Taming the R6

[Maki]

The Ohlins dampers are generic, although the mounting brackets will be model-specific.

I couldn't justify the Ohlins treatment if I wasn't going to keep a bike for at least 5 years.

Steeringu dampa wa chotto takai desu ne...

[Leyton]

I couldn't justify the Ohlins treatment if I wasn't going to keep a bike for at least 5 years.

Me neither!

[Odakyu-sen]

steeringu dampa wa chotto takai desu ne...

でもr6にハンドルダンパーを付けないといけないよ。

[Leyton]

でもr6にハンドルダンパーを付けないといけないよ。

I agree.

[captain_andrey]

One of the main reasons I picked a CBR over the R6 (which I liked a lot) was the steering dampener. It works magic.

[Maki]

One of the main reasons I picked a CBR over the R6 (which I liked a lot) was the steering dampener. It works magic.

But the R6 is better!

[SVboy]

I had a couple of major slappers on my 08 zx6r. One mid-corner had me looking for god! It was either Ohlins or....a new bike, and the change over to the gsxr was a great move. You paid a lot for your r6-whats a few more $$ getting a professional to set up base settings on your bike? Also, should moving fork legs around in triple clamps not involve some careful torque wrenching at factory tightness, to avoid any chance of distorting internals?

[Odakyu-sen]

One of the main reasons I picked a CBR over the R6 (which I liked a lot) was the steering dampener. It works magic.

Yeah, back in 2001 I tried both the CBR600F3 and the YZF-R6N. The Honda was like a pair of comfy, sensible shoes. The ergonomics were incredibly good.

The R6 was a mad little squid with the heart of a lion. Straight away it was obvious that Yamaha had put all its money into the frame and engine. I knew I would have to spend up big time on the suspension and fit a steering damper to tame the spastic front end.

[vifferman]

If you set the basic sag first, you make the whole exercise pointless if you then adjust the geometry by adjusting the front and rear preload. The only way to set sag is to set the preload and if you then change the preload to alter the geometry you may as well not have bothered.

This is the reason I said that setting sag was not relevant in this case.

WTF are you talking about?!? I don't think you even know what sag is!
You use the preload to set the sag - there's no other way to do it, except by changing springs!
The static sag is the amount the bike compresses the suspension, and the rider sag is the amount the bike + rider compresses the suspension. The latter should be about 25-30% of the suspension's total travel. The sag depends on the spring rate, and the amount of force applied to the spring, which is entirely due to the weight of the bike, the weight of the rider, and the spring compression applied by the preload adjusters.

Yes, the preload changes the geometry somewhat, but the most fundamental thing with setting up your suspension is to set the proper sag first, using the preload adjusters.
If you end up with unwanted geometry changes, you can (to some extent) rectify these by moving the forks up/down a little bit in the triple clamps, and by adjusting the rear ride-height adjustment, if your shock has this.

[Maki]

WTF are you talking about?!? I don't think you even know what sag is!
You use the preload to set the sag - there's no other way to do it, except by changing springs!
The static sag is the amount the bike compresses the suspension, and the rider sag is the amount the bike + rider compresses the suspension. The latter should be about 25-30% of the suspension's total travel. The sag depends on the spring rate, and the amount of force applied to the spring, which is entirely due to the weight of the bike, the weight of the rider, and the spring compression applied by the preload adjusters.

Yes, the preload changes the geometry somewhat, but the most fundamental thing with setting up your suspension is to set the proper sag first, using the preload adjusters.
If you end up with unwanted geometry changes, you can (to some extent) rectify these by moving the forks up/down a little bit in the triple clamps, and by adjusting the rear ride-height adjustment, if your shock has this.

It's nice to see so many knowledgeable people contributing. You wrote:

1. "The sag depends on the spring rate, and

2. the amount of force applied to the spring, which is entirely due to the weight of the bike, the weight of the rider, and

3. the spring compression applied by the preload adjusters."

************************************************** ********************************

1. I am not about to change springs until I run into some problem that convinces me that I need to. I haven't, so I won't.

2. The amount of force applied to the spring is not going to change. I am not about to carry weights to change it.

3. That leaves the preload adjusters. I am using them to alter the geometry of the bike to mitigate a tendency for tank slappers. A side effect is that the bike is more comfortable to ride. I can either do that, or I can slavishly adjust the sag according to what some "experts" tell me it is supposed to be and leave it at that. I am sure the real experts will agree that the only real authority regarding how your bike feels and what you achieve with changes to the suspension is YOU. You ride your bike, you make changes, are you happy or are you not? What are YOU feeling?

