Benge/King Lever Geometry

[Bassbone11]

I’m currently on a Benge 290 and I THINK I’m having trouble with the lever geometry on the F-valve. The way the thumb lever is setup, my thumb is actuating it where there is minimal mechanical advantage and it feel like the lag from having to push harder to overcome it is holding back my technical facility on a particularly valve-heavy passage.

I am only about 1 year into getting back on the horse so I am fully willing to admit this problem could be resolved with time (and thumb exercises!) but I am wondering if this is an uphill battle I need to work around until I can justify permanently modifying an otherwise-original instrument or if this is just a muscular development issue.

additional context: the f-valve lever points up at the bell from the valve knuckle instead of town towards it like most other instruments these days. also string linkages but the strings seem tight and were just replaced by Andy Smith at Rose City Instruments

[Bonearzt]

Have Andy look at your playing position, he'll be able to offer advice on possibly modifying the set up or your grip.

[Bassbone11]

I guess that's a good point. I have pretty small hands and relatively short fingers compared to my palm (barely a 9th on a keyboard!) and this horn is heavy so I feel tied to this get-a-grip but maybe something like a neotech brace might put my hand closer to that part of the lever too

[AtomicClock]

The mechanical advantage should be identical at every spot won the thumb lever (the part that points "up" toward the bell). If that isn't the case, you have a broken hinge.
There are two joints in the thumb. My preference is to bend mostly at the one closest to the thumbnail, but that requires the right grip & horn geometry. The other joint, at the base of the thumb, is also available. Or use both simultaneously. Using the wrong joint(s) can make a lever feel awkward. Try them all.

[AtomicClock]

I feel tied to this get-a-grip but maybe something like a neotech brace might put my hand closer to that part of the lever too

The get-a-grip -works like the Caldergrip, right? If you want your hand closer to the lever, re-bend the get-a-grip to put your hand wherever you want it. I had to re-bend my Caldergrip several times because my thumb was pressing on the edge of the Bach 42B paddle instead of its comfortable center.

[Blabberbucket]

If the strings are too tight, the valves will feel slow/heavy. There are no issues with the lever geometry on the Benge trombones unless something is bent or fit poorly.

[Burgerbob]

Could be a weak spring too.

[chromebone]

I changed the lever on two of my 190’s to this. It’s much more comfortable to hold, has better lever geometry, a stronger spring, and it combines the best of both worlds of string and mini ball linkage styles. The work was done by the great Terry Pierce, shortly before he retired.

[Bonearzt]

I changed the lever on two of my 190’s to this. It’s much more comfortable to hold, has better lever geometry, a stronger spring, and it combines the best of both worlds of string and mini ball linkage styles.

Nice!!