5 Speed gear box

Hi
Anyone have any leads or input on building or buying a five speed gear box for a Commando?

Tks

Mark

Hi captmark, welcome. I believe Quaife makes them http://quaife.co.uk/shop/search/results/taxonomy:808

Trans Tasman Industries in New Zealand make 5 or 6 speed boxes for your Norton
Regards Mike

Fairly common for Cdo racers to adapt a Triumph 5sp with its non Norton looks.

For road use, a 5 sp or even 6 sp you don't gain a lot ?

With a kickstarter fitted, it gives you 5 ratios where before you had 4.
So don't gain an overdrive in 5th, or a lower 1st so can gear a bit taller.

With its strong torque, most road work is in 4th anyway, with 3rd for the slower bits.
Unless you haul a lot of luggage or heavier passenger ?
Or do a lot of slow town work in 1st, 2nd and maybe 3rd ?

Changing the gearbox sprocket between 19t and 23t gives a fair range of gearings to suit.
Although 23 is highway gearing, probably getting too high for slow town work...

Now, if a 5 speed gave you an overdrive in 5th, now that might be useful.
Same lower ratios in town, and lower revs on the highway...

Does anyone make anything like that.?

Some of these HD boxes (as in Milwaulkie) would, wonder if they could be fitted.
Have huge clutches though, so that bit is out...

Rohan I had to give a lot of thought to Peel's deal and scope, after the 6 spd peddlers, decided to go 4 sp with custom extra low granny gear, 2nd for 30'-90's, 3rd up to 120 and 4th to who knows yet, but great mileage on low rpm cruise. But Peel has unfair torque mass advantage. I would like a 5th or 6th if really racing so mainly staying in full tilt boggey, but otherwise I'd prefer the lack of shifting on plain Jane Cdo and not really racing around. Still I always encourage taking on a difficult or expensive modification or experiments. Everyone has their own expectations and what they consider a racing course in public. Kind of depressing the ongoing take downs by those behaving perfectly so WFT, live to it max ya can take eh as hardly risking much more than just swing into a saddle.

INDEED .

theres youre overall top gearing , rpm's/ mph .

and Low Gear Ratio ,

to select ratios .

To tall a first can be hard on everything .

hobot said:

Rohan I had to give a lot of thought to Peel's deal and scope, after the 6 spd peddlers, decided to go 4 sp with custom extra low granny gear, 2nd for 30'-90's, 3rd up to 120 and 4th to who knows yet, but great mileage on low rpm cruise. But Peel has unfair torque mass advantage. \

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Just how many teeth are in this gearbox - that simply isn't all possible ?

hobot said:

Fairly common for Cdo racers to adapt a Triumph 5sp with its non Norton looks.

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Probably not so common as it was as supplies of pre-unit gearbox cases dry up. You need to get good info on exactly what Triumph 5 speed donor parts you can use. And then you need to think what mainshaft and clutch you are going to use. This is probably the cheapest route, but you are going to take time to get info and get parts together, and you are pretty much on your own with setting it all up.

The lack of an overdrive ratio comment might be misleading. The fact is that the Commando gearbox has a 1 to 1 top gear ratio, and this is true in aftermarket designs for 4, 5 or 6 speeds. So you set your 'overdrive ratio' at the primary and final drive gearing (generally a big gearbox sprocket) and run in 3rd as non overdrive....it is not ideal and gives you a higher first, unless you adopt Hobot's granny.....

Quaife Gearboxes are supplied through Mick Hemmings in the UK...he builds them....and will give very good Commando advice for all applications. The Quaife website link is good for the pictures only.

TTi probably builds the strongest box, it is also the heaviest, I have a 5 Speed XHD TTi for race use on a 750 Short Stroke, this is probably the only Commando application that would get some real benefit from a 6 Speed HD, maybe, but I don't anticipate any issues with a 5 Speed.

As the others have said for road use, build a good 4 speed and stay near stock.

