Chains and Sprockets

OK, I've ridden with the 12/43 combo a few days now along with the taller D606 rear tire. I wish I could say there was a huge difference, but it is not huge. Noticeable, but that is about it. It will surprise me now and again when coasting near a complete stop then dumping the clutch to accelerate around stopped traffic. In that scenario, the front tire will lift off and skim the ground. It also pulls sixth gear better, but it just seems to be about where stock gearing and stock tires were. Of course, my stock rear was nearly bald when I swapped it out, so the effective gearing was probably deeper than with a newer (read: taller) rear tire.

I ran the stock gearing with the taller D606 for about two or three weeks and that was a real drag. I had to use 5th if I wanted to run faster than an indicated 70mph because 6th wouldn't pull it (my dirtbagz are usually full and catch a lot of wind). I guess I got my hopes up too much and set myself up. A 12T is a good $25 test to determine what gearing I want in the future. I'll run this setup next summer and decide if I want to swap then or actually wait until everything wears out. This gives me a feel for what a 13/46 combo will be like. Since I don't plan any exhaust or programmer updates, I'm guessing I'll be going with a 13/48 combo rather than 13/46. That also leaves the door open for a 14/48 for long rides, though the 13/48 will work just fine, just get worse gas mileage running highway speeds for long distances.

Going down one tooth in front, to a 12T, is like going up about 3 teeth in back. The taller Dunlop is like taking away 2 teeth in back, so I'm netting 1 tooth gain. I didn't confirm the D606 weighs more, but I imagine there is a tiny gain there. Basically, I feel like I'm back to about stock gearing or just a sliver deeper. Oh, and no buzzy vibrations, but there is a barely noticeable harmonic sound (with associated vibe) at highway speed. It hums for a second, then off a second, then on, then off, etc. I have only noticed it 4 or 5 times, so I must have to be going a specific speed for the harmonics to be just so. No bother. Just something I noticed.

Just one persons experience. Yours may vary.

Good to know. It's probably been there all along and I just got used to it, but "re-found" it now that I was listening for anything weird with the 12T installed. Thanks.

I still kind of feel like this sprocket may cause the chain slider to wear more. On the kick stand, it looks like the chain runs at an ever so slightly tighter angle, vs. the 13T, where it angles across the top of the chain guard, but then, maybe that is not the case when my weight is on it and the swing arm and linkage move around to a weighted stance. I'm probably looking too hard and just need to ride it and not think about it. Ha.

The chain will wear a groove in it a bit but that's as far as it goes. I've run this 12 on from almost the start and the chain slider hasn't worn down any more than the two little grooves from when I first started riding it.

SheWolf wrote:

The chain will wear a groove in it a bit but that's as far as it goes. I've run this 12 on from almost the start and the chain slider hasn't worn down any more than the two little grooves from when I first started riding it.

Thanks, shewolf. Good to know. By the way, how many miles do you have on the 12T? I figure a bunch by now. I'm curious how long they hold up. Stock chain and rear sprocket?

My stock 13T was getting a bit grooved. I flipped it since I had it off and ran it flipped for a few weeks while the 12T shipped. I guess a person can get more miles out of one that way.

Update re: Primary Drive chains & sprockets from Rocky Mtn ATV -

• didn't need the tapered bolt kit for the rear sprocket after all - the Primary Drive 47T rear came pre-drilled for flat and tapered bolts, so I just re-used the stock bolts.
  
• The Primary Drive X-ring chain (112 link) came as a clip type, went right on.
  
• The Primary Drive front 13T sprocket - labeled "2008 WR250R", (edit) does fit, just fine - just be sure to clean all the mud out of the front sprocket area first!
  
• I had a Tag 12T front sprocket (for a WR250F, LOL!) already on the bike, decided to leave it there vs. swapping the stock 13T back in. WOW does the bike have some low-end grunt and control now!! While the 12/43 ratio felt really good, the 12/47 is plain silly.
  
• 
  
• Still have to try it out on the highway, but so far I like it. I was planning on running 14, 13 & 12T fronts - might just stick w/ 13 for commuting & 12T for dirt.
  

http://www.mototraction.com/ <--- I got my AFAM 12t from here

Slid right onto the countershaft splines with ease.

just regarding the removal of the stock 13T... save A LOT of time and invest in a compressor + air impact gun.. I think the compressor I got was $100 and the impact was $30.. i had my little wife (105lbs) step on the rear break and ZIP with the air gun, came right off, took maybe 1.736167 seconds.

