I have several cylinder watches that gain at a rate of knots!

They've been scrupulously cleaned and have been given new mainsprings but, if anything, they now run faster than ever. The hairsprings are flat, concentric and engaged in the curb pins and don't appear to have been adjusted in any way before they stopped working. Having said that none appear to have enough "free" at the curb end to allow for any meaningful adjustment at the collet. The regulator arm is as far over to "Slow" as possible but, with the absence of meantime screws on the balance, I'm at a loss to know what else I can do.

As a last resort I guess I could try inserting short pins in the edge of the balance wheel but, before I try this, it seems to me that there must be some common problem that I'm missing.

Does anyone have any suggestions?

Many thanks,

Dick

Dick

Not an expert but I've heard that sometimes a worn cylinder or worn escape wheel means that the teeth trip through rather than lock.

Have you tried a weaker mainspring?

Clive

Thanks for that Clive, I think you've hit the nail on the head!

On listening to the movements it does sound as though they may be tripping a little. When I can get around to it (after Xmas)I'll try progressively weaker mainsprings but if that doesn't work I'll start trawling through the parts drawer.

Thanks again,

Dick