speedo cable malfuncting. anyone can help?

ramesh kotecha · L Plate Warrior Joined: 03 Feb 2005 Karma :

I have Hongdou 125 bike. recently my speedometer stoped showing above 20MPH even when I know I am doing 40MPH. Any body has encounter similar problem. I do not want to dismantle anything unnecessary.

mchaggis · World Chat Champion Joined: 09 May 2004 Karma :

This is in the wrong section, but the problem is a far too familiar one with me at least. The speedo cable stopped showing above 45 on my Hongdou 125 after about 600 miles. 2000 miles later, and I've got a new cable, but it's at home and I'm not, so I've still not got around to replacing it.

The problem is that the cable is sticking. The speedo mechanically driven, by a spinning cable within an outer sheath. The problem is that at higher speeds, the spinning inner cable sticks to the outer sheath, slowing down and hence your indicated speed drops. Then, when it winds up enough to unstick it, it flies round and overcorrects itself as it is then going faster than the wheelspeed in order to catch up with itself. Hence the speedo will fluctuate and flap about, and not show any reading higher than a specific value where it sticks.

Eventually, given enough twisting, the cable will break and need replacing. Ideally, replace it before it breaks.

Which Hongdou have you got? If it's the same as the one in my profile, it is a direct clone (bar the engine and upgraded brakes+ electrics) of the Honda CM125. A speedo cable for that should fit, if the company you buy it from send the right one.
Rolling Eyes

Oh, and (assuming that is the same as mine) if you could let me know if you ever manage to source replacement 12V15W bulbs, I'd be eternally grateful. Mr. Green

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bish777 · World Chat Champion Joined: 11 Nov 2004 Karma :

before you fit the cable, fill it with oil-not wd40- use engine oil or gearbox oil.

I had the same problem on my old MZ. The oil is the only way to prevent this happening.

Scotsman37 · World Chat Champion Joined: 17 Aug 2004 Karma :

mchaggis · World Chat Champion Joined: 09 May 2004 Karma :

Scotsman37 · World Chat Champion Joined: 17 Aug 2004 Karma :

Take your bulbs to a bike mechanic and speak to him rather than a sales person because no doubt he has spare ones tucked away in a box some where in the garage. He'll know what ones will fit and may speak to the sales person, if necessary, to advise him/her which ones you require.