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Greetings - 100cc M/F for 2014

Posted: Thu Nov 10, 2011 8:55 pm
by ChrisACT
Hi everyone,

Just thought I should introduce myself. I'm Chris. I live in Canberra. I used to race Superlites with the Post Classic Racing Association. Had myself a big stack at Oran Park in 2008 and have had a box full of bike bits ever since. I'd love to go racing on tracks again but there are only a few tracks left now and the money and time to race every month is not so available at the moment.

So now I'm looking into running with you guys & gals on the salt. I've set 2014 Speedweek as my goal as I reckon that's how long it'll take me to get a bike put together with the performance to do a decent run.

I've already begun the build. It's certainly an oddball machine but I specialise in the weird.

It's a bitsa. I'm starting with a Yamaha DT175 frame & swingarm. Running a Yamaha DT100 engine, rear wheel & brake (from my old superlite race bike). Fuel tank from a Yamaha DX100. Forks and front brake from a CX500, rear shocks from a CB400 Super Four and the rest is probably going to be custom made.

The original DT175 spent at least 10 years under a friend's shearing shed and was completely covered in sheep poo. To that end, I have named her, "Ewe Little Beauty."

This is where I'm up to so far. She's not much to look at right now but I'm still more than 2 years from being ready to run her.

Image

The forks are sitting high in the trees because that's how I ran it on tracks to get a bit less rake. The lack of corners for this type of racing means I'll run them a lot lower.

I'm planning to run it on Methanol and maybe a bit of nitro thrown in to get us over the line. A fair bit of work there to get the fuel system up to scratch for that.

The current world record for 100cc M/F is a little under 102mph set by Darold Cummings in 2002 at Bonneville. If I can get 30HP out of this engine (which shouldn't be a problem on methanol) I reckon I'll be in the ballpark. The trick, as always, will be making it last the distance at full throttle and at redline.

I've read through the DLRA rules and I'm keen to get it all together and take that trip to Lake Gairdner in 2014.

See you there.

Re: Greetings - 100cc M/F for 2014

Posted: Thu Nov 10, 2011 9:15 pm
by RGV
Hi Chris welcome aboard, good to see another smelly noisy 2 smoker joining our ranks. :D Well thats what mine has been called, and im proud of the smell and noise :lol:

That looks like a good project you have there. As for front brakes, do you have a bin in ya shed?? Good place for them i reckon. Only going to slow ya down, not the idea here.

I have the rear brakes for around the pits and fit the front brakes for our Test & Tune days as we only have around 1 mile including braking area.

Put a fairing on it and dump it down as low as you can seems to be the general thinking.

Did Yamaha make a water cooled version of that motor as heat might be your biggest enemy even on methanol.

See ya on the salt.

Re: Greetings - 100cc M/F for 2014

Posted: Thu Nov 10, 2011 9:33 pm
by ChrisACT
Hey RGV. Thanks for the welcome. HAIL TWO STROKES!! :twisted:

No water cooled 100cc Yamaha motors around to my knowledge. Not sure if one could bore a YZ85cc engine out to 100cc. Maybe but not on my budget.

I'm running in M/F so fairings are not allowed. If I can get the M/F record then maybe the next thing will be to stick a fairing on it and go for an MPS/F record.

The front brake is what I used to run on it in Superlites. Two fingers stoppies with that one, easy. The whole bike only weighs about 80kgs. Same caliper on the old CB1100R race bikes. It's easy to take off if I want to so I'll keep it on for now. Old habits die hard. I know you're right but I just wouldn't feel good about getting on a bike with no front brake. I'm too used to corners coming up fast at the end of the straight. I might change my mind after I've been out there and had a run. Otherwise, I've got two years to get used to the idea in the meantime. Besides, I'll be running the bike somewhere before it ends up on the salt so I'll probably need it.

I've got other plans for this thing too. I'm going to put some data logging on it. Probably something simple (and relatively inexpensive) like a MyChron2 kart computer. That will allow me to log CHT, EGT, RPM, and GPS traces including speed.

I gather I'm required to have a solenoid fuel shutoff which I can activate from a bar mounted switch (and the lanyard kill switch) to run in the fuel class. I'm also wondering about what fuel lines are legal. The manual states that they must be fire resistant. I presume braided lines are the go. Are we allowed to use pushlock braided lines and fittings?

The other question I'm unsure about is helmet standards. Are we using the SNELL standard for bikes or are we allowed to run the Australian AS/NZS1698 standard?

Re: Greetings - 100cc M/F for 2014

Posted: Thu Nov 10, 2011 10:24 pm
by RGV
The last thing you want to do on the salt is grab a hand full of front brake. Its like riding on hard packed sand.

I should have read the class you were running, my mistake.

I use a combined EGT tach, cant remember the brand ill post a link later. It has saved my second engine after a seized my first one on the salt.

The fuel line has to have a solenoid before the fuel tap if its not mounted on the tank. Some bikes have remote taps, no way of turning off the fuel in case of a fire.

