Pendine Sands - The story of Pendine

Team Roy Pearson - Supercharged Honda 125

Saturday morning was clear and sunny, the bike and our kit passed scrutineering without a hitch. Due to soft sand on the middle section of the beach they could only set up a kilometer course that was being used by everyone, and the beach had been invaded by jellyfish so these had to be removed first.

Our first sighting run went well, I was changing up at 8,000 RPM and getting a feel for the sand, which makes the bike gently sway like the start of a tank slapper. We went through the speed trap at 51.289 MPH, not only setting a new a UK land speed record for the standing kilometer but faster than that set at Bonneville - as good start.

The second run I opener the bike up more changing up between 9-10,000 RPM and the speed went up to 65.812 MPH. Here we encountered a small problem as when I crossed the line and shut the throttle the bike carried on at 10,000 RPM, so I had to shut the engine off with the kill switch. Back at the pits the carb was stripped and there appeared to be sand on the slide, so even with our forward air intake it had managed to get in. We cleaned all the carb and inlet, but the multiple starts trying to sort it out finally drained the battery and by the time we had it recharged the course had shut for the day.

Sunday was cloudier, and Stuarts turn to ride. Whilst the course was set up we made an inlet filter out of a bit of old wire mesh and a pair of tights, this was taped to the inlet in the fairing. The rest of the bike was given the once over (only one lose fairing bolt) and we were ready to go. Straightliners had set up the 1 mile course for the day.

Stuart came back after his first sighting run having done a creditable 62.319 MPH, but the throttle had stuck again, everything was checked over but no reason could be found, if you left the bike for 10 minutes it started and ticked over fine, so we think possibly there was a build up of fuel in the supercharger (something we did have in testing) that was still being burnt off after the throttle was shut, it was just something we would have to live with. He was also complaining about a delay between opening the throttle and the engine picking up so pogoing down the track. as the only change was the inlet we put it down to a fueling issue. He went back out again with very similar times, the bike just didn't want to pull in fourth, and was still pogoing. We dropped the gearing and for his final run of the day he managed a 64.856, a new UK land speed record for the standing mile in our class.

Monday
We had been advised by a few people over a drink or two the previous night that the throttle delay could be caused by pulsing in the carb and that we would be better running a CV carb. We had one in the 'spares box' but no spare jets, we fitted it and although we could get the bike to start and tick over it wouldnt do any more so the needle and main were an issue. the needle couldn't be lifted, but a fellow competitor had a fix for this and went away and with the use of a needle file reprofiled the needle. But still no joy so the old round slide was refitted. We took the decision to remove the 'filter' and just give it a go.
Straightliners had set up a standing mile, and flying quarter mile trap so two records were up for grabs.
Stuart did a couple of runs both in the mid 60's MPH, the carb response had improved so we think it was the 'filter' but still the bike wouldn't pull in 4th. Talking to team Mad Max, they suggested that the intake could be producing a RAMAIR effect so presurising the carb and starving the engine of fuel. The intake was removed and we decided to try the 72,000 RPM drives for the supercharger, but sadly the bike refused to start on them, so the 40,000 RPM drives were refitted. Time was ticking on and the mad Max team were set to do some demo runs on their Helicopter jet engined bike, so we only had one run left. We decided just to ring the neck off the bike in third and see what happened.
We managed a 69.940 mile and a 70.634 average across the quarter mile, with the bike revving at 12,000 RPM. When Stuart got the bike back to the pits the clutch was fryed and oil was dripping from the casings but we got the 70 MPH.

All in all a great weekend Team Roy Pearson have three UK land speed records to their name and if we can get the bike to pull in fourth and fifth then I'm sure that we can easily do 100MPH next year.

A huge thanks for all our Sponsors and Supporters, because without you this wouldn't have been possible.