I set out to change the geometry to mitigate tank slappers. I don't know if I have achieved this, they happen rarely thank goodness. What I have noticed is that the changes I made made my bike nicer to ride as experienced by ME and that makes me happy. The bike never felt so good for the kind of city riding that I do most of the time. The idea of lifting the front end and lowering the rear comes both from the article I posted originally and from a test of the R6 that I read. According to the testers the R6 has a relatively high seat and low bars and this can make street riding fatiguing. I can only agree with that. Advice they received from Yamaha technicians was to raise the front and lower the rear to make the bike more comfortable. Well it works for me. It also makes the bike handle better at low speeds which is nice.

I dialed in slightly more damping today and I am amazed by the difference one click and half a turn on the adjusters makes. The bike feels markedly more solid at high speeds.

In the end I think that it's you and your bike. Make some changes and see what effects it has. If it's hopeless go to experts and have your springs changed and fork out $$$ for extra virgin snake oil. If you are happy with what you have got, great, even if what you did is not exactly what it says you should do according to some book.

[jimbo_on_travels]

I have had a few minor ones on the R6, trick is not to tence up when it happens..

Have had it under heavy throttle over bumps and neally one on Sunday when I lost the front on a tar strip on the crap road to Piha

Totally agree about not tensing up.. had a tank slapper not too long ago in the wet on my R6 - went to do a left corner through a shallow puddle, no more than 50km/h and the front dropped into a slightly deeper spot. I now don't do puddles!!

[Maki]

What I have done has raised the center of the bikes gravity. I have lowered the rear slightly from what I had before but raised the front by about 10mm. I guess the center of gravity has gone up by about 7mm give or take. The bike feels more responsive and quicker handling than before. I previously put this down to the fact that the slightly improved riding position made it easier for me to counter steer, etc... The change in geometry should have made the bike handling slightly slower than what it was, I have made the head angle a little less steep after all. I have given this some more thought and my conclusion is that changing the center of gravity must have quickened the handling.

I have been researching what effects changing the center of gravity should have according to theory. I found this:

http://www.motorcycledaily.com/22dec...arsvmille.html

"Aprilia raised the position of its engine 5mm. The base Mille started life with a fixed engine position (and the new model also has a fixed engine position), but Aprilia thought enough of the performance advantages of a higher engine position to redesign its frame and relocate the engine in the new model.

This seemingly subtle change comes straight out of the experience with the homologated version raced so successfully by Troy Corser in World Superbike last year. By raising the engine position, Aprilia accomplished two things, namely, (1) a more centralized mass (which aids turning), and (2) a higher center of gravity (which, contrary to popular belief, tends to aid turning, as well).

I am sure we have some readers who are engineers (and I am sure I will receive some e-mail on this), but here is a somewhat controversial proposition. It shouldn't be controversial, but apparently it is. A higher center of gravity on a motorcycle, all other things being equal, will result in a quicker turning motorcycle. Think of a pendulum. If a pendulum is standing straight up, a pendulum with a higher, heavier weight will fall to its side easier. Simple enough. A motorcycle with a higher center of gravity will also respond quicker to a rider's efforts to lean it over (while standing it back up is another issue)."

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So, the higher centre of gravity has more than compensated for the fact that I made the head angle more slack than it was before. Interesting stuff. Apparently this is controversial but true in my experience.

[carbonhed]

So what do you think the downsides of your changes will be? After all there's no free lunch. Improvements in one area come at the expense of reduced performance in another.

I reckon that rasing the front end 10mm will mean that the front end will wash out sooner, but it'll do it slower so you may be able to catch it, and you'll wind up with more tankslappers... but hey it's a better communter so...

[Maki]

So what do you think the downsides of your changes will be? After all there's no free lunch. Improvements in one area come at the expense of reduced performance in another.

I reckon that rasing the front end 10mm will mean that the front end will wash out sooner, but it'll do it slower so you may be able to catch it, and you'll wind up with more tankslappers... but hey it's a better communter so...

Good question.

I reckon the downsides are less stability, the front end will probably wash out sooner when pushed hard and the bike will be more prone to lift the front wheel during hard acceleration. All these downsides are much more relevant to track use than use on the street so I can live with them. I would probably change the bike to something near factory settings if I took it to the track.

On the street the pluses significantly outweigh the minuses.

[johan]

Interesting topic.

Will the front wash out more easily if there is less front end bias or the other way around?

Another way to look at it, is the front more likely to wash out if I stay on the throttle through a corner (transfer a bit weight to rear) or if I'm off throttle, more front end weight?

When the front lets go, do you crack the throttle to save the low side, or stay off the throttle all together?

Any thoughts?