Power to Weight Ratio

[RICSPEED]

at 6'4" I feel a bit silly on a smallie though

Mate,was on a rideout last Sun and when you see the parkas with targets on,lights mirrors etc a tall bloke on a smallie is no worries.Go for it it.If you think you look silly,think how the Lammie owner will feel when you blast past him!!

[tony]

I'm currently 9 1/2 stone. but I hope to be 9 by next race seaon. Bike however is quite a fast 'snail' with 72 kgs and 33hp .

[willwander]

With a Lambretta Series III/GP weighing in at 125kg and a Vespa GL/Sprint weighing just 90kg thats a difference of 35kg 0r 5 stone, how much power would the Lambretta need to have the same performance as a 25 bhp Vespa?

34.7 bhp?

Using your figures would give a P/W ratio of (0.126 hp/lb).
According to wikipedia space shuttle has a P/W of 93 hp/lb !

BTW I weigh 8 stone

[gadgetman]

Thanks for that it,s about what I thought. We are talking about Large Frame Vespa NOT Small Frame ( Small Frame Vespas are an amazing 50 - 55 kg lighter than a Lambretta or 8 and a half stone lighter).

[tony]

not race ones.. but yes maybe road ones.

[gadgetman]

Your bike is quite incredible Tony and I've seen how it powers past other scooters from the start line on the track. It highlights how much weight effects performance , in particular acceleration but when we talk about performance surely it's weight that also governs stopping ability and also cornering to some degree so why aren't we seeing more Vespas winning the trophies instead of the usual Lambrettas. Is it weight distribution ie to keep the front wheel down, than pure power to weight ratio that is more important?

[sean brady scooters]

i,m sure tony would agree that wheel base and weight distibution is really important also..
tonys small frame presumably has good weight distribution overall but can only be a challange to handle with 32BHP and such a short wheel base...
its testimony to his riding skills that he can ride it so...

[tony]

firstly thanks sean but I assure you I just hang on..
Re the trophies ....due to work I only raced twice this year. Hence no chance of trophies. however.. the bike is quick enough to go from 24th on grid to 2nd in less than two thirds of a lap at Cadwell the sunday before I decided to bin it on the oil put down by a classic bike.
Apart from the first time I raced it at Anglesey 08(where it set 3rd fastest lap) it has never finished below third despite always starting from bloody row ten or something. I've never had a front row start. So this power to weight (and drag coefficient) really does come into play.. As sean said tho .. the short wheelbase and light weight makes it a complete handful. You have to adapt. Also I have to set the suspension to cope with the power and high speed corners where the bike handles great.. but the compromise is having a very hard set up for the slower ones and this can cause probs.