4 replies [Last post]
emek69
emek69's picture
 Offline
VBMWMO #9260
Joined: 12/21/2010
Posts: 129

Couple of questions here.... So I have always believed that "S" stamped tranny was for a solo bike and not the sidecar. I have seen different people calling those differently and have both in my garage. What was the major difference between those trannys, just the gearing? If so would you rather use sidecar tranny in a sidecar rig or just different differential gears. What is the preferred setup?

__________________

Premo B.
'55 R67/3, '68 R69S; '67 R50/2; '64 R27; '11 R1200RT

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6652
Yes, the S is for solo

Yes, the S is for solo gearing. The difference in a bike gearing/drive for solo versus sidecar would involve:

- transmission ratios are different in 1st, 2nd, and 3rd, but the same in 4th. For a solo R60, 1st is 4.171:1 while for a sidecar it's 5.33:1
- the rear drive is different. For a solo R60, it's usually 25/8 (3.13) while for sidecar it's 27/7 (3.86). There was additional ratios for the later model bikes when they went to 27/8 for the solo bikes and then also fitted a 4.00x18 tire.
- the speedometer would have a different factor because of the different final drive.

I would think that if you were pulling a sidecar, you would want the sidecar setup, otherwise you're asking a lot of the drivetrain to pull the extra weight with the "taller" gearing.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

emek69
emek69's picture
 Offline
VBMWMO #9260
Joined: 12/21/2010
Posts: 129
Kurt, so what you are telling

Kurt,

so what you are telling is that both should be used the tranny and the rear diff gear for the sidecar use, no one vs the other ......?

__________________

Premo B.
'55 R67/3, '68 R69S; '67 R50/2; '64 R27; '11 R1200RT

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6652
Well, you can use whatever

Well, you can use whatever you want in the end. But mismatched gearing is going to make the bike sluggish and seem underpowered. You could be putting additional strain on the driveline and having to slip the clutch a bit more than normal. But again, it's up to you and what the bike might feel like and how it performs.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

emek69
emek69's picture
 Offline
VBMWMO #9260
Joined: 12/21/2010
Posts: 129
So I happen to have a sidecar

So I happen to have a sidecar tranny, no "S" on it.

__________________

Premo B.
'55 R67/3, '68 R69S; '67 R50/2; '64 R27; '11 R1200RT

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.