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A Twin Engine Whizzer at the Bonneville Salt Flats

Double Vision went 59 mph one way and 61 1/2 mph the other way. He is the only one in the class, so it will be a World Record unless someone else shows up. The class is AVG 350. (Altered Vintage Gas).

Date; August 30, 2005

Roger Brophy's "Double Vision" will run at the Bonneville Salt Flats in September

Here is an excert from an e-mail from Kenny Thomas/Roger Brophy

How fast will it go?

The goal became to get the Whizzer logo a speed record but there is no class for the Whizzer it must run on an "inch for inch" basis with bikes that go over a hundred miles per hour. Fat chance to get a 60 year old flathead with belt drive to anything close to that, and outfitting the bike to meet the AMA/FIM rules was a real challenge by itself.

None the less the effort continued, Double Vision has run in the low 50’s at previous outings and with Kenny’s engine tricks hope to bump that up, but in reality you can only get so much from a flat head and the goal was to keep the bike to near original spec’s where rules would allow. Belt drive, No gearbox, no overhead valves.

Many people tell me they had a Whizzer that went 60 mph, maybe so when clocked by grandma’s DeSoto downhill with a tail wind and weighing only 80 lbs. but consider this, that to set a record the bike must run the 5 mile course flat out, turn around within two hours, re-run the course backwards with no changes and pass all the tech stuff.

For the Whizzer that will be 10 minutes flat out at 4000 ft in 100 plus temperatures. That will be the challenge! We’ll be happy if can run 60 for the whole distance.

For you tech-ees the bike is is a 60" wheel base single loop frame, w/ disc brake, powered by 2 "J" motors, 300 series cylinders, roller cranks Standard Hi-comp heads, Carter carbs, battery ignition, and some speed secrets by Kenny.

The engines are coupled by a notch belt to keep the timing, and it fires as a "twinglle" (on the same stroke). The primary drive is via a ˝ inch V- belt and final drive is chain. Engines turn 6200 rpm and estimated 10+ hp on gasoline. Weight 110 lbs.

The event is held Sept 5 to 9 at Bonneville Salt Flats


Thanks for your support,

Roger Brophy/Kenny Thomas

Tuesday, September 6, 2005"Double Vision" clocked 59 mph in one direction, 61 1/2 mph return.

First picture is of Roger (middle) and his 'pit crew') Rod (?) on right and Terry McAllister -- on flats just before he ran the course.

Second picture is what the 'tear-down' looks like. Each entree for a record has to tear his bike and the inspectors go over it to check displacement.

Third picture is the sealed gas tank. You must run on their fuel when going for a record.

Fourth picture is the "Run What You Brung" inspection section. You can run whatever you want (not for a record -- just for a timing slip), but still must meet certain safety rules.

An innovative trailer that I found interesting. When I asked the guy if he had pulled that from Minnesota, he laughed and said no. That was just for maneuvering around the flats. Easier than using the larger trailer. Terry told him that if he had towed that trailer from MN, he was more impressed with the trailer than the motorcycle.

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