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Your opinion about a six speed gearbox on the sunburst

Discussion in 'Norton Commando Motorcycles (Classic)' started by yves norton seeley, Oct 8, 2019 at 1:25 PM.

  1. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Hi there,
    I like to swift gears, now I use a 5 TTI gearbox and its feel mutch better as a 4 gear.
    I think that with a tuned engine you will lost less RPM between gearchanges, even if you lost time changing the gear.
    Do somebody use a six box on a Commando?
    Your opinion please
    Regards
    Yves
     
  2. SteveA

    SteveA VIP MEMBER

    Joined:
    Dec 20, 2011
    Yves, when I built my Rickman I was sure I needed a 6 speed to go with my short stroke 750 motor.....but a good used 5 speed came up.....if you put in a 6 speed it will only because you want to! it will never be because you need to.

    BTW, I need some special yves sunburst inspiration right now......it will help with my 5 broken ribs!
     
  3. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Yves,

    Although there are some difference in the ratios depending on which you have already and which you choose, by and large, they’re very similar and all have direct top gears.

    So you’re not going to gain any overall gearing advantage to, for example, give a relaxed cruising speed etc.

    You’re going to gain closer ratios between the gears.

    As to whether or not this will be any real improvement or not can be ascertained be asking yourself if you have difficulty keeping the motor in its ideal powerband. If you do, closer ratios are bound to help. If you don’t, I’d say any difference is largely academic unless you’re a top rider looking to gear for specific situations on specific tracks.
     
  4. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Hi Steve,
    About my healt: The last scan and X ray show no differences with the ones from one year ago, my hip is still broken, no changes at all sadly.
    They plan to do a chiurgical intervention at november, they must fill up the fracture with pieces of bones and put an artificial hip.
    The problem is that my hart specialist says don't do it, your hart is to weak...
    I will ask my hart specialist to speak with my chiurgean before I take my final decision.
    At the moment I can walk 100 meters, I can ride the Sunburst 100 km and this is still better than pass away.
    The main problem is the pain, night and day
    Good luck with your ribs
    keep you posted
     
  5. lcrken

    lcrken VIP MEMBER

    Joined:
    Mar 15, 2009
    Yves,
    I'm with Steve A on this one. I have both race and street Commandos with close ratio 4 speed, standard 4 speed, and close ratio 5 speed. I find the 5 speed much better for racing. For the street, the 5 speed is good, but the stock 4 speed works really well with an engine built for a wide torque band. The 5 speed might be better on the street for a shorter stroke and/or high revving engine build, which might be what you have. I'm currently using the stock 4-speed in a Commando with an 883 cc engine built mostly for wide torque band, but also very good top end, and it is perfect. I find I don't have to change gears very often, unless riding in stop-and-go town environments. 3rd and 4th gear are all I ever need once up to speed on the road, and mostly just 4th. In any case, I think you won't find any benefit from the 6 speed, you'll just be shifting more often. I think with your bike, you will be happier with the 5 speed.

    Sorry to hear about your health issues. I'm very impressed that you are riding at all. I hope it works out better for you in future.

    Ken
     
    ashman likes this.
  6. ashman

    ashman

    Joined:
    Jul 11, 2010
    Its like any bike you ride if you have a 4 speed you will always be looking for that 5th gear and the same if you have a 5 speed you will be looking for a 6th gear, I have 3 bikes the Norton and 2 Triumph Thruxton's all with different amount of gears, but for street riding or on the highway each bike has the around the same ratio in top gear, well the 1200 Thruxton might be a little higher, so really if its just a road bike would that extra gear make any different unless you are racing.
    I know my hot 850 Norton with the stock box would leave the stock 900 Thruxton with the 5 speed for dead and then my 1200 Thruxton with the 6 speed well that's another thing, but it also has a different swing on the crank compared to the other 2 bikes.

    But Yves I think you have more to worry about for now with your recovery from your accident and I hope it ends up working out for you so you can enjoy riding that lovely Norton and having one less gear change might be better in the long run for your injuries.

    Ashley
     
    baz likes this.
  7. baz

    baz VIP MEMBER

    Joined:
    May 26, 2010
    My god you have some spirit Yves!!!
    Always pushing the envelope
    I'd say 100km on sunburst is probably doing you more good than anything the doctors are doing for you
    I suspect you don't need a 6 speed on your bike but if you want one then go for it
    Go well whatever you decide mate
     
  8. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Hi Ashley,
    I worry about my recovery, but my Wife and the Sunburst are the reasons to worry, they keep me figting for a full recovery, I don't wish to be in a weelchair even with a Commando engine.
    Shifting gears make my bad leg working, and 6 time working is better then 5 time.
    Yves
     
  9. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    You are right Steve, if I put in a 6 speed its for my own pleasure and not becouse I need to
    Yves
     
