whining noise from speedo cable, maybe

[mysteriousfish]

My '80 R100RT just started making a new noise this week...sounds like a whining noise from the front end...starts around 35 mph... definitely proportional to speed of bike...sounds like maybe the speedo cable? I searched the forum for related articles, and found some on lubing the speedo unit itself, but not the cable...my local mechanic advised to dose the cable with a lightweight oil, but it did not seem to help.

Speedometer works fine (usual palsy in the needle). I guess I will try replacing the cable, but it FINALLY got nice in the PNW, and I can't stop riding! I assume the worst that could happen is frying the old cable (not sure the age of the speedo cable, but likely is OE) while I am tracking down a new one. Should I stop riding until I can fix it to avoid damage to the sending unit or speedo itself? (assuming of course the problem is really just the cable)

Any ideas on the mystery whine? thanks..

 

[lmo1131]

Should I stop riding until I can fix it to avoid damage to the sending unit or speedo itself?

Just disconnect the cable at the transmission... tie-wrap the cable up under the seat to keep it clean. Pick up a rubber plug at the hardware store to "plug" the hole in the transmission casing.

 

[dennisdarrow]

For me, I would disconnect the cable from the back of the instrument. Simple knurled fastener that you can reach in gently with a small pair of vice grips and loosen it.............If it is the cable the noise will continue.........If it is the speedo, time for some serious maintenance before self-destructs........

Take that cable loose and ride bud...........You can tell your speed from the tach...........God bless.....Dennis

 

[lmo1131]

disconnect the cable from the back of the instrument. .........If it is the cable the noise will continue........

Better advice Dennis, but not as fast (but then, "fast" doesn't make it better)

Take that cable loose and ride bud..

+1

 

[JoeDabbs]

Don't forget to hold the nut on the speedo stationary while you loosen the knurled nut, otherwise the whole unit will turn...

 

[mysteriousfish]

thanks for the great suggestions......geez, it's the summer solstice, not raining in Portland, World Ride your Bike to Work Day...how can I NOT ride?

ps...was fortunate to catch Jethro Tull perform the 40th anniversary of the Aqualung album at the Edgefield outdoor venue outside of Portland last Friday night. Amazing show, lots of old hippies (hey, I resemble that remark). Lovely evening, and riding home at dusk took a joy ride out the Columbia Gorge...dang, when all the stars align and your airhead is running smoothly, well, it doesn't get much better...still have a grin on my face from that night!

 

[lmo1131]

it can't be not raining in Portland... there's a natural law, or something isn't there?

So, what didja end up doing?

 

[mysteriousfish]

disconnected the speedo cable and the noise stopped, so the problem is in the speedometer...I assume it needs to be lubed internally, or maybe there are some issues with worn or damaged cogs inside...

will review the thread on servicing the instrument and when I find time (right) pull it off and look inside to see if there is something obvious...may consider sending the unit out to Overseas Speedo for servicing...have heard good things from them, but waiting for a quote on speedo service

 

[20774]

I had a noise coming from my /7 speedo unit. I opened the speedo up and made sure that the bearings/bushings where the cable comes in were lubed with a silicone lubricant. Took care of the noise. That's the first place I'd check...easy enough to get there. Look at the brass fitting in these photos...that's what you should investigate:

http://www.pbase.com/dwerbil/1978_r1007_odometer_repair

 

[mysteriousfish]

will do...thanks for the head start...did you use a dry silicone spray (I know...NOT WD40) or a silicone-based grease?

 

[20774]

did you use a dry silicone spray (I know...NOT WD40) or a silicone-based grease?

I have a small tube of silicone grease that I've been using for just about everything...throttle cable barrels, clutch cable ferrels, throttle tube cam/gears, etc.