Anybody running at 428 chain on their 08+ 250?

[esi7esi7]

Just wondering because someone recommended it on another forum. I did some searching and wasn't able to find anywhere that sells a front 428 for our bikes. The rear sprocket, on the other hand, is easy to find.

[RaceBikeRentals]

I've been told that the chain is actually heavier, due to the increased number of links.

[kkim]

what about running a non O ring 520 chain? makes a big diff on my dirt bikes.

[RaceBikeRentals]

Yep, that's good

[ROADandTRACK]

If you can get a 420 front sprocket that is the best way to go.
We went w/ 428 cuz we couldn't get one soon enough to make the race.

[kkim]

Originally Posted by ROADandTRACK

If you can get a 420 front sprocket that is the best way to go.

they make a 420 chain??? hope you meant 520... this is getting confusing.

[ROADandTRACK]

Nope 420 is lighter and more than strong enough. RS125's use 415.

Ideally a 415 is better, but I've never seen the 415 front for the ninjette.

[esi7esi7]

I'm having no luck finding a 420 or 428 front sprocket.

[ROADandTRACK]

Sprocket Specialists used to make them, but there was a long wait for them.

If you have to use a 520, just do it. But keep trying for the 420.

Or see if Sprocket Specialist will make you a 415 front, that would be pretty cool. PMP makes the rear for sure.

[esi7esi7]

I just called Sprocket Specialists again. They said they don't make any conversions for the EX250. She also said the front sprocket hasn't changed for the newest gen. Hmm.

[esi7esi7]

**Update**

This is interesting...anybody confirm that these are interchangeable with slight modification (washers/spacer)? 2Wheelguy?

08-09 Front Sprocket


88-07 Front Sprocket

[kkim]

http://www.kawiforums.com/ninja-250r...-sprocket.html

[2WheelGuy]

I finally got around to messing with the sprockets on my 2008 bike. The sprockets from the older bikes will fit just fine. A spacer is needed for perfect alignment.

L. 2008 OEM sprocket R. 428 sprocket from my 2nd gen race bike





As you can see in the second photo there is a small 3mm lip on the 2008 sprocket on the left. I 3mm washer behind the sprocket should give perfect alignment.

[2WheelGuy]

I just measured the sprocket retaining plate from the 2nd gen and it measures 2.5mm thick. I'll just slide one of those on to space the sprocket out and call it good.

[nope]

Originally Posted by RaceBikeRentals

I've been told that the chain is actually heavier, due to the increased number of links.

Always wondered how chain sizing convention worked and this comment got me to finally look it up.

------------
Chain size is in inches, the three digit number used to discribe the chain size is based on the "rule of eights". The first digit is for chain pitch. This is the distance between the pins. The second and third digits combine for roller width, with a decimal point inserted between the second and third digits.

For example, a 420 chain has a pitch of 4/8" = 1/2" (12.70mm) and a roller width of 2.0/8" = 1/4" (6.35mm).

A 525 chain (the size my bike uses) has a pitch of 5/8" (15.88mm) and a roller width of 2.5/8" (7.94mm).

A 530 chain has a pitch of 5/8" (15.88mm) and a roller width of 3.0/8" (9.52mm).
------------

Now I'm kinda confused as it's starting to seem that the 428 would be heavier. 4, meaning the links are shorter so there are actually 20% more rollers for the same ninja chain length than the 5 series. 28, meaning the rollers are actually 40% wider than the 520 roller. What the f?

I guess it's important to keep in mind that this width refers to the roller width and doesn't account for link thickness which may vary from the 4 to 5 series. So what's heavier per unit length, the rollers or the links?

Haha sorry guys.

[esi7esi7]

I got a new 428 chain and front/rear sprockets in the garage. I'm going to take them to work tomorrow and find a scale in the lab...

When they are installed, I'll weigh the stock parts and post up the weights.

How bout that?

[nope]

Sounds good!

[2WheelGuy]

Originally Posted by RaceBikeRentals

I've been told that the chain is actually heavier, due to the increased number of links.

I just installed a 428 chain on my bike. I weighed the new and the old for comparison.

