Pic of my DT1

[Wendell Clark]

Hi there,

Firko asked for an image of my DT1 rat and here it is. Goes better than it looks.
I know I'll get ragged for the pipe but it works the best!

[vandy010]

nice pre~75 thing
whats the kickstarter off?
and does it clear the case all the way through its stroke?

[firko]

Cool DT1 Wendell...the pipe's a tad reminiscent of the Harry Taylor pipe on Siege's 'Diamond Lil' but isn't that different to what I ran on my DT1 in its final bit of development. What's it originally intended for?  As politically incorrect as it was, my Pete Reynolds fatty pipe worked a treat and we're actually hoping to use the dimensions to make the downpipe for my new DT1 flat tracker...but I digress however .

Vandy the kicker looks to be a DT2MX item, the same as what I use. You can still buy them NOS on eBay for not a lot of money and they clear everything. What's the engine specs Wendell? I can see a GYT head but can't quite see if it's got a reed cylinder or not. Except for the pipe and front wheel it's a pretty good period bike. Preston Petty's, Hi-Point tank make a great period statement. Assuming it's a piston Port barrel you'd only have to fit an earlier front wheel and the bike'd fit right into our pre '70 class.

[Wendell Clark]

The pipe is off of a 05 YZ250, it greatly improved the midrange. I originally ran the stock GYT cheese grater pipe.
The switch to the modern pipe shaved off a lot of weight cheaply. Head and cylinder are stock DT1mx stuff. The frame
has been lowered 1 1/2 inches. The swing arm is off of a 75 mx250. When you remove all of the triangular shock mount bracing from this you end up with an oval tube YZ type swingarm with no shock mounts. Yep that's a 75mx arm. I rode a stock 71 RT1mx in our pre 72 class for a couple seasons, also have a 74 a model and a 75 b model 250, I would rather ride my modded DT1 over any of my other motorcycles.

[Iain Cameron]

I would never have thought of cutting a yz or mx mono swing arm up , there you go spent weeks trying to get a 74 mx 250 swingarm and had 3 yzc 400 ones sitting under the work bench . nice bike wendell , like Firko and Vandy Im a DT/RT tragic as well

[Davey Crocket]

Thats clever engineering.....pity they aren't chrome moly.....heavy bloody arms....the bonus is you can buy an All Balls swingarm kit for the mono swingarm that gives you the spacers, shims, thrust washers etc.

[firko]

Thats clever engineering.....pity they aren't chrome moly.....heavy bloody arms....the bonus is you can buy an All Balls swingarm kit for the mono swingarm that gives you the spacers, shims, thrust washers etc

I agree...That swingarm is a stroke of genius in that it looks factory enough to pass muster at scrutineering.
At one stage I had an alloy OSSA Phantom swingarm on my DT1, it bolted straight in and was as light as a feather but the trade offs were that it was as weak as piss, full of stress cracks and most of all, ilegal for pre '70.

pity they aren't chrome moly.....heavy bloody arms..

Yeah they might be heavy but have you felt the weight of a 'square' section '68 DT1 swingarm John? They're humungous.

I'm inspired by the number of DT1/RT1 true believers that are coming out of hiding after years of hearing how bad the bikes were from folks who'd never ever knocked the top off one. The more I work on the engines the more I realise how solid a design they are. For a first up effort from a country not noted for their dirt bike expertise, the DT1 engine proved to be a gem even back in '68. From the humble DT1 grew the legendary YZ250A engine and ditto the RT1-YZ360A lineage. And parts are still as cheap as chips...I just bought a NOS single ring RT1MX (GYT) piston and ring for $20+$17 shipping http://www.ebay.com/itm/320818847480?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_500wt_949
and a 1mm over DT1 MX single ring full kit for $28..http://www.ebay.com/itm/120805099531?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_507wt_698
Try and buy CZ, Maico or Husky pistons (or just rings) for those prices.

[Iain Cameron]

Firko there has been a few of us over the years , Nifty #173 is another that comes to mind as a dt/rt tragic . Ive got Fatboy down here in Tas on a DT1 so the more the merrier . still got 4 to build 2x250 2x360 there are heaps of them out there just got to find them all . Iain                                                                                                                                                                                                                                                                        this is the one sold to Fatboy its now a 250
 but this old girl is my fav the one that started it all for me

[Wendell Clark]

Cool Bikes iainyz. Like Firko said, parts availability make for cheap and easy experimentation. So many have been raced and modded over the years, there is a lot of good info on them. I see in your sig that you have a DT2mx. Is it a future
resto or will it be a racer? They are a great bike that I believe is very competitive in pre 75 once the frame mods are done.
The one that I had was fast,it would suprise some who would ride it expecting a slow old motorcycle.

[mainline]

Hi there,

Firko asked for an image of my DT1 rat and here it is. Goes better than it looks.
I know I'll get ragged for the pipe but it works the best!

That bike looks great, the tank absolutely makes it!

mmmm....if Firko stops buying all these DT1 things, there might be one left somewhere for me?

[firko]

Seeing everybody's showing off their old Yamaha's I thought I'd repeat my old RT1 which will soon be ready again after an engine hop up and ignition upgrade.


Or the future project DT2MX I found in California for $200. Now I've had a chance to check it out it turned out to be a great buy. If you look past the shitty tank and seat it's a clean, low mileage bike.

[firko]

I was Googling away this arvo and found this nicely prepped DT1 on the AMS site. I've picked up a couple of ideas----I like his treatment on the sprocket cover/actuator and the aluminium sprayed Bassani but the tank's too plain...it needs the pinstripe or an alloy tank like Wendells, even the smaller AT1 tank would look more at home against the lumpier YZ seat. What's that rear sprocket off? I like the square holes, something a tad different.




The same bloke also owns this nice YZ250A. I like the 'worksy' graphics and his eye for detail.

[bazza]

Firko did you place photos?cant see them

[firko]

Yep....there's six photos....three DT1 and three YZ250. I can see 'em, have they gone missing for anyone else?

[Iain Cameron]

no there all there , so its a dt/rt photo fest don't you just love the old girls