Not a problem unique to the VF I’m sure, but keen to hear collective wisdom on possible causes and cures. For the first 100km or so of a journey the speedo needle is steady and accurate. Then it starts to swing on a 10kmh arc, a little later 15kmh, followed within a short timeframe by 20kmh variation. So for example if my speed was a steady 110kmh, the speedo needle bounces between 110 and 130kmh. After even more time the needle moves to a higher speed where it begins to swing anywhere between 20 and 40 kmh higher than the actual speed. The faster I go, the worse it gets. I should mention the odometer and trip meter remain absolutely correct and spot-on throughout all this crazy stuff. If I stop the bike for a period of time (eg lunch break) the speedo needle initially settles for 10 or so minutes before resuming its erratic ways. So I have two possible culprits; heat, or a faulty magnet, or both. The inner cable has been cleaned and lubricated with graphite. The outer cable has no kinks or defects. The speedo drive (at the wheel) is well greased. The plastic worm gears at the back of the speedo itself look to be in perfect condition and have been lubricated with white lithium grease. I’m assuming the fault lies within the actual speedo unit. So what exactly am I looking for? Any suggestions? Thanks
No such problem on mine but I had an issue with my kilometer totalisator…
We had the same problem with one of our BolDors and a new cable solved the problem
Thanks Bif. I did try a new cable. The problem persists. All is steady for the first 50km or so, then the erratic behaviour begins.
have just got VF, 85 model FF back on the road after a lengthy period in the shed.
How did you get on with your speedo problem? I have a similar problem, only worse- mine starts to go erratic about 10 mins after start up and bounces around 40-50 kmh of real road speed- whilst making a noise like high speed teeth gnashing. Then it will behave for a little while, and do it all over again, its very noisy and noticeable even over the motor noise.
Like you I‘ve got a new cable, and everything looks OK externally. If pxossible I`d like to stick with the original speedo unit and km reading. I do have a spare, so I spose my next step is to swap that one to eliminate, hopefully the problem?
I’d guess at the speedo drive on the wheel… take it out and completely degrease it, clean it up and reassemble after packing it out with new grease. Can you hear a whine or any odd noises? My 750f had that problem
I had the same problem on my bike, after 30 mins needle would start bouncing around, on the Scottish trip this year it got so bad the needle was hitting the stop and snapped so I had to replace speedo and that cured the problem so it was the speedo not the drive unfortunately as I have several drives and the speedo for an R was not cheap!
just went for a great solo ride after fixing front brakes- thanks Bif for the guidance, and speedo is now going berserk again.
very noisy gear sound at wheel speed when slowing down, and stops when the wheel stops turning
very erratic speedo needle- bouncing through about 40kmh above and under proper speed.
Covered about 200km with no issues or noise today, and then it went crazy.
Had previously had a similar problem- replaced cable with new- no fix, checked and greased drive unit- no fix, swapped speedo over and changed needle- fixed for about 1200km, but now crazy again.
I cant see anything wrong with the drive unit, but replacing it is the only thing I can see might fix it?
Any ideas brains trust?
That’ll be your gear drive. The high pitched sound is it squealing, and the speedo bouncing is due to it catching / not catching and acting erratically. I have a spare drive for a VF1000FE plus cable if you need?
thanks for the advice and offer, I
m guessing your in the Not United Kingdom, as Im in the Convict Kingdomm, ( hoping to also disunite and grow up one day), down below in Oztraya.
I’m still trying to fix my speedo problem, the last time I rode the bike the noise from the front wheel area was so bad I just disconnected the cable to shut it up. Have just pulled the wheel off to examine drive unit, and can’t see anything wrong with it- greased, plastic sleeve gear OK, worm gear appears OK, cant get it to slip, or catch?
The only clue I have is that the boss in the alloy hub looks a bit scored or chewed out as though the drive washer which sits inside the wheel, and engages with 2 lugs, has at some time not been seated properly. I’ll pull the seal out now and check this drive washer is seating properly.
Really can’t see anything wrong with the drive, but will get a used one from our local wrecker to try. Seems like the same part was fitted to most larger Honda models in the mid 80s to late 90s.
This mystery is starting to irritate me! So far have replaced-new speedo cable, new drive washer in wheel, S/H speedo unit with only about 60K on it. I’m certain that it’s not a speedo fault now as the noise comes from the wheel itself, so really hoping that another drive unit will fix it, even though I can’t see anything wrong with the one on the bike???
