PVD Land Speed Record Bike
Contents
Team McCall USA
Gordon McCall was put in touch with me through my friend Dan Kyle. Dan is a motorcycle tuner that knew that I knew a lot about building bicycle frames as well as motorcycle science. see: Team McCallUSA
Previous Record Bike
Fred Rompelberg is the current record holder. 268.831 km/h. 167.044 mph.
This is as close a scetch of Fred's bike that I could make from photographic details. The wheels are about 22 inches in diameter.
Rough Print for Team McCall USA Bike
The Frame
The frame will be constructed of 4130 tubing. The goal is to make the bike as light as possible, as stable as possible, as fast as possible, and most importantly AS SAFE AS POSSIBLE.
At speeds over 170mph, the forces going through the frame are huge even on apparently smooth surfaces.
At this point, the bike is going to have front suspension and a solid rear for maximum power transmission. The tire in the rear will be doing most of the work.
Tubing Choices
Special tubes avalable:
- True Temper Tandem Boom Tube, F1-TDBT, 2.125 x 1.375 Oval x 0.9mm Wall x 692mm Long ($32.40 from Henry James)
- Reynolds 525 Tandem Base Tube, KC120, 1.968 (50mm) x 0.984 (25mm) Oval x 0.035 (0.9mm) Wall x 760mm Long
- Reynolds 525 Tandem Base Tube, KC111, 1.500 (38.1mm) Round x 0.039 (1.0mm) Wall x 760mm Long
- Reynolds 853 BX2709, 34mm x 28mm Oval x 650mm Long, 7/5/7 Butted
- Reynolds 853 BX2805, 34mm x 28mm Opposed Oval x 635mm Long, 7/5/7 Butted
The Wheels
Marchesini 125 GP forged magnesium Wheels, 2.50”x17”, 63.5mm x 431.8mm
The current record bike used 18" diameter rims.
The Tires
Donlop Tires is helping us with some killer rubber. We really need to use the fastest hardest rubber that they have available. We also need to use the smallest tire.
The current record bike used tires with a diameter of 20.4 inches on 18 inch rims.
KR149
(125cc slicks)
95/70x17
C-Medium Compound
Rim Range - 2.15-2.5"
Recomended rim - 2.5"
Max width - 3.46"/88mm
Max Diameter - 22.68"/576mm
Suggested Roadrace psi - 25-27
I wish that we could find something that was a lower profile, like the rain tire but with hard compound and slick.
KR122
Compound- WA
Max Width - 3.45"/88mm
Max Diameter - 22.64/575mm
The tires will probably need to be shaved to reduce contact patch and to save grams.
The Fork
Ohlins 125 GP gas fork
The Yoke
A special lightweight yoke is going to be required. The goal is to have a 1.125" steerer extention so that different stems can be redily avalable for rider position adjustment. I think that this makes sence.
Risse Racing (not contacted yet). 1.5" offset.
If not available, then DKG
The Brakes
Brembo 125 GP
16x18 Radial brake master cylinder for single caliper
155mm rotor front?
The Headstock & Bearings
The larger the headstock the better. Current bicycle technologies are durable and light. The Cane Creek Double XC 1.5" Flush headset should maximize the headstock area.
The Dropouts
In house design, watejet cut from .3125 4130 Cro-mo.
It has not been decided if the rear wheel postion will be fixed or adjustable.
The Drivetrain
Cranks- Dura-Ace Track cranks
Jack shaft-
Gearing
Sprockets- Paragon, Phil Wood, or White.
A better choice could be Highpath Engineering
MDT does ovals as customs. These run in the $500 each range.
http://www.rotorcranks.com/s1-q-rings.shtml
144 BCD to match the Dura-ace track cranks. 5/16-3/8" thick.
To match the current record on the wheels that have been selected at 130 crank rpm, we will need twin 70/16 reductions. Twin 74/17 comes quite close, but comes just short. It's obvious that some refinement is needed here. Breaking the record will require a slightly taller gear.
The current world record bike used double reduction gearing, 70/13 teeth & 60/15 teeth, an overall reduction of about 21.5 and 114.2 ft of development. The bike used tires mounted on 18" rims with an overall diameter of 20.4 inches.
Ceramic Bearings
Expected cost - $600 for both wheels, $300 for both bottom brackets.
Testing
Record Attempt
The record attempt will be made at Bonneville or Edwards Airforce Base.
