![]() | #1576 |
Senior - BHPian Join Date: Jul 2009 Location: Calcutta
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| ![]() ^^^ Once again, my comment is on 'harm to the gearbox', not riding techniques. I would also assume that the rider has correctly chosen a gear consistent with his road speed, but even if not, not really relevant to my query. Regards Sutripta PS - have consistently shifted down twice (and still do) on one clutch pull (on the RD and the baby CBR), essentially before an overtaking maneuver, with no harm to the gearbox. Last edited by Sutripta : 18th December 2013 at 21:06. |
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![]() | #1577 | |
BHPian ![]() Join Date: Nov 2009 Location: now Hyderabad
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That is why it is not a good practice to shift down several gears at once, and why it is a good thing that KTM engineers made it impossible (if Cyrus is right) to do this on the Duke... ![]() | |
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![]() | #1578 | ||
Senior - BHPian ![]() Join Date: Feb 2010 Location: Pune
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Its impossible to match road speed and gear perfectly in correct decrements with multiple shifts - unless as I also said, you just empirically slow down and then labor up. Quote:
Depends on the spacing of gears in different bikes. Do the same in a 4 speed Bullet from 4th to 2nd and you will experience what I am talking about. What Ashok was talking about on his Duke (I'm making an assumption here) was shifting down multiple gears (more than 2) from higher gears - say 6th to 3rd or even 2nd. Last edited by ebonho : 18th December 2013 at 21:15. | ||
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![]() | #1579 |
Senior - BHPian Join Date: Jul 2009 Location: Calcutta
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| ![]() Guys, You are taking it to the extremes of bad riding technique as an example of bad riding techniques! Why is everyone assuming that there has to be a massive shock load? (Any rider who rides like that deserves what he gets.) In a bike the weakest link will be the chain and sprockets. What about the gearbox? Which was my original query. (Lets leave RE gearboxes, actually any part of an RE out of this discussion!) Regards Sutripta |
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![]() | #1580 | |
BHPian ![]() Join Date: May 2005 Location: Vasco-Goa
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Suppose I am riding at 80 Kmph at 6th Gear. My speed in 2nd gear is generally say 20 Kmph. So if at 80 Kmph speed I downshift rapidly to 2nd gear, then the rpm shoots up beyond the max as the 2nd gear max speed is what? about 80ish or less. and my bike and myself are totalled. Any rider with an iota of grey matter wouldn't do that. Of course I slow down guys. Let me give a simple scenario. I am doing 80 in 6th gear. I come across a hump which needs the bike to be at say 20-25 Kmph speed. So I apply the brake when I am near the hump, I am not using the clutch, but I use my front brakes mostly than rear brakes up to say about 70-80 Kmph ( it is a habit) . so the bike slows down to say 25-30 Kmph as it touches the base of the hump and now I am still in 6th gear. as I negotiate the hump I start shifting down the gears. I have less than 3 seconds to pass over the hump and move on again. I have 4 shifts to make to come to the right gear that is 2nd gear. This is where I try to shift rapidly without declutching. Another scenario. I am riding at 80-90 in 6th gear on the highway, I intend t overtake a truck infront of me. I see that a vehicle is approaching. I have to slow down for the vehicle to pass. I apply the brake behind the truck, and as the approaching vehicle passes simultaneously I down shift 4 gears ( remember by that time my bike has slowed down to say 25-30 Kmph because of cutting down the throttle and braking, I get 3 secs to again give throttle. I can do the clutch-declutch for every gear, but some how that would add a few extra seconds at that period of time. No guy sane would simply shift the gear from 6th to 2nd if he is doing 100 ![]() ![]() and guys there would be another argument that one cannot ride at 20-25 Kmph in 6th gear and the engine starts knocking very badly which is true, so in that case how would I be doing that speed while approaching a hump but still in 6th gear?? I cut the throttle completely as I approach and brake very late almost at the hump (front brake mostly) and the rapid gear shift. It is like a perfect symphony done in a perfect rhythm. smooth..No knocking nothing.. Try it out and let me know Last edited by ashkamath : 18th December 2013 at 21:47. | |
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![]() | #1581 |
Senior - BHPian ![]() Join Date: Feb 2010 Location: Pune
