TT250 speedo

['16 TT250]

Originally Posted by simonjester

With all the electronic stuff we have nowadays, why are we using a spinning cable in a sheath? That seems like late nineteenth/early twentieth century technology for god's sake. I'm guessing the German, Japanese and American bikes built now use a better technology?

It's also got a 2 valve air cooled carbureted engine, so that should go away too; right? Many of the CBs have drum brakes, even more antiquated stuff there.

I don't know of any German, Japanese, or American bike using a cable, they run an electronic system. I also don't know of any of them offering 250cc bikes for $1800.

A cable can work perfectly fine for many years and miles as long as it's made right and installed right. I've had MANY cable speedo vehicles and, not counting the TT, I've only one failed one on a '78 motorhome that I quickly found was caused by a routing change by someone. There have also been cable tachometers on many engines that worked just fine.

The TT cable sheath probably needs to be redesigned with a longer curved part near the speedo to keep a smoother bend or maybe no steel section at all and make the whole thing flexible so there's no hard radius change at the transition. As it is now the flexible part is pressed against the headlight creating a mild kink at the transition between the steel tube section and the flexible section. Mine was worse before they re-routed it, but it still has a mild kink that may lead to another early breakage.


Edit: That transition also has the crimp holding the two sections together so the ID of the sheath is likely reduced and distorted a little adding to the problem of having a sharp bend there.