A Manx for the road

Bike Profile

Roger Klobe's Tonkin Tornado – a stunning custom build from Steve Tonkin - pictured at the 2017 Island Classic, Phillip Island, Victoria.

Steve Tonkin has been building very special classic bikes to order for over 20 years, with around 100 different examples to date. Currently, his work is focussed on what is called the Tonkin Tornado – a full spec 500cc Manx Norton that’s happily at home on the road.

From the time he learned to ride on a rigid frame 500cc Matchless, before he was old enough to gain a road licence, motorcycles have been Steve’s chief interest. From a BSA Bantam, a 250 Matchless and a 350 Triumph, he progressed to a series of Velocettes, culminating in a brand new Thruxton. But when the racing bug bit in 1971, the Thruxton had to go to fund his track tackle – a 750cc Norton Atlas engine in a 1954 Featherbed frame. He was very successful on the Norton, which gave way to a Mk4 Seeley Commando on which he scored numerous successes and established himself as one of Britain’s leading riders.

The Tonkin Tornado is powered by a 500cc Molnar Manx engine, with overall gearing reduced to produce a top speed of 115mph.

“In those days we used to race up in the north of the country at Silloth, Croft, and Cadwell, they were the three as well as Scarborough, which was probably my most successful circuit. I used to go there knowing I could probably win. It was incredibly narrow, they had to put the sidecar onto the grass to pass. I went to the Manx GP in 73 on a TZ350. My sponsor at the time was Dennis Pratt, who had been a very successful racer on Nortons. In 1973 there was no Newcomers Race at the Manx so I entered the 350 GP and finished fifth, and best newcomer. I wanted to do the Manx again in 74 because I would have won it, but Dennis wanted to do the TT so we did, and as it turned out, it was a year too early as I finished 22nd in the Junior TT.

I did the TT for ten years on all sorts of bikes, 250 and 350 Yamahas, Armstrong, Cotton, Ducatis and Guzzis for Sports Motorcycles, and won the Junior TT in 1981 on an Armstrong.”

British-made NJB rear shocks have been developed from the original Girling design.
Fontana 210mm double sided twin-leading shoe front brake is the best drum in the business.
Rear hub on Roger’s bike is a BSA/Triumph conical.
No passengers here.

So how did a former TT winner end up building customer classics? “I’ve spent the last 23 years restoring bikes and I fancied a change. I like building bikes. I’ve done two G50 road bikes, an Mk2 and a Mark 3 Seeley, I did a Seeley Gold Star, and now I am onto the fifteenth Manx Norton, with another five to build at present. The bike (the Tonkin Tornado) is to 1963 Manx specifications, with standard bore and stroke (86mm x 86mm), compression is lowered, with standard cams. There’s an electronic decompressor which is actually a Harley-Davidson unit; a solenoid opens the valves so it kick starts easily. There’s a long shaft on the drive side to accept a standard British Lucas alternator, and I’ve used Amal Mk2 carbs on all the bikes so far, but Amal are not doing any more 36mm carbs, so the next bikes will use Mikuni carburettors. It has a Quaife five-speed close-ratio gearbox with a kickstarter, NEB clutch and belt primary drive. It has a high first gear but once you get going, I wouldn’t have any trouble riding through Melbourne. Back in the racing days the Manxes all suffered from “megaphoneitis”, whereas the two G50 road bikes I built, you could have ridden them around the workshop. It has a BTH magneto – a modern magneto with no points, it’s electronic with a remote coil, like speedway bikes. Instruments are Smiths replicas which come from Wassall in UK and they get them from the far east somewhere. I have used them for 12 years and they are dead steady, I have never had one failure. In the UK you can get a 97 octane fuel from BP and Shell so I use that, but it will run quite OK on normal unleaded.”

Roger Klobe is one happy owner!

The Tonkin Tornado is powered by a 500cc Molnar Manx engine, with overall gearing reduced to produce a top speed of 115mph. The first example in Australia went to Roger Klobe at Hamilton, but there is now a second bike at Beechworth and Steve says he has two more solid enquiries, both also from Victoria. Roger’s has done 7000 miles and all he’s had on it is a couple of back tyres and chains. He rides his fairly hard too, he uses it. It started first kick this morning. There is another one at Beechworth, and the bike that I am building now is going to Ballarat and I have two other enquiries from Victoria. Roger has clocked up 7,000 miles on his, with nothing more required than a couple of rear tyres and chains. It’s a first-kick starter too. Roger takes up the story…

“About eight years ago I purchased a 1954 alloy engine Featherbed Norton International, thinking, ‘How good am I?’ I now own the closest thing to a road-going Manx ever produced. After another two years of fettling, it is a very reliable and fun bike to ride and has since completed several thousand miles at various rallies around Australia. But like all 60-year-old motorcycles there is always the niggling in the back of your mind, will I make it home? Knowing my love of such beasts, a friend sent me a one page article about a chap in the UK who was producing a genuine, built for road use, Manx – the Tonkin Tornado. I foolishly responded to the email address and it all started. That was about five years ago. I made contact with Steve Tonkin to find out the technical specifications of this piece of magical fantasy.