Only other thing I can think of is that When I pulled the drive unit plastic sleeve gear out, there is no washer between the gear and the alloy case, is this correct?
If there was supposed to be a washer between the bush of the drive body and the gear it may make a difference with the mesh of gear to cable drive worm- can anyone confirm that it is correct to have no washer? This is probably the only VF part I haven`t got a spare for.
The symptoms you describe sound very much like a combination of drag cup bearings and control spring weakness.
What is the state of the speedo input flex drive socket, too? They have been known to wear such that the drive isn’t consistent, which causes symptoms like those you describe.
If either potential cause is the case, your best bet will be to replace the unit.
I,m assuming that drag cup bearings, and control spring are in the speedo unit itself?
Have replaced the speedo unit, and am still experiencing the same, or worse symptoms. Also the noise seems to be from the front wheel itself. Once I get another drive unit and refit wheel to test I may know. By then I’ll have replaced Speedo, cable and drive unit, and hopefully something will be betterer!
The system is very simple, comprising of an axle mounted gearbox, a flex drive and the speedo unit.
The fault can only be in one of those, or a combination of them.
The flex drive rotational speed is determined by the gearbox. A constant wheel speed should produce a constant flex drive speed.
The flex drive drives a magnetic cup, which drags round a follower cup against a spring. The faster the magnetic cup rotates, the further the needle moves around the dial,
For the needle to oscillate as you describe, it’s usually the drag cup / spring combination. If you’ve replaced the speedo, it’s possible that you’ve just replaced it with a unit that has the same fault, but that’s unlikely.
It could equally be the flex drive experiencing coiling, which manifests itself in a similar way. It twists, then releases, which shows up as the needle flicking.
There are a few companies around that overhaul speedo units. As a last resort you could consider having the unit professionally sorted.
If it was mine I’d replace the gearbox, axle drive and flex drive with known good items as a means of isolating the fault, and then pointing at the speedo itself.
I hope you’re right regarding speedo, reasonably unlikely that 2 speedos would have exactly the same fault- but stranger things have happened.
Yes, have replaced speedo cable, and today picked up a used drive unit, which looks OK, but so did everything else.
On the weekend I`ll fit it, and see how it goes. My only real clue is the strange grinding noise which seems to emanate from the front wheel, and there’s also a burring mark on the alloy of the wheel hub inside where the drive washer engages in the wheel. I have also replaced this drive washer with a new one, but still the same fault. Intriguing…
Another thought has occurred to me.
How is the flex drive cable routed? It’s very easy to get it wrong (which actually looks right).
The routing, when correct, looks wrong if that makes sense.
Starting at the speedo end, it should route over the LH indicator, then through the wire stand off, following a big curve that is almost to the back of the front wheel, through the guide attached to the LH brake caliper and into the drive gearbox.
The entry into the drive gearbox is counter intuitive. With the bike on the main stand, draw an imaginary line through the front axle, horizontal with the ground. The cable should ender the gearbox from below that imaginary line, subtending an angle of about 20 - 30 degrees. If this angle isn’t right, the gearbox isn’t seating properly.
When installed correctly, it looks wrong, because there is a lot of cable in a big curve that’s unsupported.
If the changes of direction are too acute, or the radius from the wheel to the stand off too small, the cable will be pinched and released as the forks go up and down in normal usage.
This pinch / release cycle will show up on the speedo as needle fluctuation, which will get worse the faster you go. The flex drive has a surprisingly low rotational speed, which serves to amplify the problem.
Aaah, thanks Chris,
you just might be onto something there, appreciate you thinking around my problem.
Will post how I go after reinstall. cheers
No worries. Let’s hope it’s that simple.
Slight correction to the routing above. From the speedo it goes UNDER the LH indicator, not over it as I wrote.
When it’s correctly installed it looks like this:
Note the angle of entry into the gearbox, and the big loop of unsupported cable.
Was test riding mine yesterday after the rebuild and was getting intermittent speedo needle wobble. When I slowed I could hear a screeching from the speedo end of the cable. I don’t have the fairing on yet so I dropped off the cable and the noise went. I then pushed some lubricant into the speedo connection where the cable fits and reconnected and now it seems all fine. Will see how it goes.