Hermit's Triumph 650 Tech Articles

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.

Triumph Unit 650 4-Speed Gearbox Assembly Made Easy
Of all the different ways of assembling a Triumph 650 gearbox, the standout method has to be that demonstrated by the masterful Hughie Hancox on his authoritative "Unit 650 Engine Rebuild" DVD.

Triumph Gearbox Assembly: Comparing Three Different Methods
If you're still not convinced that the Hughie Hancox method is the best, here is a side-by-side comparison of the Triumph workshop manual, Haynes, and the master himself, Hughie Hancox.

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.

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 650 Gearbox Photo Animation: Rear View.
The same great gearbox photos and photo animation but viewed from the rear.

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
Reference photos of Triumph Bonneville 650 gearbox components - assembled and apart, and new and old for comparative purposes.

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.

Assemble Clutch Hub, Rollers, and Clutch Center
Photos showing assembly of the clutch hub, rollers, clutch center, and duplex sprocket, with link to step-by-step instructions.

The "Triumph 650 Unit Construction Engine Overhaul Manual", written by Thomas G. Gunn, Jr. for Triumph Corporation Baltimore in 1967, is a field-tested, step-by-step blueprint for completely overhauling the iconic unit construction Triumph 650 engine. It lists engine changes and updated factory specs up until 1967.

In addition to correcting errors in the original and further updating technical info, Hermit's hypertext version offers seamless, one-click access to footnotes, table of contents, and direct links to corresponding sections in the 1969 Triumph Workshop Manual.
Have a look:
Triumph 650 Complete Overhaul Manual: Hypertext Version

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.

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!

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 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.

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)

650 Triumph Front Fork Rebuild
Here are illustrated step-by-step instructions for reassembling the front fork for a 1969 Triumph T120R. Complete info, including rundown of special tools.

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.

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).

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.

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: 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.