by Dale Zlock
To start with most folks have the impression that landspeed racing at the Bonneville Salt Flats is easy. After all your just going in a straight line and the bike does all the work while the rider is just hanging on. I wish it was that easy. But, with having attained several national and international records I can tell you it’s not that easy.
Every year the consistency of the salt changes. So, every year you are never sure of the traction you are going to get or how smooth the salt is going to be. Conditions of the salt can even change for one day to the next. Sometimes the salt is wet and sticking and gives you an inconsistent feel, as if you’re pushing through soft sand making it tough to control the direction of the bike. Other times the salt is hard and dry this makes it hard to accelerate as there will be a layer of salt dust on top of the hard surface. This makes the rear wheel spin. At times losing up to 7-10 mph just in wheel spin. Even when the salt conditions are as good as they get salt still only has about 30% the traction of pavement. Which brings you to the other issue: wind
Normally to keep a motorcycle going straight with a cross or quartering wind you just lean the bike into the wind to hold it in place. On asphalt this works well as the traction is sufficient to keep the tires from sliding out from under you even at a pretty steep lean angle. Not so on the salt. The bikes we run use a lot of bodywork for streamlining. That means we have a lot of sail area to catch a crosswind. Any crosswind over about 7 mph will push you right off the course.
There are 3-4 land speed events held each year at the salt flats in Wendover, UT. We compete in the motorcycle only event the Bonneville Motorcycle Speed Trials. This is the only event sanctioned by the AMA (American Motorcycle Association) and the FIM (Federation International Motorcyclist). Each year in late August a team of dedicated volunteers heads down to the salt flats to prepare two tracks: the mountain track and the international track. The mountain track is 5 miles long and the international track can be as long as 11 miles, but due to salt conditions in recent years it has been 7 miles long. There are three courses: a 3-mile short course, a 5-mile intermediate course and a long course at anywhere from 7 to 11 miles. The measured mile is in the middle. So, for the short course you have 1 mile to get up to speed, the measured mile and 1 mile to stop. The intermediate course you have a 2 mile run up, the measured mile and 2 miles to stop. The long course you have 3 to 5 miles to get up to speed, the measured mile and 3-5 miles to stop.
The short course is used for bikes that only go just over 100 mph. It is also used as the rookie course. If you are new to racing on the salt you have to go over 125 mph to move up to the intermediate course. On the intermediate course, if you go over 175 mph you are now qualified for the long course.
Your measured speed is the average speed through the measured mile. It is not just your top speed at a single point as you have to maintain that speed through the entire mile. Meaning, to get a good run you really need to be up to your top speed before you enter the measure mile and then hold it through the mile.
To actually set a record requires a two-way run through the measured mile. Using the long course as an example. You start at mile 0, get the bike up to speed in top gear about ½ mile before the measured mile. Now you start to trim out your body position by tightening up your tuck, pulling your elbows in, getting your head down onto the gas tank—anything you can do to make yourself smaller and more streamlined to eke out the last few 100 rpm from the engine. At this point the only thing you are looking at is the tachometer and the course markings as you look for the entrance flags of the measured mile. You also have to be cognizant of the fact that often there will be slight inconsistencies in the salt. When you hit them, it will cause the rear wheel to lose traction for just a second or two, making the rear wheel kick to the side and recover. At 175+ mph that will get your attention. Once past the measured mile exit flags you then slowly roll out of the throttle and let the bike coast down to stop. This is known as your “down run”.
If your down run is faster than the existing record you go to impound. Once there the scrutineering officials will check your timing slip and verify that you have exceeded the old record and are now qualified to make a return run. So now you refuel, under the watchful eyes of the scrutineers, and head back out. But this time you will start your run from mile 7 and do it all over again. Your final speed to establish the record is the average of the two runs. For a rider this means you have to remember to count the mile markers backwards to get your timing right to enter the measured mile fully up to speed.
To complicate things further, if you run nitrous boost systems on your bike like we do, the 2 pound nitrous bottle I carry on the bike is good for about 30 seconds of nitrous delivery. I have to time it when to hit the nitrous switch so I have enough distance to reach maximum speed just before entering the measured mile, but not too soon that I would run out of nitrous before getting through the entire measured mile.