Well worth the money, plus you need the compressor for tires, getting grips off, spraying dust out the computer, etc...

http://www.rockymountainatv.com/productDetail.do?navTitle=Drive&webCatId=9&navType=type&webTypeId=124&prodFamilyId=2192&listingId=&sizeAttr=1225#vehicleSelect

i'll try it again.

it's rockymtn atv/mc

the link was directly to the page with their sprocket....50 tooth for $19.95...says it is in stock

the bolt kit is listed right under the sprocket detail and says must use for a ttr,but this is the same tapered type bolt kit for our bikes too.

So based on what I've read, (head spinning) it seems if I'm looking for the most aggresive gearing for the trails, 12/47 or 12/48 is the way to go. I currently run a 12/43. The only road riding I'm doing is short 1-2 mile stints between the woods and I feel as I need more ummmff on the steeps. Am I on the right track here? Also, assuming I want something super reliable and money isn't a concern, what's my best bet? I assume I'll need a new chain as well . . .so any suggestions here for the set-up I mentioned above. Really appreciate your feedback. I'm fairly new to the sport but have been riding alot recently (I've got the bug bad). Thanks again!

If you're only riding the street for a mile or two between trails, then yeah, I'd lower the gearing more as well.
The WR-250R rolls off the showroom with moon gearing that's there to let the bike pass sound tests, not because it's ideal for off-road riding.

Any major brand chain and sprockets is fine in my book.
My person faves are DID O-ring and X-ring chains and Renthal or Sunstar sprockets.
With Sunstar, you have the option of either steel or hardened aluminum on the rear.

My WR-250R has 12/45 right now, and it's still taller than I'd have it if I never or hardly rode it on the street.
I can still cruise at 60mph easily.
I'm about to try 12/48 this weekend and trade some of the street cruising mph for trail peppiness and tighter ratios.
Should be better while enjoying all of those lovely rocks out on the NETRA Pachaup loop. :)
I'm guessing I'll be cutting the new chain to 110 links (I think stock is 108 links).
I'll let you know when it's on the bike. :)

Just to add a data point to the thread - w/ 12/47 gearing (112 link chain) I was able to get up to 85 mph (GPS indicated) at a full tuck on the interstate. Sitting normally, it'd pull about 82-83, down to 80 or less uphill.

LOVE the 12/47 in tight/steep stuff, it really transforms the bike - for peanuts!

Stock gearing (13/43) has a ratio of 1:3.31

12/43 has a ratio of 1:3.58 (a real nice set-up for highway and trails)

My current 12/47 has a ratio of 1:3.92 - perfect for insane rock crawling and other gnarly trail work, but admittedly a little low-geared for interstate.

I'll likely run the 13T front (13/47 = 1:3.62 --> pretty close to the 12/43 ratio), and put the 12T on for days of mostly trails.

The 48-tooth sprocket and new, longer chain are raring to go.
I shortened the new chain to 110 links.
Perfect for 12/48 sprockets.
Sprocket is a steel Sunstar, and the chain is a DID 520V O-ring with the optional rivet master link.



Ain't she purdy? :)

.
I like the gold look; Stealth Tri-Metal 47T sprocket and DID VT Narrow X-Ring Chain cut to 110 links with a rivet master link:

shawngrodz wrote:

Thanks for the input. Ya, let me know how you like the 12/48 in the woods and how it may compare to running the 12/45. I was thinking of going from my 43 to a 45, just to see if I notice the change but based on your comments I may just go all the way up to the 47 or 48. Good luck can't wait to hear about your experience with the 48.

I rode the bike to work today and got in a bit of trail riding at dusk.
Here's how the 12/48 sprockets felt to me:

If you're doing more off-road riding than Interstate or major route cruising, this is definately the way to go.
I thought going from the stock 13/43 to 12/45 was a good thing, but this 12/48 gearing just brought the performance of the bike up another step.
Muuuuuuuuch better for off-road use with the tighter ratios giving greater acceleration and better gear spacing.
You can lug it way down low in 2nd or 3rd while negotiating slow sections, then open the gas and the bike pulls it's way up into the meat of the power much easier.
Getting the front wheel off the ground to clear obstacles is much easier.
Basically, it feels a lot more like a dirt bike with the added snap, and a side benefit of this newfound peppiness is that the bike feels lighter because it responds better when you open the throttle.
You got to like it.

