17t to 15t

1185 Views 13 Replies 7 Participants Last post by KenR74, 9 d ago

KenR74

Discussion Starter · 18 d ago

Has anybody dropped to a 15 tooth on the front sprocket?

I've read how moving to a 16 is a big difference. That looks like about a 6% change based on the calculator I'm using which doesn't seem like much.

Wondering if 15t would make it unusable on the highway.

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PlugnPlay

· #2 · 18 d ago

I believe the diameter of the front sprocket might limit the chain's ability (or efficiency) in completing its rotation, leading to premature chain wear

Others here likely will have a cleaner explanation why 15t might be pushing things a bit

FWIW, my '14 DL1000 was a joy on both dirt and pavement when running 16 teeth front, OEM rear

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blaustrom

· #3 · 18 d ago

16 T makes a significant difference. I would try that first.

I guess a reasonably technical view would be that the smaller the sprocket the higher the load on the engaged (fewer) teeth, hence a smaller sprocket causes more wear to the chain and the sprocket. Probably not material but something to consider.

You can consider upping the rear teeth count, if 16T front is not enough of a change.

You can calculate the highway RPM's and judge for yourself if you like to cruise at those. Maybe like cruising in 5th?
5000 rpm at 17T = 5670 RPM at 15T

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KenR74

Discussion Starter · #4 · 18 d ago

They are cheap enough I may just try both 15 and 16. I've gone from 15 to 13 on dirt bikes but chain replacements are just part of the regular maintenance so I've never really considered chain wear as an issue.

Stock gearing has me at 3,500rpm at 60mph. If that only jumped up to 4kish I can live with that. I'm rarely at highway speeds so a little higher rpm is ok but I don't want to turn it into a wheelie machine either.

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Rolex

· #5 · 18 d ago

I could have been the first to go 16t and after the change never considered a 15t.

V2 + 16t = true love | StromTrooper

The 16t was perfect for my riding but I did later fit a PCFC and had a custom tune built, this lifted the HP and significantly moved & boosted the torque making lower gearing unnecessary, I got the quicker (& slower) bike without losing any motorway comfort.

I still do often find myself when on a motorway setting my cruise control while in 5th gear so a 15t may work if you don't mind the extra RPM.

I think clearance at the swingarm pivot could be an issue (I have not looked) going up on the rear would work better for that.

My Yamaha MT09 is the only chain driven bike I have owned that has not had a sprocket size change, I like things just right and the 16t done that for me.

Let us know what you decide and how it works for you.

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Fanaticalkilla

· #6 · 17 d ago

1 tooth down on the front is the same as around 2-3 on the back. I would consider trying a 2-3 bigger rear sprocket with your 16 tooth front.

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24714

· #7 · 17 d ago

I replaced my 41t rear with a 43t and left the stock 17 on the front.
Seems just right for me.

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Fanaticalkilla

· #8 · 17 d ago

24714 said:
I replaced my 41t rear with a 43t and left the stock 17 on the front.
Seems just right for me.

This is what I was thinking of doing as well.

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Rolex

· #9 · 17 d ago

I did the front because it only takes a few minutes to reverse it.

Could even be done on the side of the road if I decide to ride from one side of the country to the other.

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KenR74

Discussion Starter · #10 · 17 d ago

Rolex said:
I did the front because it only takes a few minutes to reverse it.

Could even be done on the side of the road if I decide to ride from one side of the country to the other.

That was my thought as well. 15t is on the way. I can swap it on and if it sucks I'll try a 16t.

May to the back sprocket later but for now it looks too new to replace.

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KenR74

Discussion Starter · #11 · 15 d ago

15T is on and hang on tight! Huge improvement over the 17. 60mph is right at 4k and 70mph is at 4.5k rpm. I hit a little gravel road and the TC blinky blinky was on a lot. Too much fun.

I only did a 20 mile loop but I'll put some miles on it this week to see how it feels. Definitely different bike now that I'm using all of the gears. 1st pulls great and the shift point for me is right about 20mph. Much nicer in traffic without having to clutch it all the time.

I may swap on a 16T next weekend just to see the difference.

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Rolex

· #12 · 15 d ago

Some reported TC problems with the 16t change even on black top.

I will interested in what you see with the 15 & 16.

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Niodachi

· #13 · 9 d ago

KenR74 said:
15T is on and hang on tight! Huge improvement over the 17. 60mph is right at 4k and 70mph is at 4.5k rpm. I hit a little gravel road and the TC blinky blinky was on a lot. Too much fun.

I only did a 20 mile loop but I'll put some miles on it this week to see how it feels. Definitely different bike now that I'm using all of the gears. 1st pulls great and the shift point for me is right about 20mph. Much nicer in traffic without having to clutch it all the time.

I may swap on a 16T next weekend just to see the difference.

Hey there any further thoughts on this after a week? Looking at ordering the 16 or 15 tooth front sprocket soon.

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KenR74

Discussion Starter · #14 · 9 d ago

I like the 15t 90% of the time. It lets me use all of the gears and is great in 1st gear.

It gets a little buzzy at 75+ mph so I have a 16t on the way. I am going to ride with the 15t for another week before swapping.

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