In the market for sprockets to increase fuel economy. 15T front, ?? rear?

[CZroe]

At 12K miles, I'm in the market for a new chain and sprocket set. I've long wanted to get the 15T front sprocket for fuel economy reasons but, because they recommend that you change the rear along with the chain so that they wear together, I'm wondering what I should grab there too.

The bike struggled at higher elevations when I crossed the country with the stock gearing, so I know it won't get any better if I go up in the front and down in the back, but I do want to be able to at least be able to go where I've gone before, so if that means leaving the rear at 45, so be it.

What do you guys suggest? Price is also a factor... I can't spend too much.

[Slabrocks]

if you add one in the front and leave the rest alone, the RPM will be a bit lower, which will gain mpg, but make it even worse for you in the higher elevations

im doing it this week on my 01

[CZroe]

Originally Posted by Slabrocks

if you add one in the front and leave the rest alone, the RPM will be a bit lower, which will gain mpg, but make it even worse for you in the higher elevations

im doing it this week on my 01

I'm just hoping it's not "so bad that I can't traverse it at a reasonable speed" "bad." That said, when I was fighting an INSANE headwind outside of Deming, NM and up into the mountatins in Arizona, I could only break 50MPH by drafting larger vehicles. Seriously. I mean, I *was* weighed down by a loaded backpack and tankbag and was pushing 250lbs myself, but that wasn't a problem anywhere else in the trip. I'm sure weather had a lot to do with that so I'm hoping that I could still swing it at 40-50MPH with a lower rear sprocket.

That said, SD, CA is a coastal city with lower elevations for the most part (obviously, close to sea-levels). If I ever go back to GA, I'd be going to the Atlanta area, so I should purchase with those two areas in mind and not so much any future trip to get there.

So... what's a good setup for fuel economy commuting in San Diego? How far down dare I go in the rear?

[Slabrocks]

everything i have read says there is not enough of a difference in performance to really notice. its one of those things where you consider how often you travel and might need that extra power.
for in town stuff, you might not really "need" the tiny difference

[CZroe]

If that's the case, I'm wondering how far I could push it before I begin to notice. 15/44, 16/43, 15/40...

[Rayme]

I didnt notice that much of a difference when I went to 14 to 15 as far as fuel economy.

[CZroe]

Perhaps I'll stretch it to 15/43 then.

Does anyone know if there is a set (chain + sprockets) or where I can get 'em cheap?

[Alex]

I think almost40 runs 15/41. If the gearing turns out to be too tall for a particular situation, just downshift a gear or two for that period. www.gearingcommander.com is a good site to play with the different combinations and see what the speeds/rpms would work out to.

That said, if the bike ends up being ridden about roughly the same actual road speeds, the fuel economy differences are going to be minuscule, if noticeable at all.

[jonthechron]

how much more MPG do you want? the bike is rated at 61 MPG stock.

[Sailariel]

I had a chance to try out my new 15T sprocket today. I like it, and the bike feels more responsive. The problem I had with the stock gearing was that you had to shift into second gear in the middle of an intersection or do your left turn with the engine screaming like a banshee if you leave it in first. It is amazing what the difference is by changing one tooth. I doubt if there will be an improvement in milage, but I do like the way the bike feels.

[Snake]

From my experience on the pregen I would stay with 15 front and 45 rear. The new gen has better low and mid torque so you can easily go with 15 front and smaller in the rear and downshift as needed as Alex suggested.

[CZroe]

Thanks. I'm strongly considering going 15/43. I hope I'll still be able to take off from stoplights!

Originally Posted by jonthechron

how much more MPG do you want? the bike is rated at 61 MPG stock.

And I've only managed 200 miles per tank twice and I had to hyper-mile like crazy to do it and push until it was running on fumes. I've gotten as low as 117 miles on a full tank, though I think that was bad gas (ran out leaving me stranded out of state). I just weigh too much (something else I will be working on). If Kawi claimed that the previous generation was 85MPG, I want a little bit of that.

Lately, since the bike started running poorly, I've been getting MUCH less than average (from an average ~185 per tank now down to about 147 range). I hope they can find the problem at my next servce interval or I'm going to have to scrap the whole gearing thing.

[Reswob]

I routinely get mid-50s mileage while riding like I stole it, (and I'm not light either) I would suspect something seriously wrong to be getting the mileage you are.

