CB77 speedo noise

DJM · Post by **DJM** » Sat Jun 30, 2018 9:29 am

Another possibility is that you have the wrong speedometer inner cable fitted, very easy to overlook.

Later bikes had speedometer and rev-counter on which both needles rotate in the conventional clockwise direction. Earlier bikes, probably the majority, had the quirky contra rotating needles which rotated in opposite directions, IE the speedometer needle rotates anticlockwise. This necessitated a change in the speedometer drive gearbox but also a different inner cable was used which is 'wound' in the opposite direction to those fitted to the earlier bikes. Basically the inner cable should tend to wind itself tighter as it rotates in its normal service direction. If you have the wrong inner cable it will tend to unwind itself increasing both its length and diameter which I suppose could cause the inner to bind inside the outer casing.

It all sounds a bit theoretical but Honda obviously thought it important enough to make the change so it's certainly worth checking this if the problem persists.

Change was made at CB77F 1001731

cknight · Post by **cknight** » Sat Jun 30, 2018 5:06 pm

Had the incorrect (early) cable on my 1966 CB77 when I first finished the project. Yes, there was a squealing noise and a jerky needle. Took longer to sort than I'd like to admit. Most of the new repro cables I've found recently are for the later clockwise version needle. The cable housings are the same, however. Regards, Chase

Merz64cb77 · Post by **Merz64cb77** » Sat Jun 30, 2018 9:34 pm

My engine number is CB77E-1051564 and I have the later model having both needles rotate in the traditional clockwise direction. I’m using the cable that was fitted to the bike when I got it so I would think the inner cable is correct. However, how would I determine if I did have the incorrect inner cable?

cknight · Post by **cknight** » Sun Jul 01, 2018 10:05 am

Get out the magnifying glass, and study the cable itself. If the wire strands appear to go in the direction of a standard right hand bolt, you should be good. Regards, Chase

Merz64cb77 · Post by **Merz64cb77** » Sun Jul 01, 2018 1:17 pm

Ok will do chase thanks for the information and help

Merz64cb77 · Post by **Merz64cb77** » Mon Jul 02, 2018 6:39 pm

Good news about the speedo noise. The two drops of oil must have been the trick as during the drill test the noise is now gone. I still have to study the cable for the direction but I’m glad the noise is gone. Thanks again for the help gents.

G-Man · Post by **G-Man** » Tue Jul 03, 2018 6:42 am

That is good news.

G

Merz64cb77 wrote:Good news about the speedo noise. The two drops of oil must have been the trick as during the drill test the noise is now gone. I still have to study the cable for the direction but I’m glad the noise is gone. Thanks again for the help gents.

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