You need the right size cable, nipples and ferrules. You can find cables at several locations in Bangkok, and probably in other towns, the inner and outers range between 39 Bht and 130 Bht per meter. Useful sizes include no.1 (standard throttle diameter 1.57mm) and no.3 (which we mostly use for the clutch cable 2.21mm). Four or five nipple types will cover most needs.
Ordinary electrical solder and flux is adequate but always heat the cable or nipple to melt the solder. Never melt the solder on the iron and try to pour it into the joint – it won't stick. And gets you very irritated.
Unless you have an old cable to copy, to ascertain length you need to plot a route on the motorcycle that keeps curves as shallow as possible, avoid anywhere the cable could get trapped, chafed or melted. And be sure to make allowance for clipping to the frame, fitting a tank, full suspension movement and moving the steering lock-to-lock.
Cable failure is usually caused by:
- Wear and tear – a couple of broken strands are a good indication that the rest will soon follow. Look out for signs of rubbing or chafing on the outer insulation.
- Heat – from soldering using a propane torch will easily overheat the thin strands of wire in a cable and make them brittle so that they break. A powerful soldering iron is more controllable.
- Poor flaring of the inner wire – so it just slides through the nipple.
Make your own flaring toolIt's essential to deform the inner cable so it forms a ball with the solder, to resist pulling through the nipple.
Put two pieces of flat bar in the vice and dot punch the join. Use a small center drill to make a countersink. Beginning with a hacksaw slot, file grooves to grip the cable. Finally, drill into a bar to make a corresponding punch.
- With nipple and ferrules slid onto the cable, grip the inner wire in your flaring clamp with a small amount protruding. Fit the hollow punch over the end and strike lightly.
- This should flair out the wire to a thistle shape. Dip this 'thistle' into soldering flux and tin it with solder before sliding the nipple up as far as it will go.
- Using flux as necessary, heat the outside of the nipple until the tinning on the inner wire melts, then feed more solder into the nipple until it emerges out of the heel end.
- Hold the nipple downwards to encourage the solder to form a ball. Move gently, so as not to dislodge the molted solder. Once it's cool, file off any excess.
- To cit an outer cable without crushing it, use a blade to open the sheathing, then bend it open before you use the cutters. Cut the inner wire with quality side cutters or a sharp chisel. Tinning it first will prevent fraying.