So taking a basic 500 Electric starter Classic Enfield, then add:
2) Close Ratio Gearset
3) Duckbill engine breather
4) Softer/progressive front fork springs
5) Softer rear shock springs
6) Uprated clutch springs
7) Disk front brake
All the above mods are aimed at improving the useability of the bike for the type of riding that I use the bike for.
In std form the bike is more than capable, the modifications just improve things a bit.
To be honest I was considering removing this when I first got the bike, but after using it for a year I can state that it makes riding long distances or in bad weather a lot better.
Unfortunately these are no longer imported to the UK.
The lower screen mounts have been cut & shut to fit the bullet lower fork mounts.
Close Ratio Gearset
This gearset removed the massive gap that normally exists in the Enfield box between 3rd and 4th gears.
On the downside it also raises first gear, add to that an 18t gearbox sprocket and uphill starts become a clutch challenge.
The 5 speed gearbox is a better option but costs a whole heap more.
In std form Enfields are supplied with a complicated engine breather system that feeds exhausted oil vapour to a catch can and then to the air filter.
There are several problems with this system, the pipes clog with emilsified oil (looks like mayonaise), the catch can fills up really quickly in the early days and oil ends up in the air filter chamber contaminating the paper element and dripping out onto the exhaust where it burns and removes the chrome.
Best to revert to the system that the bike was designed with originally, a flat ended rubber pipe that blows oil vapour onto the chain keeping it lubricated.
In standard form the suspension is built for rural Indian roads and can be a tad harsh on the UK's relatively smooth roads.
Swapping the springs for a softer set improves the ride but like any modification it's a compromise, on the downside you get a lot more fork dive under braking (esp. with a disk brake) and it makes it more difficult to get the bike onto the mainstand as sag increases and therefore you need to physically lift the bike onto the stand.
In hindsight it would have been better to replace the fork oil with a thinner grade and reduce the damping because I'm increasingly using the bike with a pillion.
Uprated Clutch Springs
In standard form the clutch would slip, especially when cold, it would also drag when hot and you have a recipe for trouble.
Hitchcocks sell a kit of 3 stronger springs replacing half of the 6 weak springs that are fitted as standard.
This increases the clutch pressure and prevents slippage but also increases the lever pressure at the handlebars.
Also add a roller pressure pad and fill the primary with ATF (Auto Trans Fluid) and say goodbye to clutch woes.
It will still get fussy in heavy traffic, so ensue neutral is selected whenever the opportunity arises.
Disk Brake Upgrade
This is a bit of an extravagance but when the M25 comes to a sudden halt it's not good to have the worst brakes in the lane.
This comes as a factory kit but expects you to reuse the drum brake rim, axle and bearings.
To facilitate a quick switch I bought a new stainless rim, spokes and axle with bearings.
This is a one way conversion, there is no going back as you need to remove the drum brake lug from the fork leg, this was an easy job with a hacksaw and file.
Be aware that the mirror fitting is different (10mm) and the lever is black rather than bare alloy as the drum brake and clutch levers are.
It's a good brake though, nice and progressive.
So, What are the challenges?
Running In, Luckily mine was done for me by the previous owner, don't observe the rules and it will seize.
Tappets - requires the skills of a gynacologist, 3 hands with spanners.
Points - yes this bike has points, gap setting and timing are as necessary today on this bike as ever they were in the 50's.
Exhaust - the header pipe is not affixed to the engine, it's bolted to the engine mounting on the frame and just sits in the port, once it gets a bit loose it will rattle away and fret the port away creating an even looser fit. Seal this with exhaust putty and fit a cooling ring clamp to create a better sealing surface.
Gearchanging - A right foot shift, and a fussy one to boot, there is a seperate 'neutral selector' lever but even this won't help if you come to a halt with the bike in gear. Don't sit at the lights with the bike in gear either as the clutch will get all hot and bothered and gearchanging will become even more difficult.
Yes but what are the good bits
Looks - it's a genuine retro bike not a modern interpretation, this bike did exist in the 1950's
Sound - Fit a factory aftermarket pipe and enjoy.
Riding - without doubt this is one of the most comfortable motorcycles I've ever ridden
Handling - planted and very well balanced, handles so well you'll be surprised.
Engine - quite simply a single with character, torque dominates the power delivery.