, 2005 by Webmonkey Quote Link to comment Share on other sites More sharing options...
atomant Posted July 4, 2005 Report Share Posted July 4, 2005 It would be quite possible to design a large capacity trials motor, with effective cooling system, and appropriate oil capacity what you mean like the Sherco 4t Quote Link to comment Share on other sites More sharing options...
spud Posted July 4, 2005 Author Report Share Posted July 4, 2005 Thanks for the all replies. Would i be right in saying the Montesa and soon to be Scorpa have high revving dirvied engines? I agree, Doug would be able to rev the nuts off a 4rt and get it going places 99% of us never would - as too if he even rode a ty80 he would beat me on that aswell . Picking up on one of the comments, a clubman relies more on a torque power and a bit of mid-range (fair comment?) rather than out-and-out top end power, so do high revving 250cc 4ts engines suit clubman best? Quote Link to comment Share on other sites More sharing options...
atomant Posted July 4, 2005 Report Share Posted July 4, 2005 I have a 4t and ride the clubman routes. I have found moving from the sherco 290 that i can do everything and more on this bike that I could do before, but with a lot less revs. I havent found it necessary to rev the engine to peak revs in any section I have riden as yet. Also, my scoring has dramatically improved in the short time I have had it.. just ask Elwyn A local rider in Llanfyllin trial I rode on saturday had a 4rt and we swopped bikes for a little while. I found his bike to be quite revvy in comparrison but it certainly rode ok. The 4t certainly has more low end torque and pulls through to mid range without any effort whatsoever Im not knocking the 4rt, Its just not to my liking but other peeps like them so its personal preference. IMHO Quote Link to comment Share on other sites More sharing options...
g4321 Posted July 4, 2005 Report Share Posted July 4, 2005 Optimum Size - Is there such a thing when it comes to a trials bike Some guys seem to love the 125 Scorpa - see for example http://www.trialscentral.com/forums/index.php?showtopic=4621 Both the new Montesa and Scorpa seem to have heated debates about which one is best and which one has less faults as new - to me a new bike should have NO faults, if it has I would send it straight back to the dealer - sale of goods act etc, if they cant make a bike in modern times which does not have major problems as regards starting there is something seriously wrong. have a look at the old TLR200 & TLR250, neither are perfect, no-one claims they are but look ahow easily one sells 2nd hand (granted its a twinshock bike) but there is no law saying you cant ride it in a modern trial. perhaps Honda had the correct answer nearly 20 years ago - what modern trials bike will be still going in 20 years, I doubt if its the Sherco given its low oil capacity & whether the 4RT's sophisticated electronics will suffer 20 years of bodged repairs is still open to doubt. Perhaps I am biased (I am) but buy an old twinshock TLR, at least you will get your money back when you sell it - or alternatively buy a P65 4 stroke - any size from 200Cub up to a 500 HT5; perhaps a tongue in cheek suggestion - perhaps not. Quote Link to comment Share on other sites More sharing options...
bikespace Posted July 4, 2005 Report Share Posted July 4, 2005 Perhaps I am biased (I am) but buy an old twinshock TLR, at least you will get your money back when you sell it - or alternatively buy a P65 4 stroke - any size from 200Cub up to a 500 HT5; perhaps a tongue in cheek suggestion - perhaps not. Bloody joking Nearly killed myself on a Cub last year. Not an abundance of power, so you need to get a bit of speed up for big hills if you're carrying a bit of beef. Just getting to flat out when it jumped out of gear, and it's almost unimaginable how quickly a bike can slow down, stop, then accelerate to 350mph backwards when it weighs half a ton. I know....the cub's a lightweight, I've ridden B40's, 500 triumphs, big Ariel's but they are all much of a muchness when going backwards at speed Quote Link to comment Share on other sites More sharing options...
t-shock 250 Posted July 4, 2005 Report Share Posted July 4, 2005 There will be a 280cc kit for the Mont very soon, the works bikes are almost certainly at least 280cc and the old works mono RTL of saunders and Lejeune were 270cc, so it seems the optimum capacity for a trials 4 stroke is around 270-300cc (in Honda's eyes at least) Quote Link to comment Share on other sites More sharing options...
the artist formerly known as ish Posted July 4, 2005 Report Share Posted July 4, 2005 TY yam 250 mono, only sold as a 350 in the states, don't under estimate how many will go for more CC's, it's a powerful selling point. How anyone can say what the pollution law for 2010 will be is beyond me, couple of weeks back it looked like trials in the UK would be all but ended. If anyone who has spent a decent amount of time on the new generation fourstrokes who can't see the potential of these machines in the next few years, will probably be scratching their head and wondering what happened to the two strokes in the next few years. Compare first year fourstroke reliability to that of some first year two strokes built in the last five years. Those of you who want to stick with your two strokes, that's great in my book, but don't try sell me on what you think I or any other person should ride because things are not going how you think they should in the world of trials bike development. I'm ride a fourstroke, because I have more fun on it than I do riding a two stroke, why do you ride your bikes, high retainers, all the bakini clad babes you attract, or the recognition the world sports media give you Quote Link to comment Share on other sites More sharing options...
atomant Posted July 4, 2005 Report Share Posted July 4, 2005 to me a new bike should have NO faults, if it has I would send it straight back to the dealer - sale of goods act etc Hmmm. Have you tried that with your Windows operating system ? Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted July 4, 2005 Report Share Posted July 4, 2005 TY yam 250 mono, only sold as a 350 in the states, don't under estimate how many will go for more CC's, it's a powerful selling point.How anyone can say what the pollution law for 2010 will be is beyond me, couple of weeks back it looked like trials in the UK would be all but ended. If anyone who has spent a decent amount of time on the new generation fourstrokes who can't see the potential of these machines in the next few years, will probably be scratching their head and wondering what happened to the two strokes in the next few years. I'm ride a fourstroke, because I have more fun on it than I do riding a two stroke, why do you ride your bikes, high retainers, all the bakini clad babes you attract, or the recognition the world sports media give you NOT SURE WHAT YOU MEAN HERE? The two strokes are not dead just yet and my bet is they will be around for as long as the Gas Gas pro is significantly lighter and more powerful and better suited to the top European sections. The volume of sales in the uk certainly doesn't reflect the trend you are predicting and montesa/hondas record of less than drastic year on year changes (as per 315) is not going to release that potential you predict, is it? Also what would you have the youths ride, a trailie 4 stroke? Oh yes they have that scorpa already, there is no way that a 125 4t is getting any where near the 125 GG and Shercos can do in the UEM rounds. Look at what Gubian has done since switching to Sherco. Quote Link to comment Share on other sites More sharing options...
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