The D.I.D. 428NZ chain is 9oz lighter than the OEM chain. That is over half a pound of rotating mass.

The counter shaft sprockets weighs the same.

Replacing the steel rear sprocket with an aluminum one saved 18.5oz, well over a pound. (Similar weight savings should be found with an aluminum rear sprocket in other chain sizes.)

[esi7esi7]

Nice. I got mine installed last night. I will post up some pics soon.

[esi7esi7]

I weighed the sprockets and chains and here is what I came up with.

Switching from the OEM setup on the ‘09 EX250 to a 428NZ Chain, steel front sprocket and aluminum rear sprocket will result in an overall weight savings of 2 lbs.

Chain
520 chain weighs 3 lb 10.2 oz;
428 chain weighs 2 lb 14 oz (12% lighter than OEM).

Front Sprocket
520 front sprocket weighs 5.2 oz;
428 front sprocket weighs 5 oz (4% lighter than OEM).

Rear Sprocket
520 rear sprocket weighs 2 lb;
428 rear sprocket weighs 12 oz (63% lighter than OEM; mainly due to change in material).

1 lb = 16 oz

The chain on my bike was tensioned way too tight and was in need of replacement when I bought it, so I figured it would be a good time to convert. Total cost to me was $150.

[nope]

Awesome. Thanks for posting weights.

[Racer x]

I just went to aluminum sprocket and non O ring chain. That alone cut weight and resistance. I wish I would have thought of this.Maybe later.
Good wright up.

[shiphteey]

Remember that the smaller 428 chain requires more links for the same wheelbase so some of the weight savings is negated by needing more links than the 520.

[ROADandTRACK]

It is still lighter. If it is only 1 oz. then it is worth it. Plus the chain is cheaper. This is for race bikes.

[2WheelGuy]

Originally Posted by shiphteey

Remember that the smaller 428 chain requires more links for the same wheelbase so some of the weight savings is negated by needing more links than the 520.

I don't understand. How is a lighter chain made bad because it has more links?

[shiphteey]

Its not made BAD. What I'm getting at is that if one were to only compare the weight of one link vs the other, sure the smaller one weighs less. I was pointing out that usually with a smaller-link chain one must have MORE links than the original larger one to maintain the same length needed, which does offset some of the inherent weight savings of going smaller. Thats all.

[2WheelGuy]

The weights posted by both Lisa and myself were installed weights not per link weights. The 132 link 428 chain I installed weighted over half a pound less than the 106 link (I think) 520 chain I removed.

More links but still less weight.

[shiphteey]

Originally Posted by 2WheelGuy

The weights posted by both Lisa and myself were installed weights not per link weights. The 132 link 428 chain I installed weighted over half a pound less than the 106 link (I think) 520 chain I removed.

More links but still less weight.

Good to know

[nope]

So for those who have the 428 setup happily working on their new-gen 250's:

From what I gather I get the impression those who want to undergo the 428 chain, you're looking for a pre-gen front and rear (with whatever tooth count), plus like 3 of those spacers mentioned in the kawiforums thread, and whatever 428 chain. My searches and even that drawing comparison posted earlier by esi7esi7 show pre-gens and new-gens both use 520 so I'm confused.

Could you spell out exactly how the chain and front/rear sprockets and spacers were sourced and their interchangeability (like which bikes they swap over from)?

[nope]

Thanks for all your PM's for help on hunting down the 428 parts.

Being stubborn as I am, I did my own searching for how to get a 420 set together for the new-gen ninjettes that race or hit the track. I spoke to several companies and then directly with a machine shop who is the sprocket supplier. I also spoke to a direct DID chain supplier to most moto stores to get the length we'd need since it's slightly longer than the available retail chains. I ended up making some cool discoveries.

I can get a complete 420 setup made to fit the 08-10 ninjette (eliminates spacers) provided I get an order quantity of 5, including my own set. Actually I can get a set just for myself but it'd cost a little more being a one-off. Would any of you be interested?

