600cc Gearing and Sprocket Combinations

Dom17

Intermediate Intermediate
I was wondering what the most poplar gearing conversions are for the 600 bikes. My understanding is that 600cc bikes are limited in top speed by horsepower and the gearing is too tall to ever reach theoretical top speed.

My stock gearing is 16/47. I was thinking about dropping a tooth in the front (15/47) as a good place to start. Does anyone have any wisdom to share or suggestions? My stock chain is 116 links, should I be able to keep the stock chain as long as I match the pitch? I understand this will lengthen my wheel base which I am okay with because the daytona 675 is rather twitchy as is in its stock config. (89mm trail)

Thanks!
 

Otto Man

John
Control Rider
My thought from what I've seen over the years... bike setup can be as simple or as complicated as you want to go.

That being said, stock gearing on any modern 600 (2003 and newer) is just fine for 90% of track day guys. I have watched guys as they progress over the years chase their tail with gearing. Normally, "it's too tall" when they are in Novice/Intermediate so they shorten it up a bit. It might help them a bit, but then they'll progress to the point where it's hindering them. At that point, the once seemingly "too tall" gearing now starts to makes sense. Gearing for the theoretical top speed is never a consideration by any fast rider.

It may sound harsh, but it's reality. As long as your gearing isn't wildly radical from stock, the gearing isn't the problem. It's not the gearing, the tires, or the bike, it's the rider. Obviously, having a clean, maintained and tech-ready bike is implied here.

If you're in Novice, Intermediate, or even a new Advanced group rider, you'll benefit far more from improving your own skill set to be consistent then continually messing with your bike. What encompasses being an "Advanced" group rider? Being consistent on your lines, hitting your apexes, ability to set up and execute clean passes, and eliminate a large portion of 'coasting' while circulating on track. Is that an easy task in itself? No, that's why it's called Advanced after all. If this stuff was easy, we'd all be Advanced riders. But if you're in Novice or Intermediate, I can promise you there are several things that you can work on that will provide ten fold improvement in your riding, lap times, and safety than pissing around with gearing will ever net you.

You have to know your audience and who you're asking advice from. If you ask the Apex/ Team Hammerhead racing team gearing advice on their 675's, they might talk to you for 45 minutes on what to do. But those guys are at the very pointy end of the 600 class, where every little thing begins to matter. If you're running 20 seconds+ slower than them, none of the things they'll talk about really matters.

You can have the most perfectly set up bike for a given track, but it ain't gonna do shit for you if you aren't consistent and can't hit your apexes.
 

chrisplm

Chris
The most common swap on the "common" 600s is -1/+2, that typically lets you keep stock chain length.
That being said, a -1 in the front is a very cost effective (about $35) noticeable change.
Your 675 has a little different power curve than most 600's. I've ridden a 2012 675 with just a -1 front like you are planning and it felt good.
I'd start with that and go from there!

Also, your right about top speed, Not too many tracks that will give you enough space to hit rev limiter in 6th gear even with -1/+2 gearing.
 

tdelegram

Control Rider
So what your saying John is that shity lines equal shity times? I agree and my times are not great, until you're in the upper end of A gearing isn't as important as skill, comfort and confidence. The confidence comes with suspension set up and seat time. I read an article a few years back and Nicky was talking about chattter and entering turn with chatter trying to get chain slack out with throttle and rear brake...... shit way above mere mortals heads. What the fast guys are focusing on to shave a 1/10 isn't what we should be focusing on to shave seconds off a lap time. In the N, I and a lot of A groups there are huge chunks of time that can come out with good lines and doing everything better, brake later, accelerate harder sooner, no coasting, better vision, better body position..... the list is long. Find Ken Hills podcast and start there, it's a great listen and some well thought out techniques.
 

Dom17

Intermediate Intermediate
Thank you for the wisdom guys! I understand lines and technique trumps all and I have taken the time to listen to all of ken hills podcasts so I really appreciate that resource. I think I am going to start with a -1 in the front which will give me 6% more acceleration without increasing any rotating mass and keep my theoretical top speed around 150. I really appreciate the input!

Sent from my SAMSUNG-SM-G890A using Tapatalk
 

bmart

Control Rider
Hey Don. I sent through my GPS records and my '03 R6 went 153.7 at Road A last year with that 15/50 (giant rear hoop) last year, and I wasn't even against the limiter.
 

mpusch

Micah
I run -1/+1. You'll definitely notice the difference dropping a tooth on the front. With the Daytona's great bottom end, I'm rarely below third gear (though I'm sure the fast guys would use second more).

