Honda Foreman 500 to 450 Swingarm Swap/Extension

[01SSRedA4]

I never intended on doing a swingarm swap on a bike who only had 500 miles on it. But, plans change. Here's the bike the day I brought it home:


I took it to a nasty ditch around the corner from the house. It let me down miserably.




I then added a Highlifter Signature Series 2 inch bracket lift.



And EPI clutch kit:



Then, I added 28 inch tires.




Then went and played:

[01SSRedA4]

Within about 50 miles, I was getting a bad popping coming from the swingarm area upon initial drivetrain loading. After reading up I realized the tires, clutch kit, and lift were probably all causing a ton of strain on the u joint. So after some reading I decided a 450 swingarm swap was what i needed. Plus the 28s were rubbing the plastic, and one day I'd like to have 30s on the bike so this would give me some additional clearance later. So I ordered parts based on what I read online. I bought a 450 Swingarm (used off ebay $50, part# 52100-HN0-670), 450 driveshaft ($50 new OEM Honda), 450 foot brake cable ($15 new OEM Honda), All Ballz SwingArm bearing kit (Part# 28-1056 02-04 tapered style bearings) and I bought a Moose Racing U joint for extra strength (part# 1205-0201). Here's the goods:







Close up comparison, Moose on top, OEM Honda 500 on the bottom: But, let's be clear here, Moose does not claim this joint is good for any greater working angle then a stock joint, it just "should" be stronger.



Let's examine these joints a little closer. Moose overall width dimension: 2.112

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[01SSRedA4]

Stock Honda piece is 2.021


Bearing cap O.D. on the Moose unit: 0.746



Bearing cap on the OEM unit: 0.667.



500 swingarm on the left, 450 arm on the right. I did a quick sand blast and repaint to it as some of the powdercoating has some rust.



500 DS up top and the 450 below.



500 swingarm 9.75 inches



450 swingarm 12.25, so exactly 2.5 inches longer



Honda 500 DS 6.25 long, 450 DS is 8.75, so about 2.5 inches longer here also...meaning drive clearances should stay the same.

[01SSRedA4]

Back of the 500:



The swingarm must be cut and re-welded to do this swap correctly IMO. I snapped a pic of the cuts I made. The first bend with be the bring the passenger side of the arm closer to the centerline of the bike and the cut towards the bolt holes will be to straighten the arm back up so it will align with your bolt holes on your axle tubes.



Installation is the reverse of removal. And, a highlifter 2 inch lift will still work and put you back to basically the original height but with a much more favorable u joint working angle. I made no changes to their lift EXCEPT remaking the outer brackets because one was found to be broken (after 100 miles). I will be contacting them about this failure as it in unacceptable in my opinion.



I did originally file the OEM plastics some because the 28s were rubbing slightly, now, 30s will fit with room to spare:






Looks like your back is gonna get slightly dirtier.



Bad news is the foot brake cable for the 450 is exactly the same length as the 500 meaning it did not fit. :dry: The hand brake cable had no trouble reaching. Questions, comments........

[01SSRedA4]

Fast forward 6 months and 150 miles: Wanted to update this thread. Don't buy the garbage Moose u joint. Here's why: and I've only put about 150 miles on it.

[Dave_D]

Very cool read
That sucks about the ujoint hopefully it dident take anything else out when it went

Dave

[01SSRedA4]

Output shaft and rear engine cover is cracked.

[Dave_D]

Originally Posted by 01SSRedA4

Output shaft and rear engine cover is cracked.

Damn
Still runnable or you going to need to replace ?

Very nice looking quad btw

Dave

[01SSRedA4]

Thanks, output shaft splines are screwed and rear cover is cracked. Better to just replace then try to patch it back together.

[Weldangrind]

I wondered if that Moose joint would last. Despite the Honda joint being smaller, I bet the materials are superior.

Thanks for an awesome write-up!

[SpudRider]

I'm sorry to hear about the U-joint failure. However, thanks for documenting your work with the superb photographs and excellent writing.

[01SSRedA4]

Originally Posted by Weldangrind

I wondered if that Moose joint would last. Despite the Honda joint being smaller, I bet the materials are superior.

Thanks for an awesome write-up!

I agree, and I've ordered a new Honda joint. They aren't impossible to break but I'm gonna trust it more.