4 replies [Last post]
johnstas617's picture
Joined: 07/12/2015
Posts: 70

Hello from Israel.
I restored this nice R51/3 year 1951 and I was wondering if the 4th gear can be replaced with another one to make the ride at more ease at cruising speed?

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schrader7032's picture
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6808
I've heard about gear changes

I've heard about gear changes in much later bikes, like /7-on Airheads. But why not change the final drive instead? Seems like that's easier to do.


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

johnstas617's picture
Joined: 07/12/2015
Posts: 70
Final drive changes all gears

And I don’t know what effect it can make?
I don’t know just guessing

The Plunger
The Plunger's picture
VBMWMO #8356
Joined: 09/03/2012
Posts: 240
I assume it has a 35:9 final

I assume it has a 35:9 final drive? You can try an R67/2 drive at 32:9 to get a better top end but acceleration will drop.


'52 R67/2
'63 R69 S
In what space, sir. In what space!?

Grant R26
Grant R26's picture
VBMWMO #8145
Toronto Canada and Long Island, Nova Scotia
Joined: 03/28/2011
Posts: 205
Hello John the bike looks

Hello John
the bike looks great...well done. I've had an early 1951 R51/3 for several years and done thousands of km on it and it cruises comfortably at 115 to 118 kph...will do that all day.
I wonder if yours could have a side car ratio rear end ? I'm certainly no expert but I gather that the R51 was often sold as a utility or police bike and those would have been fitted with the sidecar ratio if intended for European market. if you have the sidecar ratio then it would be really humming at 90- kph. Just a thought.

Grant in Toronto

I got my bike with the same bent header pipes as yours. Much later somebody pointed out that they are the wrong pipes for the half hub early R51/3 models. Note that I really care (grin) but it is a real fight to get them to line up with the mufflers. I used straight pipes on my on my second one everything lines up easily. That said, I would not suggest that you change yours... they still look great. And in your climate they will probably last for decades

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