Aermacchi Photo Gallery

Paul Brodie Aermacchi Race Gallery

Photo Courtesy Phil Tanner, tel 360-693-8740. Email tanphi@juno.com

Dean Hubble is my Nemesis, mostly because he’s almost always faster.  We both went to race school at the same time on freshly prepared Vintage race bikes. Dean’s a great mechanic too.  Maybe he’s a better rider because he’s always taking notes, but how many times can you write down your tire pressure in one day?  I guess the thing that impressed me the most was when he dropped three full seconds off his best lap time at Seattle during the first race of the year . . . pretty tough to beat that!  However, he won’t race in the rain.

 

Paul racing Aermacchi

Photo Courtesy Phil Tanner, tel 360-693-8740. Email tanphi@juno.com

End of fourth season, 2002. Paul exiting Turn 4 at Seattle Raceway, on his way to winning three championships in 2002: WMRRA 500 Vintage, SOTP 500 Vintage, and WMRC 500 Vintage. Number of DNF’s = 0. You can clearly see the belly pan from this angle.

 

Paul having a bad day at the races

Here’s Paul having a bad day at the track! This was shot a few years ago at Sears Point Raceway. Paul had just run out of gas with one lap remaining in the race . . . he is not a happy camper! Photographer unknown.

 

Paul having a good day at the races

Photo courtesy Fiona Raven

Here’s Paul having a great day at the track!

Paul's Aermacchi racing bike

Paul's Aermacchi racing bike

 

2001. My race bike, like many others, is the result of development and evolution. The first frame I made was a copy of a 1966 CRTT, extended to fit the longer 350 motor. It handled well, until I started to go faster. Then, the front end would “push”, or move over in the corners, especially if the track wasn’t particularly smooth. I was at the stage where my bike was holding me up, and I began planning my next bike.

My friends in New Zealand have been making Aermacchi frames with 3″ oversize spines, and liked the difference in handling. Their hi-tensile tubing had come from a conveyor belt system and had a wall thickness of about .071″.  This was a little thin for my liking; I wanted 4130 cr-moly with an .095″ wall, couldn’t find it, so settled for .120″ wall . . . heavier but stronger! The tubing was ovalized for the head and cross tube on a 40-ton press. A friend CNC’d the side plates from .5″ high carbon sprocket steel, after I’d given him an AutoCAD drawing.

I designed the frame to put more weight on the front wheel by steepening the head tube to 25 degrees, and moving the engine forward an inch. The swingarm pivot was moved closer to the engine, and lowered slightly. The stock pivot on all Aermacchis is too high, making precise chain adjustment difficult. Also resulting in premature chain wear. The swingarm is the rear part of a 1972? swingarm with the slots narrowed for the 15mm axle, but the front is 1.5″ 4130 with a big brace. It’s 1.9″ longer than stock, but the wheelbase stays the same because the engine and swingarm pivot are both moved forward. The swingarm pivots on needle roller bearings, XR200 parts ordered from Honda.

It’s difficult to find good replacement shocks that are the stock length of 11.8″. I used Konis that measured 12.5″, so the seat rails were moved up to accommodate the increase in length. The rear hub is from a 1974 Honda XL175, and weighs 3.5 pounds less than the stocker. With the hub flanges centered, the sprocket line is perfect, and the rubber cush drive is a nice touch. Ordering sprockets is no problem, either. Braking power is not great, so I rely more on the front brake which is a Honda 450 twin leading shoe, with a modified backing plate and air scoop.

Front forks are 35mm Betors, shortened 65mm and revalved for road racing. The triple clamps have much less offset than the stock forks, which reduces wheelbase and increases trail. I started with 10W fork oil, but went down to 5W, which reduced the front-end chatter in the old frame. The new frame has no undesirable characteristics, at least not at the speed I’m riding it. It turns with a minimum of effort, and the 25-degree head tube is not too steep, as I once feared. There’s no wobble, even when riding over holes in fast corners! I raised the foot pegs .5″ so my feet weren’t touching the ground as often, but as the season progressed and the racing became more aggressive, even these pegs weren’t immune to the asphalt’s abrasion.

The gas tank is very small and made of aluminum, hidden under the fiberglass shell. I can save 3-4 pounds by carrying less fuel, and the weight is more forward too. Dry weight of this bike is 218 pounds. The seat is kevlar/carbon. All parts have been designed with weight consciousness in mind.

 

Paul on his Aermacchi Racer

Photo Courtesy Phil Tanner, tel 360-693-8740. Email tanphi@juno.com.

End of first season, 1999. Paul exiting turn 9 at Portland Raceway. Big changes to the front end: 35mm Betor forks and a Honda 450 front hub with Ferodo brake linings. Engine is still very stock.

 

Paul Brodie's Aermacchi Racing bike

April 1999. This is a shot of my race bike’s first outing at Race School. I’d finished it the night before, and had ridden it up and down the street a couple of times. The engine wasn’t grounded to the frame, and I was getting some really good shocks through the clutch lever!  I had guessed at the jetting and ended up drilling out the main jet with a 1/16″ drill in the lathe, which turned out to be correct. The bike started well and ran well, but was hopelessly undergeared. Despite my precise calculations, I’d used the wrong ratio for the primary drive. Plus, the clutch would slip massively once the power hit five grand. However, I didn’t fall down, and I did graduate from Race School, which all spells Success!

 

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