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Will a YZ 80 swingarm work?

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My friend has a 1982-88 YZ 80. Will the swingarm from that subsitute the BBR swingarm? I dont want to spend $300 on a swingarm. I am not gonna use the forks from that bike because they wont fit (I know). But will the swingarm work? :)

Also, anywhere where I can get a works performance shock for cheap? Thanks! :D

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That's some old tech you are working with. I hear PRC may have a "kit" to fit later model YZ80 swingarms. If I get one, my Works shock will be on ebay. I haven't seen anyone sell one once they bought it. It's pretty much worth the $ if yo have an old TTR.

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I dont care... I just want to spend all my hard earned green on something as little as a swingarm. I would rather buy the big bore kit, but I am gonna MX my TT-r, so I need the suspension upgrade. But, will a stock YZ 80 swing arm work instead of a BBR swingarm? And will 1981 KX 80 forks and triple clamps work? :)

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That's some old tech you are working with. I hear PRC may have a "kit" to fit later model YZ80 swingarms. If I get one, my Works shock will be on ebay. I haven't seen anyone sell one once they bought it. It's pretty much worth the $ if yo have an old TTR.

yes,prc does have a kit for later model yz80/85 swingarm and shocks

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So this "kit" will let you addapt a YZ80/85 swingarm & shock to the TTR frame? I havent saw this & dont remember seeing it on theyre site but if it is available then i'll have one lol

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Brian, from PRC, sent me the following email this morning:

"As far as swapping the YZ suspension to the TTR frame.. It does require a bit of fabricating. You'll have to run the GYTR big wheel swingarm to keep things in proportion. The swingarm itself if a direct bolt on. However for proper ride height you have to modify the linkage mount on the frame. You can bolt the linkage to the existing mount though you'll have to run the forks up in the clamps slightly less than one inch. You also need to relocate the top shock mount position. Easily accomplished by drilling the proper sized hole through the frame where the subframe is welded to the back bone. I've found that each frame is slightly different so it's best to assemble all of the bits first prior to drilling. From there, it's a matter of fabricating mounts for the rear master cylinder as well as a brake pedal.

I found two problems with this type of conversion. For one, it's impossible to get the shock angle absolutely perfect as the frame isn't designed for the YZ shock. What I've had to do as a result is run the shock as soft as possible while valving the fork as hard as I could. Secondly, since you'll have suspension that actually works, it's much easier to override the bike. In my case, I snapped a TTR frame!"

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The "how tos" for this have been on a lot of Japanese web sites since mid 2001. The Japanese got the TTR locally about 8 months ahead of USA from memory.

I would be very reluctant to put a full YZ rear in a TTR.

A long time ago I emailed one of the guys in Japan and he said that the upper shock mount must be heavily braced. Originaly he used large thick washers to spread the load but it didnt last. He also extended to the rear shock mount "box" so the shock angle is right and the backbomne cracked. That info duglasfur has is very accurate on the need to line everything up to get it to work. Revalving the shock may help slow cracking or breakage.

The YZ linkage should be used also and spacers made to fit it to the frame. The cost of this conversion is very high for USA guys as the longer big wheel swing arm is expensive GYT part and you need spokes, rim and longer brake hose. Japan, Europe and Australia get big wheels so its cheaper BUT by the time you have gone this far its probably easier and cheaper to get in the USA a grey import big wheel YZ80/85 and put the TTR motor in that. Somebody who imports second hand bikes out of Japan should be able to get one. I know of one big wheel conversion down here and it appears to be lasting well.

I have yet to actually break the frame. A few cracks have appeared and SX has shown up a problem that proves the frame flexes big time along the backbone. The head mount on the top of the head has cracked off bits of aluminum!

Frame breakage is generally a problem with the suspension bottoming harshly. I had a bit of a problem with the CRF100 that was virtually solved by having the shock valved in a way that the bottoming was limited. TTR has been done the same.

Our home track has a 60ft table top that pounds anything. The SX training track we use has 40ft doubles (TTR cant clear the jump as a triple) that really tests the bike.

Nearly 2 1/2 years of destruction testing........... I now have a BBR bike.

Johny Rotten has a TTR with the YZ setup in front and rear. Hes a bit hard to catch on here but his stable of bikes are very interesting!

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