Speed Twin Gas Tank Swap

Evan · Jul 28, 2025

Hey All,
I posted the question below on the "Techical Help" forum but thought it might be wise to post it in the "Twin" forum as well. Let me know what you know...

Hi Folks, anyone out there know if a late model Speed Twin 900 gas tank will fit on a late model Speed Twin 1200 without modifications? I've seen threads that suggest there may be a gas gauge reading issue but nothing definitive. This is just a cosmetic mod as the 1200 tank looks a little bulbous with the aftermarket seat I installed.

While I'm here, I'd also like to ask if anyone has experience with changing out the stock 2024 1200 gauges with aftermarket or perhaps the 2025 Speed Twin gauge? Again, just thinking of cosmetics. I think the stock gauges are absolutely beautiful, but entertaining thoughts of a more compact look.

Thanks!
Evan

beerkat · Aug 6, 2025

As far as I'm aware the Speed Twin 900 fuel tank has remained unchanged since it began life on the Street Twin. I very much doubt the tank is a straightforward swop onto the Speed Twin 1200.
I find one of the best ways to get answers to questions like this is to ask the technicians (or mechanics as they used to be known) at the dealers who actually work on these bikes. It's no good phoning Triumph. They won't tell you even if they know.

beerkat · Aug 6, 2025

RevPaul said: ↑

I asked the reverse question of one of the Triumph design engineers whilst at an event at The Triumph Factory a couple of years ago. And got a very firm no.

The Speed Twin 1200 uses a different frame from the Speed Twin 900 (formerly Street Twin/Cup/Scrambler). The problem is the distance between the front tank mounts (that slide onto the frame) and the rear bolt mount, and also how long the rear mount projects from the tank itself (which is covered by the front of the seat).

Your quest for aesthetics would also cost you in fuel tank range; the Speed Twin Tank is 2.5litres smaller.

Haven't got a clue about the clocks but personally I'd rather have the classic twin dial look.

Enjoy your ride
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I knew you'd know

Evan · Aug 7, 2025

Gents, thank you both for your replies. I kinda figured there would be some differences and what you say, Revpaul, makes perfect sense. Sounds like you know your stuff. I'll stick with the stock tank and enjoy it.

Ride on bros!!