• SHS 19 tooth piston for long SR25 and R85 gearboxes, blue polymer with a steel rack
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SHS Piston — 19 Teeth, Long Gearbox for SR25 and R85

SHS Piston — 19 Teeth, Long Gearbox for SR25 and R85

£10.95
£10.95
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DETAILS

SKU: 53816478
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SHS 19 Tooth Piston for Long Gearboxes — the longer rack, for SR25 and R85 pattern shells. Not a Version 2 part.

Long gearboxes run a longer stroke, and the piston has to carry more teeth to match it. This one carries nineteen.

Put a standard rack into a long shell and the sector gear picks it up at the wrong point. You lose stroke, the timing goes out, and the engagement lands across fewer teeth than it should.

Platforms using this length include the SR25 pattern and the R85. If you are not certain which shell is in front of you, count the teeth on the piston you removed before ordering.

Specifications

Specification Detail
Type Piston
Teeth 19
Rack Steel
Body Reinforced polymer
Fits Long gearbox shells, SR25 and R85 pattern
Sold as Single piston

Good to know before you buy

This is a platform part rather than an upgrade. It suits shells built for the longer stroke and it will not go into a Version 2 or Version 3.

Frequently asked questions

Will it fit a Version 2 gearbox?
No. The rack is longer than a Version 2 shell allows. Those take a fourteen or fifteen tooth piston instead.

How do I confirm my gearbox takes this?
Count the teeth on the old piston. Nineteen puts you in the right place.

Does it come with a piston head?
No, the piston is supplied on its own.

⚠ Count the teeth before you order: long gearbox pistons and standard ones are not interchangeable in either direction, and the shell will not close on the wrong length.
💡 Titan Forge Airsoft tip: Keep the old piston once it is out. It is the quickest reference you have for tooth count and head thread the next time round. Browse pistons and piston heads.