1982-1983. 750cc OHV air-cooled twin
Why you might like a TSX...
Looks: One of the better factory customs.
Morris cast wheels: Strong. Solid. Maintenance free.
Starting: Kick and electric, and the electric works well.
Spares: Most parts are available. But expect some hunting.
Maintenance: Same as with all Bonnies. Simple. Clear.
Transmission: 5-speed gearbox is excellent and durable.
Handling: Positive. Confident. Wet or dry, the ride is fine.
Comfort: Slightly lower seat than stock T140. Easy riding.
Fuel economy: Expect 50-55 mpg. Never below 45mpg.
Performance: 100mph max. Cruise at 70mph. Torquey.
Investment: A TSX Triumph will sell. Values are rising.
Street cred: All you can eat. Meriden eye candy.
Vibes: Improved crankshaft machining lowers the buzz.
Dogleg brake/clutch levers: Reduced reach and strain.
Rubber mounted rider foot pegs: Every little bit helps.
Balance: Heavier than standard T140s, but well planted.
Build quality: Careful assembly by Meriden shows.
...and why you might not like one
Bing CV carburettors: Prone to leaks, but this bike is fine.
Sprag clutch: Kickbacks shorten electric starter life. Fixable.
Vibes: Moderate. Improvable. Irritation for some riders.
Gear change: Left side only. Trad Brit bikers beware.
Main lighting: Enough, but certainly not a feast.
Tank transfers: Hard to replace. Will need a paint job.
Clutch: Heavy-ish. Mods and upgrades are available.
Instruments: Basic. Speedo. Rev-counter. No frills.
Kickstarter: Optional. Not all examples have them.
Centre stand: Not standard. Needs a dedicated item.
Black engine cases: Need TLC to avoid scabbing up.
Rear wheel: 16-inch rubber hates removal and loves a fight.
Tank: Indian copies exist, but often need remedial work.
Switchgear: Passable, but a poor design. Doesn't like rain.
Front indicators: Shroud mounts vibrate and crack. Fixable.
Originality: Hard to find 100% "correct" examples.
Handlebars: Lower, "western bars" would improve things.
▲ This rare "factory custom" is one of just 371 TSX's made. We hear that 100 bikes stayed in Blighty. The Yanks got 200 units. The rest of the planet squabbled over the final 71. That colour is, we also hear, Gypsy Red. Midnight Black was an option. Note the chromed chain guard and 16-inch back tyre; the first 16-inch tyre on a Triumph motorcycle (they shifted the engine a quarter of an inch or so to the right to fit that). The front wheel is 19-inch, incidentally, and that front mudguard has hidden stiffeners that we haven't seen before on a T140 Triumph.
▲ The TSX riding position is fine ... if you like the sit-up-and-beg style. Flatter, "western bars" would help, but originality is what the world wants, and this isn't the kind of classic bike you want to alter very much, not if you want to preserve its value. Those are Morris cast wheels and not Lesters (as fitted to the 1979-1980 T140D Special). Note that some TSX brake discs have a four-hole mounting. And some have five. They're not interchangeable.
▲ You might have seen the TSX side panel before. Or, rather, later. They're the same as fitted to the Les Harris-era Bonnevilles built in Newton Abbot, Devon. That's a Bing constant velocity carburettor hiding its shame in there. They leak occasionally and cause some frustration. No one knows how to fix 'em. You just have to yell a lot and then they behave ... until the next time. We recommend shutting off the fuel half a minute or so before full shutdown. Note the owner repositioned indicator mounts and the small tag on the rear of the fork shroud which is all that's left of the original (fractured) mounts.
▲ TSX electric starter housing. Meriden did a very good job with this T140-based cruiser. Yes, it adds unwanted weight and bulk to the otherwise tidy and iconic timing chest design. But we've owned Triumph electric starters new and second hand, and the system works well. If your knees and ankles ain't what they used to be, and if you still want to get some fun out of a 750 Bonnie, this TSX could be your ticket to ride. Image above right: Brembo rear brake master cylinder. Better positioned that the T140 Lockheed item.
If you like the Triumph TSX, you might also be interested in ...
Triumph T140 Bonneville
& TR7 Tiger guide
£9.99 plus P&P
These T140 Bonnies are underrated and practical classics. But before you buy one, read this little A5 guide and get the inside track. It'll be worth it...
Triumph TSX sign
£14.99 plus P&P
This is our own design and is available only from Sump. Manufactured right here in the UK, the metal sign is made from mild steel and is printed direct-to-metal. The size is 400mm x 300mm. The image quality is high resolution.
Sorry, sold out!!
£14.99 plus P&P
All Sump T-shirts are original designs, and we're adding to the range all the time. Come and check 'em out and see which one is right for you.
Copyright Sump Publishing 2014
The Triumph TSX was built between 1982 and 1983. It was designed as a "factory custom" and was cobbled together on a tiny budget and aimed largely at West Coast America riders. But perhaps "cobbled" isn't the right word because the Meriden factory actually did a very good job and put a highly attractive spin on an old roadster idea.
