We test such super scooters for their suitability for confident trekking tours, on and off the road.
29ers are being praised from all sides as the big thing: Bikes with large tyres roll better - and promptly all the well-known bike manufacturers rolled out complete product lines of new 29er models on the German market. Around 2001, this trend began to grow in Germany under the heading of "balloon bikes" as a tender seedling among trekking bikes, long before MTBs: Voluminous tyres roll more comfortably and safely because they can be ridden at lower pressure.
The fact that with the same tyre model, the larger tyre even rolls with less resistance at the same air pressure is a paradox that shows how complex the issue is. The larger tyre develops more grip and traction, despite having almost the same ground contact area. Big wheels need space. The frame and fork on the 29er must therefore offer sufficient clearance at the rear triangle and fork so that the tyres can rotate freely at all times.
As the wheelbase increases, the rear stays become slightly longer. The steering angle is slightly slacker so that the front wheel can also move further forwards, but without the top tube becoming longer. Another necessary geometry adjustment concerns the bottom bracket: as 29er tyres are higher, they lift the entire bike by two to three centimetres at the dropouts. This also increases the bottom bracket height.
When it comes to touring, the advantages of large bikes outweigh the disadvantages. If 29ers are as well-designed and sensibly constructed as the top of our test field, then they are the better touring alternative for any cyclist over 170 centimetres tall compared to 26 or 28er bikes.
The 29er in the test:
Centurion Backfire Carbon Ltd, http://www.centurion.de
KTM Life Race, http://www.ktm-bikes.at
Patria MTB Trail 29, http://www.patria.net
Radon ZR Race 29er 6.0, http://www.radon-bikes.de
Rocky Mountain Trailhead 29, http://www.bikeaction.de
Rose Black Creek 400, http://www.rose.de
Red Deer R.T1, http://www.rotwild.de
Specialised Carve Expert 29, http://www.specialized.com
Storck Multitask, http://www.storck-bicycles.de
Utopia Roadster, http://www.utopia-velo.de
The full-length article from issue 5/2012 is available as a free PDF download.