    SteveA likes this.
  10. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Hi Nigel,
    TTI offer 3 possibility for the first gear for the 6 box
    Standart 1st 2.294
    Low 1st 2.438
    Close 1st 2.169
    I will go for the Standart, 2.294 is the same as on my 5 box.
    If I remember wel, when I was a Side-car rider with a Konig engine, I first use Quaife 5 speed close ratio, after I change for a Shaftleitner 6 close ratio and the 6 give me better lap times.
    Years later I was riding a Yam 750 R7 Superbike with full factory tuning kit (on the road only)
    The R7 as originaly a close ratio 6 speed, in first gear the bike was already going over the Ton, and still 5 other gears to go, very funny, so funny that some gents take pics when I was passing on the highway, very good pics, but so expensive.
    The Sunburst is very light and a very good mid and top power, she lost a bit of bottom power; so I think a 6 will work, I am not a top rider, but its good looking to gear for specific situations even on the road.
    Yves
     
  11. yves norton seeley

    yves norton seeley

    Joined:
    Feb 13, 2014
    Hi Baz, You understand my filosofie
    Thanks
    Yves
     
    baz likes this.
  12. Dances with Shrapnel

    Dances with Shrapnel VIP MEMBER

    Joined:
    Jul 8, 2011
    Yves,

    Depends upon exactly what you are wanting to achieve. I ran a six speed on a 75mm short stroke 750 cc Commando. It was nice but really not an absolute necessity. A better rider than me could make use of it but for me it was more of a nuisance as I never knew whether I was in top gear while racing so I would check (wasted throttle time). I suppose if I became more familiar with the six speed on that particular build it would make sense. For the 59.6mm 500 cc the six speed makes good sense.

    From what I think I know about your bike and your needs, a five speed is the proper choice; your motor should have a very broad torque curve. Even for drag racing, what you think you may gain with the extra gear would likely net you a loss for the loss of throttle time to shift.

    One application where it would make sense is in land speed racing.

    If it were me, I would certainly stick with a quality five speed and focus resources on handling, stopping and power.
     
    Last edited: Oct 10, 2019 at 4:04 PM
    SteveA likes this.
  13. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    I've had my bike sitting idle waiting for me to pull the 6 speed box apart and reseal it. I previously used a 4 speed close ratio box when racing, which was excellent everywhere except off a clutch start. If you only have four gears and they are close ratio, you can set the overall gearing high and still have legs at the ends of the straights, or you can set it low and come out of the corners faster but run out of puff towards the ends of the straights. With 6 gears, the ratios are usually closer, but as you raise the overall gearing they spread out to be similar to the 4 speed ratios, but with two lower gears. That means, that if you are racing, the ratios are more appropriate for most situations. With the 4 speed close box, once you are rolling, it is superb. With 5 gears, you can fit a lower first gear to get you mobile. Once you are rolling, you never go back to first gear anyway. In my case, the 6 gears will only be of real benefit on the first two corners of a race. If you can race-change off the start line, that is much faster than revving the tits off the motor, trying to get mobile with a 4 speed close box. When I race, I usually go around the first two corners as fast on the first lap as I do on the last. If you are up front after the first two corners, life is much easier. What you lose on a slow start, is very difficult to regain.
    I don't know how you would use a 6 speed close box in a Commando on public roads, unless you were drag racing from traffic lights.
     
  14. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    With my bike - when racing, I usually only use the top 1500 revs of the usable rev range. With the heavy crank, you cannot afford to lose revs. A light crank would not give the same boost when you race-change up through the box. Crank inertia can be used to improve acceleration. Once the Commando crank is spinning high, nothing stops it. All I do coming up through the gears, is ease the throttle enough to take a bit of pressure off and stand on the gear-change.
     
    Last edited: Oct 10, 2019 at 1:56 PM
  15. acotrel

    acotrel

    Joined:
    Jun 30, 2012

    There is a lot of pleasure in having your bike as good as it can be. However functionality is more important than appearance. A friend of mine once said to me 'at least your bike looks right'. It looks right because it cannot be any other way and still function correctly.
     
  16. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    What are you doing with 5 broken ribs ? You need to be smarter than that.
     
  17. SteveA

    SteveA VIP MEMBER

    Joined:
    Dec 20, 2011
    You need to be politer than that.
     
    baz, lcrken, maylar and 1 other person like this.
  18. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    I would not have thought many European circuits would have blind corners. I'm under the impression that the racing there involves a lot of extremely fast riders and many more than we have here in Australia. With my bike, your head always has to be around the next corner. A lot happens between braking and where you come out of the corner. If you cannot see what is there, where does that leave you ? It is all too fast for that. On Winton Raceway, there is only one potentially blind corner and there is always room to go, if it all happens.
     
    Last edited: Oct 11, 2019 at 1:57 PM

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