36-inch tyres & 3D printing: The Jersey Giant gravel bike from Huhn Cycles

All of Huhn Cycles' project bikes are actually attempts to challenge the bicycle industry: What works with new production processes? How do new processes behave? But also, how can we produce more sustainably, more locally? And Ralf has also tried to test what works with his latest and fattest Huhn: the Jersey Giantnamed after one of the largest chicken breeds. A bike that lies between gravel and hardtail MTB, loves bikepacking and stands on incredible 36-inch wheels. The ingenious thing here is that you can't tell the Jersey Giant is out of proportion - the proportions are perfectly harmonised.

The Gravelbike is a customer project for Tim Ahnsorge, founder of the bike furniture company 44-elf. Tim is 2.06 metres tall, hence the idea for the huge wheels. In addition, Ralf and Tim's plan was to utilise the possibilities of today's 3D printing technology. The chicken bike celebrated its premiere at this year's Bespoked.cc trade fair.

Innovative 3D printing process for small series

Even with the Huhn series bikes - whereby series here only means that the product is basically the same, but is usually produced on request - Ralf already works with connection points from the 3D printer, which are produced in a process called Cold Metal Fusion arise. Without going too deeply into the process: Put simply, a 3D mould is injected, consisting of a base material and the desired metal. The sleeves for the Jersey Giant were produced with an Ultimaker Desktop Printer using BASF Forward AM Ultrafuse 17-4PH material.

Which gravel bikes are available? Which one is right for me?

Ultrafuse 17-4PH can be used with commercially available 3D printers, such as those you can buy for home use. The material is used to manufacture parts from 17-4 stainless steel and can be processed with fused filament fabrication (FFF) printers. It has a metal content of over 80 per cent, is extremely resilient and stronger than 316L stainless steel. Further processes are then used to turn the printer mixture into the final component, which hardly differs from solid components in terms of material properties - but can be designed much more freely because it is printed beforehand and not cast, forged or welded. This is where Huhn from the Fichtelgebirge works together with a specialist from Würzburg: Headmade Materials.

The Jersey Giant gravel hardtail, which has a steel frame, also uses Reynolds 853 tubes in such printed joints. The British manufacturers were chosen here because their frame tubes are made from recycled steel. Another point for the environment!

3D printing has already made history

The 3D printing process should also be available to a wider audience in the future, and research is now focussing on ways to make the process cheaper. It has already made history. At the beginning of October, Filippo Ganna pulverised the world hour record on his Pinarello Bolide F HR 3D. The Italian's Pinarello is the first (serious) racing bike from a 3D printer.

For Ralf Holleis, the topic of sustainability is also important, which we are addressing in the BIKE Project Europe He had already tried to light up a bike that should consist entirely of parts manufactured in Europe. That's why he very quickly switched from carbon to titanium and steel in his career as a bike builder. Although the raw material for titanium frames is still largely produced in China, it is at least wonderfully recyclable. And that actually makes steel Ralf's favourite: it is recyclable and also durable. What's more, it doesn't have to come from overseas, but - as with Huhn - from the UK.

Bikes like Jersey Giant are still unique

This is where Cold Metal Fusion comes in: it could make local production possible in the future. The 3D-printed sleeves do not require a huge foundry or enormous amounts of energy. Small, specialised manufacturers can respond to customer requests in small series. Until this becomes common practice, Huhn Cycles will build one-offs like the Jersey Giant.

Huhn Cylcles: individualisation at the limit

The Giant Gravelbike jersey, which is not only very striking in terms of colour, has some components worth mentioning. Exciting, because they also come from the 3D printer. The grips come from the Stuttgart-based start-up Personomic and the Posedla saddle (see picture above) was printed in the Czech Republic... well: printed. According to Huhn, the Ingrid rear derailleur is also "custom 3D printed".

Also Intend - who already supplied the suspension fork for our EU bike - have produced printed brake lever prototypes for Huhn. The 80 mm upside-down fork for this bike is also a prototype by Cornelius Kapfinger - after all, it has to hold the huge tyres that are installed here. The 36-inch wheels from Alchemist itself with Veetire T-Monster 36x 2.25-inch tyres are particularly striking. True monsters, because according to Ralf, one of these tyres reaches up to the door handle - try putting a 29er on a door...! The unique dropouts were designed by Simon Metzner from Actofive Cycles. In the end, the giant chicken weighs 17.9 kilos - including bags and pedals.

Ralf reveals more details about the equipment in his Instagram posts.

Ralf from Huhn Cycles doesn't want to keep his feet still any time soon. After the Jersey Giant is before the next Huhn. And the creative mind already has another idea up his sleeve. So we can look forward to seeing which egg the chicken will lay next.