Ultima box info please

[Anorak_ian]

After building up a new Enfield gearbox for my bike, and realising that it is behaving more or less the same as the old box, I'm now looking for alternatives.

So I'm now thinking Ultima, but I need some info.

How much?
From where?
How long is the main shaft?
Is the mainshaft splined or taper?
Where are the fixing holes, front to back, top to bottom or sides?
Is there an overdrive gear available?

Thanks for your help

Ian

[coachgeo]

... looking for alternatives.

So I'm now thinking Ultima, but I need some info.

How much?

$600 USD + shipping from North TX. Zip 76258 Also have 3" belt drive available. For an Enfield you could sell this part and get a smaller one say a 2" or 1.5"???

From where?

My shelf

How long is the main shaft?

from case to end or from?

Is the mainshaft splined or taper?

Splined

Where are the fixing holes, front to back, top to bottom or sides?

sides. There is a plate that is part of it. Can be seen online if you search for places that sell them new

Is there an overdrive gear available?

there is a 5 speed and a speed model. 6 speed has a different ratio for several of the gears and if I recall right 6th is overdrive. Mine is a 6 speed.

What side is your gear shift on your bike?

[Anorak_ian]

Thanks for the reply.


from case to end or from?
Lets say from the outer edge of the sprocket (is it sprocket or pulley) to where the splines start on the main shaft.

What side is your gear shift on your bike?
It is at the moment a right hand, hand shift.

[coachgeo]

....

from case to end or from?
(is it sprocket or pulley)...

Neither; either/or. Nothing is mounted. Your choice to add sprocket or pully. This is brand new still in box with orginal Ultima certification papers. Never was installed when I bought it. Previous owner(s) including myself changed mind on project and never installed it.

Will get it pulled down and measured soon

[Crazymanneil]

Looks like Coach is on the ball for you. The gear ratios are -

1st gear -2.94
2nd gear -2.21
3rd gear -1.6
4th gear -1.23
5th gear -1.00
6th gear -0.86

Good solid big gearbox although weighs in at around 19kg. A range of final drives available as Coach says, with varying offsets and so on. What clutch would you want to use with it?

N

[Anorak_ian]

Thanks for the info,
But it's just dawned on me that if it's big I can't use it as the down tube of the frame will be in the way.
The back of Enfield box is only a couple of millimetres away from the down tube.

I have a 5 speed Enfield box that I have had for years, and that’s where my thoughts are at the moment. I don't know what I'm going to do about the extended main shaft though. I don't fancy the welded shaft from Price part.

Thanks guys

[tappy]

Hi Ian,
I'm curious to know a few things about the problems you're having with that Enfield box. Any thoughts on why? I calculated that you're turning the box at lower speed that on the Enfields, but at similar power levels - could the resulting excess torque be causing problems? I couldn't find much info on standard Enfield primary drive ratio tho' so I might have the figures wrong.

Reason I ask is 'cos I'm planning to use one - with the trials ratios - just as you've done. I wasn't going for an extended shaft tho' - I'm planning to mount the clutch on its own bearing and use a stub shaft from there to the gear box. I'm still planning and may yet discover there's not enough space, but it might be an option for your 5 speed box?

[Anorak_ian]

Hi Tappy, this box will always find false neutrals, they all do.

But the main problem with mine even after a rebuild is it occasionally will not engage third gear so it jumps from second gear to fourth, then back down to a false neutral and then second, and then try again. It's beginning to be more than just a pain, it's damn dangerous.
This may well be caused by the bob newby clutch dragging, even after re greasing the bearings it's hard to turn by hand.
When you pull the clutch on and off you can see the outer cover of the gearbox move in and out, there is a mod to stop this happening but I haven't made it yet. Anyhow, this movement of the outer gearbox cover takes up the adjustment that bob newby says there should be at the clutch cover adjuster. I'll get around to making the mod after making the box oil tight .
I don't understand why Enfield kept this crap Albion design, by 1962 there was a far better five speed Albion box (greaves cam barrel).

I've been thinking about the five speed box and extending the main shaft, either for this bike or the next. I'm thinking about making a device made from four Enfield clutch centres, drill out the three prongs and remove them, take off the big round plate, take off the bearing surface, and now attach it to the main shaft.
Do the same to two more clutch centres and cut out the splind parts making them in to rings with three holes in, and weld the three together. The fourth is the same as the first one, only weld this to the shaft of your choice, and then use three bolts to bolt the whole thing together. Maybe run it on a double bearing holder.

[Sphere]

Very offtopic: can these boxes be modified to shift 1-down, 2-3-4-up?

[Anorak_ian]

I don't think it can.

When I put the box back in the bike, with mod, and if it still has the same problems then I'll use the gear change on the neutral finder shaft. This will do away with the gear change mechanism; this will make the gears 1-down, 2-3-4-up. The only thing there is the lever will not return to its centre position. This will be ok for a hand change as previous versions of this box from the 1930's used the same shaft with a hand change.