All info supplied courtesy of AF Rayspeed/ UK

The RB20, RB22 & RB25 Kits

The Kits

	RB20 kit The RB20 Kit is made up of a 66mm cylinder, a two ring vertex piston kit, an inlet manifold, a dual reed block assembly, and a top end gasket set. This kit is intended to be fitted to the 125cc, 150cc, 175cc crankcase. Offering dramatically improved performance over the standard. This engine is very smooth and free reving making it easy to put the power down and exhilarating to ride. This is the highest level of performance we offer using the small crankcase. This kit will need a number of other main engine components changing in order to allow it to work and remain reliable. For a full break down of our tested specification click here.
	RB22 Kit The RB22 Kit is made up of a 70mm cylinder, a two ring Asso piston kit, an inlet manifold, a dual reed block assembly, and a top end gasket set. This kit is intended to be fitted to the 200cc crankcase. It offer a significantly higher power output than standard . This engine offers an exceptionally rideable bolt on high performance set up. With a wider powerband and higher peak than our TS1 and acceleration all but the most highly tuned engines cannot stay with. Click here to see our recommended specification. Alternatively call us to discuss a specification to suit you.
	RB25 Kit The RB25 Kit is made up of a 72mm cylinder, a two ring forged Asso piston kit, an inlet manifold, a dual reed block assembly, and a top end gasket set. This kit is intended to be fitted to the 200cc crankcase that has been machined to accept it. It is our most powerful RB kit and as the top of the range provides truely exceptional performance. This kit runs with a 60mm race crank. Click here to see our recommended specification. Alternatively call us to discuss a specification to suit you.

The History | The Technology

To see a full specification of our RB engines please click on the logo below.

The Road/Race NK offers the higher rpm peak power and operates between 6000 rpm and 9000 rpm making it ideal for fast fun riding and top speed. This is our most popular choice.

The Rally NK offers it's peak power lower in the rev range than the Road Race NK, operating between 5500 rpm and 8500 rpm. This pipe helps bring the peak power of the bike slightly lower to help with fast touring use.

The Fresco offers a smooth easy to use power delivery between 5000 rpm and 8000 rpm. This pipe is the easiest to use around town but still offers a lot of fun. With the power lower down the range the rider doesn't need to 'try' as hard to get the performance out of the engine.

Other pipes are being manufactured by a number of suppliers to help keep up with demand. Currently available are Andy Francis's Franspeed pipe in both Road and Race spec (the race spec is lovely). PM Tunings Fat Mamba (very impressive and surprisingly useable) and Reedspeeds modified JL3 and a few others we have not had chance to test. RS Performances, B- Race, Pro Porting, MB Developments, and a number of others will also have exhausts available shortly.

Exhaust choice has a large impact on your choice of gearing, always discuss your intended engine specification and intended use with your local scooter shop, ourselves or a professional engine builder to ensure the parts you've chosen will work together how you expect.

Below is a selection of dyno runs superimposed upon each other. This gives some indication of the level of performace of each of these kits. However it should be pointed out that this does not accurately translate to on road performance and should only be considered a very rough guide. We have intentionally removed the scale as often once people have see outright figures they can have trouble seeing anything else.

The 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.

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.

The Technology
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.

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.
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.

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.

Boost Ports
The twin boost ports of the RB22 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.

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.

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..

The name chosen for the new kits will be the RB22 (for the 225cc variant) and the RB25 (for the 250cc variant).