Lengthening a DT-1 Swingarm

[gt96]

Quote from the article:
"A fishtailing problem that we thought was caused by the combination of tire/power band, can be easily solved by extending the trailing arm one inch on a diagonal cut. Refer to the photo for details."

[Iain Cameron]

this is the Freaky s/arm in the Vandy framed , Iain built , Firko and many site members input DT1 pre 70 Yamaha

[albrid-3]

I like it, I have the engine, but know frame

[Iain Cameron]

dave the frame is chopped and lowered by 45mm  by Vandy  . Iain

[OverTheHill]

Wrote a long winded story & sent it to [dunno where!!] so start again.
Not long after the first DT1 arrived at the shop [december "68] something turned up from USA on modifying the square arm which was add an inch & step it 'up' an inch [to rake the front out more] Think there idea was to give it more stability for desert racing. So i did this to mine & the boss's  bike. Also we altered the forks [steel slider first model] as per instructions which meant welding up damper holes & drilling smaller ones. Recall that after that we had to run less oil [think 190mls as opposed to 2something] or couldn't get full travel--doesn't make much sense now but anyway. Also [wish i knew where it got to] was an air cleaner box to make [not by me], had a large 'still air area' between filter & carb & used a car type paper element [which was useless in dust but we didn't know any better--till the Filtron green filter came out]. Mod to arm was done at the axle plate, sort of a Z shape plate, [not a Z but straight down & 1 inch wide then contoured top & bottom so it looked right. These days i'd just go back an inch without stepping it up!!. Might start another DT1 story [thinking]. Cheers Morley.

[Iain Cameron]

The mods you mentioned where in Dirt Bike in 73 the story ran over 6 issues  . the z plate was used to get the s/arm in a parallel plane to the ground  then they used Girling shocks . Iain

[OverTheHill]

"73's a bit late to be thinking of modifying the square arm, [broke mine more than once by then haha] did ours in probably 69/70,maybe "71, might be wrong, december "68 on ownership papers but damn it i scrapped the frame many years ago, so bike as it is--is a bit like an axe with a new head & new handle!! & numbers don't relate. Just sulking looking at your YZb photo, remember getting a couple of A model redundant stock bikes to sell where i worked, think sold for $800 or something after the B model then MX models came out. If only we could turn the clock back. Morley.