Review: Riding the gebioMized Sleak 135 custom fit saddle

The gebioMized lineup includes a few iterations of what is essentially, three saddle types. But what exactly is a custom-fit saddle and should you be bothered?

The saddles feature a carbon-reinforced, nylon-composite shell, covered with lightweight variable-density foam padding and hollow titanium rails. None of them are startlingly lightweight (from 210g) or particularly budget orientated (+/-R2900) but they are all designed to optimize performance and comfort for you, me and the champs of Le Tour.

The brand’s promise: Next Level Fit

The Lineup

The GebioMized Stride is a Triathlon or Track-specific model available in one mould with a standard or soft foam density. The Area, which is suitable for road, MTB, gravel and track, has a larger base which makes it popular amongst female riders, although it is not a gender-specific saddle. It is available as a 145 V-Shape and a 155 T-Shape in both a cut-out or channel option. The Sleak model is also suited to road, MTB, gravel and track conditions for riders with a narrower pelvis. The Sleak is available as a 135 T-Shape with a cut-out or channel and a 145 V-Shape with a cut-out or channel.

Choosing the right GebioMized saddle

This is not a saddle you should just walk into a bike store, pick up off the shelf and buy. I mean, you could do that, quite easily in fact, but that approach probably wouldn’t unlock the full spectrum of comfort and performance gains on offer. You see, GebioMized are  ‘custom fit’ saddles that are matched specifically to your body shape and to the way you sit on the bike – ie: the position and tilt of your pelvis.

In short: Some analysis of your anatomy and riding style is needed to determine which model is best for you. This is done with the help of a bike fitter who places a ‘smart’ saddle cover which has a sensor mat, onto your existing saddle to measure real-time pressure. After a few minutes of pedalling, the pressure map reveals where the high-pressure areas are, where discomfort and other issues like saddle sores may be coming from and that data is then used to guide the bike fitter, (in my case Dave George at Gear Change in Cape Town) in determining which saddle is best for you.

As it happened, I had a few pressure issues and mild discomfort with my old saddle. Dave is clearly very experienced with bike fit and the GebioMized range (which he distributes in SA) and we settled on the slightly flatter Sleak 135 model, with a channel as opposed to a cut out. Dave fitted the saddle, we made a few small tilt adjustments and I did a few more minutes on the bike before packing up and heading home. Right from the first pedal stroke in his bike fit studio, the comfort levels had blown my mind, but I wanted to get out onto the road and get some real-world miles in.

After my pressure map test results at Gear Change, plus some consultation with David George we fitted this Sleak 135 T-shape model which has a long pressure relief channel — as opposed to a full cut-out.

Three months with the GebioMized

When I ride, I like to move around quite a bit on the saddle. I tend to slide back on the saddle on longer climbs, I slide forward when in the drops or hoods on the flats and I like to slide far forward, to the tip of the saddle when trying to hang onto a fast bunch or motor pace an eRoadie. The long flat design of the Sleak and long pressure relief channel, which just about extends across the full length of the saddle, complements this riding style. On steeper climbs, when grinding a bigger gear, it feels like the T-Shape of the saddle helps lock my pelvis into position which I feel helps sturdy my trunk and allow me to drive more power into the bike.


With more than 2000km of testing, I’ll go so far as to say the Sleak is the most comfortable saddle I have ridden, ever. That’s in 35 years of road riding. It’s the kind of saddle that is so comfortable that I tend to forget about it when riding – even on long rides. Only on a 4-hour or longer ride is there some mild discomfort – which, in my books, is pretty much the norm really. It’s no wonder many of the world’s best use GebioMized.

So what’s the secret behind GebioMized and how do they pre-make custom saddles?

The brand first developed a pressure mapping system over 15 years ago and have since evaluated over 50 000 saddle pressure measurements. To develop this lineup of custom saddles, they founded a community of bike fitters known as the Secret Saddle Club. These fitters provided them with valuable input from their daily experiences of fitting. The research covered an equal share of men and women, considered various sitting strategies and bar positions, the full range of pelvic flexibility and different body shapes. Combining this intel with their own data and experience gained from serving Pro Tour riders (including winners of the Tour de France) they set about defining, designing and manufacturing the GebioMized range which was finally officially launched in February 2019.


Very small changes in saddle shape and setup can have huge implications on pressure distribution and comfort levels. I went through this fit process a few months ago and as I reflect on it and consider the comfort gains — it seems daft that I didn’t pay attention to this technology sooner. I’d highly recommend this pressure mapping and fit process for any endurance rider, especially if you’ve experienced any level of discomfort. I’d also recommend finding an experienced bike fitter and that you open yourself up to the fact that bike fit is a process and not necessarily a 60-minute job.


| IMAGES: Gary Perkin |

| WITH THANKS: Gear Change |

1 Comment

  1. Thank you for this article Miles, this is the kind of saddle I would look to buy

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