Hermit's Triumph 650 Tech Articles

Truth be told, I'm not much of a mechanic. But I learn from my mistakes and with a little help from my friends I manage to keep the old '69 Triumph T120R roadworthy.

You know what they say, "Triumph! Makes a mechanic out of a man!".



Field Guide to the 1969 Triumph Bonneville T120R

  • The Bonnie Ref: A Maintenance & Repair Manual
    This compendium of useful information is a veritable treasure trove for anyone wanting to maintain and repair their Triumph 650 unit twin. What are you waiting for? Have a good look and then start wrenching.
  • Triumph 650 Ignition Timing
    If your Triumph 650 unit twin is running on points, you need to know how to quickly and accurately check and set ignition timing. The Triumph Workshop Manual's ignition timing section is enough to confuse anyone, but Hermit's illustrated guide explains exactly what the heck each and every one of all those little screws in there do, and gives detailed, step-by-step instructions on how to properly set up the timing from start to finish using both static and dynamic methods. Improperly set ignition timing can have catastrophic results for your engine (and your pocketbook). Get it done right!
  • Hermit Gives You the Gears

  • Triumph gear cluster power transmission
    Still photos and animations of a 1969 Triumph Bonneville T120R motorcycle gear cluster in all gears and neutral showing drive transmission, part numbers, etc. Views from front and rear.
  • Hermit's Field Guide to Bonnie, the Gearbox
    Having Triumph 650 gearbox issues? With perseverance and good info you can, erm, Triumph! Here's Hermit's stash of gearbox illustrations, diagrams, factory bulletins, assembly methods, and links to sage advice.
  • Triumph Gearbox Assembly Methods Comparison
    There are many ways to put a Triumph 650 gearbox back together. Here is a side-by-side comparison of the methods described by the Triumph workshop manual, the Haynes workshop manual, and, the master himself, Hughie Hancox.
  • Triumph 650 Gearbox Components Reference Photos
    Here are some reference photos of the Triumph Bonneville 650 gearbox components - assembled and apart:
  • Triumph 650 Gearbox Animation (front view)
    Watch as this Triumph 650 gearbox photo animation shifts up and down through the gears.
  • Triumph 650 Gearbox Animation (rear view) Watch the same gearbox animation but viewed from the rear.
  • Pushrod Alignment
    Here's an idea for getting those pushrods properly aligned with the rockers during reassembly, even if you're using larger diameter custom lightweight pushrods.
  • The Usual Suspects
    To dispell my confusion about the order and orientation of front and rear axle rings, retainers, and dust covers on my 69 T120R, I organized these hyperlinked, illustrated, cross-referenced parts line-ups. Cleared things up for me; have a look.
  • Wheel Rebuilding - by Phone
    You can't tune a fish, but you can tune a motorcycle wheel! If you don't know a hop from a wave, read guest tech writer Geoff Collins' article about his first-time experience of wheel rebuilding. He rolls out the basics for you.
  • Installing a New Center Stand Spring
    The easiest way to install the pesky center stand "super-spring". Some things are easier to pull than push!
  • Rear Wheel Alignment Using Mason Line
    Proper rear wheel alignment is crucial to preventing excess wear on tire, sprocket, and chain. If you're not a carpenter or mason, here's some tips on how to set a line.
  • Proprietary Clutch Locking Tool
    A couple of used clutch plates and a short piece of iron pipe are all you need to make a handy little tool essential for clutch and gearbox work.
  • Switch Position Pin-Out for Lucas 35710 Lighting Switch (Triumph Part # 99-0563)
    The three positions of the Lucas lighting switch are DIM, FLICKER, and OFF.
    Unless, of course, you have the earlier switch, in which case the three positions are SMOKE, SMOLDER, and IGNITE.
    In either case, the chart here covers all the bases for what's happening, electrically speaking, in all three positions of the Lucas 35710 lighting switch. Abbot and Costello could do no better.
  • Blimey! Why do my headlamp bulbs keep breaking?
    Because you keep dropping them on the shed's cement floor? Because your pothole radar is defective? Or because you forgot to grease them?
    Seriously! Also, some helpful(?) 'insights' on headlamp bulb test methodology from our own in-house motorcycle mechanic extraordinaire, Fardbark Dungwall.
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