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| ![]() Ashok I am surprised bro. You are riding the clutch basically. And there is a period of time in your riding where you are freewheeling with the clutch in and no engine control. A LOT longer than the cumulative clutch time making the downshifts towards the 20-25 kmph you need to reach in the first place. Last edited by ebonho : 18th December 2013 at 21:50. |
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![]() | #1582 |
BHPian ![]() Join Date: May 2005 Location: Vasco-Goa
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| ![]() Nope Doc. you are wrong. infact I use clutch as less as possible. I brake very late. so I would be maintaining a fair speed till end. and for the same reason that I use clutch minimal, and I throttle gradually and a host of other reasons, I used to get the best mileage on my bikes. Those days over a decade back, on my P-180, myself, venkat and others went on rides to practise some riding techniques and venkat used to always tell everyone- Ashok has some of the best riding practises. Doc, tomorrow I will try to recreate the exact scenario on the road. will check the speed, the gear, when I use the clutch, brake and will provide some data. Even I will be clear if I am riding the clutch. If I am doing that then I need to change the bad habit asap. But I am the guy who spends minimum time on the clutch always. let me check it out anyway. Last edited by ashkamath : 18th December 2013 at 22:06. |
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![]() | #1583 | |
Senior - BHPian ![]() | ![]() Quote:
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![]() | #1584 | |
Senior - BHPian ![]() Join Date: Feb 2010 Location: Pune
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Second is since you are finally clutching and dropping a number of gears in a hurry, you are for a period of time (much longer than the final downshift in individual progressive downshifts) actually freewheeling without any engine and still on the brakes (dangerous) at the exact final moment (either almost on the corner or bump or overtaking maneuver) when you actually need most to be in the right gear and in the middle of the meaty part of the powerband - with engine engaged. Yes I do agree that you will get better mileage from your way of riding. Which is why I probably get a km or two lower than norm in all my vehicles - car or bike. Hope this is clearer. There is no one correct way and I am merely sharing my take with an equally senior and tenured rider. ![]() Last edited by ebonho : 18th December 2013 at 23:06. | |
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![]() | #1585 | |
BHPian ![]() Join Date: May 2005 Location: Vasco-Goa
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![]() | #1586 |
BHPian ![]() Join Date: Oct 2013 Location: Hyderabad
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| ![]() woot! I was away for dinner and 2 pages already ![]() @ebonho, thanks for clarifying the points doc. Like I and ebonho mentioned in the above posts, depending on scenario, the action would be different but the tumb of rule is avoid downshifting from top to bottom at one go because the clutch is not 'neutral'. Some of you might understand when I say that when you pull the clutch, the drivetrain is not fully disengaged, there is a slight amount of gear friction. This you can test by pushing your bike in gear while holding clutch and then pushing it on neutral. You will see the difference here. Now, when you do multishifts from the top on a single clutch pull, if you have not exactly slowed down to the powerband/wheel-to-engine speed of that gear before engaging it, you will hear essentially a big clunk/thud, basically the sound of two differential speed clogs coming together. Here is where you can cause gear teeth damage because the flywheel and that gear cog are running at differential speeds before it comes together even when you are holding the clutch. At the same time if you wait for too long in clutch before you change to the right gear, essentially there will not be enough momentum for the gear cogs to disengage and move down which is what essentially gives you the feeling of a ghost gear or the gear just refusing to click down. This is why it is essentially to move to each gear at it's designated powerband/engine-to-wheel speed. @Ashok, the premise of the argument was to point out that the lack of multi dowshift on a single clutch pull is not a mechanical problem with the Duke and it isn't going to get any better if you change any oil or take to any mechanic to fix it. Now is your opportunity to dump the bad practice and get into the practice of the standard quick downshifts. So more than the argument of whether anyone have the right to downshift whichever way they want, please understand that the Duke not allowing you to multishift in a single clutch pull is not the bikes fault. Having said that, if you are overtaking a slow