Battered but unbeaten in Road class - Underdog moves up to Race class...
Battered but unbeaten in Road class – Underdog moves up to Race class…


We’ve done too well really, and now we must pay the price. SLUK has been the only team to win their class two times, and according to British Scooter Endurance Club’s rules, we now get ‘upgraded’ from the Road class to the Race class.


Thankfully they’ve added a ‘Pro Race’ class now for all the BSSO regulars and our new class only allows one recent race licence holder per team.


Time to spray over battle scars
Time to spray over battle scars


The first rule about Race class is…


In Race Class, we are still allowed to have something between our legs (like our Underdog SS90 had when it left the dealer) but we’ve been banned from using the retro-fitted auxiliary centre fuel tank we’d been using for the last two meetings. Endurance racing is all about tactics, reliability and quick pitstops.


He may wear ridiculous headwear but this man can work wonders with an empty cereal packet...
He may wear ridiculous headwear but this man can work wonders with an empty cereal packet…


Strategic Thinking


The little Quattrini isn’t bad on juice but it uses just over 5-6 litres per hour – depending on who is riding. Sadly the standard Vespa smallframe tank only holds five litres so there’s a good chance with only one tank we’d end up pushing it. Not ideal.


The solution I came up with was a rough sketch of a seat tank drawn on an envelope and based on the styling of Underdog’s old Norrie Kerr fibreglass race seat.


Nest step was to rope in club-mate Dan – who runs a fabrication business called Total Revamp – to see if he could make it for us. Yeah of course he could.




The advantage of a seat-tank is that it gives us storage for around 10-litres of fuel but there’s only one fuel cap to undo and fill instead of the two we had to do before. It also saves us having to remember to switch the fuel tap on for the auxiliary tank mid-race and switch two taps off and on when we come in to refuel. This arrangement should actually save us pit-stop time and lessen the chance of mistakes.


Sam from custom parts specialist, Motone supplied us a flip-top aluminium Monza cap and the threaded steel adapter tube needed to weld into the tank.




From Cardboard to Steel


The process Dan used for the tank was pretty interesting to watch. First he mocked up the layout in cardboard which was glued and taped into shape. The idea is that the seat hump flows directly into the base part of an original tank so hopefully, there won’t be any delay to filling it. This still needs testing.


The next stage was to cut the sections from 1.5mm steel and start to stitch them together with TIG weld. There are clever pressed ribs in the seat pan and support struts underneath to ensure it doesn’t dent if presented with the backside of a pudding enthusiast.


Once it was obvious that it was all going to work, he welded it all together and pressure tested it for leaks. The fuel tap is a novel solution because it had to fit from the outside since there was no longer a way to fasten a nut on the inside as per Piaggio’s favoured method.


It took a bit of effort and ingenuity to clean the inside of the tank of weld scale but fingers crossed, it should work.




Dan then proceeded to paint it orange on the basis that his Mrs told him that he couldn’t paint it pink. He did such a nice job of it that I couldn’t bring myself to matt black it. Not yet anyway…


Over 40 hours work!


It’s worth mentioning that Dan stopped counting at 30 hours work when he was making this tank, it’s not something you can just ‘knock up’ in a day but the finished item is a work of art and it puts the rest of Underdog’s shoddy looks to shame. Making these tanks to sell to other tuned smallframe owners and racers isn’t really financially viable unless you have deep pockets. 



Limping Home


After the last 6-hour race – and Iggy once more firing the poor thing at the scenery for no good reason – we’ve come to a couple of decisions:


Firstly we had to stop the forks coming loose. There’s not enough thread left on the shortened PK fork for the little locking washer. This was resolved by drilling and tapping the top locking nut and fitting a grub screw. Hopefully, that’s not going anywhere now.


Stop clowning around


Our methods for dealing with the other loose nuts – the ones that hold the handlebars – has been to introduce a penalty system for anyone who crashes without a reasonable excuse.


The idea of an endurance race is to finish, so avoidable, unforced crashes are only performed by clowns. Therefore our forfeit is a clown suit that no doubt one of our team of merry SLUKers will be wearing until the next one crashes…




Gear Boxing


The engine still seemed to run fine, but sadly it sounded like it was about to self-destruct at any moment. Iggy came down to help strip and rebuild the engine. With his reputation for mechanics, this was as risky as lending Gary Glitter your wifi password but a lack of free time meant I was glad of the help (beggars can’t be choosers).


Iggy finally gets his typist's hands dirty...
Iggy finally gets his typist’s hands dirty…


Engine out and a delve inside revealed that we’d dodged a bullet. Before the first BSEC event in 2019 I discovered a crack in the engine casing and had to quickly replace it at the last minute with one donated by Wayne Hayes.




It’ll all come out in the wash


What I did by mistake was to fit the top bolt and spacer washer for the gearchange wishbone into this casing without noticing that there was already a spacer washer in position (under the socket in the pic above left). This allowed the gear selector wishbone to ride up in use and rub (chewed up and spat out pic above right) on the gears, filling the engine with filings that made the oil look more Glittery than, er, Gary…


Sticky pretends to look like he knows what he's doing, just before discovering we should have changed a bearing...
Sticky pretends to look like he knows what he’s doing, just before discovering we should have changed a bearing…
Thankfully Sam Round finished his paper round early and showed us how it should be done
Thankfully Sam Round finished his paper round early and showed us how it should be done


Let’s strip it again…


Within five hours we had the scooter rebuilt with another donor wishbone and got it running again before teatime… To our dismay, it still sounded like it was about to explode.


As ready as it'll ever be!
As ready as it’ll ever be!


The problem, as it turned out, was the flywheel side main bearing – which was a ball-bearing on this engine – had more rumble than a psychobilly gig. One fancy NU204 roller bearing later and it’s back up and running and hopefully ready to rock at Whilton Mill on Saturday.


We look forward to the race – may the best team win.



Live Race Broadcast This Saturday – sponsored by SLUK


If you hadn’t already sussed, BSEC are taking a technological leap forwards for scooter sport and via YouTube will be broadcasting the race live with a professional 3-camera crew. SLUK is co-sponsoring the broadcast together with ScooterNova Magazine and AME Auto.


Sadly NO SPECTATORS will be permitted but you can watch live from 10am GMT, including the LeMans Start at 11 am this Saturday using THIS LINK.


Fate has thrown BSEC an additional curve-ball in the form of Prince Phillip’s funeral. At the request of the local village, all the scooters will stop for two minutes silence at 3pm before resuming racing.


sluk racing



If you fancy supporting us, feel free to get yourself some limited edition SLUK Racing merchandise here.