Chains and Sprockets

If you choose a length of chain where the adjusters are near the middle, you will have no problem fitting -1 tooth front sprocket.

I do it all the time.


I have a sandman casesaver and cover, theres some slight rubbing with a 14 tooth, but no problem. Dont know about the stock one.

I just did 13/47 with a 112 link chain. I'm guessing 112 will fit the 14/51 combo... On mine the rear tire sits a little less than 3/4s of the way back in the adjuster. You could use gearing commander as a reference. They break everything down nicely. Top speed for every gear. That site will let you know if your gearin will cause unnecessary wear too. Like me throwin a 12t on the front with a stock 108 link chain is technically bad cause the same front teeth hits the same chain link every time... This is easy enough to figure out on your own too. Say if you do 112 with the 14 front you will have the same issue. 112/14=8. So when the front sprocket goes around eight times the chain has gone around once and is back on the same tooth same link as it started. Don't know how much longer you can run a system that's phased properly but they say it matters. The only other advice n this maybe wrong, but is my understanding of how it works... You should change how you tighten the chain. Doin it by the book it should be able to pushed to around 5/8" away from the swingarm. If you make both diameters that the chain goes around bigger this technically should get bigger too. If you were measuring the slack movement from top to bottom I don't think it would change but your supposed to measure to the swingarm... Theres a chard here that makes sense of this. https://wr250rforum.forumotion.com/t2022-chain-adjustment

dicklane625 wrote:

I just did 13/47 with a 112 link chain. I'm guessing 112 will fit the 14/51 combo...

I run 13/51 with 112 links and it's at the far end of adjustment range.  Not sure I could get this to work with a 14 tooth countersprocket, especially since I run a riveted master link which requires a little wiggle room to get the chain on or off of the rear sprocket.

looking to get a 12T sprocket with my standard 43 rear

what is the different between countershaft sprocket, and standard?

1 tooth. Stock is 13.
1 out of 13 is roughly 8%.

I recently got myself a 2009 WR250R and the previous owner had geared down from stock to 13/49. Not having ridden the WR in stock form I have a question which I hope someone could answer for me about "gearing down the WR".

I have read on different articles and forums about gearing down the WR250R to make it more rideable on the highway and out of the trails. I understand the part of the trail being easier with gearing down so slow speed crawls without the inconvenience of multiple stalls as compared to stock.

What baffles me is how does it make it more rideable on the highway, for gearing down means lower top speed which translates to higher RPMs.

My WR is mostly used for commute purposes and the weekend trails when I find them (Auckland doesn't have too many open to motorcycles) and I notice I am probably riding at least 1500-2000rpm higher (as per stats from the gearingcommander website) at a 100kmph as against what a stock bike would do.

So why do people say it is more rideable on the highway geared down? How bad is the stock ratio in slow-speed traffic and crawling trails?

motonakul wrote:

What baffles me is how does it make it more rideable on the highway, for gearing down means lower top speed which translates to higher RPMs.

The short answer is that the taller gearing the WR250R comes stock with is a case of being over geared (geared too tall for best performance).

Here's what I believe:

The reason the WR250R comes with the sprocket sizes it does is for one reason:
Get the bike to pass required noise regulations.
With sprockets?
Yes.
The bike has to be able to pass a drive-by noise test during testing before it's put into production on the assembly line at the Yamaha factory.
This test is conducted by having the bike drive by the noise measuring equipment at a certain speed in a certain gear.
If you gear the bike so tall that it's turning ridiculously low RPM during the drive-by sound test, it will make less noise.

That's the concept.

That's why it comes over geared for best performance - the sprocket sizes used to pass the sound test are what's used in the production of the bike at the factory.
Same for many, many, many (if not all) street-legal bikes.
That's why a new Yamaha YZF-R1 comes geared so tall, you can break the National speed limit in first gear.
By a lot.

So, to at least some riders, they eventually realize that actually gearing it down to something more realistic for the 250cc engine actually performs better for them in most conditions.
The stock gearing is so tall, some riders report that sixth gear is usable when the road is flat and no headwind.
Sure, the bike will turn more RPM with lower gearing, but there is a sweet spot between too low and too high of RPM.
If you do a lot of highway and cringe at the engine turning more RPM, leave it.

On my own WR250R, I used 12/47 sprockets, riding a mix of street and trails.
On my WR250X, I ran 13/49 sprockets, all street use.

You can add a 14 up front to cut the difference between what you have now, and stock, in half.
Its 15 bucks, see how you like it.

I also find that 13/49 is too low for sustained high speed, so I mostly run a 14 up front. And have also used stock gearing, which I never had trouble pulling with a little powermods.

I kinda change my gearing alot, as I use the bike for both enduro, and out of the country trips where I need to cover some distance.

YZEtc wrote:

The stock gearing is so tall, some riders report that sixth gear is usable when the road is flat and no headwind.

So stock gearing isn't ideal for New Zealand where our roads are not always flat & windspeeds are decently up there though out the year!

Might have to look at other options of gearing combos. I was think 13/45 or 13/47 which may be better than 13/49 for the highway which is the majority of my commute.

