If you like our site, please consider joining our club!
By joining you will help ensure that we can continue to provide this service
JOIN HERE!

Curious about the Clock

Post Reply
User avatar
Slash2
Posts: 538
Joined: Sat Oct 17, 2015 10:22 am
Has thanked: 1 time
Been thanked: 2 times

Curious about the Clock

Post by Slash2 »

It has always been somewhat puzzling to me that BMW would design a clock that acted like a parasitic draw on the battery of so many of their 70's and 80's motorcycles. When I first got into an R100RS years ago I was told by the PO that he would just unplug the clock between rides which seemed somewhat inconvenient considering this meant resetting the clock every ride and providing frequent opportunities to damage the internals, connecters etc. I kept the bike on a tender and didn't think much more about it. Fast forward ten years and I no longer have that RS but I do have a G/S in the garage and it has the accessory clock as well. While going through this bike and refreshing it for service I ponied up for Motobatts fancy new Hybrid tech battery which claims to offer the best of both worlds and provide significantly greater capacity than what is necessary for my old bike. (Probably an unnecessary waste) That said, if I don't ride the bike for a week or so, the clock draws enough current to sufficiently drain the battery to the point where I can no longer start the bike with the electric starter. So I keep the bike on a tender and all is seemingly well.
That brings me back to my initial question and curiosity of what might these designers and engineers have been thinking owners would do with these constant parasitic draws on their batteries? I suppose if these designers assumed that these bikes would be ridden daily or at least several times a week, then I would guess the draw from the clock would likely be insufficient to drain the battery to the point of rendering it incapable of turning over the bike. But aside from that assumption, it strikes me as odd that they wouldn't have designed these clocks to run on watch batteries or some other secondary source of power. Unlike on the RS, the G/S clock harness runs into the headlight bucket and isn't simple to disconnect so it seems that keeping the bike on a tender is the only viable option for me and it certainly doesn't keep me up at night but it just seems like a rather odd design and I wondered if anyone might have some deeper insights to share.

Best!

-Chris
Western Pennsylvanian - Airhead Extraordinaire

User avatar
srankin
Posts: 1054
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA
Been thanked: 14 times

Re: Curious about the Clock

Post by srankin »

I would imagine BMW figured any draw from the clock would be so minor during the life of the bike it would not be a problem.

The bikes were built to be ridden and I would bet the BMW designers never figured owners would have multiple bikes or would let them sit idle so long the clock would run the battery down.

If a person is not riding enough miles on the bike to keep the battery charged during riding season, what is the point of having the bike? LOL. St.
Owner of a 84, R80RT and 78, R100RS

User avatar
Slash2
Posts: 538
Joined: Sat Oct 17, 2015 10:22 am
Has thanked: 1 time
Been thanked: 2 times

Re: Curious about the Clock

Post by Slash2 »

So what you're saying is that I need to ride the bike more? I'll pm you my wife's phone number and perhaps you can take this up with her. Please prepare in advance several well rehearsed rebuttals to the standard talking points especially regarding my 2 year old daughter and her 6 month old little sister and why I shouldn't be expected to be running around like a maniac cleaning up messes and changing diapers. While you're at it put a bug in her ear about a couple nice weekend trips this summer. I would like to do some overnight camping trips on the G/S and it's probably best if she hears this coming from you first.

Thanks and I'll stay tuned.
Western Pennsylvanian - Airhead Extraordinaire

User avatar
schrader7032
Posts: 9016
Joined: Fri Oct 27, 2006 3:00 am
Location: San Antonio, TX
Has thanked: 2 times
Been thanked: 29 times

Re: Curious about the Clock

Post by schrader7032 »

My /7 has a clock in the Luftmeister fairing. Since the early days of owning my /7, I read about how you could cut out the ring terminal at the battery ground spot, so that the ground/speedo bolt could be loosened and the ground cable could be pulled out, preventing any draw to the battery. I'm aware of the potential issues with tightening that bolt. I think it's been long enough that I have found out what "snug" is for that bolt and don't over do it. Knock wood, it's worked for me.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

SDCR
Posts: 132
Joined: Sat Mar 05, 2022 7:50 am

Re: Curious about the Clock

Post by SDCR »

So what you're saying is that I need to ride the bike more? I'll pm you my wife's phone number and perhaps you can take this up with her. Please prepare in advance several well rehearsed rebuttals to the standard talking points especially regarding my 2 year old daughter and her 6 month old little sister and why I shouldn't be expected to be running around like a maniac cleaning up messes and changing diapers. While you're at it put a bug in her ear about a couple nice weekend trips this summer. I would like to do some overnight camping trips on the G/S and it's probably best if she hears this coming from you first.”


Since the majority of late night “ comedy” programming has all but ceased being funny, it’s great to have VBMWMOC members contribute levity when appropriate.

Regarding the clock, the one in my S fairing, has, what I see as a clever feature. In advancing the time, one simply holds the button in the back, and the hands magically move rapidly through time, until the desired hour/minute is reached. Very cool
1983 R100
2000 R1100

User avatar
srankin
Posts: 1054
Joined: Fri Jul 14, 2017 8:45 pm
Location: Spencerport, NY USA
Been thanked: 14 times

Re: Curious about the Clock

Post by srankin »

LOL, either ride more or as you wrote, use a battery tender. There is no wrong or right amount to ride, only to ride as much as possible.

Of course family comes first always. I am lucky my wife lets me ride as much as I want. Then again, I don't work anymore and don't have small children. LOL, some may say when you reach my wife's and I's ages, she might be happy to get me out from under her feet and go riding. St.
Owner of a 84, R80RT and 78, R100RS

Post Reply