swingarm

[irish1]

Hi, looking around for a different swingarm for my tr500 forever project. Tried a t20 arm and didn't think it looked right, made bike looked all scrunched? Up to me. Found a kl250 box type swingarm that I managed to fit in but would like something bigger. Lots of newer style aluminium arms on ebay but all to wide. My question, anyone see a problem fitting a dirt bike swingarm and make a spacer that would take up space where engine pivot was.

[titan performance]

I think some of the racing fraternity fit Gt250 swing arms, to shorten the wheel base and gain some turning speed, but as you say, it isn't in proportion, and looks scrunched up ! Back in the day, Dresda produced a purpose made box section swing arm for a number of machines including the 500. I have seen these crop up on Evilbay. I have one on one of my 500's which I bought probably 35 years ago now, convinced that I would instantly acquire perfect handling by adding a rigid swing arm to an elastic frame LOL. Proportions are similar to stock, and it will bolt right on....if you can find one.
Here's a GS one, but they look about the same.
http://www.ebay.co.uk/itm/DRESDA-SWING- ... 5b0b05a6e7" onclick="window.open(this.href);return false;

[cyclocrossfool]

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[titan performance]

I'd say that it's largely down to the seat unit on your race bike. The over-hang is vast.....

[Pete O'Dell]

only the daft fit shorter swing arms in the 500 frame, there is a reason Dave D made the dresda box arms std length, a shorter arm will make it handle worse

[Suzukidave]

I'd say that it's largely down to the seat unit on your race bike. The over-hang is vast.....

I would bet the tail smooths the trailing air flow though

[tz375]

I think it's an anti-draft seat which is designed to spill air behind the bike to break up the draft to avoid that last lap at Daytona problem of getting drafted at the finish line.

[cyclocrossfool]

I think it's an anti-draft seat which is designed to spill air behind the bike to break up the draft to avoid that last lap at Daytona problem of getting drafted at the finish line.

wont be at Daytona this year. ill let you know if it works at another track. you being "tz375" probably have one like it on your Yamaha?

[cyclocrossfool]

only the daft fit shorter swing arms in the 500 frame, there is a reason Dave D made the dresda box arms std length, a shorter arm will make it handle worse

daft ? ive been called worse.

[tz375]

I think it's an anti-draft seat which is designed to spill air behind the bike to break up the draft to avoid that last lap at Daytona problem of getting drafted at the finish line.

wont be at Daytona this year. ill let you know if it works at another track. you being "tz375" probably have one like it on your Yamaha?

I did indeed but sold that bike with a stock seat. People that buy race bikes all seem to want them stock as "collectors". I'm not sure that there isn't a disconnect there

I can't imagine what a short swingarm does for handling as it moves C of G backward relative to stock. Maybe with steeper steering head and less fork offset and maybe a shorter frame.....But I have not raced a T500 with either length swingarm, so it's all just speculation on my part.

[cyclocrossfool]

"I can't imagine what a short swingarm does for handling as it moves C of G backward relative to stock. Maybe with steeper steering head and less fork offset and maybe a shorter frame.....But I have not raced a T500 with either length swingarm, so it's all just speculation on my part." ive only been out for 2 races on it.(njmp thunderbolt and lightning tracks)bike "seemed" to handle alright./it was solid down the straights.... although i didnt race it w/ the stock swingarm. one thing i do know is -im the limiting factor of the bike not a swingarm. im always on the lookout for performance parts/swingarms and such. makes me wonder now. ill put the stock swingarm on for one race weekend and the shorter one another weekend and compare them. then ill know. nothing is "carved in stone" so to say. apologies to irish, wasnt trying to hijack your thread and ill butt out. and T, let me know when that bike gets in from AUS

[Pete O'Dell]

the 500 frame handles as best it can happily with the std length swing arm, if you use a t20 swing arm which is a much weaker arm it will step out coming out of corner and you will struggle keeping the front down, in the wet it will tuck under. if you are capable of pushing the std (ish) frame past its capability's then you need a proper race frame.

box swing arms save a little weight but in all honesty tune the riders mind more than anything else, and give it taper rollers instead of bushes.

[irish1]

Well, glad I stirred some shite up here, always more fun when Pete joins in. So long swinger is better, you could be right, that was a little trick that helped old tr350 yamahas. Back then some used (don vespa) large seats, I didn't need one but today I think it would fit me better. So, I think I will try to fit an early fzr600 swingarm, its long Pete and looks fairly substantial but will need some cutting and welding. Thanks for pictures and input.

[ChrisK]

the 500 frame handles as best it can happily with the std length swing arm, if you use a t20 swing arm which is a much weaker arm it will step out coming out of corner and you will struggle keeping the front down, in the wet it will tuck under. if you are capable of pushing the std (ish) frame past its capability's then you need a proper race frame.

box swing arms save a little weight but in all honesty tune the riders mind more than anything else, and give it taper rollers instead of bushes.

Interesting, I'm building up a box section for mine, so I'll keep this in mind. The C of G argument makes sense though.