Smiths-replica instruments look the part.
BTH magneto has original appearance but modern internals.
Amal 36mm Mk2 carb will give way to Mikuni on future production.
Mick Hemmings supplies the Quaife design 5-speed gearbox.

“It turns out that Steve commissioned Andy Molnar to produce 20 modified Manx cranks to accommodate regular British type alternators, this being the main stumbling block when people have tried to create such machines. The engine is standard race type Molnar Manx except it has 10:1 compression to run 98 octane petrol. A 36 mm MK2 Amal carb and self-generating electronic BTH magneto ensure usual first kick starts and when hot it has a lazy idle at 1,200 revs. The delightful gearbox is a 5 speed by Mick Hemmings. There always seems to be the right ratio available as circumstances require. Gearing is set at 4,500rpm (max torque) at 70mph so she never sees a hill and you can work out top speed at 7,000rpm. Fuel economy is 65 miles per gallon cruising and down to 25 in anger. When dyno tuned, torque is flat from 4,500rpm and power of 38hp at the back wheel was still rising at 6,500rpm.

“The frame is made of the best materials by Molnar (made from CDS instead of the original Reynolds 531 tubing), with billet yokes and Manx Roadholder forks. Front brake is a 4ls Fontana with superb progression and fantastic feel. Rear hub is a Triumph conical made to look like a Manx, with 18” alloy rims. The 5 gallon alloy fuel tank is custom made, as is the catch tank, oil tank and seat to complete the package. The primary belt drive and NEB clutch are housed in a custom made alloy Commando type primary case and cover which is actually 50mm longer than the original. I have now owned the Tornado (#4 built) for three years (#8 and #13 are also coming to Australia) and completed over 7,000 miles, the longest trip being approximately 600km in one day. Surprisingly the ride is quite soft given the superb handling, when you encounter the bumps on our shocking rural Victorian roads it doesn’t matter how far you’re cranked over, the Tornado always stays on line. I seem to have inadvertently ended up as Steve’s world R&D officer. There are not many small things that have had to be remedied along the way. Steve has been most forthcoming with any backup or bits required.

Steve Tonkin with his creation.

“A big bonus out of all this is that Steve and I have become good friends. He came over to a that I ran two years ago and he returned the hospitality last year when I attended the Classic TT and Goodwood Revival. You definitely meet all the right people when a past TT winner is making the introductions at these sort of events.”

Steve Tonkin attended the 2017 Island Classic at Phillip Island and spent many hours chatting to people about his creations. Roger’s Tornado was parked in the garage area all weekend and was the subject of hundreds of snapshots and videos. Steve says the price depends on the specification. With a Manx 4ls front brake and the higher of the two specifications for the Manx front fork, they are 43,000 UK pounds. Roger’s bike has a Triumph rear wheel but they are now supplied with a Molnar-made Manx rear and a Fontana 210mm front brake and in this specification the price is 40,000 UK pounds.

2017 Tonkin Tornado Specifications

Engine: 500cc Molnar Manx air-cooled DOHC single
Bore x stroke: 86.0mm x 85.5mm 499cc
Compression ratio: 9.5:1
Lubrication: Dry sump
Gearbox: 5-speed with kick starter.
Clutch: Dry, belt primary drive.
Final drive: Chain
Carburettor: Mikuni 36mm
Forks: Manx Norton
Brakes: Front: Fontano 4ls 210mm double sided. Rear: Manx conical 7 inch
Wheelbase: 1447 mm
Fuel capacity: 3.5 gallons (15.9 litres)
Tyres: Front: 90/90 18. Rear: 100/90 x 18.
Weight: 322lb (146 kg)
Top speed (with alternate gearing): 130 mph.
Builder: Steve Tonkin Classics
18 Main Road, Bolton Le Sands, Carnforth Lancashire LA5 8DH
Tel: +44 (0) 1524 825205
This article first appeared in Old Bike Australasia Issue 66.