Vintage BMW Motorcycle Owners

This is my first bike without a tach so its been a bit of learning curve for me understanding when and how to shift and what the optimal speed/rpm range is for best power, smoothness, etc. Can any please provide me with the best speed range for each gear? I am bit hesitant to give her the "beans" for fear of blowing something up!

Shifting is a personal thing...goes back to when we were all driving standard shift cars...you just knew when to shift. On my R69S, I tend to shift 1st-to-2nd around 20 mph, 2nd-to-3rd around 35 mph, and 3rd-to-4th 45-50 mph. Might not be ideal, but works for my ear.

You can still 'give her the "beans"' any time you want.

Those small blue tick marks on the outer edge of the speedometer face are the recommended limits for each gear. The first gear limit is the single tick, the second gear limit is the double tick, and so on. You'll quickly learn to go by ear and feel anyway, but until you get used to how it sounds/feels, those tick marks are reasonable references for "time to shift".

therealkennyboy wrote: ↑

Tue Sep 20, 2022 9:25 pm

You can still 'give her the "beans"' any time you want.

Those small blue tick marks on the outer edge of the speedometer face are the recommended limits for each gear. The first gear limit is the single tick, the second gear limit is the double tick, and so on. You'll quickly learn to go by ear and feel anyway, but until you get used to how it sounds/feels, those tick marks are reasonable references for "time to shift".

Whoa! I never noticed those little blue marks. Thank you. So I see marks at 38, 60, 84 mph. I'll go with those limits.

I'm not sure about the R69S, but most speedos seem to say 32 mph for top end on first gear.
I push my R69 to 30 in first when traffic dictates a quick get away. Mostly just shift as early or as late as feels good at the moment.

The limit might be when the push rods and valves can't keep up.
I have never pushed mine that hard.

Don

Just don't lug it! I used to lug it when I first got my R60/2 since the engines sound so noisy at speed,I have since then learned to rev it a little and don't shift into 4th until 45-50!

Thomas is correct-
"Just don't lug it."

Back when these bikes were current, the old German, with the one man BMW dealership across the street from us, would issue that same caution. (in his past life he'd been a wehrmacht motorcycle wrench)

Most of his clientele were the area's doctor/lawyer/professional type, as these bikes were fairly exclusive in the day, and the usual progression seemed to be folks would start with an R50 or R60 and then often trade up to the R69S.

He said he was repairing a lot of spun rear mains, because guys didn't adjust their riding style, they would continue to ride the S as they had their R50 or 60.

He contended the S needed to be driven up on the cam, which has its powerband much further up the rpms than the cam in the 50/60.
This is borne out by the cam spec differences; the 50/60 cam having valve duration of 208 degrees and a negative valve overlap of 12 degrees, while the S has 228 degrees valve duration and an 8 degree overlap.
Which means the 50/60 cam is a torque cam with max power at low rpms, while the S is a horsepower cam, with max power at high rpms.

He compared it to the hotrod 4 wheeler of the day, the 911S, which also had a horsepower cam and a roller crank, and was also susceptible to bearing damage from lugging.

Our area is mostly hilly twisty roads with 35-45 mph speed limits, which he said was too slow for top gear in either the Porsche or the S bikes; so he cautioned to stay in 3rd gear or be driving well above the speed limit.
Best-
George

Thank you George. So the engineer in me needs to ask for more specifics. What speed range per gear would be considered ideal and not lugging it?

And this is why the R69S is especially not suited for sidecar work.

Dave

I too had not noticed those blue marks on my mph speedo - you learn something new every day! They must correspond to max rev limits with standard gearing (34, 60 & 80 mph). I change-up on my R69S at speeds a lot lower than those; into top gear at about 50 mph. Bike certainly keen to rev and smoother at higher revs (can’t remember if mine still has the crank damper on it).