vehicle, stay behind it till you gradually shift to the right gear and then accelerate rather trying to shift down all at one go before you overtake because as mentioned from the above several post, this is not only a wrong practice but also unsafe in several degrees. If you have to suddenly slow down for a speed bump from 6th gear, hit the brakes and pull the clutch just before you start to hear it stalling/tire locking, then once you have crossed the bump, as you decide to accelerate, downshift one, give a little bit of gas and let go of clutch very slightly and pull it back immediately, downshift one more, let go of clutch lightly and pull back, repeat till you get to the right gear. You may even try 2 gear at a time but not more than that. The whole point is you should avoid downshifting 6th to 2nd or 1st at one go while you are 'slowing down' rather you should do it while you are trying to 'accelerate' out of what ever reason you slowed down in the first place for because of the simple fact that no matter how good a driver you are, if you are trying to downshift multiple gears at one clutch go whilst trying to slow down, you are riding clutch and not slowing down rather going faster than your mind perceives you are and now you have already arrived at the point 30Kmph faster than you should be and you are in a phantom gear. Last edited by Cyrus_the_virus : 18th December 2013 at 23:53. |
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![]() | #1587 |
BHPian ![]() | ![]() Nice discussion this! My 2 cents. 1. You're doing it wrong if your shifting down thud thud instead of a click click. If you're in a situation where you're too fast for a lower gear, blip the throttle and shift down for a smoother or near perfect 'click' shift. 2. Shift down the way you shift up according to the vehicle speed. Be in neutral before you come to a complete halt. Edit: Cyrus has written a more elaborate version of what I meant to say! ![]() |
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![]() | #1588 | |
Senior - BHPian ![]() Join Date: Feb 2010 Location: Pune
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Wonder why you did not come earlier and save us from typing out such long posts! ![]() P.S. Sound-wise though, I'd go with Cyrus's description of a clunk clunk over a thud thud. Last edited by ebonho : 19th December 2013 at 00:09. | |
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![]() | #1589 | ||||
BHPian ![]() Join Date: May 2005 Location: Vasco-Goa
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regarding the oil change it is because my bike has done over 2200 kms since last service and I want to change the engine oil for a different grade and it is a personal matter of choice and not connected with this issue. but yes I was keen to know if change of gear oil would help Quote:
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So that essentially means you are engaging the clutch between 6th gear and 5th gear while passing the hump, and then gradually you will downshift to 5th give a little gas -declutch-then to 4th - give a little gas- then declutch- then to 3rd -give a little gas- declutch - then to 2nd gear and then accelerate. If that is what you meant, then that means either you have approached the hump at a very high speed ( then it makes sense), if you are already hit the brake and very slow, then the above exercise will simply create knocking in the higher gears. If that is what you meant (as I understand from your reply), then I dispute your way of riding the hump. Quote:
I agree to Doc when he said that approaching the hump with brakes and appropriate engine braking and arriving at the hump at the right / slightly more / at the right gear / one up gear is the way to ride and not riding the hump with clutch engaged between 5th and 6th gear. I would never do that. I would never ride over a hump with clutch engaged. it will always be with engine power ( in gear) Guys it is not that I am trying to say that the way I am riding is correct or defending my view point. I agree fully that multi-gear shift in a single clutch is not a good practise and is unsafe too. I shall definitely unlearn this practise and change to better riding practise. Thanks to all of you, for helping me in this regard. Last edited by ashkamath : 19th December 2013 at 00:55. | ||||
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![]() | #1590 |
Senior - BHPian Join Date: Oct 2008 Location: Bangalore/Goa
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| ![]() Multiple downshifting is definitely ok if you know you're coasting to a stop. Slick gearboxes like the ones on most Yamahas lend themselves to such antics without the accompanying clunks/thuds. What I find strange is the Duke 390's lever not retracting back. This is definitely not a safety measure or an engineering design. Cheers, Jay |
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