We bought this one some time ago and have been pleasantly surprised at how well it performs and handles. We'd had the idea that it would wallow on its 16-inch back wheel, but far from it. It rides as well as pretty much any other T140-based Bonneville (which is essentially what this bike is), and returns surefooted cruising performance.
Electric & kickstarter
The kickstarter was an optional factory extra, and we'd strongly recommend retro-fitting one. Why? Because the starter sprag clutch/bearing is a weak point and doesn't like kickbacks. For some owners, that sprag (friction bearing) works happily for years, but for others it can fail prematurely. For a while, there were no replacements bearings available. But lately there is. Better buy a spare if you can.
The electric starter motor itself is a gem and should give decades of use. Ditto the rest of the starter gear train (excluding the sprag).
We've had three electric foot Bonnevilles (one brand new, and two secondhand), and all were good. In fact, these electric starters are perhaps the best that the (old) British motorcycle industry ever built (which isn't necessarily saying much).
The 750cc engine whizzes into life at the touch of the little green button. But keep the ignition timing spot on. Any doubts, kick it into life from cold and use the electric starter only when the engine is warm. The electric starter, note, prefers a (taller) 14amp/hour battery.
Most parts are easily available. Some models were built with twin front discs. All bikes will eventually fracture the fork shroud indicator mounts. We shifted our indicators to the headlight position as employed by earlier Meriden T140s. It's a simple modification.
32mm Bing carburettors
The 32mm Bings are typically (for CV carbs) slightly larger than the 30mm Amals found on the standard T140. MPG is around 50 - 55.
Note that Bings have a habit of developing spontaneous leaks (ask BMW Boxer owners). Those leaks will come and go at random intervals. You'll probably be okay when the engine is running. But you're advised to switch off the fuel 30 seconds or so before final shutdown.
You might fix the leaks by fiddling around with gaskets and floats, but chances are they'll fix themselves. For a while.
For long term, everyday riding, you might want to fit a pair of Amals.
Note too that stock T140 centre stands won't fit (not on our bike, anyway). But some TSXs do have centre stands, so they are around. The problem is the big-bore megaphone silencers. They foul standard centre stands.
Also, the kickstarter can connect with those silencers, so check and adjust (usually by loosening bolts, mucking around with the balance pipe beneath the engine, and re-tightening.
Paioli, Brembo and Lockheed
Other unique TSX features include the wire headlamp mounts (a la Triumph Hurricane), rubber-mounted rider pegs, the unique fuel tank and saddle, Paioli shocks, and a Brembo rear brake master cylinder (slightly more conveniently mounted than the T140 Lockheed item).
Above all else, these are just great bikes and currently fetch big money. Moreover, they're rising in value. We'd ride these anywhere, anytime.
If you really wanted to improve them, you'd fit a single carb head from a TR7 Tiger, but that would reduce the bike's originality (so keep the Bings and twin-carb head in an original parts box if you travel this road).
Forget primary belt drives. These 750s are fine as they are. You might upgrade the clutch, but we're happy with the standard set up.
The ignition is a maintenance free Boyer Bransden unit (Lucas Rita when new). Second warning: keep a full battery charge to avoid lunching the starter gear. Or use the kickstart.
TSX brakes and suspension
The brakes are Lockheed. but with a Brembo master cylinder at the rear. As with all well-set up T140s, these brakes are good, but not superlative.
Suspension is adequate with Triumph's standard front fork as used on the T140 Bonnevilles, but matched to the aforementioned custom rear shock absorbers courtesy of Paioli (when buying, check that these shocks still have the black plastic tops which often break and detach
The fat rear wheel and tyre adds a little weight, but also adds a little comfort without making the rear end "squishy".
The cast front wheel is heavier than a T140 wire wheel, and the ride is therefore a little harder. But TSX Morris wheels are maintenance free, and that's a real bonus.
Two-up riding is never ideal, but it's not bad on these customs.
General maintenance just isn't a big deal. Like the T140, there's not a lot to do except change the fluids and check nuts, bolts, and chain tension. Few special tools are needed, and factory workshop manuals and parts books are available.
When buying, other unique items to watch for include the rear plastic number plate mount, Goodyear Eagle Tyres with raised lettering (Avons were fitted to production bikes, but Goodyear tyres featured on the brochures), the chrome rear chainguard, and the unique TSX grab rail.
Current values (2015) are between £7,000 and £7,500 for a good, original example. Rougher machines will fetch maybe £5,000 to £6,000. Even incomplete TSXs will change hands for £4,000 - £5,000. And yes, there's some overlap here.
The bottom line? The Triumph TSX is one of the best Bonnies ever built. Buy. Enjoy. Sell at a profit.
Values are rising.
Click here for tips and advice on TSX parts