3D printed saddles: TOUR check on an expensive trend

Anyone who has found their favourite saddle and is able to ride their bike without any seating problems can count themselves lucky. For many, however, it still doesn't fit, or it has never really fitted. Pressure points, numbness and chafing in the crotch were and are annoying companions for many road cyclists - and the search for the right saddle in the huge and confusing range on offer can be frustrating. The "trial and error" method can lead to success, but it doesn't have to. Few saddle manufacturers offer the opportunity to test different saddles extensively, and only a few dedicated bike dealers give their customers this option. The company Gebiomised has been involved in searching for and finding - or manufacturing - the perfect saddle since it was founded as a start-up around 20 years ago.

The Münster-based company was one of the first to measure the buttocks in the saddle while pedalling using a pressure measuring film. "Dynamic pressure measurement on your own bike provides the best approximation for the right saddle," says Gebiomized boss Daniel Schade, who offers his measurement expertise to other manufacturers such as Fizik in addition to producing his own bicycle seats. At ergonomics specialist SQlab, measuring the distance between the sit bones is an integral part of buying a saddle and is part of the service offered by partner dealers. The Munich-based company's principle is based on supporting the sit bones with the saddle in such a way that the nerves and blood vessels in the sensitive perineal area are relieved and protected. In our experience from many test rides, this technology can work well after a certain familiarisation phase.

>> SQlab ClipOn saddle: Bicycle saddle for "clipping on" in the TOUR test

3-D in 30 minutes

Saddles from the 3D printer are now in vogue and promise even better seating comfort. Although the technology is quite time-consuming - it takes around 30 minutes to print a saddle pad - and the printers required for this are still very expensive, the industry is nevertheless focussing on the new manufacturing process. Proof of this is the growing number of 3D printed saddles, for example from Fizik, Selle Italia and Specialized. So far, they have mainly offered their top models with a printed seat surface and a significant price premium; the versions with the classic foam padding are still available. This raises the question of whether and how the identical saddle model with the same frame, shape and size changes "just" by changing the seat pad. Or improved.

James Read, saddle designer at Specialized, argues that the damping properties and the transition between soft and hard zones can be adjusted more precisely with printed padding than would be possible with padding foams of different densities and firmness. This could, for example, result in better cushioning and the associated noticeable relief, because sitting bones cannot press through to the saddle cover; this protects the surrounding tissue from painful bruising. However, those who tend to sit "flat" benefit less from the differentiation in padding firmness.

Under pressure in the lab

We used two models to test whether and what differences you can feel between saddles with classic padding and 3D pressure padding. During a comparison lap on the road, our 70-kilogram test rider on his racer in the usual sitting position did not notice any major differences in comfort. The biggest difference is that you don't slip on the surfaces with the printed honeycomb structure - but you can't slip either. The laboratory test with pressure measurement film on the saddle while the bike is clamped in the Smarttrainer provides more insight: the images show a strikingly even pressure distribution on both 3D saddles. With the standard saddles, pressure peaks of up to 30 newtons per square centimetre occur, whereas with the pressure pads they are only half that. The 3D technology therefore makes a difference, and saddles with identical model designations can have different characteristics with classic or printed padding. However, without prior analysis, it is again a question of trial and error as to whether you can cope with this. In this respect, 3D printed saddles are another - but also more expensive - option for more seating comfort.

Printed VS. Foamed: Fizik and Selle Italia in comparison

Model: Vento Antares R3

• Price: 149 Euro >> available here
• Weight: 213 grammes

Model: Vento Antares R3 Adaptive

• Price: 259 Euro
• Weight: 234 grammes

Model SLR Boost Ti 316 Superflow

• Price: 230 Euro
• Weight: 164 grammes

Model:SLR Boost 3D Ti 316 Superflow

• Price: 360 Euro
• Weight: 207 grammes

The top saddles from various manufacturers are available with conventional and printed padding. Using a test rider (70 kg) as an example, we measured the pressure distribution on the two Vento Antares models from Fizik and the SLR Boost from Selle Italia using a pressure measuring film. Apart from the fact that the 3D models are heavier and more expensive, the 3D versions show a more even pressure distribution in the area of the sit bones compared to the conventional saddles. With the 3D Antares from Fizik, the weight force of 15 newtons per square centimetre in the area of the sit bones is half that of the Antares with classic padding. The weight of the test person is distributed more evenly over a larger area, which can be measured and seen on the impression. Whether this is perceived as more comfortable can only be answered individually, as more weight is consequently shifted to the front, usually more sensitive pubic area. Women in particular may find this uncomfortable. The SLR from Selle Italia is different. Here, the pressure on the 3D model is distributed over a smaller contact area with fewer pressure peaks. Our tester rated this as favourable.

Printing and baking

Fizik, Specialized and Selle Italia use the same manufacturing process. It is called stereolithography (SLA). The SLA 3D printers use a resin container with a transparent base, which is filled with a so-called liquid photopolymer. A laser hardens the resin with pinpoint accuracy to the final mould. The still very elastic and sensitive saddle pad must then be cured for several hours under UV light and cleaned. At custom manufacturer Posedla, the saddles are produced using the multi-jet fusion process, also known as the powder bed fusion process. In this process, thermoplastic powders such as nylon or TPU are fused together using heat (infrared light). At the end, the finished saddle lies in a bed of unused, reusable powder and is cleaned by suction and brushing. In contrast to production with liquid polymer, the saddle is ready after cleaning and can be connected to the saddle base and saddle cover without any post-treatment. The finished product is only cleaned at the end. According to the manufacturer, the advantages of this production method are that no expensive mould changes are necessary for different shapes and there is no material waste.

If the tested saddles are still mass-produced products, the next logical step on the way to the right saddle would be customisation. The manufacturer Posedla has already taken this step. The young company from the Czech Republic offers customised saddles. The package price of just under 500 euros for the customised saddle includes individual measurements. Ondřej Janků, responsible for the company's profitability, is satisfied with the business development. Several thousand saddles have already been sold since the company was founded in 2022.

For the customised saddle from Posedla, an impression of the buttocks is left in the frame and then photographed; surrounding QR codes and the foam grid serve as reference points. A programme calculates the printer data from the photos and these parameters. The process is called photogrammetry. The same technique is used to create three-dimensional profiles of the earth's surface from satellite photos.

From impression to 3D printing

The first step towards a customised saddle is to create an online account on the Posedla website (https://posedla.com/de), where you enter your personal details about your sitting posture and rider type. Posedla then sends the "Smiling Butt Kit" for the butt mould. This mould is photographed by the customer according to a predefined pattern and the images are uploaded to the manufacturer via the account. A programme calculates a three-dimensional image from these pictures and feeds the data to the printer, which produces the customised saddle. The Posedla concept currently offers the comparatively greatest potential for success from the perspective of the saddle seeker, as it utilises modern 3D technology for both measurement and production. Naturally, we wanted to try out the service - but the delivery time of up to eight weeks after providing our own data exceeded the time frame for this article. We will deliver the practical test of the customised saddle as soon as possible.

Mass saddle from Fizik

While Specialized has stated that it will not be offering customised saddles in the future, Fizik has taken this step and has been offering "One2One" since the second half of June. This is a similar concept to Posedla, although the type of measurement and the distribution channel are different. The Italians cooperate with selected dealers, where data is collected on their own bikes using pressure film measurement and processed with other data in an app (from Gebiomised) to create a print template for saddle production. The comparison of the two customised saddle concepts will be an exciting topic for one of the next issues of TOUR.

>>Fizik One2One: With saddle pressure measurement to the custom saddle from the 3D printer