Downshifting

[csmith12]

Yours sounds like the stock few mm's of throttle slack. Not sure of the the factory measure but many riders adjust it to whatever is comfortable for them and yea... you should have at least a little.

 

I ride and 06 r6 with 4mm or 5mm of slack, shouldn't be too much different from yours. Between throttle slack, speed of the bike, rpm of the engine and rider inputs, it takes some patience and practice to get down. A quick search on youtube yields some great example videos but nothing replaces some one on one coaching you will get from getting further training. It's also covered well in in the video Twist of the Twist II, which I highly recommend you get a copy of.

 

Practice and keep asking questions as you need and wish you the best.

[Lnewqban]

@ Lnewqban: I ride a 2007 Yamaha r6s. It is all stock as far as I know. I thought it idled at 500 rpms its actually 10-1100rpms in neutral I just didn't pay enough attention to the tach it seems. I tried downshifting at different rpms to experiement. I figured I may have had an easier time practicing at lower rpms than higher rpms. The reason I blip is to match the higher rpms of the lower gear I am downshifting into. I'm not sure if that's the answer you are looking for though. If i do hold the throttle open after blipping won't I run the risk of wheelieing the bike if I let the clutch out too fast?

 

Thanks for all the replies btw! Hoping I can get this technique down eventually.

 

I asked because I was not sure if you knew what happens inside the gearbox.

Now I see that you know; however, let’s use some numbers to put things in perspective.

 

I couldn't find the specifications for the 2007, but let's use the gear ratios for the 2013 YZF-R6:

 

6th gear = 1.150

5th gear = 1.286

4th gear = 1.444

3rd gear = 1.667

2nd gear = 2.000

1st gear = 2.583

 

Downshifting from 6th to 1st, we have different % in which the rpm's of the engine must be increased for an ideal synchronization of the gears at the instant of engaging and for not upsetting the rear tire:

 

6th to 5th gear = 12% increment of rpm

5th to 4th gear = 12% increment of rpm

4th to 3rd gear = 15% increment of rpm

3rd to 2nd gear = 20% increment of rpm

2nd to 1st gear = 29% increment of rpm

 

That means that you have to blip a little harder for low gears (and again, that is independent of the speed of the bike).

However, it is never too much as to induce a wheelie.

Normal throttle range is about 90 degrees or 1/4 turn.

Once you clutch-in, a little twist goes a long way increasing engine's rpms'.

 

Yes, you should avoid over-rev first and then let the engine die and act like a brake for the rear wheel.

Keeping two fingers on the brake lever has helped me fine-modulating my inputs to the throttle during downshift.

 

If you are downshifting for slowing down, then you can allow the rpms' go down gradually after each downshift, so the next blipping takes the engine only up to the initial top rpms more or less.

 

If you are downshifting for more torque (passing), then your engine will turn at sustained higher rpms' after the downshift; hence, don't do it if the engine is high in rpm before the downshift.

 

You are welcome !

[Cobie Fair]

A quick comment here: "blip" means to quickly bring the throttle on then off.

 

Big truck drivers have been doing this for years, but usally slower. Many of the older big trucks wouldn't even shift, unless the RPMs were matched correctly.

[Pommerac]

I managed to pull off a super smooth clutchless upshift today from 2nd to 3rd gear followed by a really smooth downshift from 2nd to 3rd using the "blip" technique. Most of my previous experiments were in first and second gear at lower speeds so I think I'm making some progress hopefully! My bike tends to give me problems switching between 1st and 2nd either upshifting or downshifting at lower speeds.

[Alfred.Rodriguez]

I dont know how others learn the brake and downshift - but I first practiced with the higher gears. Once I got the hang of it, then I work on the 1st to 2nd, 2nd to 1st.

 

BTW, some other stuff that Ive learned from experience:

 

- During shifts (excluding starting from full stop), you dont need to pull in the clutch lever all the way. Near halfway would suffice to disconnect the engine from the train.

- You could also do clutchless downshifts! (recommended to be tried only at low REVs)

 

Cheers!

 

PS: Best not to rush the exercise. As done in CSS, 75% of your ability, and concentrate on one thing at a time...

[Hotfoot]

I managed to pull off a super smooth clutchless upshift today from 2nd to 3rd gear followed by a really smooth downshift from 2nd to 3rd using the "blip" technique. Most of my previous experiments were in first and second gear at lower speeds so I think I'm making some progress hopefully! My bike tends to give me problems switching between 1st and 2nd either upshifting or downshifting at lower speeds.

