CLAS­SIC TECH­NIQUES

Last month, Stephen Her­bert set about prov­ing that five into four does go, by re­plac­ing his En­field 350’s old Al­bion 4-speed gear­box with a more mod­ern 5-speed set-up. This time he ex­plains why, and what it’s now like to ride…

Real Classic - - Led Lighting - Pho­tos by Stephen Her­bert

The only suit­able word to de­scribe the En­field now is MOST EX­CEL­LENT. OK, I know that’s two words, but EX­CEL­LENT on its own doesn’t seem enough. But be­fore I ex­plain why it is now so de­scribed, let’s wind the clock back. Why did I do this? When I first re­built Rusty a cou­ple of years ago (when Rusty was truly rusty), one thing I didn’t strip and re­build was the gear­box. ‘What could pos­si­bly be wrong with a 1993, rel­a­tively new gear­box from In­dia with less than 9000 miles un­der its belt?’ I re­mem­ber say­ing to my­self.

The answer, it seems, it quite a lot. I spent a lot of time com­mis­sion­ing Rusty with his su­per-fast tuned en­gine (big­ger carb, gas­flowed head, al­loy bar­rel, higher com­pres­sion pis­ton, free-flow ex­haust, go-faster stripes), and ini­tially the odd false neu­tral and/or missed gear seemed unim­por­tant. It was only when I started to use Rusty in earnest on club runs (see VMCCcheshire­cats.co.uk for more) that Rusty’s gear­box woes truly sur­faced.

For in­stance, there were a lot of ex­tra neu­trals in the box. Don’t know where they were, I opened it up a few times but couldn’t find them lurk­ing in the greasy depths. Some­times these false neu­trals were in one place, other times else­where. It was like the bike was try­ing to out­wit me (suc­cess­fully!). On some runs I was wor­ried about dis­as­ter strik­ing if I couldn’t find the right gear when ap­proach­ing a steep hair­pin on the Horse­shoe Pass. Eek.

I did try to fix the box by do­ing all the ob­vi­ous things like ad­just­ing the clutch, de­tent plunger, se­lec­tors (such as they are), etc, but to no avail. There are tech­ni­cal pages on these tech­niques posted on Hitch­cock’s in­ter­webthingy if you too are strug­gling.

Turn the clock back even fur­ther and we dis­cover that the cogs in the orig­i­nal Al­bion box – upon which that this In­dian one is based – have seen ser­vice in many guises from in­dus­trial lathes through small ca­pac­ity bikes to the mighty In­ter­cep­tor. It’s a very old and fairly crude de­sign, par­tic­u­larly with re­gard to the se­lec­tor mech­a­nism, so I sup­pose we shouldn’t be sur­prised that it

strug­gles in the 21st cen­tury. How­ever, my Con­stel­la­tion has a sim­i­lar box and it’s sweet as a nut. Any ideas?

In the late 1990s, RE com­mis­sioned a new, 5-speed box for its fu­ture mod­els (Bul­let 65, Elec­tra-X, etc). I had an Elec­tra-X a while ago and a very good box it was too. Still not a Ja­panese gear­box, but the se­lec­tor sys­tem uses a proper cam­plate in­stead of match­ing soup spoons and forks so is a mas­sive im­prove­ment on the old Al­bion one. Most of these boxes were in­stalled on En­fields with left-change, 1-down and 4-up con­fig­u­ra­tion but are eas­ily mod­i­fied to right change with the con­fig­u­ra­tion ei­ther the right way up or up­side-down, de­pend­ing on your point of view. This was ex­actly what mine was. I sourced it as a sec­ond­hand item from Hitch­cocks with an up­side-down (to me) 1-down and 4-up mech­a­nism.

BE­ING RATIONAL ABOUT RA­TIOS

I promised not to get into too much math, but it’s worth hav­ing a look at some num­bers. These are the gear ra­tios of the two boxes:

I don’t find these tables of gear ra­tios par­tic­u­larly help­ful, as they’re just num­bers and my brain finds it dif­fi­cult to draw com­par­isons. If you draw the num­bers as a graph, you get this: ( Top Graph)

This ac­tu­ally shows what’s go­ing on. ‘ Top’ is the same on both (1:1) and you can see that, for ex­am­ple, first on the 5-speeder is slightly lower than first on the 4-speeder. Fourth on the 5-speeder is be­tween third and top on the 4-speeder. But this doesn’t show what Rusty is truly do­ing, be­cause I’ve fit­ted a larger (17T) gear­box sprocket which nat­u­rally af­fects the over­all ra­tios. With me so far?

