David

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The RB22

History

Since the release of the Rapido kits, we have been conducting research and looking at many concept ideas for a new design of cylinder. With the TS1 reaching it’s 20th birthday the time seemed right. We wanted to make the new kit something very special, to offer TS1 owners a really significant upgrade.

We tentatively approached a number of companies we believed capable of producing our new kit with our ideas and concept drawings. We were amazed at the level of service and involvement one particular company was able to offer us. Airsal fast became our favourite; being family run they understood our passion for our work. They provided a technical experience and manufacturing knowledge that allowed us to quickly work through many ideas. The resultant concept was beautiful and intimidating. The early dyno charts gave some indication of what was to come. However knowing that dyno figures only bear the most tenuous link to real world performance we were very keen to get the kit on the road.

< Dyno chart without figures>





With collection of the first sample at the Cologne show, our excitement and anticipation was almost unbearable. We had worked very hard to keep our work secret, and had not released the name of the company we were working with to anyone outside of Rayspeed. Even so Airsal’s stand was visited several times before we arrived by some clever Germans, members of the scootering press, and a number of dealers and wholesalers. Airsal were amazed at this level of interest in a single product. It is for them unprecedented.



Once back in the country we worked as efficiently as anticipation would allow, getting the first RB kit fitted. Steve Riley (our expansion specialist) made up an exhaust for the new kit in record time, and our TS1 test engine was rebuilt as an RB22. The first test ride was very pleasing. Ray came back with a big smile. The second run was recorded and used as a teaser on our web page, showing just a few seconds of footage. Later this video was updated again as we refined the set up. Extensive testing has been carried out on the RB22 kit and although the graph shows a vast increase in BHP over the TS1 this does not mean that on the road the TS1 is much slower. It merely reflects the different characteristics of each engine.



Technical.



The RB kits like the TS1s are an aluminium casting with Nikasil plated bore, reed valve induction and a bridged transfer layout (An explanation of this layout is provided on our web page devoted to the TS1). But the similarity ends there. The design is completely new, it is not a development of our existing work, it shares more in common with the technology in motocross and snowmobile cylinders.



<Image of Cylinder>





Transfer Feeds

One of the most significant features of the new cylinder is the addition of feeder ports between the inlet port and the entrance to the transfer ports.



<Image of transfer to feeder windows>




This allows us to get a flow in to the transfers that would not otherwise be possible without significant modification to the 200cc crankcase. More so than any other aspect of the design, this feature allows us to push the boundaries of what is possible on a standard crankcase.



Reed Block

The RB reed block was designed to offer exceptional flow characteristics and a very quick response. This was achieved by using a W or dual design. In comparison to a more conventional reed blocks the dual block has twice the area of petal tip. Giving a greater flow rate from a smaller movement of the petals. This also contributes to the reduced spit back of fuel through the carb, and more importantly allows the cylinder to make the most of its transfer feeders.



<Image of Reedblock>





Transfer ports,

The transfer ports on the new kit have been shaped through extensive testing at Airsal to achieve the optimum duration, angle and width to work with the other features of the cylinder.



<Image of port layout, specifically transfers and boost>





Boost ports

The twin boost ports of the RB cylinders work in conjunction with the transfer ports to efficiently scavenge the cylinder.



The Triple Exhaust Port

Testing led us to a triple port layout. We tried a more traditional single port and altered shapes but found the addition of the two side ports gave the cylinder exceptional high rpm performance whilst maintaining the lower rpm power delivery. The 60° angle of the port, directing it at the combustion chamber helps both the flow of exhaust gas and the strength of the pressure pulse utilised by the expansion system.



<Image of Triple Exhaust port>





The Inlet port

The size of the inlet port and its direction are critical to maintaining the (air fuel) mixture velocity through both the inlet and the transfer feeder ports. So retaining the low rpm characteristics of the engine and still supplying ample flow at the top end of the rev range.



<Image of the Inlet port>




The Piston

For the 225cc RB22 Kit we have chosen to retain the Asso Werke Piston produced for our TS1 225 kits. This piston has demonstrated exceptional reliability and performance in our road and race TS1 kits over the last 20 years, and in testing of the RB22.



The 250cc RB25 will have an all-new Asso Werke piston designed to ensure the RB25 has exceptional high rpm characteristics and smooth power delivery. More information on this kit will follow later in the year.



Sum of its Parts



To ensure our customers get the best out of this new kit, both in terms of performance and reliability we recommend that only experienced mechanics fit these kits, and that customers follow the advice given by their local dealers.

On release of the kits we will provide a base specification we consider to be the minimum required. With many optional extras to tailor the kits to the individual.



A selected number of specialised dealers with proven experience in performance engines and who showed early interest in the kits will be the first to receive them. This will give them time to test and develop their own components . So they can best advise and help their customers.



At the time of release we will have two exhaust variants available. One will be for lower rpm and focused on making the kit easy to ride and we anticipate this being the most popular (this is the exhaust shown in the video clips). The second expansion will be designed for hi rpm for those who want road race style performance. I’m confident that the various exhaust specialists through the country will rapidly develop a range of expansions to suit different applications.



We have full confidence that the RB22 offers a fantastic level of performance with a sublime power delivery ideally suited to those customers who want a fast road Lambretta that is a pleasure to ride with others, but can also provide that adrenaline-fuelled grin when the throttle is wound open

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Grande nouvelle: il est produit par airsal en ESPAGNE!!!!!!!
http://www.airsal.com/ c'est des potes de Patrick en plus!!!!! cool pour le Biz RS

en plus pour les boost ports ils nous ont copie desus. juste 3 lumieres en + a l'echappement!

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monte sur un scoot d'essai




pas cool: la pipe a l'air de toucheer le cadre!!!!

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étonnant qu'ils lachent autant d'info et aussi vite, à part ça, ça ressemble beaucoup aux modif de Pat sur le TS1 de Sam.

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