The amazing thing is, the gearing can still allow easy 50-55mph cruising on the street.
In fact, if the bike came geared this way off the showroom floor, I'd probably think the streetability was just fine.
This just goes to show how incredibly tall the stock 13/43 gearing really is.

Just remember to reprogram your speedometer recalibrator if you use one. :)

A 110/100-18 tire is something you get on a bigger bike, like a WR-450F.
It will fit, but I feel it's a fatter, taller, and heavier tire than needed.

I use Brigdestone M22/M23 hard terrain tires, and the rear I run is 100/100-18 (which is an equivalent to the stock 120/80-18).
Feels perfect for the WR-250R.

Probably gonna' be 110 links with 13/47 sprockets.

Today, I rode 50 miles of the 65 mile Pachaup loop (AKA Netra E8), and only cut it short because the sun was getting low.

I'm so glad I lowered the gearing further with the 48-tooth rear sprocket.
I was able to just leave the transmission in 3rd gear and torque up rocky sections with wet leaves all over the place.
2nd and 3rd were the bread-n-butter gears.

On the paved sections, cruising at 55mph was easy.
With bona-fide motocross knobbies fitted, that's all you need. :)
The bike just flat out worked a lot better with the lower gearing.

I keep wondering about 14/48= 3.43. Pretty much splits the difference between stock R 13/43 and popular 13/46. I thought maybe this would give me just a bit more pep in 6th without hurting mileage too bad or increasing vibes. I ride much, much more highway than dirt. Then I'd drop to a 13 front for the trails; I'm a wuss needing all the help I can get off-road.

Has anybody tried 14/48?? Just shut up and go 13/46 like most folks?? Thanks, everybody.

Sarah

Had to edit an earlier post - the Primary Drive 13T that I bought DID in fact fit, must have been some mud blocking it when I tried earlier, plus I neglected to get a trouble light on the situation the evening I tried the installation.

Very happy w/ the Primary Drive setup from Rocky Mtn ATV - $8 for a front steel sprocket (12 and 13T) and $20 for a rear steel sprocket (40, 42, 47, 48, 49, 50, 51, 52T). They also have aluminum rear sprockets for $40 in 47 to 52T.

http://www.rockymountainatvmc.com/vehicleFilter.do?prevVehicleType=&prevMake=&prevModel=&keyword=&vehicleTypeId=&make=&model=&year=&applyFilter6964=Search&navTitle=Drive&webCatId=9&navType=type&webTypeId=124&uri=%2FtypeDetail.do

just put on a new 13, 47 combo and new chain - havent put on the new 606's on yet but love the fact that the bike will now easily idle around in the dirt - makes things much more fun and a whole lot easier!!

Speedo is off by 10k's at 60k's an hour - reads 70, so I think Im in for a speedo healer. Why yamaha released these bikes with the 43 baffles me - with the 47 it still easily does the legal speed limits around here.

Now I just need the tempreatures to drop below 43 degrees celcius... bring on April - cause riding in this heat is like breathing from a hair dryer

you guys running the 12 tooth front may want to check your LOWER chain guide and swingarm for excessive wear. Big Dog recommends against it--see here, first photo and paragraph above. I've also read somewhere, can't remember where, that one dude running a 12 tooth had the chain eat thru the lower guard and into the swingarm all the way to the bearing, and had to have it welded up.

This isn't exactly a new issue.
I've seen bikes over the years with similar wear.
You just got to keep an eye on your stuff. :)

+10 You should be checking everything any way from time to time as part of maintenance, stock chain/sprockets or whatever. The only wear I've got is on the runner, and it's not bad. Nothing on the swingarm either. I don't run my chain loose or too tight, which is usually how that crap happens.

I searched first before asking and found nothing, so here it goes:
Will the stock chain fit 12/44 ?
I already have a Renthal 44 rear, should I go with a Renthal front 12T, or does brand compatibility not really matter?

It will fit. You can go to a 45 rear with the 12 before you need to go to a bigger chain. Brand shouldn't matter, I'm running 2 different types.

D1EHARD wrote:

Hey guys, I'm having a hard time finding a black or blue (or any color for that matter) 45t rear sprocket in any brand. Does anyone know where I could find one online? I have found some plain steel 45t sprockets, but I figured if I'm changing I might as well make it look good! Seems everywhere I look it's 46t and up.

Thanks.

GYTR sprockets are blue and come in 45T (aluminum). I don't know where to buy them online though. A quick part # google comes up with websites though. . . Maybe that's a start.