With a 12-tooth front sprocket, has anybody discovered how large of a rear sprocket will fit with the stock chain and still be able to achieve proper chain slack? :)

And the answer is 45 teeth. :)

When you say proper slack, are you using the latest procedure as per Yamaha?

http://www.supermoto...308&postcount=8

you knew this but, 12t will significantly reduce the life of the chain

mwakey:
Yes, I've read the new proceedure and it passes. :)

highmarker:
Yeah, I've always heard that.
I haven't done any scientific tests of my own on the matter, but whenever I've run small front sprockets, I still got chain and sprocket life that wasn't unusually short so the whole affair went pretty much unnoticed to me. :)

Well, I've got a 12T on the front, almost 4000 miles on that and everything looks pretty damned good. :thumbsup: Let us know what kind of top speed you get with that setup.

SheWolf said:

Over 5000 now isn't it? Still looking AMAZING I might add :worthy:

SheWolf said:

I'll give you the details after my next ride, which will probably be Saturday after work. :)

well it only stands to reason, the more you work something, ie. bend a chain more then you did before then streighten it out and put it under a load, over and over, then your shortening the life, the light that burns twice as bright kinda thing, the difference between 12 and 13 however is so small. going from 13 to a 9 might be more noticeable, so how is that 12/45 working out? does it have noticeably more rip that say 12/43?

I'd like to tell ya', but I ain't ridden it with both of those sprockets, yet.
I'm expecting it to be another step toward proper off-road gearing versus something that's geared to the moon for the sake of passing some kind of sound test the Yamaha factory must subject the bike to.

Stay tuned. :)

Awesome! I know I love the 12/43 setup...if you get good response and don't lose too much p top that would be a great thing.

I'm using the 13T on front, and a 47 tooth on the back. Yes! a new chain, but I think there is room for a 48 tooth. What's the new Yamaha proceedure for chain droop?

Opps! got it! I guess I can't use that way to measure chain slack!

Just to jump in, I burned up my stock 13T up front...

I've been using 13/47 offroad and it's worked really well. 13/46 never felt right with the gearing and 13/43, well, it will get you there, but barely. Since the only thing I had in storage was a 12T, I mounted it and used it with the 47. Lots of grunt but almost too much. I'll try the 12/46 combo this weekend.

As far as street,
I was running 13/43 street (stock) which never felt right, and tried 13/46 which also felt off. Since putting the 12T on I have to agree with Shewolf that 12/43 works great for street. I might consider trying 12/41 just to see what that does...

Ideally it would be great to have a single front sprocket and just change out the rear, but I fear to make the wr feel right it will take swapping both out.

Has anyone tried a 14T up front?

Alrighty, then. :)
I decided to get up with the roosters and leave the house early and get some off-road riding in before work (and after work this evening in the twilight, too).
Here's how 12/45 sprockets feel to me:

If you want to concentrate riding your WR-250R off-road and don't mind lowering your cruising speed on the street a bit, the gearing is much better while off-road.
Seems to be about 10mph less at any given RPM while cruising on the street in 6th gear.
Still, I'm able to comfortably keep up with 55mph traffic on secondary roads, and since all I need my WR for on the street is to be able to ride it to the off-road action, that's OK by me.

Once off road, 1st, 2nd, and 3rd gear are the meat-and-potatoes gears for my riding areas, and the spacing of the ratios is better suited to the bike's powerband.
I think I'll be keeping this choice of gearing for my WR-250R. :)

Aaahh, yes.
The WR-250R powerband.
Does anybody else out there in WR-250R land feel that the power is a bit road-racey?
In other words: The middle RPM is flat with a hit up top?
The power delivery is usable, chugs around at slow trail speeds surprisingly well just above idle with good pulling power down there, is smooth through the middle, ends with a nice burst of power on the top end (like 10,000 RPM), and feels practically vibrationless.
I just wish that smooth middle region (which feels wide) had more torque to pull the bike into the manic top end a bit more easily.
I'd just love to find out that the bike was being electronically restricted (like the 2006-and-later Yamaha FZ-1) to protect the rider from himself (and protect the environment, too, of course :) ) by reducing power under certain conditions.
These days, I wouldn't doubt it. :)

Great to hear! I can't remember if you've got the PB up front or not...

What my WR has is:

Power Commander lll USB
FMF Powerbomb head pipe
FMF Q4 muffler
Airbox flapper deflapped
12/45 sprockets

:)