Front sprocket (cross-drill lightweighted, no need for spacers)
Rear sprocket (hard anodized aluminum)
DID 420 NZ3 Super Non-Oring chain (custom length)
Shipping inside of US

Prelim cost estimate is $200.
($185 with plain alum rear sprocket, $190 with colored rear)

[nope]

Nice link for reference:
http://www.rcramer.com/bikes/ex250/428.shtml

If you take the weight for 100 of the 520NZ (non-oring) links and multiply by 4/5 to get their weight for the same effective length as 100 of the 420NZ (non-ring) links you get, 3.52lbs * 4/5 = 2.816lbs. So with a little more math, for the length needed on the ninja, the 420NZ is 1.41lbs lighter than the 520NZ.

Add like 0.2 lbs for lightened front sprocket, and about 1.25 for an alum rear sprocket, you're at 2.86lbs loss.

I know most people could care less, but hey, good free info!

[Shwig]

Originally Posted by nope

Thanks for all your PM's for help on hunting down the 428 parts.

Being stubborn as I am, I did my own searching for how to get a 420 set together for the new-gen ninjettes that race or hit the track. I spoke to several companies and then directly with a machine shop who is the sprocket supplier. I also spoke to a direct DID chain supplier to most moto stores to get the length we'd need since it's slightly longer than the available retail chains. I ended up making some cool discoveries.

I can get a complete 420 setup made to fit the 08-10 ninjette (eliminates spacers) provided I get an order quantity of 5, including my own set. Actually I can get a set just for myself but it'd cost a little more being a one-off. Would any of you be interested?

Front sprocket (cross-drill lightweighted, no need for spacers)
Rear sprocket (hard anodized aluminum)
DID 420 NZ3 Super Non-Oring chain (custom length)
Shipping inside of US

Prelim cost estimate is $200.
($185 with plain alum rear sprocket, $190 with colored rear)

how would i go about ordering these parts in maybe a month or two?
What color options are there?
Would the bike still be geared the same way, or are there options for the number of teeth?

I know I'm about half a year late, but I'd rather ask then never know.

Thanks in advance

[SPG]

I would also like to know where to source either a 428 or a 420 setup. Any info is appreciated.

[nope]

Yeah, I need to get back on this..

There's no straightforward place to get this setup. I had contacted sprocket machine shops and DID directly to get part costs. I'll see if I can revisit all my leads soon and get it going.

I'd be taking a risk with the cost involved so I probably will only get like 5 sets or so, including one for myself and Rexbo, then just selling the other 3 here at no profit. I really want to share ideas and progress I make on my bike to help encourage competitive 250 riding, but I've been pretty busy though so don't start holding your breath just yet! I really want this too, so don't worry, it won't fall off my to-do list.

[SPG]

I found sources for all of the parts except the 420 front sprocket (in an 18T). If we can get the front sprockets made for a reasonable price I would probably get one and a spare. I wish it was just a matter of taking a 428 sprocket and turning the thickness down on a lathe, but I realized the roller diameter is different as well.

Chain was around $40 (but not custom length), rear 56-58 alloy is $64, so assuming the front sprockets are not crazy expensive, we could be good to go. Also, the savings from 428 to 420 is about $15-20 for the chain and $30 for the rear sprocket, so the 420 with the custom front could actually be cheaper.

Let me know what we need to proceed with the countershaft sprockets.

-Sean

[nope]

Yeah, the front sprockets are a significant cost and they're only even affordable because the vendor was willing to cut some parts on the side for us. Anywhere else, they would definitely be crazy expensive. Also, I found that off the shelf 420 DID chains weren't long enough to fir the ninja (hence the custom length).

[Bueller999]

I am interested in a 428 setup, if anyone gets that going.

[metalseth]

Did this happen? I'm interested in the results, possibly going smaller than 520.

[spooph]

I've heard good things about these: http://sidewindersprockets.com/

Muy pricey though.... But I guess you wouldn't need a replacement.... EVER? I would love a 15/43 setup in 420 from these guys, but I think that's close to $400/set....

I also found this from a long time forgotten post on newninja.com
http://www.denniskirk.com/jsp/produc...200014#fitment

And have been unable to find a 420 sprocket with those input-drive dimensions...

[Nemesis]

Originally Posted by ROADandTRACK

Ideally a 415 is better, but I've never seen the 415 front for the ninjette.

ITW my friend...ITW.