[CZroe]

Originally Posted by Reswob

I routinely get mid-50s mileage while riding like I stole it, (and I'm not light either) I would suspect something seriously wrong to be getting the mileage you are.

That's what I've been sayin' all along, but CycleWorld's review got about what I get and none of my dealer services turned up anything.

I do lots of surface street commuting and freeway driving, so anytime I'm not start/stopping I'm driving much faster than is efficient (80-95MPH indicated).

My surface street driving is usually short distances with some warm-up time.

[Alex]

link to mileage poll ----> here

[CZroe]

Oh, and I have the CDI variance.

Originally Posted by Alex

link to mileage poll ----> here

Thanks. I participated.

[JokerSeven]

Im thinking about trying 15/41 or maybe 15/44
ahh hell now I'm in the same boat you are

Where is a good place to shop for them ?

[CZroe]

I see plenty of chain and sprocket sets (both sprockets) for the previous-generation on eBay. Nothing for the current-generation though. If I can't get any suggestions, I'll at least report what I find here.

[Rayme]

Here's my fuel logs if anyone is interested.. highway is where I got best MPG, I dont know if the sprocket did any change but not by much, the way you ride will affect it more.
http://www.gassavers.org/garage/viewgaslog/2531

[CZroe]

Strangely, CheapCycleParts.com doesn't have the front CS sprocket. Hmm.... and they only have a gold chain. I kinda want the get rid of anything that isn't black or blue (exactly why I want to black-out the exhaust), so I'm not too sure on that, though the price is right[unfortunately, the product isn't; it's just a link ]... dealers are INSANE! They quoted me $78 for a new chain (not kidding).

I do want to order something today if possible so I can hurry up and get this service done.

Rayme: Your log says that the 16T was too tight so you reverted to a 15T... I'm guessing that it was so tight that adjustments weren't enough. Would less teeth in the rear change that? Of course, a few down in the rear and it's be like having a 17T front (putt putt putt). It would, assumedly, be a smaller diameter sprocket. Think it's possible to be too loose if I go with the 15/42? 43 looks a little harder to get and 44 doesn't sound like it would be noticible.

[Sailariel]

Jet, Dennis Kirk is reasonably priced and has everything you need. Their service is superb

[cnichols79us]

I changed out to a 15T front (left rear stock) about a year and a half ago. I think the one tooth difference was a good one for me. I was doing a lot more freeway riding and the 15T basically dropped my RPM by about 1,000 at cruising speeds, but NEVER made me feel like I was lacking for power anywhere else. Glad I did it. MPG went from 54 to usually closer to 57 too!

[CZroe]

Originally Posted by Sailariel

Jet, Dennis Kirk is reasonably priced and has everything you need. Their service is superb

Actually, I was already on their website and had sorted all their product for compatibility with our bike. I browsed through all 111 compatible products and they had "Sunstar" brand ones: 1 front sprocket and 1 rear sprocket, only 14/45. I didn't see a chain either. I guess I'm going to have to pick a brand and search for model numbers.

JT Sprockets, it is then. [Err... maybe not. They don't have 43T.]

[Sailariel]

Jet, CNichols79US has answered your question. Were I in your position--and I was--my approach would be as follows: Get the 15T sprocket (same same as for all the pre-gens) and get a new chain. Our bikes take a 106 link 520 O Ring chain. Reading the Kawa Shop Manual, their version of changing a chain is, in my view, pole vaulting over mouse turds. I nvested in a chain breaker tool/rivetor Break the old chain, attach the new chain, pull it through, de-attach the old chain and pitch it, and then re-rivet the new chain. All this pulling the swing arm etc. to me is a lot of wasted work--unless, of course you want to re-bush the swing arm, re-grease, or whatever. Hold off on the rear sprocket until you have tried just changing the front. Give it a chance--one ride is not enough. If after you have run that setup for a while, and you are still not happy, then get a one tooth lower rear sprocket--about $75US. For swapping out the rear sprocket, you have a superb DIY on this forum. Swapping the rear sprocket is a lot easier than the front. The same DIY tells you how to do the front sprocket. We are indeed fortunate to have these great DIYs published on this forum by some real talented wrenches.

