Norton at Bonneville blog: Day seven
04 September 2009 15:30
Norton Motorcycles is making its first visit to the Bonneville Salt Flats in the USA, where boss Stuart Garner is riding the NRV588 flat out.
The team is using this year to get an understanding for the salt flats – it is hoped the FIM will introduce a new class for rotary-engined bikes in time for next year, so the team can aim to set a world record in 2010.
On the final day of riding, Stuart Garner and the team pushed to find a few more mph to build on yesterday’s 173mph:
With 173mph under our belt, Stuart Garner is a little reticent at risking his butt and the bike unless there’s something to go for, so our first task of the day is to check the telemetry feeds into the laptop.
Speed and revs match perfectly, so we’re not suffering from the wheel-spin so many other bikes seem to complain of – indeed there are many quite heavily ballasted bikes running, some like Tom Mellor’s beautiful 1969 Triumph Triple engined semi-streamliner simply stuffing 105lb of lead somewhere inside the rear bodywork.
Others like our wonderfully gritty new friend Tobey on his ’09 Kawasaki 1000 cunningly pouring in lead-shot to fill the hollow-cast swinging-arm, and yet others simply getting hold of large, inch-thick sheets of lead and bolting them to the swinging-arm.
Despite our feather-weight of around 140kg, the Dunlop full-wet is doing its job magnificently, supplying all the grip we need and showing literally no sign of wear, other than the brief scrubbing-in it had round Norton’s home track of Donington Park before being shipped to The States.
However, we’re some 800 rpm off maximum revs, enough for another 15mph if we can access it. So, looks like another run may be worthwhile, but only if we can make some changes that will give us a chance of reaching those higher revs.
Changing the gearing is discussed by Stuart and Chief Race Mechanic, Tony Squires. However, it’s soon dismissed as dropping one tooth will result in lower speed even at full revs, and raising the gearing is unlikely to help given we’re not getting to the red-line anyway.
The salt surface creates considerable drag, pulling speeds down by around 10% compared to tarmac, so it’s in this direction we turn to see if there’s anything we can sensibly do.
We’re reluctant to change the rear tyre, for the reasons stated above, but changing the radially grooved full-wet front might well make a difference, especially if we can bump up the pressure to reduce the contact patch as well as reducing the friction of the heavy tread.
We have a cut dry slick front, so the decision is made to swap to this and to submit ourselves to one more run.
This being the last day of the Bub Motorcycle Speed Trials 2009, and the runs finishing at 2 p.m. rather than the 6 p.m. of all the other days, many have left already, so our progress through the first staging post is instantaneous – wow!
How good is that, not to have to sit out in the blazing sun for an hour or two!! Down at Mile Zero though, things are more back to normal, with a queue of 6 machines ahead of us, so it’s back to the waiting game for a while.
Fortunately, though, it’s not too long a wait, as the bikes are called through to the green flag reasonably quickly today, in contrast to the other days we’ve been out.
Stuart is started up by Tony, and gets flagged away so quickly I’ve not had time to follow him up to photograph the occasion this time, but he gets away cleanly once more with no spinning, no rooster-tailing – Stuart has clearly got to grips with the clutch, high power-band and tyre-grip very well.
The motor sounds fantastic as he pours on the gas, gear after gear clicking home instantly – we can clearly hear him the entire 3 miles of the run, then there’s the wait for the timing tower announcement – it’s 173 mph once more!!
There are mixed emotions – disappointment that we’ve not been able to find that tiny bit more to crack the 175 barrier, but more so satisfaction that Stuart is clearly capable of wringing the most out of the bike.
Back in the pits, we download the telemetry, and sure enough, revs and speed match perfectly, and we’re still that 800 rpm short of maximum. Oh well!
At least Stuart has been remarkably consistent, and let’s face it, 173 mph for a 566cc lightweight racer on the new and strange salt-flat surface is nothing to be ashamed of in any way.
We’ve succeeded in all we set out to do. Stuart has used the opportunity of coming to Bonneville to cement an agency arrangement for the new Norton 961 Commando with Sam Capri’s South Bay Motorcycles, and their assistance at Bonneville has been invaluable, not just in the logistics, but in building an excellent rapport with the team there.
The NRV588 has proved to be a potentially potent force, and not disgraced itself in the slightest – Tony has had almost sod-all to do all week.
An occasional oil-change, a daily clean-down to get the salt off, a regular oiling of the chain that tightens as the salt works its way into the rollers, destroying the ‘O’ rings link-seals, fuel top-ups and one wheel change. Howzat for a trouble-free racer, then?
There are many, many at Bonneville who would swap their reliability records for ours.
And we’ve gained the experience of running on salt.
And we now have a good understanding of the running of the World Speed Record trials.
And we’ve some ideas on how we can improve things in the future.
So, will we come back next year, to put all this valuable information to good use? Stuart is already talking about a 220bhp bigger-engined NRV that will be eligible to race against 1200cc twin four-strokes, using the 1.7:1 equivalence algorithm we’re assessed by the FIM to provide parity.
And bringing it to Bonneville – looks like the sat-bug has bitten!!
One big obstacle to overcome is how the Impound engineers would be able to measure a Wankel engine, when we get to set a new WSR.
Their current methods, using cunning devices inserted through the sparkplug-hole won’t work with a rotary, so it’s down to us and them to work out a practicable methodology that can be used in the field, or more accurately, on the salt!!
Norton are back!! Here’s to 2010…