Making progress on Joe Potts’ Desmo

I thought I would share some pictures of the newly manufactured chassis for Joe Potts’ Desmo. The frame is a replica of the original 500cc Razorblade frame that Alec Crummie made prior to the start of the 1958 season. The frames are made to be ass authentically as possibly. The rotary tube swaging machine used to make the original tapering down tubes was even tracked down and used for the manufacture of the new tubes. Even the resin used when bending the tight radius tubes came from one of Joe Potts' friends who he built racing cars with.





 It should be noted that the frame has been made to the same specification that Bob McIntyre raced the original Razorblade from the Silverstone Saturday meeting onwards. Before the Silverstone meeting, Alec Crummie added two extra tubes running from swinging arm pivot to the top tubes in order to increase the frame stiffness. The original 500cc Razorblade subsequently had these tubes removed (but the original brazing can still be felt) when it was converted into a 250cc Manx by Archie and George Plenderleith.

The front brake has also been sourced for the Potts Desmo. It is just as Joe was going to fit into it – a 4LS Gilera unit that McIntyre brought back Bellshill. The brake has had the ‘Potts treatment’ in the same manner as he did to the original.

Gilera 4LS drum brake modifed in the same manner as Joe Potts

Flow Bench setup for a 250cc Manx Norton cylinder head.

The following pictures show the setup that will be used for checking the air flow characteristics of a cylinder head from a 250cc Manx Norton. The 250cc was originally built and raced by Archie and George Plenderleith . More than 50 years after developing the engine, Archie will be putting the cylinder head onto his flow bench. It will be interesting to see what modern methods make of the work done all those years ago....

Bianchi team and the Bellshill brigade at the 1961 TT

Both Bob McIntyre and Alastair King were entered for the Junior TT on works 350cc Bianchi twin cylinder machines. Bianchi were to send over three bikes for Bob and two for Alastair which they could pick their preferred bike for the race. The Bianchi’s were late arriving, which meant that several practice sessions were missed. I will reproduce a great anecdote relating to an incident between Bob Mac and the Bianchi team during practice that was given to me by Archie Plenderleith who was at the TT in 1961 and who spent a lot of time with the Potts team:

      

There was another misunderstanding involving Bob Mac and the Italian Bianchi mechanics one morning during TT practice. Bob Mac had got himself stranded out on the circuit one evening during practice when the Bianchi stopped. His Italian mechanic went to rescue him in Bob Mac’s van. They arrived back at the Bianchi garage quite late and proceeded to investigate the Bianchi and ready another for the next morning practice. By the time they were finished all the petrol stations were shut and Bob Mac’s van was extremely low on petrol. Bob Mac asked the Italian mechanic if there was any petrol and he pointed to some jerrycans. Bob Mac threw one in the back of his van and set off for his digs on the Loch Promenade. Next morning Bob Mac filled up the van from the jerrycan and set off for the Grandstand with Pim Fleming. I left for the Grandstand some time after them (our digs were only 50 yards apart) and I found their van outside the Villa Marina with all the doors wide open and the engine cowling lying in the roadway along with a toolbox. Pim saw me coming and waved me down. “Could you give us a tow, the van stopped halfway up the hill and now it won’t start” – he said! Bob Mac was in about the engine! “Should go” he said, “it has got a spark and it has got petrol”. We collected all the tools and gave it a tow but it would not run properly, it was spluttering, misfiring and would not rev up and whenever the clutch was engaged it stopped. We towed it again – and again – and again!! No joy! We towed it back to his digs and left Pim to sort out the problem. I gave Bob Mac a lift to the Grandstand where the Bianchi Boss man was waiting!! He didn’t look too pleased.

Chapter 1

Boss Man (annoyed) – “Ahh ha! Meester Bob, where you been, we here at 5 o’clock waiting you, but now you come at 6.15 and the Bianchi she is back in the garage so you no go out! What is the matter, you like a big sore head, you been to a party huh?

Bob Mac (now very deliberate) – “I DON’T HAVE A SORE HEAD         and I HAVE NOT BEEN TO ANY PARTY but I wish I had! I DID NOT MEAN TO BE LATE, my van stopped on the way here and there is no need for argument!”

It was obvious that he was not in a good mood!

Boss Man (very sarcastic) – “Ooohhh, I be sorry to hear that, very sorry, then the van must have been to the party huh?”

Bob Mac (getting madder by the minute) – “THERE HASN’T BEEN ANY BLOUDY PARTY but there soon will be to your acute embarrassment”

Boss Man and the Italian Mechanic confab in Italian!

Boss Man – “I be really sorry for you Meester Bob, very sorry, true, Ruffo here (Italian Mechanic) vill soon feex your van.”

Bob Mac (becoming suspicious) – “WHY HIM? What does he know about my van?”

Boss Man (more friendly) – “Ruffo, good man to feex your van, he knows moteyrs. And, he wants his VINO back. You took his VINO last night, see!”

The penny drops all round! The jerrycan contained VINO. Van problem solved.

Boss Man – “Beeg mistake, very beeg mistake Meester Bob, very sorry, very sorry, verry sorry your van does not like the VINO. But funny ha ha, verrry funy, ha ha ha, yes?”

Bob Mac (still mad, does not think funny) – “If you lot went on fire I would dial 998. Silly buggers! Come on, let’s go back to Pim”

Pim Fleming in front of Alastair King's van

Chapter 2

I drove Bob Mac back to his van where we met up with a very irate Pim. When Pim was “up tight” he spoke very loudly in the true Scots Vernacular and that morning was no exception.

Bob Mac – “I know what is wrong with the van!”

Pim – “Ye dinny need tae tell mi, ah ken whits wrang wi it, its foo o bloody water an sose that @=&+%*£+$ jerrycan ye goat frae thae Eyetye mikaniks! Nae wunder yer beeanchy disny go, its gie likely foo o water an aw!”

A translation of Pim’s reaction – “You don’t need to tell me, I know what is wrong with it, it’s full of water and so is the jerrycan you got from these stupid Italian mechanics. No wonder your Bianchi does not go, very likely it is full of water too!”