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Hermit's Triumph 650 Tech Articles

Complete tutorials on setting Triumph 650 ignition timing as well as assembling and indexing the gearbox, and many other basic maintenance and repair articles.

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

Overhauling the Triumph 650 Unit Construction Motorcycle Engine

Triumph 650 engine
The "Triumph 650 Unit Construction Engine Overhaul Manual", written in 1967 by Thomas G. Gunn, Jr. for Triumph Corporation Baltimore, is a field-tested blueprint to disassembling, inspecting, renewing, and re-assembling these very special engines. It includes methods and techniques, and it references specialized tools and modifications and changes.

Presented here are the Original as a PDF, and an Annotated and Updated hyperlinked version.

How to Set ignition timing for Triumph 650 Motorcycles with Points

Triumph Ignition Points
Triumph 650 Ignition Timing
Having trouble setting the ignition timing on your Triumph 650 points ignition? Then you've come to the right place! Hermit's illustrated guide to setting points ignition timing identifies and explains exactly what the heck each and every one of all those little screws in there do! Includes detailed, step-by-step instructions for both static and dynamic timing.

How to Assemble the Triumph 650 Gearbox

Triumph Gearbox Parts
Triumph Gearbox Assembly: Comparison of Three Methods
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, Haynes, and the master himself, Hughie Hancox.

Triumph Gearbox Parts
Fastest, Easiest Triumph 650 4-Speed Gearbox Assembly
Of all the ways to assemble the Triumph 650 gearbox, the easiest and fastest way has to be the one used at the factory and demonstrated by the masterful Hughie Hancox on his DVD. Hint: it's not the way shown in the Workshop manual!

How to Index the Triumph 650 Gearbox

Illustration of Triumph gear change mechanism
Indexing the Triumph 650 4-Speed Plunger Gearbox
The Triumph 650 gearshift mechanism illustrated and explained followed by step-by-step instructions for three different methods to index the gearshift quadrant to the camplate.

Gearbox Photo Animations

Triumph gear cluster
Triumph 650 Gearbox Photo Animation: Front View
These photos show you exactly how the camplate and gears move in all the gears, in stills and as a unique photo animation of the Triumph 650 gearbox. Diagrams show the transfer of power through all the gears and indicate which gears spin and which gears are splined to their shaft. Highly educational!
Triumph gear cluser from back
Triumph 650 Gearbox Photo Animation: Rear View.
The same great gearbox photos and photo animation but viewed from the rear.

Gearbox Reference Photos

A Triumph plunger spring
The Spring Report - Mike James
Between '68 and '70, Triumph made many tweaks to 650 Triumph gearbox plunger springs, plungers, plunger holders, and gearshift camplates. What did it all mean? Mike James evaluates and analyzes the changes in this detailed and superbly illustrated guide. Learn the difference between spring rate and spring force and why it matters. A must-read for those interested in a deeper understanding of these intricately related parts and the method to Meriden's "madness". (PDF, 8.5mb)
Triumph 650 Gearbox Components Reference Photos
Triumph 650 Gearbox Components Reference Photos
Reference photos of Triumph Bonneville 650 gearbox components - assembled and apart, and new and old for comparative purposes.

More Gearbox Information

Triumph 650 Gearbox Components Reference Photos
Hermit's Field Guide to Bonnie: The Gearbox
Hermit's stash of gearbox illustrations, diagrams, factory bulletins, overhaul methods, and links to other sources. The gearbox section of The Bonnie Ref.

Miscellaneous Tips & Techniques

Rear Wheel Alignment Using Mason Line
Proper rear wheel alignment is crucial to preventing excess tire, sprocket, and chain wear. If you're unfamiliar with working to a line, here are some tips on how to set a line on your bike to check alignment.

Triumph center stand spring
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!

Triumph engine pushrods
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.

Triumph front
    and rear axle retainers and dust covers
The Usual Suspects
To dispell my confusion about the assembly order and orientation of front and rear axle rings, retainers, and dust covers on my 69 T120R, I organized these illustrated, cross-referenced parts line-ups. I also included photos identifying the rear axle nuts and distance pieces. All illustrations include parts book references, part numbers, and specs.

A Triumph plunger spring
Triumph T120 Fork Dimension Changes for 1968/1969 - Mike James
Mike James guides us through the mine field of subtle changes that Triumph made to fork components during the years 1968 through 1969. All the part numbers, specs, and illustrations you need to sort out your late-sixties Triumph front end. (PDF, 5.3mb)

Motorcycle Wheel
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.

Lucas Logo
Pin-Out for Lucas 35710 Lighting Switch
Here is a chart showing the electrical connections in all three positions of the Lucas 35710 lighting switch (Triumph Part # 99-0563).

Homemade Triumph clutch tool
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 tool which is essential for clutch and gearbox work.

Triumph headlight bulb with greased contacts
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, Bardfark Dungwall.

The Bonnie Ref

Triumph, makes a mechanic out of a man logo
The Bonnie Ref: A Hyperlink Junkie's Illustrated Field Guide to the Triumph Bonneville
The Bonnie Ref is a compendium of information about caring and repairing the 650 Triumph Bonneville. Includes ramblings of Bonnie's non-mechanically inclined owner. It's a warehouse of highly organized easily-accessed info, including factory service bulletins, photos, full parts, and links to informative on-line discussions.