Nations represented in the class:

Denmark   Finland   Germany  
Greece   Hungary   The Netherlands   Norway   Sweden   United Kingdom

European record holder:
Dave Beck, UK 
elapsed time: 7.067 sec
speed: 302.91 km/h (188.25 mph)

To learn more about Pro Stock Bike, we interviewed UK based Stephen Moon, who is highly involved in the European record holding team Dave Beck Racing.

Can you tell us the facts in brief? What performance/power/fuel/cylinders are we looking at?

There are two engine configuration types in UEM PSB, the 2,600cc twin-cylinder Buell motors as used by Ulf Ogge and the four-cylinder Suzuki motors, which can range in size from 1500cc to 1755cc. There are UEM prescribed minimum weight breaks for each motor configuration, in order to keep the class competitive. Regardless of engine configuration, the bikes all run on unleaded petrol and are naturally aspirated, using either carburettors or fuel injection. Power is transmitted to the track through a ten inch slick. The current class ET record is 7.07 seconds, by the UK rider Dave Beck, but already this season Jesper Thiel has come very close to that mark at the Hungarian season opener. Terminal speeds are in the mid-180s. So very impressive performances for normally-aspirated petrol engines. The competitors tend to be very cagey about the power outputs, but it’s safe to say the leading riders have 350bhp at their disposal.


Jesper Thiel from Denmark is after Becks record

What has the evolution been like in recent years in terms of technology Performance? The class as regards to number of teams, etc..?

The class has developed very strongly in recent years, as evidenced by the number of teams, the appearance of new riders and some very close racing indeed. Sixteen bike eliminations are the norm and indeed the Main Event sees a full field contesting this premier event. A full quarter of the field now consists of the twin cylinder Buells, including reigning UEM Champion Ulf Ogge. The rest of the field consists of four cylinder Suzukis, which this year will see a number of 1755cc bikes competing to take advantage of the new rules. The Veidec Racing team, led by young star Kalle Lyren, will be a force to be reckoned with, as will European record holder Dave Beck and Swden’s Anders Abrahamsson. But a number of riders have recently achieved personal bests, so 2011 promises to be a good year. Expect to see some very close racing – the 7.0 zone has already been broken and the first six second run can’t be far away.

Technology development for the Suzukis has seen a series of incremental gains over many years, with a lot of attention being paid to cylinder head design. Vance & Hines provide motors to a number of competitors, including Kalle Lyren and Anders Abrahamsson, while Ward heads are favoured by riders such as Dave Beck. While these bikes use Lectron carbs at present, the leading US riders are now switching to fuel injection and it is expected that this will become more common in Europe shortly (indeed some teams have already tested fuel injection). The Buell motor was developed a handful of years ago by the legendary George Bryce of Star Racing and is very competitive in the NHRA. On this side of the Atlantic, it has proved to be a potent motor, as demonstrated by Ulf Ogge’s championship-winning performances. The teams look for tiny performance gains, every fraction of a horsepower might make the difference between winning and losing, so attention is given to things such as ceramic bearings in the transmission and ceramic coating of pistons.

What variables are used to adjust the bike for the track? What is most critical?

Key variables at the track tend to be clutch adjustment and fuel metering. Finding the right balance of traction in order to get that all important sixty foot time right takes a lot of time, so you see teams spending a lot of time looking at logger data in order to tune the clutch correctly. Given the engines are naturally aspirated, the air conditions and weather play a major role in horsepower delivery, so again you will see crew chiefs spending hours on getting the fuelling right through tiny changes to the fuel injection or carburator jetting.


Elvira Karlsson from Sweden - young lady rider who enters the class in 2011 with a fresh competition license.

European Champions 2010:
Team Bikeline from Sweden with rider Ulf Ögge

Do the riders adjust the way they run the bike for different tracks and track conditions?

As mentioned, clutch and fuelling are two of the major tuning weapons that the teams have while at the track, so the riders and crew chiefs will pay attention to the weather conditions and the track surface on an hour by hour basis at meetings. Air quality will be checked at the last minute before leaving the pits to go to the staging lanes, with any jetting or injection changes made just before the bike rolls out. And while clutch settings will have been made during in between rounds maintenance, you will see riders and crew chiefs watching the track surface closely in the minutes before each run in order to select the best racing line.


Len Paget from the UK has quick Santa Pod Raceway as his home track

What kind of maintenance is normally done between runs on a race weekend? Between runs, the teams will spend a lot of time looking at the data from the previous run, in order to dial in changes for the next round. The clutch will be removed in order to clean it and make any necessary adjustments. Quite often a compression check will be carried out to see if the motor is healthy. The valve trains on these bikes wear quickly, given the radical camshaft configurations needed to make this sort of power, so some teams will check clearances or replace valve springs. Of course, minor work such as checking tyres, filling air shifters and refuelling is done. These motors take a lot of hours and care to put together, so if there are any serious problems, then it tends to be that a team will change an engine if needed, rather than rebuild it between rounds.

What about parts wear for Pro Stock Bike? Service intervals for parts like connecting rods and crankshafts?

The service intervals depends on the configuration of the motor and the type of setup. A Suzuki will need new valve springs somewhere between 10 and 20 runs, depending on the cam profiles used. The Buell motors need new valve springs every two runs, so extreme is the configuration of valve size and camshaft lift! Crankshafts will see in excess of 25 runs before needing attention, indeed some can last for over 50 runs before needing work. The engines are built to very tight tolerances, so between races, it is quite common that motors are stripped down and inspected, then carefully rebuilt. Every ounce of power is squeezed from these motors, so they run on the limit, meaning building is key – as is a spare motor in the trailer!


Kenneth Vik from Norway - team Veidec Racing is a strong contender with capability to win event titles

How fast do you think a Pro Stock Bike can run the 1/4-mile under optimal conditions? And what does it take to get there?

The NHRA bikes are running as fast as 6.8 seconds and in the mid 190mph range, of course this is as a result of a lot of dyno time, a lot of track time and some very good tracks. But European tracks are improving all the time and the riders and crew chiefs over here are very knowledgeable and stay closely in touch with leading edge US tuners. So expect to see European bikes go into the six second bracket and over 190mph this season. Both the Suzuki and Buell teams have worked hard and invested a lot of money over the close season, so they will be pushing hard to break through both of these barriers.


Dimitrios Petridis - one of the Greek riders in the class

Favorite/best track for a Pro Stock Bike?

The quality of tracks is improving all over Europe, so there are a number of good Pro Stock tracks now. Santa Pod always delivers a good track, as evidenced by the ET record being set there. The new Tierp track is very promising and expect to see some very good performances there in June. And even the new tracks such has Hungary can deliver the goods if the tuner is on his game, as evidenced by Jesper Thiel going into the 7.0s at the UEM Drag Bike Championship season opener in Hungary.


Kalle Lyrén Sweden, does his second season in the class and it started well with a place as runner-up at the season opener in Hungary.



Check out Europe´s best performance!
Records, ET and speeds listings for all Pro Stock Bike riders in co-operation with European Drag Racing Database!