I mostly agree with the above comments essentially saying KISS. However, to your point on how the Daytonas can be a bit twitchy... Being someone who knows next to nothing about geometry, I put my forks flush to the triple tree, which gave it more stability (which of course means you're sacrificing a bit of the quickness of turn in).
 

Dom17

Intermediate Intermediate
I run -1/+1. You'll definitely notice the difference dropping a tooth on the front. With the Daytona's great bottom end, I'm rarely below third gear (though I'm sure the fast guys would use second more).

I mostly agree with the above comments essentially saying KISS. However, to your point on how the Daytonas can be a bit twitchy... Being someone who knows next to nothing about geometry, I put my forks flush to the triple tree, which gave it more stability (which of course means you're sacrificing a bit of the quickness of turn in).

I did the forks flush with the triples and it made a world of difference. Could have been placebo though. I appreciate your experience, im going to look at the gearing commander website to see where things will look with different ratios.

Sent from my SAMSUNG-SM-G890A using Tapatalk
 

Otto Man

John
Control Rider
Hey Don. I sent through my GPS records and my '03 R6 went 153.7 at Road A last year with that 15/50 (giant rear hoop) last year, and I wasn't even against the limiter.

Comparing sprocket sizes against multiple bikes is useless, as the physical gearing in each bikes transmission is going to be different. I know 100% without a doubt that running 15/50 on a 3rd gen R6 will have you pegging off the rev limiter for days at Road A. I've hit the limiter on my '08 R6 running 15/43.
 

bmart

Control Rider
Yes, and all of that info is available if someone wanted to go through the calculation. I was just making the point that while folks make fun of the pizza platter on my R6, it works fine at all tracks I go to. And it is handy for serving pizza.
 

Dom17

Intermediate Intermediate
I saw someone make a post about moment of inertia stating that a bike moving at 120mph could have up to 60lbs more inertia through esses than a bike with a smaller rear sprocket or one made from a lighter material. I haven't been able to do the calculated differences from different teeth sizes but it is something interesting to think about.

Also this website is pretty useful: http://www.gearingcommander.com/
 

Otto Man

John
Control Rider
I saw someone make a post about moment of inertia stating that a bike moving at 120mph could have up to 60lbs more inertia through esses than a bike with a smaller rear sprocket or one made from a lighter material. I haven't been able to do the calculated differences from different teeth sizes but it is something interesting to think about.

Also this website is pretty useful: http://www.gearingcommander.com/

Ohhh....ok now you got my attention. I love this stuff. :D (I know Emerson and a few others are laughing right now) Couple of questions.

- Who made the post and where is it. I gotta read this.
- What tracks have you ridden that have esses you go through at 120MPH
- "Could" or "does"? That is like saying "Dropping this hammer on your toe could hurt" vice "dropping this hammer on your toe does hurt". Either it does, or does not.
- If it does, how much faster did that person go on the claimed lighter sprocket setup?
 

wmhjr

Grandpa
Control Rider
I saw someone make a post about moment of inertia stating that a bike moving at 120mph could have up to 60lbs more inertia through esses than a bike with a smaller rear sprocket or one made from a lighter material. I haven't been able to do the calculated differences from different teeth sizes but it is something interesting to think about.

Also this website is pretty useful: http://www.gearingcommander.com/

I think this is kind of misleading. What they're probably trying to claim is that a lighter sprocket might have 80 less pounds per square foot moment of inertia. That sounds like a whole bunch - even if you assume you're doing esses truly at 120mph. But then, let's really look at the reality. A "typical OEM" aluminum rear wheel according to some wheel manufacturers has a moment of inertia of (wait for it)..... 3291 kgm2, or 78,096.6 lb:ft2. According to the same references, a full carbon fiber wheel has a MoI of 1987 kgm2, or 47,152.2 lb:ft2. So, reducing those numbers (lb:ft2) on either wheel by 80, gives you a total difference of roughly between 1% and 1.7%.

So, given the very unlikely 120mph speed through those areas as John said, and the minute math differences even if the person claiming 80 is correct, there is nobody who would ever read - much less post - on this forum that would ever in their best day be able to notice the slightest bit of difference.

Now, on the other hand, if we calculated the MoI of helmet and head, even though it is sprung versus unsprung weight, there are some folks on the forum that would be very surprising. Your calculator may not have that many digits :)
 

bmart

Control Rider
My rear hoop must be my problem. Definitely like...379.2 extra pounds. Seriously, it looks like a pizza platter.
 

Otto Man

John
Control Rider
My rear hoop must be my problem. Definitely like...379.2 extra pounds. Seriously, it looks like a pizza platter.

Well see...now you know, if you got a rear hoop made out of titanium, you'd be running lap record pace....

Right?!?!

1:24's at Road Atlanta here we come!

:D
 
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