[CZroe]

Originally Posted by Sailariel

Jet, CNichols79US has answered your question. Were I in your position--and I was--my approach would be as follows: Get the 15T sprocket (same same as for all the pre-gens) and get a new chain. Our bikes take a 106 link 520 O Ring chain. Reading the Kawa Shop Manual, their version of changing a chain is, in my view, pole vaulting over mouse turds. I nvested in a chain breaker tool/rivetor Break the old chain, attach the new chain, pull it through, de-attach the old chain and pitch it, and then re-rivet the new chain. All this pulling the swing arm etc. to me is a lot of wasted work--unless, of course you want to re-bush the swing arm, re-grease, or whatever. Hold off on the rear sprocket until you have tried just changing the front. Give it a chance--one ride is not enough. If after you have run that setup for a while, and you are still not happy, then get a one tooth lower rear sprocket--about $75US. For swapping out the rear sprocket, you have a superb DIY on this forum. Swapping the rear sprocket is a lot easier than the front. The same DIY tells you how to do the front sprocket. We are indeed fortunate to have these great DIYs published on this forum by some real talented wrenches.

Thanks, but I do not have the tools to do it (or the space... I share parking space at my apartment with a car!).

Basically, I'm at my 12K mile service anyway, the bike already needed service for running rough (even broke down in the rain), I'm getting new rims mounted thanks to the city's negligence, I may even be getting a fork oil job, and people both here and elsewhere have advised to change sprockets together with the chain so that they wear together. The timing couldn't be more perfect for having the dealer do it, I just need to source it myself... that $78 for a chain (assumedly OEM) was NOT including labor!

Even if I go up a tooth in the front and leave it at that, it is still time for a new rear sprocket, so regardless of the tooth count I ultimately decide on, I still need to buy a new sprocket. That's why I kinda need to make the decision now, while I'm buying the sprocket, rather than later. Also, if you recall from the DIY tire change thread, my friendly "helpful" coworker ruined one of my hex bolts by using Standard/English instead of my provided Metric keys, so I wouldn't be able to do it myself should I decide to later.

It is good advice generally, it's just that I have overwhelming circumstances pushing me to do this now. Oh, and, FWIW, I've seen it mentioned that the pregen CS sprockets need a spacer/shim to align properly, though many seem to have done it without (chain wear concerns me). I figure that I can leave that up to the dealer too.

I KNOW I want the 15T front sprocket. As for the rear, I really want something that I can call an upgrade to justify buying one, so I want to go down at least a tooth or two. My concern is that 1 less tooth in the rear isn't even noticable... it takes about 3 off the rear to equate to 1 added to the front. I would settle for two off the rear (43) but it appears that this is an uncommon rear sprocket and JT doesn't even make one. Places seem to stock 41, 42, 44, and 45. Makes me wonder if I should stay at 14 in the front (with a new 14T of course) and just go down to 42 in the rear.

Thanks for all your help and input.

[min nin]

I got a 43 rear from dennis kirk. I dont remember the brand, but I found it on line.
My pre gen 2006 gets 69 to 72 mpg, usually with 2 of us on it.
I dont go on interstates, so most riding is under 55 MPH.

The power is fine for me because I dont expect, or ask the bike to be more than a 250.

[CZroe]

Does a EX250F rear sprocket fit a EX250J rear?

[CZroe]

Originally Posted by CZroe

Does a EX250F rear sprocket fit a EX250J rear?

Bump.

I don't see anything about how to determine fitment. What do you people do when a retailer's model-specific filtering doesn't work?

[camaroz1985]

I'm pretty sure it does. I think that's what I bought. I have been running 15/41 for about 2K miles, and think it is just fine. You might have to down shift here or there, but nothing to worry about in my opinion. I saw a 3-4 MPG improvement overall, and 4-5 MPG on mainly constant throttle riding (highways, or long higher speed back roads).

I ordered both sprockets from bike bandit. They are JT brand 6054463-001 front, and 5291205-001 rear.

Edit: Just checked JT Sprockets website and the rears are the same.

[CZroe]

Originally Posted by camaroz1985

I'm pretty sure it does. I think that's what I bought. I have been running 15/41 for about 2K miles, and think it is just fine. You might have to down shift here or there, but nothing to worry about in my opinion. I saw a 3-4 MPG improvement overall, and 4-5 MPG on mainly constant throttle riding (highways, or long higher speed back roads).

I ordered both sprockets from bike bandit. They are JT brand 6054463-001 front, and 5291205-001 rear.

Edit: Just checked JT Sprockets website and the rears are the same.