You don't mention your application or state of tune of engine, if it is standard the proposal to go 5 speed is expensive, and probably pointless.

Quaife or TTi may also be out of your proposed budget, you don't mention that either, a new box is not an inexpensive route and any second hand box that has had much use is a real gamble.

Also bear in mind that if you plan to use the bike on the road, some 5 speed boxes don't have a kick start.

I have a quaife downstairs that I wanted to use on a road bike, but on stripping the box I found you couldn't fit a kickstart to it.

Edit: With some Quaife you can, some you can't.

I had theMk3 Commando out for the first time in four years this summer, took it on a good run thru the Rocky Mountains.
Prior to that I had been riding a newish Triumph Daytona which is rated at 149 hp and 74 ft. Lbs torque, 6 speed gearbox. On top of that it has the Triumph race can and tune, good for +12 hp according to Triumph. On top of that someone has bumped the rev limiter from 11,000 rpm to 12,000 rpm. So somewhere over 160 crank HP and 12,000 rpm.
By rights, after riding such a potent machine the Commando should have felt like an old slug, but it did not. I thoroughly enjoyed the fact that it only has four gears and mostly only needs the top one at highway speeds. It dragged up the big 10 mile long Salmo Creston climb holding 90 on the speedo, fourth gear. I was actually slowly gaining on a friend who started a mile or so ahead on his 1970s 750 Augusta with all of its carbs, overhead cams and four cylinders. Supposed to be a 70 hp bike, but they are heavy. On the other hand, the Commando had more gear loaded on board plus my extra weight, about +80 pounds, so probably similar loaded weight to the MV.
Four gears on a road Commando is very nice and the torquey 850 motor is wonderful.

Glen

worntorn said:

I had theMk3 Commando out for the first time in four years this summer, took it on a good run thru the Rocky Mountains.
Prior to that I had been riding a newish Triumph Daytona which is rated at 149 hp and 74 ft. Lbs torque, 6 speed gearbox. On top of that it has the Triumph race can and tune, good for +12 hp according to Triumph. On top of that someone has bumped the rev limiter from 11,000 rpm to 12,000 rpm. So somewhere over 160 crank HP and 12,000 rpm.
By rights, after riding such a potent machine the Commando should have felt like an old slug, but it did not. I thoroughly enjoyed the fact that it only has four gears and mostly only needs the top one at highway speeds. It dragged up the big 10 mile long Salmo Creston climb holding 90 on the speedo, fourth gear. I was actually slowly gaining on a friend who started a mile or so ahead on his 1970s 750 Augusta with all of its carbs, overhead cams and four cylinders. Supposed to be a 70 hp bike, but they are heavy. On the other hand, the Commando had more gear loaded on board plus my extra weight, about +80 pounds, so probably similar loaded weight to the MV.
Four gears on a road Commando is very nice and the torquey 850 motor is wonderful.

Glen

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+1

I have to say I disagree with the four speeds is plenty brigade. A five or even six speed box will always give the engine an easier life. How many times have you changed down from third to second for example, only to find that second is too low but third would have been too high to pull out of the corner quickly. The other benefit of the TTI box is strength. The downside is of course the price.
Regards,
Martyn.

Matchless said:

I have to say I disagree with the four speeds is plenty brigade. A five or even six speed box will always give the engine an easier life. How many times have you changed down from third to second for example, only to find that second is too low but third would have been too high to pull out of the corner quickly. The other benefit of the TTI box is strength. The downside is of course the price.
Regards,
Martyn.

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Only a couple times.

Then maybe what you need is a three speed box. ( :

Over all w/o trying to be the fastest or best handling cycle the mostly factory Commando is likely the most cost effective and pleasing real life do everything good runner I can imagine with more interesting flavors of sound and looks to boot. IIRC Doug MacRae - Herb Becker racer has the Truimph 5 spd and gave us a brief install summary a year or so ago.

Just how many teeth are in this gearbox - that simply isn't all possible ?

