Very nice Rany! YOu are making me jealous. I can't wait to see the finished product. How much did you extend the swing arm to make the 50" wheel base?

 

Thanks! Lots of hard work there! Can't wait to ride it, but I have this big hole in the middle of the frame.....

I added 4 inches to the swingarm.... How 44.5 + 4 = 50 I'm not sure about, but I just double checked.... Its 50 on the nose. One thing that may explain it is the chain adjustment. I must have had a short chain on when I took the 44.5 measurement. Now I have the carrier all the way back as if I had a long, stretched chain on.

Speaking of chains... I think I have it down to DID's ERT2 or EK's MRDL6. DID's ERS2 looks nice, but I'm not paying $100 for a chain! Anyway, the ERT2 and MRDL6 weigh 2.99lbs and 2.84lbs respectively. That's about as light as it gets in a 520 chain (except for the ERS2 at 2.53lbs). Still not sure I want to pay an extra $30 to save 1/2 a pound either. The EK 520SR weighs 3.23 lbs and costs only around $35-$40.... Instead of $70. Hmmm.... How important is 1/2 a pound????

I'm not 100% certain on the math, but the way I figure it takes .1ft-lbs to accelerate 1lb of chain to 20 mph in 1 second. So, I guess 1/2 a pound is worth .05 ft-lbs to me when I need to go from zero to 20 in 1 second. I think a second is kinda slow though when you think about how much time it takes to break the tires loose and rev out 1st gear. That's damn near instant! We could be talking about .5ft-lbs or more. That's 2.5% of peak engine output. Worth $30 for 2.5% more acceleration???? Maybe I should post this on the physics boards and let them chew on it for a while.

 

Just for reference, i went with a basic none O-ring chain, but I never looked at weights, I just assumed it would be less. Lighter would be better considering the whole less rolling resistance argument.

I am sure there are some factors not being considered in the physics problem that they might shine some light on.

 

I posted it over there.... See if anyone bites. Generally, ATV-specific chains are heavier than regular chains.... And o-rings are the worst of all. They're heavy and have a lot of friction. They say x-ring is better, but still is heavy and has a fair amount of friction. I figure whatever the entire Honda 125cc motocross team races with HAS to be what works.

 

Keep us posted, it will be interesting. Probably over kill, but every little bit helps.

 

Well, just like you can feel the difference in a 12 gauge bird shot vs a slug, small amounts of mass can make a difference. The question is can the chain accelerate anywhere near fast enough to make small amounts of mass important or "feelable".

Anyway, more pics!

Looks like my frame is bent.... You can actually see the right tire lower than left against the backdrop of the garage door. It makes sense these quads have clipped a lot of trees in 20 years!



How does one fix such a problem????

Here's how I did it. Was pretty easy. Actually, I was commenting to a buddy that I'd rather my frame bend than my a-arms. Much easier to fix a frame than to figure out how to press or spread something as small as an a-arm. That's why I've been beefin the arms so much! I know I'm going to hit a tree.... Its just a matter of when, not if, lol.

 

See that big hole I was talking about? Bri.... where ya at????

 

wow randy i guess i really didnt realize how narrow the 230's were granted i never measured but damn....maybe the +5's would be better cuz that would get me to sit right where my buddies 450r sits...hmmm....

How much would you charge if i sent my stock arms out to you (i pay shipping) and you do the work to them? That would get rid of some of the costs you were talking about earlier...The quad is getting torn down this winter so i could send em when i do that and you can do it at your leisure as long as they would be done for spring...hopefully by then id have my axle too....

 

It seems logical to model any quad after the 450's regardless of engine size because that's what works for stability. The key factor is center-of-gravity. The higher you sit off the ground, the wider you need to be to stay on the trail. Funny how the 250 class has about the same seat height as the 450's, but they aren't nearly as wide.

If you draw a triangle that is 30 inches high and 48 inches across you will have drawn an egyptian pyramid exactly... with 51 degree sides. 51 degrees is also the angle that wind blows sand into piles (that's why they chose 51 degrees to build the pyramids.... they'll last longer and not be damaged by wind as much). Neat, but I would have thought you'd want an angle of less than 45 degrees. I guess 51 is good enough.

I don't know.... Let me think about the price a few more days. I'm sure we can work something out. Winter is still a few months off (at least here in GA it is [img]i/expressions/face-icon-small-smile.gif[/img] ).

Are you sure about the axle? I have the stock axle and from the outside of the tires mine measures 46 inches. I just have the douglas rims and a couple of washers behind the rims and behind the hubs. The washers probably add 1/2 inch or something, lol. I like the back to be shorter anyway. I figure if I can miss a tree with the front, I shouldn't have to worry about the back. And the back doesn't matter too much in a turn anyway. Think about it... If you had a 3-wheeler with the one wheel in the back and the two wheels in the front, you could turn pretty well. So, even having a back end that's 10 inches wouldn't hurt too much unless you started to slide around. Widening the back might help a wee little bit, but not worth $300 or more to me. Something to think about until next spring anyway. [img]i/expressions/face-icon-small-happy.gif[/img]

 

is that you trying to sell me stuff? lol i definetly may be interested in the rims but if its just a stock axle with washers why would i buy yours when i can do it myself...im lookin to stay right around 48 a lil less is ok too... how much would you want for the rims if you are tryin to get em outta the backyard...