Ex, Polizia V50

My ex police V50 (1979 MkII) goes quite well but seems to be very under geared to me, 50mph at 5000 rpm or so. Is this the way they are and how was it done? in the gear box or back bevel? Or maybe both, what if anything can be done about it?

I wonder if its got the lower ratio bevel from the V35 rangeI just looked in the big book of guzzi and it says the V50 PA engine has a lower compression ration to make it more tractable top speed 150Km/h the standard bikes diff ration is 3.875is the ration stamped on the bevel housing anywhere

I know the Monzas are longer geared than the regular V50s but mine (Monza) is geared at 10mph/1000rpm in 3rd. Consequently, it’s a gear I use most of the time. 4th is useful for cruising on A roads. I rarely, if ever, use 5th.

I thought all small blocks used the same final drive (diff) and that the main gearing alterations were made at the primary reducing gear that sits in the bell housing between clutch and gearbox input shaft with just minor differences and updates within the gearbox?

If this is incorrect, please let me know as I am planning to use a V35 diff on my Florida build. The Florida diff is in poor shape, trying to save money.

Anyhow, if I am correct, the way to change your V50 gearing is simply to replace the primary reducing gear. Not a small job though, need to separate the gearbox from the clutch and remove the bell housing for access. This require some special tools.

I thought the only difference in the small block diff was that later versions have a modification to improve oiling of the pinion bearing.

Please correct me, those who know lawries2014-05-23 07:03:43

Ok well this got me worried so I dug out the bible.

The final drive casing was updated in 1987 to improve oiling. A larger rear pinion bearing (22mm) was used from frame PG 33558 onwards.

All Small Block final drives were 8/31 teeth, 3.875 ratio starting with the V35, V50, V65 & V75 (except the Nevada Classic). All small blocks from Nevada Classic to date use a 8/33, 4.124 final drive.

Guzziology does not specifically mention the Polizia V50.

Primary reducing Gears:
Tooth Ratio Models
13/24 1.846 V35, V35II, V35 Florida, V35 Nevada & V35 Imola
13/23 1.769 V35 Imola, V35 GT
12/24 2.000 V35 III, 350 NTX, & easrly V35TT
12/25 2.000 350 NTX, late 350TT
14/23 1.642 V50, V50III, V50 Custom, V65TT & 650 NTX
15/22 1.466 V50 Monza, V50 Monza II, V75, V65 SP, Custom, GT & Florida
16/21 1.312 V65 & Florida, 750SP Targa & Nevada, Breva V7 classic etc.

So, if you can find a late model 4.125 diff this would improve your gearing, might be a bit spendy tho

lawries2014-05-23 07:42:24

Thanks. Following on from you post I have been looking in the parts manual, and listed under “Varianti Polizia” are two items listed as “countershaft” (Z=13) and “intermediate gear” (Z=24). Can’t seem to find corresponding items in the main transmission drawing though, Police bikes geared down to make them more suitable for town/traffic use maybe?As you say it would seem to be quite a lot of work to change it