Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Quiet motors

Years ago I was at a British M/C swap meet and two guys rolled in on Triumphs. The only way you could tell that the motors were running was because of the exhaust sound. How did they do that? No rattle. No clatter. No spoon in the garbage disposal sound.

Electric motors?

Stock, mid 60's Triumphs.

I got my old '70 t120 crate to be be relatively quiet by sorting timing gears,
using lash caps, mushroom head tappets etc.
Timing gears are the main thing, they vary a lot. It was expensive as i bought about 3 sets to get
a selection to sort through.


Some blokes just fill 'em up with 70 weight oil, great for a short time.

...today I put 500km on a new Husqvarna 401; plenty of noise; like a Triumph but new...

I have little to add to this, only that I use T140/TR7 timing gears as they're better made and heavier.
Lighter gears used to be seen as a "go fast" must but the added weight tends to dampen out much of the oscillations in the camshaft.

SR

They were a 'select on test' item at the factory, sizes varied off the one
machine they had to cut them. It was probably as knackered as the other
stuff there at the time. You could get idler pinions and crank pinions that
were stamped 05 and 02 years ago, they were oversize and would take
up the backlash etc.
Loads of them came out of the factory sounding like tin of nails.

What SR said. After I got the local machine shop to bush the hole in the crankcase after the PO had put the engine back together with only the broken half of the intermediate pinion spindle which then thrashed about, enlarging the hole, I found that they had located the hole a thou or two away from where it needed to be to use the gears that were in the engine. As I have a few used engines on the parts shelves, I mixed and matched pinions until I found a combination that gave a good fit ( as I had seen Triumph do in a film on the assembly line back in the day of the pre unit engines ). This was on a 67 Daytona engine and the fit is good and it is reasonably quiet.

Cheers, Wilf

This must be something to do with the ear of the beholder. Once when I pulled up on my 67 TR6r someone said that my engine was nice and quiet but to me it sounded rattly!

The biggest clatter I heard was my friend's BSA Starfire but it was very fast. My Triumph Blazer was a a bit of a rattler, too. On these engines I think it was piston slap.


Dave

I wouldn’t waste five minutes of my time trying to make the valve gear quiet.

Good point raised above about the bigger stronger 750 timing gears though. They’re also easier to take off and put back on, than the older type.