250R Swing Arm Extension Project

[Mr. Sandman]

After way too many years of riding my 250R with nothing but brute strength to keep the front end down on launches while hill shooting the dunes, I finally decided to extend my swing arm. Now I like to wheelie as much as the next guy, but ever since I bolted on my 310 kit a few years ago, the unwanted wheelies had gotten ridiculous. So….after reading up on extended swingers both brand new and stretched stockers, I decided to undertake the project myself. After all, how hard can it really be? I only wanted 4 more inches but didn't want to spend a fortune to get it.

I decided not to cut up my original but shinier than stock swing arm so I bought a thrashed one on ebay. A little measuring here and little measuring there and I broke out the hacksaw. Fifteen minutes later, the swing arm was in two pieces. A little more measuring to see what size steel I needed and I found out that the Japanese in their infinite wisdom used a size of rectangular tubing that cannot be found at my local steel supplier. With an O.D. of 1 3/16” x 2 3/8” there was only one thing I could do to make it work, look clean when finished, and still be plenty strong. So, I bought another swing arm on ebay to use a sacrificial steel supply.

One thing I noticed about most stretched stockers is that they didn't have clean lines due to the weird angles that were left after they were welded up. Because the swing arm gets narrower as it gets longer, the extensions have to be angled out to meet up with the pieces of tube left on the carrier. Now I’m sure there are other ways to go about it, but I decided the easiest way would be to cut the dog bone mount yoke right down the middle. By doing it this way, I was able to spread the tubes apart, insert a 5/16” spacer to make the narrowed end wider, keeping everything straight without any weird angles and not affect the pivot point where it bolts up to the frame. Going this route on anything longer than a 4"
extension would probably not work as the pivot wants to bind on the swing arm bolt. But, a problem with doing it this way is that the dog bone mount tabs are also 5/16” further apart as well, so some new filler tabs were made up to weld into place to get the correct dimensions back. The semi-trick particle board extensions were made up first to make sure everything lines up as planned. Now it's time to start cutting up the sacrificial swinger. More to follow as things progress.

[Gdkarma]

I'm interested in seeing the progress of this project!

One question: how do you line things so that they are nice and parallel when you are done. Are there any adjustments that can be made if the carrier and swingarm mounts aren't parallel? I would imagine it's real important, but maybe not?

Looking forward to more, as I would like to fabricate one myself in the future.

[Mr. Richard]

looks good so far,, i took some 1x2 rec tube and slid it inside the stock tubefor strength,, you can't possibly make it strong enough with out something inside,,,i made mine 6 plus,,, i love it!!!!i had a 4plus it was ok,,, 6 rulz!!!

http://www.3wheeler.org/vb/attachment.php?attachmentid=1955&stc=1&d=1046918993

[Mr. Sandman]

I'm interested in seeing the progress of this project!

One question: how do you line things so that they are nice and parallel when you are done. Are there any adjustments that can be made if the carrier and swingarm mounts aren't parallel? I would imagine it's real important, but maybe not?

Looking forward to more, as I would like to fabricate one myself in the future.

Hopefully I'll have every thing lined up before doing any welding, but with tack welds to start, if something gets out of whack it I can still make adjustments.

looks good so far,, i took some 1x2 rec tube and slid it inside the stock tube for strength,, you can't possibly make it strong enough with out something inside!!!
I plan on doing the same thing.

i made mine 6 plus,,, i love it!!!!i had a 4plus it was ok,,, 6 rulz!!!
Yeah but yours is a 500. Mine is a measly 310 err I mean 297cc 310.

[wild200x]

i have extended 2 200x swingers but never though to cut the "dogbone mnt yoke" and i just shoved my 2x1 steel tube inside with brute force. but first i added a 1x (i think) 3/16 flat bar to the tube to make up the diference as the insidedimention is bigger than 2".
your cutting idea is great but you could releive the stress on the reer by either cutting the tube close to the back as posible and rewelding or heating it carfully. there may be problems either way as with the heat method you would heat one side and all the stress would be releived from that side then when you heated the other side it wouldnt move at all this would be easely remedeide by going slow with the heat and moving back and forth from one side to the other. the problem with a releif cut and reweld it that there would be no way to put a tube on the inside for strength.
just my thoughts but now you got me thinking as i still dont have a swinger for my R project that i am happy with.
one more thing, on my 200x swingers that i did, i put in the 2x1 tube only. i did not go to the trouble of finding metric tube to match up the outside. it looks proffesional and i have had many compliments. it realy dont look bad at all.....

[Troll]

Looks great Sandman! Thanks for the post and keep us updated!!..........:thumbsup:

[firefirefire90]

looks good so far,, i took some 1x2 rec tube and slid it inside the stock tubefor strength,, you can't possibly make it strong enough with out something inside,,,i made mine 6 plus,,, i love it!!!!i had a 4plus it was ok,,, 6 rulz!!!

http://www.3wheeler.org/vb/attachment.php?attachmentid=1955&stc=1&d=1046918993



That is exactly how mine was done and it is a 4+

[zya5.0]

thats cool...i never gave it a thought to make my own extended arm. been shopping for one, 300 dollars plus!!! i finally aquired a water cooled r and the first weekend i rode it the axle bearings went out. since i plan on keeping it, i thought i would rebuild the whole back end. extended swing arm, new axle(plus2?), new hubs, wheels and tires! hey sandman, how do you like that esr 310? how long have you been running it? any reliability issues?