 

It is MUCH easier to get smooth upshifts and downshifts in higher gears. Although I do clutchless downshifts 99% of the time, I am cstill cautious about going down to 1st gear clutchless - it is just really hard to do it smoothly and really easy to slide the bike tire going into 1st. I'm sure you will find it exponentially easier to get smooth shifts playing with 3rd and 4th gear (or 5th) instead of 1st and 2nd.

[Lnewqban]

..........My bike tends to give me problems switching between 1st and 2nd either upshifting or downshifting at lower speeds.

Note that the reduction between 1st and 2nd is double than among 3rd and 6th; hence, it requires a stronger blipping.

 

Check this video out:

 

[Cobie Fair]

I just about never use 1st gear, aside from taking off, and for sure crossing over neutral is a clunkier shift on almost anything.

[Pommerac]

Most of my riding is in the city at the moment; Miami to be exact. I basically never have a reason to get out of second with the traffic. I thought about it and it may sound dumb, but I always thought that guys who revved their engine like no tomorrow on the STREET did so for no real reason except to get some attention - maybe some of them were just trying to get into first gear really badly lol. I like to keep my bike as quiet as possible, and I know there is a rev limiter but usually I never had the urge to rev really high on the streets. I like to keep my bike around 6k RPMs in case I need to get into the power band which from what I've experienced starts around 8-9k RPMs. I used to keep my little ninja 250 at 8-9k RPMs all the time at beginning of the power band, but with my r6 that sounds like way too many trips to the gas station. Also I feel comfortable enough going from cruising to accelerating or breaking in a split second if necessary so there's no real need that I see to keep it in the higher RPMs. I had to really slow that video down frame by frame to appreciate it, but I think i get the idea. I can only dream of being able to afford to get on a track someday which brings me to my next questions; how much time would you say is spent in first and second gears on a track? Do racers tend to avoid getting into first gear unless absolutely necessary to stay in their particular power band for accelerating?

[Hotfoot]

Personally I almost never use first on the track. It's tough to roll the gas on smoothly in first, easy to overpower the rear tire and slide, and easy to run out of gear while still leaned over. Also shifting down to first carries the risk of getting neutral accidentally, which REALLY blows the turn. Second generally has plenty of torque to get through a slow speed turn just fine, and is much easier to manage smoothly.

 

If, however, I was setting up a pass on a slower rider that held up my entry speed in a very slow turn, I might drop down to first (on a 1000cc bike) to get a monster drive out of the corner and pass. But I'd be sure to square off the corner to get a straight-as-possible drive and be prepared to shift quickly before I ran out of gear!

[csmith12]

A lot of track day riders cruise around the corners in 3rd without any problems. But an extra blip down into second on entry puts the stock R6 right in the sweet spot post apex for a good, hard drive out of the corner. As you have already seen, R6's get a pretty good surge of power when they enter the powerband. Otherwise they are kinda sluggish, and feel like they have to "build up". A lot of riders elect to change the gearing to a -1 +2 setup to address this. From my perspective, it just masks a shift point on the track. I did do the -1 for the front sprocket, but not the +2 in the rear, I will instead downshift as needed. So... I spend lots of time in 2nd gear on the track. Especially to set up passes on exit.

 

I hope you are able to make it to the track someday. The experience is worth every penny.

[Pommerac]

Yeah I would love to attend the CSS classes one day and get some track time in, but I'm just trying to graduate at the moment. Another question on downshifting; I've never tried it on purpose and I'm not sure I've ever done it by accident either, but does anyone preload their shifter for downshifting? I know I do it to upshift as often as I remember, and as soon as the clutch is pulled in enough it goes into the higher gear.

[csmith12]

I don't, my R6 shifts butter smooth at higher rpms. Same for my 250. Other bikes, maybe not so much. I remember my old HD sportster, it took some "authority" to downshift. lol I would imagine some of those guys that race the vintage HD's might preload the shift.

 

Knowing how others ride different bikes is very interesting.

[Hotfoot]

Yeah I would love to attend the CSS classes one day and get some track time in, but I'm just trying to graduate at the moment. Another question on downshifting; I've never tried it on purpose and I'm not sure I've ever done it by accident either, but does anyone preload their shifter for downshifting? I know I do it to upshift as often as I remember, and as soon as the clutch is pulled in enough it goes into the higher gear.

 

I'm told that pre-loading the shifter is not good for the bike. Maybe someone else can chime in about exactly why it's detrimental but Will (who maintains the school fleet) tells us not to do it, it's hard on the bike. On the BMW, it also can confuse the quickshifter so it won't shift properly.

[Lnewqban]

I'm told that pre-loading the shifter is not good for the bike. Maybe someone else can chime in about exactly why it's detrimental but Will (who maintains the school fleet) tells us not to do it, it's hard on the bike............