The true ef­fects of the 17T sprocket on the com­par­i­son be­tween the boxes looks like this: (Be­low Graph)

This shows that first and sec­ond on both boxes are ef­fec­tively very sim­i­lar. Top on the 5-speeder is a bit higher than on the 4-speeder, and third and fourth on the 5-speeder are well spaced be­tween these other ra­tios. This (the well-spaced ra­tios) is ex­actly what it feels like when rid­ing Rusty. A cog for all sea­sons!

TAKEN FOR A RIDE

So how does it ride? As hinted ear­lier, MOST EX­CEL­LENTLY! The 5-speed gear­box snicks qui­etly into first with­out any alarm­ing clang­ing and bang­ing. It’s even pos­si­ble to select neu­tral at a stand­still, which I could never achieve with the old box. Smooth, pre­dictable, plenty of feel, no slip­ping or drag­ging of clutch. No false neu­trals what­so­ever.

The pedal move­ment is slightly ‘longer’ than on the Al­bion box, but that’s not a Bad Thing, as it lets you know it’s do­ing what is should be do­ing. My mem­ory is hazy, and I sold the Elec­tra-X with the same 5-speeder a while ago, but I think this box is bet­ter than the Elec­tra-X one. This is pos­si­bly be­cause the Elec­tra-X had left-foot change, which worked via a long spindly rod pass­ing through the oil tank and pri­mary chain­case to the pedal, or pos­si­bly be­cause of the ex­cel­lent Henry Price 5-plate clutch con­ver­sion fit­ted to Rusty.

I’m re­ally glad I upped the gear­box sprocket size too, be­cause the over­all ra­tios on this set-up seem near-per­fect. Fifth cer­tainly feels a lit­tle taller than the old 4-speeder due to the 6.25% up­lift, but it doesn’t cre­ate a prob­lem as the gap down to fourth isn’t too wide. As the change is pre­dictable and easy it makes it easy to change down. All the gears seem to be ‘right’ – cer­tainly for my kind of rid­ing. They prob­a­bly wouldn’t work well if I were rac­ing Rusty at Oul­ton Park,

but I wouldn’t let him loose on the cir­cuit in case he dam­aged him­self. RE Bul­lets aren’t rac­ers… but the ‘Bul­let Whis­perer’, Paul Hen­shaw, might dis­agree with that state­ment!

Some­how, whether real or imag­ined, Rusty seems to go bet­ter with the 5-speed box. I don’t know if this is be­cause the new gear ra­tios suit the mildly-tuned 350 en­gine, or per­haps it’s re­duced in­ter­nal fric­tion, or sim­ply be­cause the box changes prop­erly when I want it to. Maybe it’s zen or some­thing su­per­nat­u­ral. I don’t know, but the bike feels pos­i­tively trans­formed. That might sug­gest that Rusty was un­pleas­ant to ride be­fore his trans­for­ma­tion. This would be in­cor­rect. I al­ways en­joyed rid­ing him, but gearchanges were a bit of a chal­lenge and cre­ated some ner­vous­ness when ap­proach­ing ob­sta­cles which ne­ces­si­tated pre­ci­sion in the box depart­ment. Now that Rusty’s changes are en­tirely pre­dictable and with­out drama, he’s much bet­ter.

The only slight is­sue I still have is the ‘up­side-down’ change. I was brought up on an RE Cru­sader back in the day, with a 1-up and 3-down con­fig­u­ra­tion. Rusty now has the op­po­site and the first ride was ‘in­ter­est­ing’, to say the least. I have started re­peat­ing the mantra ‘up means up and down means down’, which seems to help…

FI­NAL FETTLING

A cou­ple of things needed do­ing af­ter that first, ten­ta­tive ride to make sure ev­ery­thing else worked OK. These were chain and electrics re­lated. Dur­ing the gear­box trans­plant, it be­came ap­par­ent that by fit­ting a 17T sprocket to the gear­box out­put shaft, I needed a slightly longer chain, as there was no ad­just­ment left on the wheel / swing­ing arm. No prob­lem. Those friendly guys at Hitch­cocks sup­plied a 95 link chain the very next day.