If you are running for national records certified by the AMA (American Motorcycle Association) you have to make your return run in the same day. If you are running for international records certified by the FIM (Federation International Motorcyclist) you have two hours to make your return run. FIM records also require you to have an official escort from the end of your run to impound and then an official escort back out to staging for your return run. You are never out of sight of the race officials.
Zlock Racing started land speed racing at Bonneville in 2013. That year it was just Dan Zlock that went. Dale Zlock’s first year was in 2014. Our first national records came in 2016 with both Dan and Dale setting records in two separate classes. We set records again in 2017 and 2018. In 2018 Dale set a record of 181 mph with a Suzuki GSX-R 750 engine in a custom chassis. Dan rode a modified Kawasaki ZX10 to a record of 204 mph.
We have also built record setting bikes for a close friend Jeff LaMarche and Dan’s partner Lisa Cipolla. Jeff has the distinction of being one of the oldest individuals to set a landspeed record over 200 mph. He was 78 at the time. Lisa, is known as the “world’s fastest librarian”.
I have attached a list the records obtained but there needs to be a brief explanation of the class structures. AMA and FIM use differing designation systems. Both systems come down to three basic things: Engine size and extent of modification, Chassis modifications, and amount of streamlining.
For AMA designations, the first three letters refer to the frame and body work and the last two refer to the engine. Below is only a partial list but covers the classifications we run.
A = Altered – the frame has been changed from stock
PS= Partially Streamlined – most streamlining allowed where the rider still sits on the motorcycle. Rider must be visible from the sides and the top.
B = engine has either a turbocharger or supercharger
G= motorcycle is running on gas
F= engine running fuel, ie nitrous, alcohol, etc
FIM classifications are similar but use a completely different number system. Additionally, the FIM make a distinction between singles, twins and multi-cylinder motorcycles. But they have no fuel designation so you can run whatever you want.
1 = One drive wheel
A1 = motorcycle, two wheeler making a single track
B = bike has streamlining bodywork but is not a fully enclosed streamliner, similar to PS above in AMA
I = naturally aspirated if the bike has a supercharger it would be type II.
Dale Zlock, Lisa Cipolla, Jeff LaMarche and Dan Zlock
Zlock Racing Records
| Engine size | Classification | Speed | Rider |
| 1350cc inline 4 | AMA APS-BG | 203.4 | Jeff LaMarche |
| 1000cc inline 4 | AMA APS-AF | 203.8 | Dan Zlock |
| 1000cc inline 4 | AMA APS-AG | 203.7 | Dan Zlock |
| 750cc inline 4 | AMA APS-AF | 181.0 | Dale Zlock |
| 750cc inline 4 | AMA APS-AG | 172.2 | Dale Zlock |
| 650cc inline 4 | AMA APS-AF | 169.5 | Lisa Cipolla |
| 650cc inline 4 | AMA APS-AG | 156.7 | Lisa Cipolla |
| 750cc V-twin | FIM 1.A1.B.I | 158.9 | Dale Zlock |
| 600cc V-twin | FIM 1.A1.B.I | 150.8 | Dale Zlock |
| 600cc inline 4 | FIM 1.A1.B.I | 146.8 | Lisa Cipolla |
| 600cc inline 4 | FIM 1.A1.A.I | 135.4 | Lisa Cipolla |
Zlock Racing was founded by brothers Dan and Dale Zlock in 1984, to compete in regional and national motorcycle roadracing. Both brothers have won multiple regional racing titles and raced at the professional expert level on the national circuit. Since retiring from actively roadracing themselves they continued on in the sport as team owners and builders of racing motorcycles, winning three national championships in 1990’s and early 2000’s. This year Kevin Pinstaff from Portland won the overall championship in Washington and Oregon on a Zlock Racing prepared and supported motorcycle. This was his third overall championship. His brother Brian Pinkstaff, also on Zlock Racing equipment, took 2nd in the championship.
Zlock Racing started in Dan Zlock’s garage but now operates out of a 4000 square-foot machine shop and fabrication facility in Spanaway, Washington.