Post by sportsracer on Jun 3, 2013 3:54:17 GMT
We've just held our annual Braidwood Billy Cart Derby and the locals didn't even make it to the open finals. That makes 2 years in a row we've been beaten by out-of-towners. We’re only a small town of 1100 people so to regain local pride I want to build something that kicks a$$ at next year’s event.
Top speed this year was 47 kph and my cart (a converted Jason recliner lounge chair) did 37 kph so I have a long way to go but at least I was comfortable.
The winning cart for the 2nd year running is called Whistler and it has a slim windcheater body with 10 inch bicycle wheels. It’s rear tyres were pumped up to 90 psi, fronts were 70 psi.
I want to build a streamliner similar to Whistler, running solid axles front and rear. Wheels will be 10” bicycle but with aftermarket bearings. I’m toying with the idea of bolting the rear wheels to each end of a hollow axle running across the rear of the cart and having the rear axle rotate in its own bearings. This would allow inboard brakes and therefore less wind resistance. It would also allow a thicker (stronger) bolt to hold the wheels on and with only 2 bearings it may be justifiable in buying ceramic bearings. 2 bearings would halve the rolling resistance of the rear end but the added inertia of the axle and bolts would have to be taken into account.
The race is held on a straight bit of road over 450 metres so my cart doesn’t need fancy steering, a solid front axle does fine.
The rules allow any length and width but it cannot exceed 70 kg without driver. It must also have 4 wheels – 2 up front and 2 at the back.
To see the track, look at Gillamatong Lane, Braidwood, New South Wales on Google Earth. We race from the intersection at Sandholes road down to Araluen Road.
If you go to the Braidwood Times site www.braidwoodtimes.com.au/story/1481922/braidwood-community-bank-billy-cart-derby/ you will see some pictures of the event including my racing lounge chair and Whistler.
Any advice on building a Whistler beater will be much appreciated.
Cheers
Paul
Top speed this year was 47 kph and my cart (a converted Jason recliner lounge chair) did 37 kph so I have a long way to go but at least I was comfortable.
The winning cart for the 2nd year running is called Whistler and it has a slim windcheater body with 10 inch bicycle wheels. It’s rear tyres were pumped up to 90 psi, fronts were 70 psi.
I want to build a streamliner similar to Whistler, running solid axles front and rear. Wheels will be 10” bicycle but with aftermarket bearings. I’m toying with the idea of bolting the rear wheels to each end of a hollow axle running across the rear of the cart and having the rear axle rotate in its own bearings. This would allow inboard brakes and therefore less wind resistance. It would also allow a thicker (stronger) bolt to hold the wheels on and with only 2 bearings it may be justifiable in buying ceramic bearings. 2 bearings would halve the rolling resistance of the rear end but the added inertia of the axle and bolts would have to be taken into account.
The race is held on a straight bit of road over 450 metres so my cart doesn’t need fancy steering, a solid front axle does fine.
The rules allow any length and width but it cannot exceed 70 kg without driver. It must also have 4 wheels – 2 up front and 2 at the back.
To see the track, look at Gillamatong Lane, Braidwood, New South Wales on Google Earth. We race from the intersection at Sandholes road down to Araluen Road.
If you go to the Braidwood Times site www.braidwoodtimes.com.au/story/1481922/braidwood-community-bank-billy-cart-derby/ you will see some pictures of the event including my racing lounge chair and Whistler.
Any advice on building a Whistler beater will be much appreciated.
Cheers
Paul