Head Angle Adjuster & Rear Shock Shim Question

So while I'm waiting for my 17 zx10 to come in, I've been researching and picking up parts for it.

One of the things I'm considering is
Race kit head angle adjusters (to reduce from 24 degrees to 23.5 degrees) and a 1mm shim for the rear shock.

Both of these videos touched on the mods, saying that the change in geometry improved the bike's turn-in significantly:





What I'm questioning is this:

When something is gained, something is generally lost. What would be the detriment of doing these mods on the geometry?

Lastly, for reference, this is a street bike build that gets ridden aggressively in the twisties. Eventually it'll be trackbound, so having this done sooner is fine, as long as there's no major detriments for street application.

 

They will likely make your wallet lighter without you really being able to tell the difference.

 

both vids say that the sum of the changes for the RR contribute to better entry. so the lighter wheels, better tires, head angle, shock shim, and damping changes all play a role. the wheels and tires very likely have the largest effect. i wouldnt bother with head angle or shock shim until its a dedicated race bike.

 

1 mm shim ....ha!

 

Ya 0.5 degrees and 1mm shim isn't a whole lot. I'm sure it could help for sure but those are pretty small changes a lot of people can't feel. Others obviously can.

 

The shim, I'd be inclined to agree. In my experience, 2mm is about the threshold for most riders to immediately be able to feel.

The head angle change, however, most riders would immediately be able to feel and quantify.

 

So, for the "shim" on the zx10r, buy a washer that's about 1mm thick and give it a try. For 50 cents of washer, you can see if you like or notice the difference. If you're going to use an aftermarket shock, you can just adjust the clevis.

In either case, I've read before that those geometry changes are due to the extra grip of slick tires on a nice clean racetrack. If you're on street tires, you'll probably find the less stability of the bike to not be a good thing.

Short of it: I wouldn't touch either part unless you notice some traction and/or steering issues.

 

I contend that 9.9 out of 10 people could not tell the difference in a blind test of a bike with those adjustments made and one without those adjustments made. Unless your name is Tom Sykes or Johnny Rea neither of them would have any impact on your ability to go fast or not go fast on that bike. It certainly isn't going to have any impact riding through the mountains to the next stop to eat.

 

half a degree is cute , waste of money for street riding.

 

+1

On our 675's half a degree change in head angle was a big difference (3mm in trail if I am not mistaken).

 

I'm not questioning the validity of the claim that the adjustments make the bike handle a bit differently. I am questioning the ability of the average rider to be able to tell the fucking difference or even accurately identify what improvement it made.

 

Not a bad looking Yamaha.....

 

Hella thanks for the input, fellas.

Let me collectively respond to everyone's responses:

The bike will be set up exactly like the one in the videos, save the race ecu, as it'll just be flashed, plus a decent amount of bolt-ons. So all of these small changes that add up that the reviewers opine on are in play.

Money isn't an issue now, but will be once I hit the track. I will have to take a major decrease in pay to be awarded the free time to pursue a track life. So, I'm much more inclined to make these changes now, purchase these parts and not install them now, or come to the conclusion that it's not worth bothering with altogether now.

I'm very cognizant of minor changes in my bikes/cars. But let me qualify that statement. I cannot detect a behavioral change in the removal of one to three pounds of non-rotational mass. But a click or two on rebound or compression, I can. This is certainly relative to how much time I've spent on the machine. A certain amount of oneness with the bike has to be achieved, if that makes any sense.

Nice setup, wheeliest!

The turn in is where this bike lacks the most. Just like with the unforgiving ESD, I'm trying to focus on where it lacks the most and correct the issues now. An improvement on turn in over the stocker ZX10r will be nice.

Again, I very much appreciate the feedback and advice. Geometry changes are a new subject I'm interested in learning about, and it looks like I came to the right place to kick the subject around.

 

Sounds like Metric and Riders are telling you it will make a difference.....I dont know if 16 and 17 are the same?

I do know a MA zx10 rider, that had chatter problems on dunlops, running MA rules last year, when you couldn't change it. This year you can and it appears that and probably other stuff eliminated his chatter issues.

 

I prefer the bike with the standard head angle. Each rider is different and prefer different set ups, but for a base line starting point on the ZX-10 I would keep the standard head angle, +2 to 3 mm in the rear and run the swing arm in the lower position. I'd also go with the kit ECU just for the plug and play adjustment benefits.

 

If you get chatter on the 2016/ 2017 ZX-10 with US Dunlops, it's a tire pressure issue.

 

Thx Rob! Much appreciated.

Ddk - Great info. Exactly what I'm looking for. Looks more and more as if buying the parts and waiting to experiment with geometry is the way to go. I appreciate the baseline!

Have you found that half a degree of head angle change makes the bike unstable?

What makes you prefer messing solely with the rear geometry?

I'll pick up a race ecu and wiring per your recommendation.

If there's any other advice that comes to mind, feel free to drop it my way!

Thx a mil.

 

For me the bike has a better balance with the 24 compared to the 23.5. More stability during braking and through the mid corner as well. If you use the 23.5 I'd suggest increasing your wheelbase. It'll help with stability and chassis balance.

Raising the rear will decrease your trail numbers and also raises your CoG. Both can help with handling characteristics....but if you go too far you'll lose rear grip. Find the balance that suits you, your riding style and speed.

 

Exactly the info I was looking for, DDK. Couldn't be more pleased. Thank you so much for taking the time to educate me. It's most humbly appreciated.

 

I was able to test a 16 zx10 on a very technical course and it turned in to quick for my liking (Stock trail).. But then again I ride a Suzuki Brontosaurus R