 

Our foot, via the leverage of the shifter and the selector drum (shift cam), can develop a lot of force on the forks and dogs.

 

Not having been designed for such forces, the shift forks could be permanently bent and the dogs could be worn (rounded): only transmission surgery can fix that.

 

This article explains it:

 

http://www.gadgetjq....ransmission.htm

 

From the TT2's DVD: "Pads are cheap, transmissions are expensive."

[Alfred.Rodriguez]

Yeah I would love to attend the CSS classes one day and get some track time in, but I'm just trying to graduate at the moment. Another question on downshifting; I've never tried it on purpose and I'm not sure I've ever done it by accident either, but does anyone preload their shifter for downshifting? I know I do it to upshift as often as I remember, and as soon as the clutch is pulled in enough it goes into the higher gear.

 

Based on your posts, I think you are doing it right... But like any skill, it takes time and practice to become proficient and smooth. If it takes but just a few days to master braking and downshifting, most of us should Pros by now...

 

Some pointers, though:

 

- Practice with the higher gears

- Brake first (priority is braking NOT the downshift)

- Downshift at the lower RPM range (around 3K to 4K) - this reduces the engine braking and makes it easier to do the technique (while you aree still learning), ie., blips...

- Do NOT practice with the objective of getting into the higher RPM range and/or the Power Band after the shift - learn the technique first.

- Good technique first - smoothness and quickness will come later

- Do NOT pull the clutch all the way in (all you require is as far as the "clutch meet point")

 

Have fun!

 

[Pommerac]

Thanks for all the feedback! I'm sure I'll have more questions soon enough

[Stroker]

Err, sorry to barge in but, AFAIK,

 

1. Clutchless upshift - Any rpm, decrease throttle slightly and shift.

 

2. Clutchless downshift - Any rpm, blip and shift.

 

Am i wrong?

[Hotfoot]

Err, sorry to barge in but, AFAIK,

 

1. Clutchless upshift - Any rpm, decrease throttle slightly and shift.

 

2. Clutchless downshift - Any rpm, blip and shift.

 

Am i wrong?

 

No, you are not wrong.

 

If you are responding to Alfred's post above, where he is talking about shifting at lower RPMs, he is just talking about WHILE LEARNING to do the throttle blip or clutchless shifting, that is easier to do it smoothly in higher gears at lower RPMs. Trying to get a smooth clutchless downshift from second to first gear at high RPM is tougher than getting a 5th gear to 4th gear downshift at 4,000 rpm. Does that makes sense?

 

 

1. Clutchless upshift - Any rpm, decrease throttle slightly and shift.

 

 

Incidentally, the amount you have to roll off for an upshift varies from bike to bike, it can be more than a slight decrease. On my racebike, for example, I have to roll off almost to the stop to get it to shift at high RPM, which took a while to get used to!

[Cobie Fair]

Lnew,

 

Good point. My brother had to rebuild his transmission (2nd gear) due to this. Will does not recommend pre-loading at all (and it's not needed once you get the timing sorted out).

 

CF

[Stroker]

Thanks HF.Here are my observations, albeit on low power bikes.

 

Clutchless upshift - At econo rev ranges of 4-5K, there is a very smooth shift.Even the suspension is not disturbed.At peak power of 9-10K, you have to roll off about a 20-15% from the earlier 5-10% so that the engine speed drops to the start of the power band/peak torque.So you roll off a quarter and the needle drops to say 7-8K in that interval.So when the next higher gear engages, there is a bit of a wiggle as the torque kicks in.

 

Roll off rises in proportion to the power the engine is making at that rev range.

 

Clutchless downshifts are hard on the bikes we have here, which have clunky boxes.

 

A question.Can you short shift without using the clutch?

[Hotfoot]

Sure. Takes less roll-off.

[Stroker]

SO if i want to go from second to fifth, how would i do it?

[Hotfoot]

SO if i want to go from second to fifth, how would i do it?

 

Hm, we may have a difference in definition of short shift. To me, short shifting means shifting early, before it is really necessary - in other words, shifting at low rpm. Often done if you want to get an upshift done early, possibly before you lean the bike in a corner, or maybe if you want to NOT be in the peak powerband in a corner.

 

If you are talking about shifting from 2nd up to 5th, you would shift three times rapidly, with a quick roll-off for each shift, and rolling back on in between. It can be done very fast clutchless, but I don't think you can do it without a throttle roll on and back off between each shift. I'll have to give it a try.

[Alfred.Rodriguez]

Longer roll off the throttle, and just shift _straight_ up to 5th. Albeit, you'd be very low in the revs in 5th compared when you started in 2nd...