Dammit. Why is it that just about every used motorcycle I’ve bought in recent years has demanded a new set of fork seals? When totting up the real cost of a purchase, I now allow for seals as a matter of course.
In this case, I shouldn’t have been all that surprised. Though it has only a couple of thousand miles under its belt, the T160 is nearly 40 years old, which means most things have been sitting idle for far too long.
Within seconds of the seals letting go, I also noticed the weirdest shimmy from the front end. Yep. The front wheel bearings (the original open ball-bearing type) were also on the way out. You wouldn’t think just sitting quietly in shed could wear out a motorcycle, but it can.
The good news is parts are plentiful and cheap. However I’m relatively inexperienced when it comes to Meriden Triumphs and went scuttling off to Phil Pilgrim of Union Jack Motorcycles, knowing he’d have the resources to do the job quickly while I hovered around and tried to learn something.
SEAL IT WITH A KISS
Changing fork seals is one of those jobs that (with a few exceptions) takes patience rather than high-end skills. However there are the inevitable tricks or traps for the unwary.
In this case, Phil said we could go for conventional seals, but he prefers a floating type – distinguished by being held in by a large press-fit metal washer. The payoff is better sealing, though your fork legs need to be in top condition. In this case they were – thankfully we found no signs of pitting or rust. Disassembling the front end presented no great dramas, requiring the removal of the front wheel, plus shifting the handlebars so we could get at the fork tops. Keep an eye out for the small parts, particularly the crucial small washer at the bottom of the slider.
Shifting the damper valve can require the use of a long screwdriver, but not always. Phil had a monster on hand, which was perfect. Speaking of odd tools, he also had a hand-made front stand for the bike – nice, solid and very useful.
THE ‘BIG O’
While we were in there, we checked the condition of the O-rings on the damper valves. We also ditched the stock springs for some new progressive items. They supply a more supple ride and the old ones were probably past their use-by date.
Reassembly was straightforward enough, with Phil adding a measured amount of auto transmission fluid (a common option for forks of this era). Instead of replacing the original scrapers on the top of the sliders, we opted for a pair of Norton gaiters, which will protect the legs from stone damage. It suits the period and is a no-brainer when it comes to minimising maintenance.
We also ended up tackling the wheel bearings. The rears were fine, but the fronts had got notchy, possibly from standing around too long. Phil had (another) special tool to remove the covers, though you might get away with a pair of right-angle circlip pliers. The bearings are a different size to each other – one narrow and one wide – and we opted for modern sealed units.
In all it wasn’t a massive job – about two-and-a-half hours of labour. Springs cost around $70 for the pair, seals about $45, bearings around $30 and $25 for the gaiters. Pilgrim’s view is these are “a good honest bike” that is simple enough to do regular maintenance on.
Somewhat frustratingly, we also noticed the front rim is out of alignment. Some judicious spoke-tightening has pulled out the worst of the wonkiness but I think I’ll be taking it to a wheel builder to get it properly trued.
At some stage it will almost certainly have the original ignition points taken out and replaced with a solid-state timing set. It’s fine for now, but the stock system is fiddly and not all that reliable. A similar conversion on a T150 I owned a couple of years ago did wonders for it.
SO FAR, SO GOOD
I’m writing this on the first of a four-day run around the countryside, starting at the national Vincent rally in Marysville, Victoria. Early signs are the bike is good on the highway, with plenty of power. Braking is only so-so but is respectable by classic motorcycle standards.
It seems the decision to go with the narrower-than-standard front tyre was a good one. Stock, the T160 had the same size front and rear. No doubt that made for interesting production economies but to me the stock steering felt a little muddy and I wasn’t a fan of the way it looked. Now it’s a little more precise.
The oil seal behind the gearshift has sprung a leak and I’m closely watching the old-style non-O-ring chain. Oh, and the range of the American small tank is marginal, so I’ve slung a spare fuel container on board.
By far the biggest risk is jumping on a machine that’s seen so little use over the decades. Phil is a believer in doing a strip and check before recommissioning a motorcycle that’s been standing for years and he’s got the experience to back it up. However I’ve decided to take the risk and see what happens.
Wish us luck…
THUMBS UP – Surprisingly civilised – Decent performance
THUMBS DOWN – Heavy – Not very robust
1975 Triumph T160 Trident
ENGINE: Type: Air-cooled in-line triple with two pushrod valves per cylinder Bore and Stroke: 67 x 70.5mm Displacement: 741cc Compression ratio: 9.5:1 Fuel system: Amal carburettors
TRANSMISSION: Type: Five-speed constant mesh Final drive: Chain
CHASSIS & RUNNING GEAR: Frame type: Single downtube steel Front suspension: Conventional 35mm fork Rear suspension: Twin Girling shocks, preload adjustment Front brakes: Single 254mm disc Rear brake: Single 254mm disc
DIMENSIONS & CAPACITIES: Dry weight: 229kg Seat height: 794mm Fuel capacity: 14 litres
PERFORMANCE: Max power: 58hp at 7250rpm Max torque: Not stated