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Rohan, Ms Peel is meant to be a world class do everything well, parking lot stunter, raw ravine runner, long distance cargo hauler, drag strip terror and land speeder all weather daily commuter with stereo and deer hunter that does not weight too much. Hope to come under even Ludwig's world class example that leaves me tingling at all his features invocations. So:
Two basic configurations, Most practical and light general use configuration is as a 920 with single carb for 90's hp/ 80's torque, and Qualfe shell with AMC guts. This should do everything I want up to 140's mph, which includes spanking racers in tighter courses and in real life here and no need of cage as no blower to wipe off. Cage does add about 15 lb.
The other set up is to take on record attempts on airport run ways and 200 hp 200 mph bikes on tracks and hill climbs like Pikes Peak but also race back down Pikes Peak and hill climbs just to rub in her superiority of tamed isolastic wonder. With Drouin and TTI tranny Standing start leaps will be done in 2nd then air shift skip to 4th. Dang it I never did send them peaks at Ms Peel will do it now.

To supply 4 spd XHD with Magn cases $4700.00 New Zealand dollars, plus an additional $200 New Zealand dollars if you require a kickstart mechanism fitted.

Ratio's:
1'st 2.67 60mph
2'nd 1.46 110mph
3'rd 1.21 132mph
4th Direct 160mph

We Would love to see a picture of "ms peel"

Regards
Megan

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Matchless said:

I have to say I disagree with the four speeds is plenty brigade. A five or even six speed box will always give the engine an easier life. How many times have you changed down from third to second for example, only to find that second is too low but third would have been too high to pull out of the corner quickly. The other benefit of the TTI box is strength. The downside is of course the price.
Regards,
Martyn.

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For the type of riding I do, which is usually in the Mountains, never. The bike handles most everything in fourth or third, except in really twisty areas where there are switchbacks. With the switchbacks, I go sometimes go all the way down to first then back up thru the gears, but four is plenty, it doesn't stay in the intermediate gears for long.
The steepest Mountain grades in BC and most of the US are eight percent on average, although some have little sections that may be at 10 percent. I find that solo but with luggage it will handle the 8%grade nicely in fourth and pull well beyond speed limits. For ten percent grades it will still do it in fourth, but if you want to climb sections this steep at 85-90 mph then third is the gear. It might be useful to have another gear if riding two up in the mountains, although with the torque of the motor, I doubt it.
I have a 21 tooth CS sprocket on at the moment.

A low first can be usefull on the steep mountain tracks , specially when theyre a bit damp .



:mrgreen:

Go Geoff . http://www.ontarionortonowners.ca/docum ... iaries.htm good Story .

The funnest gear for me is 2nd while dragy-est gear for me is 3rd, so splitting 3rd spread with two gears sure would help keep the sense of pull going to snick 4th at high enough rpm/speed it still in decent power band. Just don't see a need unless trying to keep on the boil all the time. We've plenty of over 10% grades and on Peel even on low throttle she'd be so responsive I'd find myself trying to snick over drive. If ya do seek pressuring the snot out of Commandos, which i encourage, better put similar attention to engine and suspension.


i've got The Norton Rat's Inn advertising logo in my clinic window Matt, a real rat head and body with jacket on a blue Cdo. There's a thread on it on forum. Some places are best left to the lamas and lovers leaping, sheeze. On beaten paths with decent surface the engine drag might be useful but its tires cleats and both brakes only after going over some edges and often enough they are useless so better lay it down before real flight time begins or add power to slightly out accelerate gravity to keep front in some steering effect - depending on how far down and whats at the bottom and why ya leaped off into it in first place. One thing the Ozarks steeps teaches is racing up ain't half the thrill of racing down loose paths. I only see one way races up Pikes Peak but I see doing it both ways on Peel. TTI assured me their needle bearings on lay shaft instead of bushes is up for those long on and off throttle blips all the way down. For me this ties into the positive and negative polarity of wobble those experiencing it while mostly up right just don't differentiate but down Mt. racing sure does for me.