Big Twin Flathead / Knucklehead / Panhead

The GasBox Upsweep TT Pipes

Header pipes to create a 2-1 upsweep exhaust system. It features a classy and sporting TT style end tip. Completion requires front and rear header plus a squish pipe.

more …

The GasBox 1939 CHP Upsweep Mufflers

Authentic reproduction of the special muffler for the California Highway Patrol (CHP) as introduced in 1939, with upswept tail section and spot-welded seam construction. Designed for rigid frame Big Twins for which a special hanger bracket is available, too, but can be Custom fitted to most models with 1-3/4" pipes.

more …

Custom mufflers for Knucklehead, Panhead and Big Twin Flathead

The big twins with OHV and SV engines share the same pipe diameter and mufflers. That is why our custom silencers fit all the models mentioned. Custom applications on later models (Electra Glide conversion) are also possible. Extra suspension at the rear end is recommended to prevent vibration cracks. It would be a shame, wouldn't it?

Have any questions?

Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: service@wwag.com