Yeah, I pulled up the rear on DennisKirk by the part number found on JT's website (JTR48645) and, sure enough, they only list up through 2007 (EX250F), even though JT's own site says that they also fit 2008+ (EX250J).

OTOH, when I tried to do the same thing for the front sprocket (JTF153914), DennisKirk had no search results. When I found it the hard way by pretending I had an EX250F and sifting through all parts, it has a completely different part number (JTF51614).

ARGH! This is unbelievably frustrating. I'm not going to blindly order a completely different part even if we know that pre-gen CS sprockets fit the cur-gen (due to the uncertainty introduced by the shim/spacer requirement).

EDIT: Well, it looks like JT Sprocket's distributor (partner?), BikeAlert, is local to my brother. If they didn't close 15 minutes ago I might have been able to arrange for him to pick one up and mail it to me ASAP. It looks like I'm just going to have to put off the service until next week (my next window of opportunity). Ah well. It's best that I get the right part I suppose. I wonder how much they will charge though.

I want to know what they meant by this on ninja250.org though:
"Remove 4 links from the stock chain for 15/38. 106 would become 102."

Are they saying that you CAN, SHOULD, or just COULD? Would I have to remove any for 15/42? I mean, it's more than halfway there to 15/38 so, without understanding why or why this is the first I've heard of it, it seems to imply that I should remove at least two links.

[Ramen]

I just today received my JT Sprockets 15T (JTF516.15) front sprocket for my 2008 Ninjette. According to the JT Sprockets website, the difference in thickness between the old and new model sprokets is .5mm.

Old gen front sprocket:
http://www.jtsprockets.com/52.0.html...el_uid=4912&p=

New gen front sprocket:
http://www.jtsprockets.com/52.0.html...el_uid=4913&p=

According to this guy, he was able to use this sprocket with shims:
http://www.kawiforums.com/1453183-post102.html

Originally Posted by SPNinja

Just got done changing both sprockets. I used JT sprockets which are the same that Kawasaki uses. I changed the front to a 15 tooth (JTF 516.15) & 44 tooth rear (JTR 486.44). This was a great change, It still pulls good in the lower end but has a nice top end. You will need to space out the front sprocket to keep it inline with the rear. I used 12 (0.01mm) shims to make up a total of 1.2mm. These can be purchased fron McMaster Carr (part # 98055A251). They come in a package of 25 for about $ 7.00 + shipping. There web site is mcmaster.com
-----------------------------
2008 250R Ninja Black, Two Brothers Pipe, Compettion Werkes

I wonder if shimming is really necessary. Unless someone tells me it's going to send metal flying, I'm not going to bother.

[Ramen]

Upon further research, the board owner on another forum was able to put in a JT Sprockets 16T front sprocket (JTF516.16) without any modification to the sprocking housing or using shims. He evens bumps the thread after a year without complaint.

http://www.ninja250forum.com/index.p...6&topic=738.15

I think I'll be fine when I change it out in the next couple of weeks.

[CZroe]

Hmm... well, I contacted the eBayer that sells the chain and sprocket sets for the pre-gen. He says that he can do the whole set, two sprockets and a chain with the teeth/gearing I choose for $80; $83 w/ a colored chain. Sounds like a deal, but I'm willing to bet that it's a pre-gen sprocket that will need a shim. AFAIK, they all are except for that one JT sprocket made out of unobtanium.

I hear some people saying to go with that new J-specific sprocket from JT for long distance / high mileage road use and implying that the shims are only good enough if you will be changing sprockets often. I'm going to return his emails to see what he has and can do (I may have my brother pick up the JT sprocket from their distributor in Lithia Springs, GA).

Originally Posted by Ramen

Upon further research, the board owner on another forum was able to put in a JT Sprockets 16T front sprocket (JTF516.16) without any modification to the sprocking housing or using shims. He evens bumps the thread after a year without complaint.

http://www.ninja250forum.com/index.p...6&topic=738.15

I think I'll be fine when I change it out in the next couple of weeks.

Makes me wonder even further what Rayme meant by "too tight."

I know that people have been throwing on the same front sprockets that the pre-gen used all along, but this is what has me the most concerned (from the link above):

The new front sprocket is not a "floater".

Collar/shoulder thickness, spline depth, and attatchment method are all different. There is no way to make them interchangable.

If I can get the new JT sprocket, I will. I imagine that a misaligned front sprocket will wear the chain out faster than I am comfortable with.

