RB20 as a tourer ?

[TrackTen]

Hi guys

Are any of you using a RB20 on the road as an every day do everything scooter including distance work

Or do you consider your RB20 as something to get out for a thrash only ?

[dscscotty]

Contrary to popular believe RBG 20's are a very versatile kit, yes they are considered to be high revving, thrash about kit, however they are as all 2 stroke very dependent on the type of exhaust system which in my experience can be tailored to alter the power delivery of the RB20 to a more subtle touring type motor.
We (Tem DSC/Darlington SC) currently run two RB20 kitted motors in the LCGB production class along with around 20+ other competitors and to date there has been no failures relating to the kit the kit, they are able to run possibly the tallest gearing on the BSSO grid (4.8 and sometimes over) and rev to around 8400/8800 with the pipe used for class-(Franspeed Race) and produce good torque in relation to rpm and power spread. So with this gearing at around 7000 rpm, road speed is around 70mph.

The RB20 gives a very smooth power delivery mainly due to the 116mm conrod /low compression height piston used and fitted with something like a Franspeed RB touring pipe or even the race can in fact make a very good touring engine.

Good Luck!

Scotty-DSC

PS- her's some footage of our production class RB20's, if you listen to the rpm you should hear how well they pull from low RPM, they also handle the relatively large gap ratio wise of the Indian GP200 gearbox which is a requirement of the class regs, this was at Anglesey race circuit which has some pretty steep inclines up which all the production class RB's pulled very well.

https://www.youtube.com/watch?v=f40yvfg ... ture=share

[TrackTen]

Hi Scooty

Thanks a lot for your reply.

That's an impressive reliability for a high revving kit.

I didn't realise you had to use the Indian box in the class - I am wondering about the Pinasco cluster in my road version I am planning. I am very seriously tempted after seeing what the new Chiselspeed RB Pipe did on the dyno and then riding the result on the road ( RB225 though ) on a scooter I have ridden a few times before with a Fran ST. I think the RB20 with the new pipe could make a very nice road scooter.

Any tips when building one of these - are you running the AF crank and Prox piston ?

[dscscotty]

Hi there,
I tend to use the black MEC/Ricambi type webs which i build myself, although in saying that AF etc,ones are fine if loctited or tigged, my preference piston wise is the Wossner,

[corrado]

I've got one in a road scooter but it was built with sprinting in mind [on a budget]. AF race crank, Wossner piston, PHBH 30,Franspeed race and 5.00 final drive. It performs fine on the road and even around town, all down to how quickly you turn the twisty handle.

[Norrie Bodge]

As title
A mate gonna chuck some ££££ at his S1 soon
He’s considering goin with the RB20 kit & using a 60 stroke crank & wants a box pipe adding !!
What’s the best options on box pipes for the RB Kits to give a tourer setup ?
Cheers

[dscscotty]

Hi Norrie, regards using 60mm stroke, this will increase port durations which are considerably high on rb20's, consider using a longer rod than the 116mm required for the kit, this will enable the cylinder to be adjust for poet heights/durations more suitable for touring/box pipe use. Regards box pipes suitable, I'd recommend Ron Moss, ST, although the use of box pipe will dramatically reduce the bhp available from these kits.
Scotty DSC

[Norrie Bodge]

Thanks for reply Daz
What about using a 60x118 crank mate ?
To give even more options with port timings & an increase in CC
Cheers