FIVE into FOUR
In recent years, Royal Enfield swapped from an old-fashioned fourspeed gearbox to a newer unit with five ratios. Following their example, Stephen Herbert investigates whether five into four really will fit…
In recent years, Royal Enfield swapped from an old-fashioned four-speed gearbox to a newer unit with five ratios. Following their example, Stephen Herbert investigates whether five into four really will fit ...
Rusty is my 1993 Royal Enfield Bullet 350 Superstar. He graced these pages before, back when he was genuinely rusty before the rebuild. The name stuck and I got on with riding him. All was well, but problems with the gearbox soon surfaced. These old Albion-derived Indian boxes are well known for false neutrals, jumping out of gear, leaking lubricant, etc. I had all of this and despite a few goes at sorting it, the problems remained and it was becoming more of a chore to ride Rusty. Which was a problem cos Rusty is inherently a nice bike to ride. Time to do something more radical, then.
The notion that ‘five into four’ does go sounds like a primary school arithmetic lesson from the 1960s. Actually it is all about a transplant – replacing the 4-speed Albion box with a 5-speeder from a more modern Indian Bullet. In this case, a used box from (I think) a 2003 Bullet 65 sourced from Hitchcocks. This was originally a left-foot changer but a simple mod swaps it to a right-footer. The action is better too, as the left-foot arrangement involved a long spindly rod passing through the crankcases, oil tank and primary chaincase to emerge on the left.
This instalment describes how I did the transplant. Next month, I’ll explain why, and what it’s like to ride with the five-speed box fitted. The next thing about swapping gearboxes with Enfield’s pre-unit design is that you can leave the engine in situ, together with all the attached stuff like carburettor, cables, wires and zorst, and just swap out the gearbox. In fact Roy, my brother-in-law, asked ‘is it just: unbolt, line up new one and bolt in place?’
Right: This is the new five-speed gearbox ready to be fitted. Bought used from Hitchcocks, sprocket changed and some paint applied