850/1000 – Le Mans I/II Close Ratio Gearbox Conversions
By way of a reference these are the standard gear ratios for all 850/1000 models:

Factory Standard Gearbox helical teeth
With Primary Drive
Clutch transmission gear:
Ratio:
Z 17
Z = 17/21 or 1:1.235
Overall Gear Ratios vs Road Speed mph @ engine rpm
with final drive = Z 7/33 or 1:4.714:
rpm: 1000 2000 3000 4000 5000 6000 7500 Ratio:
1st
2nd
3rd
4th
5th 		6.4
9.23
12.23
14.74
17.08 		12.81
18.46
24.47
29.48
34.16 		19.21
27.68
36.7
44.21
51.23 		25.62
36.91
48.93
58.95
68.31 		32.02
46.14
61.16
73.69
85.39 		38.43
55.37
73.4
88.43
102.47 		59.94
48.03
69.21
110.54
128.08 		11.643:1
8.08:1
6.095:1
5.059:1
4.366:1


Close Ratio Kits
14 21 00 41


The 850 Le Mans I/II etc. may be fitted with a new set of straight-toothed gears and mainshaft to give different gearbox ratios. These are non-standard racing parts and may violate type approval specifications.

Kit 'A':
Straight-toothed close-ratio cluster (1st & 2nd high)
Moto Guzzi part No. = 14 21 00 41 with mainshaft 14 21 05 40
*



With Primary Drive
Clutch transmission gear:
Ratio:

Main shaft:
Z 17 ('normal')
Z = 17/22 or 1:1.294
(standard = 17/21 or 1:1.235)
Z = 24 - 22 - 20 - 17
Overall Gear Ratios vs Road Speed mph @ engine rpm
with final drive = Z 7/33 or 1:4.714 (standard):
rpm: 1000 2000 3000 4000 5000 6000 7500 Ratio:
1st
2nd
3rd
4th
5th 		7.99
10.18
12.22
14.68
16.09 		15.98
20.37
24.45
29.36
32.18 		23.98
30.55
36.67
44.03
48.27 		31.97
40.74
48.89
58.71
64.36 		39.96
50.92
61.12
73.39
80.45 		47.95
61.11
73.34
88.07
96.54 		59.94
76.39
91.68
110.08
120.68 		9.329:1
7.321:1
6.1:1
5.03:1
4.634:1

Kit 'B':
Straight-toothed close-ratio cluster (1st & 2nd low)
Moto Guzzi part No. = 14 21 11 41 with mainshaft 14 21 05 41
Overall Gear Ratios vs Road Speed mph @ engine rpm
with final drive = Z 7/33 or 1:4.714 (standard)
and Main shaft: Z = 24 - 22 - 19C - 16C
rpm: 1000 2000 3000 4000 5000 6000 7500 Ratio:
1st
2nd
3rd
4th
5th		7.52
9.68
12.22
14.68
16.09 		15.04
19.36
24.45
29.36
32.18 		22.56
29.04
36.67
44.03
48.27 		30.08
38.72
48.89
58.71
64.36 		37.61
48.4
61.12
73.39
80.45 		45.13
58.08
73.34
88.07
96.54 		56.41
72.59
91.68
110.08
120.68 		9.914:1
7.703:1
6.10:1
5.08:1
4.634:1