I still think that small sprocket will add too much stress on the chain and amplify the chain problems these wheelers have. You'll have the same force on the chain over a smaller area and since stress= Pressure / area, a decrease in area will result in a higher stress.

 

<div class="FTQUOTE"><begin quote>Originally posted by: JustRandy

<div class="FTQUOTE"><begin quote>Originally posted by: UGLY88



I am not sure the cost to go with custom sprockets is worth the little gain? But if you have been through every other part of the machi9ne for power then you know how it goes with power sports, it si the last 1/2-1 horse power that costs the most! </end quote></div>



Yeah, ain't that the truth!



Bot not too bad this time.... My front 11T was 8 bucks I think from rockymountain. The 37T rear I found on ebay. I think it was $30 with shipping? Something like that. So, about the cost of a KN filter.



There's a bigger difference in power than you'd think. Something about that 11T that really puts the power to the ground. Its about like the difference you might notice with temperature or altitude differences. You know how somedays it seems your quad runs better than others??? Its kinda like that.



I've tried 14/41, 13/39, 13/41, 12/39, 12/41, and 11/37. 11/37 is a bit low, but its still a hair taller than the stock 12/41. I wish I could find a 36T for cheap.</end quote></div>

DK has a good sprocket selection, not sure if they have the size you want though.

http://www.denniskirk.com/jsp/...re=Main&catId=112&np=0

 

<div class="FTQUOTE"><begin quote>Originally posted by: atvman29

Ok, so according to my calculations, the weight saved in just the chain would be a tick under 2 ounces (.12144 lb). It would be a mere 2.5" of chain saved, so if its 3lb per 100 link, and the pitch on 520 chain is 5/8, 3/(5/8*100)=weight per inch then times that by 2.53 which is the difference in circumferences/2 (since you only use half the sprockets) for 13+39 and 11+33.</end quote></div>

Its close to half:

 

well if we're already talking only 2 ounces, that's going to be a pretty minimal change.

 

<div class="FTQUOTE"><begin quote>Originally posted by: atvman29

I still think that small sprocket will add too much stress on the chain and amplify the chain problems these wheelers have. You'll have the same force on the chain over a smaller area and since stress= Pressure / area, a decrease in area will result in a higher stress.</end quote></div>

Why does the engine care what stress the chain is feeling? 520 is used on bigass street bikes, so a little 230 isn't going to worry the chain.

 

Well don't these wheelers have a tendency to snap chains? I know the engine couldn't care less, I'm just suggesting that it might be an unwanted addition of stress on the chain for the minimal benefit it would provide.

 

Your next post is #3000 Randy, make it a good one!

 

Hey guys, if anyone is interested, there's a brand new swing-arm on ebay.

http://cgi.ebay.com/ebaymotors...ameZWDVW#ht_2268wt_910

 

i'm all for saving weight but shaving a couple ounces vs running a higher risk of chain failure isn't worth it to me. there's a decent selection of sprockets to get just about any final drive ratio you might want. i think you're better off trying to dial in the right ratio for your motor/riding style. i'm running a 3:1 and i still don't bother w 1st gear. now, if i went with a 37t r sprocket, that would bump it up to 2.84:1 and prolly make 1st gear a little more useable and i might save an oz. or 2 by just using the 37t. the area you really want to lose weight is on the unsprung mass. re-do your rear caliper support and you can save a oz. or 2 there. rims are a weight issue too but i'm still gonna run .190's for peace of mind.

 

<div class="FTQUOTE"><begin quote>Originally posted by: atvman29

Your next post is #3000 Randy, make it a good one!</end quote></div>

Ok, a good one it will be!

I did this last fall, so I had to go thru and try to understand everything again. I think I have the bugs out.



Check it out. I completely forgot what acceleration I chose, but it seems like I assumed the quad could rev-out first gear in a second or so and the wheel speed would be somewhere around 20mph. Whatever it was, I divided the speed by .5 to get the acceleration. I remember putting a lot of thought into acceleration and got a lot of opinions online. If you rev up to 9000 rpm and dump the clutch in 1st gear, I don't think it would take a full second for the rear wheels to reach full speed.

My sprockets are 22 inches apart. And instead of calculating diameters from chain specs, I measured the sprockets I had and extrapolated for the sprockets I didn't have. I think everything is based off the 12 tooth sprocket. The 3000rpm comes from a 9000rpm engine speed geared down to first gear gearing. First gear is about 3:1.

A few thing we can immediately see (even if the numbers aren't exactly right) is that the chain is shorter on the smaller sprocket set and the acceleration and velocity is less. So, not only is the weight less, but you'd need to accelerate it less to achieve the same wheel speed. Neat huh. [img]i/expressions/face-icon-small-smile.gif[/img]