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threaded bar for gearshifters
JoelP - 27/8/06 at 06:45 PM

well, i bent my last one. Easiest fix is to remove the remains of the old bar and replace with a length of threaded rod. Its the long piece going forwards down the tunnel. Technically its only going to feel tension and compression. Do you think threaded rod is up to it? The failure before was where a thread had been welded onto a tube.

Thoughts?


Jon Ison - 27/8/06 at 06:48 PM

what size ? I used M8 with no problems.


timmyb - 27/8/06 at 06:54 PM

I use M8 threaded bar on rose jointed gear linkages I make for Saxo's/106's. They're more than up to it.

If you want extra rigidity, just sleave it in 10mm bore steel tube.

Tim


JoelP - 27/8/06 at 06:57 PM

it looks closer to m6 tbh. worth a shot i suppose then cheers!


ChrisGamlin - 27/8/06 at 07:16 PM

A tube with 6mm bar welded into it should be lighter and stronger than a single bit of M6 bar though, if you think about it M6 threaded bar is only really ~5mm of actual solid bar thickness, so may well flex a bit.


JoelP - 27/8/06 at 07:20 PM

its just tempting cos currently i have female rose joints. Id rather have male ones and use a tube with threaded inserts, but thats more money and more time, both of which im short of!


ChrisGamlin - 27/8/06 at 07:27 PM

Buy some 8mm tube with 1mm wall thickness and weld some 6mm threaded bar into each end. Voila! If you could get thicker wall thickness you might even be able to tap it and simple screw the threaded bar into it and lock it with a nut.


Jon Ison - 27/8/06 at 07:58 PM

My latest ones use ally tube with male M8 rose joints, velly light again with no probs.


the_fbi - 27/8/06 at 08:22 PM

I tried using M8 threaded stainless (no idea what grade) for my linkage. It was all fine apart from the 82cm (from memory) long section from lever to bell crank.
With the engine off (and clearly the gears don't mesh too well like this) I managed to create a nasty kink right where it sent into the rosejoint (female) when selecting a gear.

I'd go with steel tube and a steel rivnut with a bung weld (or whatever its called when you drill through the tube and weld onto the rivnut) to hold it in place. Or same with ally tube and ally rivnut.

Or, as you've got female rod ends, a stud welded in.

I now use Westfields solution as it just works out of the box (almost).


RichardK - 27/8/06 at 08:36 PM

Joel, I've got a couple of male rose joints if you want to swap for your female ones, I decided not to rose my upper rear wishbones so are only going on ebay after I've finished, thread is 1/2" UNF, they maybe a bit big for you but they won't bust again I have got the tap a die as well is you needed to thread your connection rod.

The offers there mate.

See ya

Rich


ChrisGamlin - 27/8/06 at 08:40 PM

Puddle / plug welding? Thats how I'd do it in Joel's case, drill a couple of holes across either end of some 8mm tube, then slide some 6mm threaded bar up inside and weld it through the holes you've drilled, and also around the ends


RazMan - 27/8/06 at 10:58 PM

If you find that the long length is flexing under compression (if it is kinked to get round an obstacle) use a guide made from some heater hose midway and lash it to a chassis tube - it keeps everything straight.