[camaroz1985]

I didn't remove any links from the chain, and still have plenty of adjustment left.

[Ramen]

Originally Posted by CZroe

AFAIK, they all are except for that one JT sprocket made out of unobtanium.

LOL tell me about it. Being helpful that I am, I tried googling for it without success. Finally, I found a link where the JTF1539.15 front sprocket for the newgen is available:

http://www.amazon.com/JT-SPROCKETS-S...8153270&sr=8-2

I would order this one if I hadn't already gotten the JTF516.

[Rayme]

Originally Posted by CZroe

Strangely, CheapCycleParts.com doesn't have the front CS sprocket. Hmm.... and they only have a gold chain. I kinda want the get rid of anything that isn't black or blue (exactly why I want to black-out the exhaust), so I'm not too sure on that, though the price is right[unfortunately, the product isn't; it's just a link ]... dealers are INSANE! They quoted me $78 for a new chain (not kidding).

I do want to order something today if possible so I can hurry up and get this service done.

Rayme: Your log says that the 16T was too tight so you reverted to a 15T... I'm guessing that it was so tight that adjustments weren't enough. Would less teeth in the rear change that? Of course, a few down in the rear and it's be like having a 17T front (putt putt putt). It would, assumedly, be a smaller diameter sprocket. Think it's possible to be too loose if I go with the 15/42? 43 looks a little harder to get and 44 doesn't sound like it would be noticible.

I'm pretty sure a smaller rear sprocket would have made the chain tension within specs, stock chain was way too tight. I changed my sprocket very early in the bike's life so I didn't bother getting a new chain.

[almost40]

Stock up front 41 in the rear gives the best 1/4 mile times for me on my modded bike.(Im short and skinny) I run either the 41 or a 43 at the track depending on track configuration. Both will give you a FEW more mpg.

[CZroe]

I called the closest dealers with Parts-Unlimited catalogs but I wasn't getting my calls returned, or even answered for that matter. I was calling during business hours. So, I called JT Sprockets/BikeAlert again regarding the JTF 1539.15 sprocket. They said that they do not sell directly (I already knew this) and that my brother, who is local, couldn't pick one up because they aren't set up for paying GA sales taxes and such (being a wholesaler). They DID say that Parts-Unlimited is the only one selling it in the US. They also said that Parts-Unlimited does sell directly, which Parts-Unlimited denied when I called their 1-800 number (provided by BikeAlert). Parts-Unlimited just told me to get in touch with another dealer if I'm not getting calls back. Another nearby Parts-Unlimited-affiliated dealer told me that he's not finding a 1539 part, only 1538 for a ZX-series bike... the system keeps kicking him back to the 516 part like everyone else. He's going to check a few things and give me a call back shortly (hopefully), but I think I'm just going to have to beg JT/BikeAlert to make an exception and sell me one.

Originally Posted by Ramen

LOL tell me about it. Being helpful that I am, I tried googling for it without success. Finally, I found a link where the JTF1539.15 front sprocket for the newgen is available:

http://www.amazon.com/JT-SPROCKETS-S...8153270&sr=8-2

I would order this one if I hadn't already gotten the JTF516.

So it is available! It looks like it's about 50% more expensive than your typical $15 516 and shipping adds another 50%. The front sprocket will cost almost as much as a rear!

[camaroz1985]

They can't sell directly. I worked for a company that made safety parts for Corvettes/Porsches, and people would call all the time. The only thing we could do was direct you to a distributor.

[CZroe]

I finally got a call back from CycleSector (local guys). They had it for $18 and the rear for $27. Sounds like a deal! They said that a 1539 sprocket would be about $5 more to have it shipped directly to you, so if anyone else is looking, there you go.

I'm getting the chain from that guy on eBay who sells sets chain and sprocket sets for the classic 250R (Blue 520 for $45 + shipping).

All in all, it looks like it's going to cost me almost exactly $100. Not bad, considering the $91 shipped price the guy offered for the older front sprocket, rear, and blue chain (would still need spacers). It's worth it because it feels good to get the right part and know what I'm getting (never even mentioned a brand for the set).

Anyway, I settled on JFT 1539.15/JTR 486.41 and an unknown blue 520 chain. I'll let you guys know how it works out!

Question: Is there any quick way to tell if they get me the right part without breaking out the micrometer and measuring?