Sherco 4 stroke.

[Jonala]

Here are a couple of links on the new bike.

http://www.repsolypf.com/eng/bienve...tualidad/noticias.asp?PaginaID=62600&nivel=00


There is a video which I haven't seen because of my 56K modem.
http://www.trials.co.uk/4strokes/4ttrialwmv.wmv

 

[Rich Rohrich]

That's a pretty cool video. If you want to PM your address I'd be happy to burn it to CD for you so you can check it out.

 

[Jonala]

Thanks Rich,

I was able to see the video at work.

 

[Rich Rohrich]

Here's some additional info on the Sherco 4t
http://www.sherco-moto.com/mailnews/0804/index.html#noticia_1


Because of the FIM changes in the current regulations – which promoted the participation of bikes equipped with four-stroke engines in the World Trial Championship in the near future, Sherco started to develop a new bike that will surely become the future of the Trial specialty.
Sherco has repeatedly shown a taste for challenges, and this was a really exciting one. This is the reason why, unlike others, Sherco stopped chasing victories at any cost two years ago, concentrating instead on the task of designing and developing a new 4T engine capable of convincing even the most skeptical. Sherco has also tried to avoid any kind of inferiority complex when comparing the 4T with the 2T. The 2T bikes will still be available, due to market demand, while regulations still allow this situation. Moreover, the 2T 2005 Trial model lineup has been completely and thoroughly renovated and have passed the Euro2 official approval, the current 2T models are approved until the year 2008.
However, Sherco is convinced that the 4T engines will be dominating the sport in the near future, and our main objective is to become the front-running firm when the 4T engines start their reign. Today, Sherco – using our proprietary designed engine and chassis – owns the most compact, reliable and efficient 2T bike in the market, and it would be a shame to waste all the effort behind it. This is why the main goal of the Sherco Trial 4T designing team – led by Josep Rovira Paxau – has been very careful to ensure that the 4T mechanism is perfectly adapted to the existing cycle part. As everyone can see, this goal has been fully achieved.

What has been the key to this success? Undoubtedly, the fact that the designing process started from scratch. Just like we did when we entered the trial category, and when we designed our enduro bike – unlike other trademarks -, we did not simply resort to adapting an already existing mechanical base. Instead, we worked with the idea that to obtain maximum efficiency we needed to design an entirely new engine. Designing each component specifically for trial has always been the best way to create an engine which is, at the same time, perfectly apt for trial practice, and perfectly adaptable to a cycle part which has proven its efficiency throughout several years. The new Sherco Trial 4T engine is as compact and light on the outside as it is efficient and reliable on the inside!

The results that Josep Rovira Paxau wanted to obtain were the same goals he has always pursued: mechanical simplicity and maximum efficiency. Right now, there is no other reference in four-stroke trial mechanics. Therefore, trying to use an already existing mechanical base was out of the question. The only premise – which guided the whole process towards finding the ideal formula – was that the new 4T engine had to be, at least, as powerful as the two-stroke Sherco 2.9 (272 cc). After testing different combinations of material, systems and components, the final internal measures were decided: 82mm-diameter bore and a 60mm-stroke; that is to say, a super-square engine with a short stroke and 317cc. A lower cylinder capacity would make a four-stroke engine much worse than a two-stroke engine, especially regarding its dynamic qualities. This high cylinder capacity provides a powerful engine, while the four valves ensure excellent ventilation and, at the same time, a high rpm potential (if needed). The cooling system is liquid-powered, the timing gears are driven by a Morse chain controlled camshaft (maximum reliability) and a VHST 28mm Dell’Orto carburetor takes care of the intake system. Despite the knowledge about electronic injection that Sherco has acquired – thanks to the Enduro 4.5i -, the lack of similar systems in the trial category advised against its use. After all, using a conventional carburetion system ensured that there would be no problems at all and it would put the minds of the customers at ease. Finally, after working together with Leonelli to design a programmable digital ignition system, the usual retention problems with four-stroke engines have become a thing of the past – at least, that’s the case with the Sherco Trial 4T. With this bike, trial can be practiced inside a range of 1,400rpm and 2,500rpm, thanks to the incredible response of the engine, which provide outstanding traction capabilities. And if the road we are riding needs an rpm increase, the Sherco Trial 4T provides it easily and quickly, thanks to the four valves and to the lightness of the engine components.
As we have already stated, one of the keys to success of this bike is having taken full advantage of the cycle part from its two-stroke counterparts. This is a good proof of its compactness and lightness. This way, the frame is a perimeter-type double loop with a rectangular-section steel tube, and an aluminum swingarm. The main difference resides in the front braces of the frame, which are now detachable, and make the engine easily accessible.
The front suspension is controlled by a conventional 38mm Paioli fork. The rear is controlled by a progressive system with links that act on a Boge rear shock absorber. Both wheels are equipped with disk-brakes.
As a result, the new Sherco Trial 4T is practically identical to its Sherco 2T counterparts regarding size and dynamical performance, and its weight is only increased by a few kilograms, thanks to carefully selected materials and to individually designed engine parts. Broadly speaking, the 4T weighs just 2 kg more than the 2T but, considering the fact that the new exhaust pipe weighs 1 kg less, the new Sherco 3.2 4T is still lighter than most of the rival 2T bikes in the market.

As difficult as it seemed, Sherco has done it!

Hi Res picture here (it's BIG :) ) http://ds1.downloadtech.net/cn1052/dwn_mailnews/0804/32_01.jpg