Any approved fuel line is allowed for the Gas class as far as i know. Not sure about Fuel class. 7.B.2.5 I think that rule applies to fuel pumps.

No worm drive fuel line clamps, just fuel injection screw and nut types although you can now get FI rated worm drive clamps. After reading the 2012 rules it dosnt mention fuel clamps.

Helmets with Australian AS/NZS1698 standard are fine to run on bikes.

Ill have to have a read of the new rules again i think. Ive read the old ones so many times i might be getting a few rules mixed up so if anyone wants to correct me please feel free to do so.

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 6:44 am
by ChrisACT
Ahh, OK then. I just need to run the fuel tap on the tank and EFI clamps on the fuel line. Excellent. Also good that we can run Aussie helmets. Thanks again, RGV.

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 8:31 am
by gennyshovel
ChrisACT wrote:Ahh, OK then. I just need to run the fuel tap on the tank and EFI clamps on the fuel line. Excellent. Also good that we can run Aussie helmets. Thanks again, RGV.
Welcome Chris, in fuel class, you will need to turn off the fuel supply without removing your hands from the 'bars.
Some folk have made cable operated taps and old style choke levers, I bought a 12V "normally closed" solenoid valve to use in 2012.

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 8:39 am
by ChrisACT
Fair enough. Back to plan A then. :)

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 4:45 pm
by momec3
Welcome aboard Chris.

At least you've got the right name even if you are another "Bloody mad Biker" :lol:

Chris

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 6:34 pm
by ChrisACT
gennyshovel wrote:
ChrisACT wrote:Ahh, OK then. I just need to run the fuel tap on the tank and EFI clamps on the fuel line. Excellent. Also good that we can run Aussie helmets. Thanks again, RGV.
Welcome Chris, in fuel class, you will need to turn off the fuel supply without removing your hands from the 'bars.
Some folk have made cable operated taps and old style choke levers, I bought a 12V "normally closed" solenoid valve to use in 2012.
Does that mean I need a tap AND a solenoid valve? Or can I ommit the tap if I have a normally closed solenoid valve which is operable from the handlebars? In theory it will be shut off unless I supply it with 12VDC.
momec3 wrote:Welcome aboard Chris.

At least you've got the right name even if you are another "Bloody mad Biker" :lol:

Chris
Thanks Chris. I'll do my best to uphold the esteem in which the bikers are held. :wink:

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 9:58 pm
by ChrisACT
Here's another question for those of you that have raced on the salt.

Suspension. Is it really necessary? How smooth is the surface? Anybody running hard tail rear ends? How much suspension travel is usually required?

I read somewhere that it feels really smooth at ludicrous speeds but what about 100mph which about what I'm aiming at?

Re: Greetings - 100cc M/F for 2014

Posted: Fri Nov 11, 2011 11:36 pm
by RGV
I havnt run a bike without it but would imagine it is a unnecessary luxury, the salt is very smooth at any speed up to 118 mph, thats as quick as ive been on it LOL. Next year will be different. :D

Re: Greetings - 100cc M/F for 2014

Posted: Sat Nov 12, 2011 11:29 am
by ChrisACT
I guess it would let me run the bike lower to the ground if I didn't have to allow clearance for suspension travel. Would still run the forks on the front but perhaps spring them harder and shorter.

More to think about ....... :shock:

Re: Greetings - 100cc M/F for 2014

Posted: Mon Nov 14, 2011 8:03 pm
by grumm441
Chris
Front suspension is a must
There was a guy at Bonneville this year who built a bike to try and take back his record from Mal Hewitt
He built the bike without front suspension, rode it once, and put it back in the trailer
Rear suspension is up to you
Have a look at the back of your rule book, at the back there is a motorcycle tech sheet.
Looks a lot like this
http://www.scta-bni.org/pdf/2011%20Insp ... 20back.pdf
Have a look through this
G

Re: Greetings - 100cc M/F for 2014

Posted: Mon Nov 14, 2011 8:28 pm
by ChrisACT
Thanks, Grumm.

I will definitely be sticking with the forks. Just going to lose the rear shocks and replace with solid struts. After having thought more about RGV's comments on the front brake, I'm going to lose that too.

At this rate, the thing will be so light I'll probably have to put ballast on it.

Re: Greetings - 100cc M/F for 2014

Posted: Mon Nov 14, 2011 9:38 pm
by BONES
Hey Chris
That dirt bike frame is going to be real HIGH. The smaller hole you can punch in the air the faster you will go.
The BUD FAB streamliner went 187 with an rs125
Maybe see if you can lengethen the chassis.
When you are setting your riding position try and get your back straight
If you are using a magneto I would go with Tiny's suggestion of the choke lever to turn the fuel off. Less wires on a saltracer the better.
Without a fairing the engine will be covered in salt
Dont worry too much about weight.
My son may be riding an APS/G 100 next year-- yz80 engine
The American record is good to aim for but check our records and it may be open-- DLRA record is a good start
cheers Bones