Elastomers seem to be having a comeback in an effort to tame vibrations throughout off-road bicycles. The small rubber bumpers made their most notable appearance in RockShox's 2023 forks and O-Chain’s Active Spider that reduces chain feedback. So, it would seem logical to integrate a cushioning system into a saddle.
Bike Yoke has been doing exactly that with their Sagma saddles for a few years now. Interchangeable elastomers are placed on the rails where they connect to the saddle base and allow riders to tune the level of compliance they are looking for.
Sagma Carbon Details
• Carbon 7x10mm rails • Carbon reinforced base • Lateral articulation, vertical bump absorption • Soft, regular (2x), & hard elastomers • idbeam foam and PU skin • 130 or 142mm widths, 240mm length • Colors: orange, blue, pink, lime, ruby, black • Weight: 205 grams (130mm) • MSRP: €169 • More info: bikeyoke.com
Although the Sagma design isn’t new, on top, the padding uses a special construction. Bike Yoke has licensed the foam technology from idbeads. Thousands of foam beads make up the volume of the saddle padding which is covered by a pliable polyurethane coating.
The elastomers provided vertical compliance and lateral articulation.
The Sagma saddles come with two regular-density elastomers installed. Pictured are one hard and one regular density rubber bumpers, noted by the letters "H", "R" and "S" .
• Carbon 7x10mm rails • Carbon reinforced base • idbeads foam and PU skin • 142mm width, 240mm length • Colors: black • Weight: 169 grams • MSRP: €139 • More info: bikeyoke.com
Pricing and Weight
The suspended Sagma Carbon saddle costs 169€ / $169 USD and weighs 210 grams, 15 less than the existing alloy rail version. Those carbon rail sets are retrofitable to the existing Sagma saddle for 40€ and replacement alloy ones cost half of that.
If you’re looking for a simpler approach but like the Sagma profile or idbeam foam support, then there’s the Sagma Lite series that ditch the elastomer system. There are two models to choose from: a chromoly railed version with a nylon saddle base for 89 € / $89 US and a full carbon option that weighs just 169 grams. Considering the weight and construction materials, the Sagma Lite Carbon’s price tag of 139 € / $139 US doesn’t seem unreasonable.
Besides the difference in their structure, the traditional railed Sagma Lite models are only available in a 142mm width and black graphics. It’s also important to note the carbon rails on both the Sagma Carbon and Sagma Lite Carbon use oval 7x10mm rails that may not work with all seat post saddle clamps.
To make the most of the Sagma experience, I went all in and mounted the softest elastomer at the rear and the medium at the front. The side-to-side flex is very noticeable on the trail, even on an enduro bike. It’s almost a bit unnerving at first because of how much the saddle tilts side to side, but that does make it mega comfy. The nose is well padded and wider than most saddles I’ve tried too. That alleviates pressure underneath when you need to slide your weight forwards to keep the front wheel from lifting on steep climbs.
At times though, I’d brush my legs against that area while adjusting side to side on dynamic climbing moves more frequently than on a slimmer saddle. That's when I noticed the hard base material around the perimeter is exposed without any padding. With that said, Bike Yoke does state that the narrower 135mm saddle is best for enduro-style riding where riders tend to move more dynamically on the bike.
Moving back to the medium elastomer on the rear mount toned down the pronounced side-to-side tilting action and the firmest felt like a conventional saddle. Claiming that the movement gained by the elastomer would make any performance difference would be challenging to prove but if you’re comfier, then why argue against it? What it does best is reduce pressure on the sit bones on the already plush idbeads foam technology.
Throughout the test I never experienced any unwanted noise from the moving parts of the Sagma. The saddle saw its fair share of dust and water through the quick transition from summer heat to a chilly autumn. All of the hardware stayed tight too, even after removing and installing the different elastomer parts.
The Sagma Lite and Sagma Lite Carbon use fixed rails and are only offered in a 142mm width.
7x10mm oval rails are used on the Sagma Lite Carbon.
When I switched over to the fixed rail Sagma Lite, the raised portion under my sit bones was more pronounced and didn't flex out of the way like the articulating version. I found myself regularly lowering the post height ever so slightly to accomplish technical climbs because the wings of the saddle didn’t bend downwards as I extended my leg on each pedal stroke.
Overall, I found the Sagma model with two medium elastomers to work best for my body size and shape. That combination provided enough flex for the saddle to tilt side to side under for my 77kg frame without feeling like I was sliding sideways off of the saddle.
BikeYoke Sagma Carbon 142
Specialized Power Mirror 143
How Do They Compare?
Saddle shape and width depends so much on body shape. How the bike is fitted plays a huge role as it ultimately comes down to what you find comfortable. What I can speak about is the profile of the Sagma saddles. I'd say that they fall into the category where your sit bones rest of raised pads, much like WTB or SQ Labs' product lines.
Conversely, Specialized seems to take an opposite approach with rounder saddle profiles that you'll find on the Power or Bridge models. Those seem to fit me more naturally, but the Sagma Carbon (the one with the elastomers) was equally as plush as the 3D printer Power Mirror.
+ Interchangeable elastomers on rail-suspension allows for optimized comfort and control + idbeads are extremely plush + Sagma Lite Carbon has an excellent price to weight ratio
- Exposed plastic trim on wide nose may bother some riders - Sagma Lite models not available in 130mm width options
The ability to tune the flex in the Sagma saddles brings a unique feeling to pedalling while seated. With the softest elastomer installed, and taking into consideration my weight, the range of motion side to side was a bit too extreme for my taste. Swapping for the medium density elastomer calmed that down but still helped to lower the raised portion of the saddle under the sit bones as my hips cycled through each pedal stroke.
As for the Sagma Lite Carbon, the idbead foam layer is certainly plush, but the wider 142mm profile doesn't tip out of the way while cycling through the pedal stroke as well as the Sagma did. I would prefer the elastomers featured on the standard Sagma that reduce the width as the saddle flexes side to side. That's more of a "me" problem than the fault of either saddle, but a narrow Sagma Lite option would be welcomed for smaller riders.— Matt Beer