Cyclone gearing.

[10 inch Terror]

Hi all, I'm toying with the idea of fitting a Cyclone into a spare Imola engine i have laying around. It was a fun little engine in 1st, 2nd and 3rd but always ran out of steam in 4th. Engine spec: 15/46 with Italian 150 pacemaker box, NK race and 30mm Del'orto carb. I've been looking at final drive ratios for the Cyclone and i can pretty much get the same final drive as i have now with the pacemaker box. My only concern is if both boxes produce the same final drive then surely i'll just have the same issues of it dying in top gear or am i missing something here? Could anyone with a bit of experience / knowledge of these boxes shed any light for me? Thanks in advance Pete.

[wack 63]

I would have thought you are under geared,ie lots of revs ,low speed in top? I built 2 Imola's when they first came out ,one with GP 200 gearing the other with SX 150 with bigger sprockets and they were both 70 mph + bikes . Have a look here and perhaps try the 18 x 47 option to see how it pulls http://www.lambretta5speed.com/gear_rat ... io_P3.html

[10 inch Terror]

Hi wack, I'm actually using 15/46 not 15/47 as originally stated (now edited) As I've already said it goes well in 1st, 2nd and 3rd but it just screams in 4th and doesn't seem to go anywhere. What would be your recommended final drive figure? Thanks for your help thus far Pete.

[wack 63]

I would have thought somewhere between 5:0 to 5:2 would be a good starting point for top gear with the NK race

[10 inch Terror]

I would have thought somewhere between 5:0 to 5:2 would be a good starting point for top gear with the NK race

The closest I can get to this final drive with the standard Cyclone is either 4.97 with 18/46 or 5.27 with 17/46. Is there a massive difference in these drive ratios? I was thinking start with 4.97 and if thats no good try 5.27 as it will only be a case of changing the front sprocket and chain and I have plenty of those as spares in my shed. I'm hoping it's a simple as that cheers Pete.

[Andy W]

Hi
I run an Imola with Li150 gearing and 16/47 primary gives 4.99 final ratio, it will pull 70mph quite easy and go on to just over 80 realtime speed. We had it up to 98mph on Dan's dyno, but there is no wind resistance there. When it had GP150 gears and 15/46 sprockets it would accelerate rapidily in all gears then run out of steam about 70 in 4th, I changed this to run 17/46 giving 5:1 final and it was a lot better. When I rebuilt in to a new casing and had Dan fast road tune it I fitted a Li box and new sprockets.
I am interested to see how yours goes with the Cyclone fitted. Andy