[3wheelergod]

looks good so far,, i took some 1x2 rec tube and slid it inside the stock tubefor strength,, you can't possibly make it strong enough with out something inside,,,i made mine 6 plus,,, i love it!!!!i had a 4plus it was ok,,, 6 rulz!!!

http://www.3wheeler.org/vb/attachment.php?attachmentid=1955&stc=1&d=1046918993

I did the same thing to a cr 250 a year ago or so. We didn't like it. It just looked funny with the different size tube and the angle of the fill in piece's. We built a jig to build chro-moly swingers and have had GREAT luck with them. Made them for r's zook 250's and 500's and 2 shee's. We have built +4's and +6's. I kinda copied a little from my lonestar but not enough that you can tell. I run a +6 on my r and can pull wheelies on command, up hill or down. I am around 279cc, but there are some other goodies in there also. I will not ever use anything but the moly swingers now, cause they are tons lighter and look great. I have only built one for jumping though. Most that we make are for hill shooting so the dont have the extra bracing. Although we have never broke one yet. We also use banshee carriers in the rear. :thumbsup:

[Mr. Sandman]

Three months later and I'm almost finished with this project. For what it's worth, it sat there waiting for work for more hours than I've actually worked on it, I've just been lazy in finishing it. At this point I just need to decide on silver powdercoat or chrome for the finish (what you see in the pics is sand blasted steel).

zya5.0, I've had the 310 for the past 5 years or so, have been very happy with it and have had no problems to speak of.

[firefirefire90]

Wow that looks really clean! Awesome job! Well worth the wait IMO

[Doc86R]

Sano:thumbsup:

[wild200x]

very nice and clean!! my vote is for chrome. oh ya this isnt a vote hu...lol

[Rex Karz]

How is it constructed? Box tubing on the inside, filler plates welded all around, welds ground down?

[Mr. Sandman]

How is it constructed? Box tubing on the inside, filler plates welded all around, welds ground down?

Genuine Honda swing arm tube steel was used for the extensions with 2, 1" x 1" stacked steel tubes welded into the extensions and then welded into the swing arm end and carrier end. Filler plates were used where the dog bone mount was split and where the tabs are to narrow the mount back down to the original width. All welds were ground down where accessible.

As for the finish....Chrome it is! (Per the suggestion/vote of two highly respected board members who shall at this point in time remain nameless).:thumbsup:

[Mr. Sandman]

Another two months later and it's finally done. I just need to put it back on and take it for a spin. Hopefully that spin will be out at Dumont next week with everyone else.

While I was in the fabricating mode I retrofitted some Raptor footpegs to my peg mounts. I would've stuck with genuine Honda parts but I liked the look, size and feel of the Raptor pegs better than the Honda 450R pegs. No biggie though as I still bleed Honda red.

[Red Rider]

So, did you use that chrome spray paint that you were telling me about? :rolleyes: That came out nice!

[Mr. Sandman]

Here's the final product in all it's glory. I'm very pleased with my additional length, girth and overall size...wait a minute. I meant to say the additional length is very helpful to keep the front end down when hill shooting but it still wheelies with ease and a blip of the throttle. The rear shock is definitely softer but not so much that it bottoms easily. I just wish I had done this years ago.

[wild200x]

wow man, that came out realy sharp

[Stealthduner]

Very Nice, looks like an OEM piece other than the chrome

VERY NICE:headbang:

[Dammit!]

Is your chain loose or is it just the picture? I've heard that with an extended swinger the chain is a lot more likely to get thrown so be careful.

[Mr. Richard]

i have been running extended swingers for years and years,,, NEVER threw a chain yet,,,,,,


I've heard that with an extended swinger
been talking to the wrong people,,,,,,,,,,,

[wild200x]

i threw a chain w/an extended swinger. my falt completely though. had it to loose! they stay on if the guy adjusting them aint a dork!:doh:

[dunerash]

I threw a chain ONCE when after a rebuild only had the rear spocket finger tight:doh: :oldman:

[Mr. Sandman]

Is your chain loose or is it just the picture? I've heard that with an extended swinger the chain is a lot more likely to get thrown so be careful.
Not any more so than normal. It tightens right up as soon as I climb on and mount her.:chuckle:

[dovesprings250R]

very, very nice! Who did the chrome?

[Mr. Sandman]

Metal Masters in Chino, CA., (909) 627-4403. I've used them quite a bit for aluminum polishing and chrome and they've always done an outstanding job.

[Insane Rider]

That is noice. It really stands out. Looks like it was made to be there. So when are you gonna start selling them? :)

[200x_Basket]

it looks great. I just wonder how much you have in it? Is it worth it to save a few dollars?

I am guessing you have $250 in it with the chrome and stickers.

I REALLLLY like the pegs :iluvu:

[crackshot]

Well since you are the expert now, you can fab mine up.
I will sent the swingarm. Don't worry about plating, I can do that here!

[Mr. Sandman]

it looks great. I just wonder how much you have in it? Is it worth it to save a few dollars?

I am guessing you have $250 in it with the chrome and stickers.

I REALLLLY like the pegs :iluvu:

Good used swingarm from eBay - $40
Sacrificial swingarm from eBay - $25
Chrome & stickers - $165
End result - priceless (but less than $250 with the pegs)

Worth doing it myself? Yes, I think so as I know it was done right, fits right and I can say I built it.
Going into full production mode - Nope, to time consuming.

[ChrisPerkins250r]

thats bad ass, it looks stock and unmodified. good job