Jens Eskildsen wrote:

You can add a 14 up front to cut the difference between what you have now, and stock, in half.
Its 15 bucks, see how you like it.

14 upfront pretty much means I need to pull out the front stock chain/case saver since a bigger sprocket will definitely eat up the plastics.

Do you have another alternative case saver you are using? Sandman Parts are probably the best way to go, but don't see shipping rates making it feasible to send shipping across continents.

I used a sandman, and got it shipped to europe. Theres others who make something similar.
Dont know how the stock one fits, but you might be able to modifi it a bit. But i dont think it will protect the engine much anyway.


If your tensioner blocks are pretty forward, you might be able to fit a rear sprocket with 2-3 teeth less. That will get the rpms down by around 400-600 rpm in 6th gear. Or else you could cut out a couple links, and fit a new rear.


Different sizes rear tires also play a huge role in the final drive gearing.
A taller tire with a 14/49 combo, might be the same as a different tire with a 14/47 gearing.
So play with it a bit, and see what you like.

Hello,

Anyone try 13/49?

Hello, I'm looking for a gear ratio for a good mix of enduro and road riding. I live in Germany and am looking for a gear ratio with a good top speed, ideally around 130 km/h and good off-road drivability. I don't do anything extreme with the WRR, but I have to travel 50km to the training area. Are there any recommendations? Thank you and best regards!!!

kingstyle wrote:

I live in Germany and am looking for a gear ratio with a good top speed, ideally around 130 km/h and good off-road drivability.

Do you just need a top speed of 130 km/h, meaning you only hit that number occasionally, or do you need to maintain that speed for a prolonged period of time? The former is doable with a 14/48 combination: you can maintain 120 km/h at about 8200 RPM, hit 130 km/h at about 9000 RPM every now and then, and you get usable off-road gearing.

The latter though would be tough: with a 14/48 combination 130 km/h comes at 9000 RPM, which is not a comfortable range. Even with stock gearing you would need to be at about 8600 RPM for 130 km/h, and that gearing is a bit too long for off-roading.

johnkol wrote:

kingstyle wrote:

I live in Germany and am looking for a gear ratio with a good top speed, ideally around 130 km/h and good off-road drivability.

Do you just need a top speed of 130 km/h, meaning you only hit that number occasionally, or do you need to maintain that speed for a prolonged period of time? The former is doable with a 14/48 combination: you can maintain 120 km/h at about 8200 RPM, hit 130 km/h at about 9000 RPM every now and then, and you get usable off-road gearing.

The latter though would be tough: with a 14/48 combination 130 km/h comes at 9000 RPM, which is not a comfortable range. Even with stock gearing you would need to be at about 8600 RPM for 130 km/h, and that gearing is a bit too long for off-roading.

Thanks for the answer! The description fits quite well, a constant speed of 100-120km/h on the country road is ideal. For overtaking, speeds of up to 130 km/h (which can be achieved without a 5 km run-up) are almost ideal. One question for the budget, is there also a similar gearing with the original 13 sprocket at the front and original chain?

kingstyle wrote:

One question for the budget, is there also a  similar gearing with the original 13 sprocket at the front and original chain?

A 13/45 combination is the one that comes closest to the 14/48. You may be able to use the same chain, depends on how much slack you have available now.

johnkol wrote:

kingstyle wrote:

I live in Germany and am looking for a gear ratio with a good top speed, ideally around 130 km/h and good off-road drivability.

Do you just need a top speed of 130 km/h, meaning you only hit that number occasionally, or do you need to maintain that speed for a prolonged period of time? The former is doable with a 14/48 combination: you can maintain 120 km/h at about 8200 RPM, hit 130 km/h at about 9000 RPM every now and then, and you get usable off-road gearing.

The latter though would be tough: with a 14/48 combination 130 km/h comes at 9000 RPM, which is not a comfortable range. Even with stock gearing you would need to be at about 8600 RPM for 130 km/h, and that gearing is a bit too long for off-roading.

One more question, are the stated speeds real?

kingstyle wrote:

One more question, are the stated speeds real?

Which stated speeds are you referring to? The ones I mentioned are GPS speeds, so the speedometer will show about 5% more. Don't forget that if you change the gearing, both odometer and speedometer will be off, so if you want to keep correct mileage you will need to get a speedo healer.

Here's your options, available elsewhere here. If you want the possible speeds with each combination, Gearing Commander will help you with that if you supply your tire size as well. (Speed is what a GPS tells you it actually is; the odometer/speedometer isn't particularly accurate even with the bike in stock trim).

STOCK:
13/43 = 3.31

CHAIN/SPROCKET OPTIONS
110 Link:
12/43 = 3.58
12/46 = 3.83

13/45 = 3.46
13/46 = 3.54
13/47 = 3.62

14/46 = 3.29
14/47 = 3.36

112 Link:
12/47 = 3.92
12/48 = 4.0

13/46 = 3.54
13/47 = 3.62
13/48 = 3.7
13/49 = 3.77
13/50 = 3.85

14/46 = 3.29
14/47 = 3.36
14/48 = 3.42
14/49 = 3.50
14/50 = 3.57