The first thing I no­ticed on the road was that there was a bit of a scratchy / rat­tly noise com­ing from the dark places some­where un­derneath. This seemed to vary in in­ten­sity as I went over bumps and when ac­cel­er­at­ing / de­cel­er­at­ing. It didn’t take long to re­alise that the chain was just rub­bing on the lock­nut at the back of the brake pedal hanger. Maybe this had been hap­pen­ing all along, although the wit­ness marks on the new chain sug­gested not. Maybe it was a re­sult of a very small dif­fer­ence in the ax­ial po­si­tion of the gear­box sprocket on the new box. Trou­ble was, the lock­nut played an im­por­tant role in stop­ping the brake pedal pivot un­screw­ing it­self so couldn’t sim­ply be re­moved.

Af­ter a bit of head-scratch­ing, I worked out that I could move the lock­nut out­board and still have the same func­tion. The chain had a free run and the marginally out­board po­si­tion of the brake pedal didn’t seem to mat­ter. The scratchy noise def­i­nitely dis­ap­peared.

The other thing I wanted to do was to make use of the neu­tral switch on the new box. It’s re­ally use­ful on my Beemer, so why not con­nect it up on Rusty? Noted En­field Experts will know that the orig­i­nal 4-speed Al­bion box has a neat trick in the form of a neu­tral fin­der. This is a simple ex­tra gear lever which, when stamped on, puts the box in neu­tral. The 5-speeder has none of this non­sense, so that neu­tral switch to an in­stru­ment light is a must.

All I had to do was to run a wire from the ter­mi­nal on the switch on the back of the gear­box to an id­iot light some­where on the dash­board, and from the other side of the id­iot light to the am­me­ter for power. Very easy to do, slightly naff id­iot-light sit­ing, but it all worked per­fectly. I may tidy this up at some point in the fu­ture – and/or add a main beam id­iot light as Rusty doesn’t have one.

But this cre­ated another po­ten­tial prob­lem. Due to the po­si­tion of the neu­tral switch at the back of the gear­box, it was vul­ner­a­ble to spray off the rear tyre. Rusty, like all In­dian Bul­lets, has a mud­guard ex­ten­sion which sits in be­tween the tool­boxes, but it doesn’t ex­tend down low enough to pro­tect the neu­tral switch. Hav­ing made up a new bracket to se­cure the bot­tom of the mud­guard ex­ten­sion dur­ing the trans­plant, I sim­ply made a mud­guard ex­ten­sion ex­ten­sion out of thin ally sheet and se­cured it to that bracket.

Af­ter all that, Rusty now has a fully func­tion­ing gear­box which in­spires con­fi­dence and tells me when it’s in neu­tral. As a re­sult, the En­field has be­come my favourite bim­bling bike. I use it for most of our club rides now, and the Bul­let is even old enough to be VMCC el­i­gi­ble. I can thor­oughly rec­om­mend this trans­plant / con­ver­sion for any Bul­let with a dodgy (or even oth­er­wise) gear­box. Snag is the 5-speed­ers don’t come on the sec­ond­hand mar­ket very of­ten – I was lucky to phone Hitch­cocks just as they were pre­par­ing this one for sale. They do, how­ever, ap­pear new on eBay from In­dian ven­dors, and most come with a match­ing clutch, so you could take a chance with one of these if you feel brave!

Now, would any­one like to buy a 4-speed In­dian Bul­let gear­box? One care­ful owner. No? Oh well, suit your­self!

Rusty, the Real­ly­im­proved En­field

The sil­ver coloured lock­nut fouled the chain be­fore be­ing moved out­board, where it works just as well and with­out catch­ing the chain

Tak­ing that vi­tal test ride around Cheshire; the en­trance to Peck­for­ton Cas­tle

A test ride re­vealed that the new box’s neu­tral switch was ex­posed to the el­e­ments, so the mud­guard ex­ten­sion grew its own ex­ten­sion

Right: The new gear­box, com­plete with the mud­guard ex­ten­sion which pro­tects its back, and the neat lo­ca­tion of both the reg-rec unit and ig­ni­tion switch

Left: Con­sid­er­ably re­vised flight deck in­cludes the rather bright id­iot neu­tral light

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