Opening up the world of tyre production

A visit to the Continental tyre factory in Germany exploded the myths of bicycle tyre production and opened my eyes to the incredibly complex and involved process of producing the apparently simple mountain bike tyre...

I was lucky enough to be invited to take a tour of the Continental tyre factory in the small town of Korbach, which is bang in the centre of Germany, about 20 minutes from the Willengen World Cup DH course. When I say that the Continental factory is in the town of Korbach, it more or less is the town of Korbach

A massive operation housing all of the bicycle tyre operation, along with some of the company’s motorcycle and auto production.  There are an amazing 6000 bike tyres per day produced here.

Continental tyres have been rolling out of here since 1907

A simplified version of how I thought a tyre is produced was basically, weave a casing, then injection-mould some rubber onto it. How wrong could I be?

The first stage is stretching of the pre-woven casing, this takes place through a 20m long machine that would look more at home in Charlie & The Chocolate Factory, this is then rubberised by having rubber mechanically pushed into the fabric. The raw casing is then cut into strips at a specific 45deg angle to obtain the correct casing strength.

Massive sheets of tyre casing ready for cutting to size

The pre-cut casing then goes through a hand operated process where it is joined into a single hoop through heat and then pressure rolling. The casing is then wrapped around the bead which produces a two-ply side wall and three-ply centre. 

A ‘breaker’ is then applied. This is basically an extra protective strip under the tread for puncture and cut resistance, and is either made from nylon or Vectran material, which is the same stuff car air bags are made from. Following this the rubber strip which will later form the tread is applied, along with an additional strip of protective fabric at the bead, to stop damage from the wheel rim.

Blank rubber tread being applied by hand to the casing

The blank, unshaped hoops are then placed into a steam press for up to 5 minutes where the high pressure and heat of the steam forces the tyre outwards into a mould to form the tyre shape and tread. The excess material is forced out through tiny holes in the mould, and that is what the tiny rubber ‘hairs’ are on your new tyres.

Before and after the steam moulding process.

Banks of pressure moulding machines and a very German dude

The production process takes place over three floors of the factory, and although machines are used, it is by no way an automated process, with German hands involved in the entire construction of every tyre.

This was an eye opener, and an education into why a tyre costs you £30+. When you buy a ‘Handmade In Germany’ Continental tyre, it is that intricate and exacting process in its construction which is costing the money.

Look out for a test in MBUK very soon on the new and very exciting, if slightly dubiously named, Rubber Queen tyre. This is aimed squarely as a tyre for the modern AllMountain rider, with a large volume casing and tacky compound, reasonable weight, low rolling resistance, durable wear characteristics and great puncture protection. Big claims indeed.

Here’s a sneak preview of the tyre, featuring Apex sidewalls with a special pinch resisting and supporting inter-casing rubber insert, a completely new tread pattern and Continentals new Black Chilli rubber compound.

Black Queen sees a tread pattern departure for Continental

Apex protection sandwiched in the casing

I’m off to Continental’s auto testing area now to learn how to do skids in cars, so Auf Viedersehen.

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