If you spend a lot of time cruising trails on your e-bike, then Ergon SM E-Mountain saddle is amazingly comfortable and we'd recommend it.

Product Overview

Overall rating:

Score 8

Ergon SM E-Mountain Core Prime saddle


Ergon SM E-Mountain Core Prime saddle review


Price as reviewed:


The name doesn’t really make this clear, but the Ergon SM E-Mountain Core Prime saddle is designed specifically for e-bike use. My instant reaction was probably similar to yours; do we really need an e-bike specific seat? The answer is not really, as any saddle will work on a e-bike, in fact most of the e-bikes I’ve tested over the last few years have regular saddles fitted, but I was interested to give this a go.

Read more: Best mountain bike saddles – six of the best MTB saddles out there

The first thing I noticed is the weight – at over 350g the SM E-Mountain Core Prime is not light, but to be fair the extra grammage doesn’t really matter on an e-bike that weighs the best part of 25kg. For that reason, the saddle doesn’t need to feature titanium rails or a skinny carbon shell, and the knock-on effect of that is it can be stronger. Which is a good thing on a e-bike because things break off when you crash or even if the bike just falls over. To offset some of this abuse the SM E-Mountain Core Prime saddle has 7mm chromoly steel rails and a hefty TwinShell, with four-layer construction.

TwinShell consists of a smaller base shell to which the rails are attached, a layer of moveable padding (called Infinergy), a secondary flexible shell and then the regular padding/cover on top. The Infinergy layer sort of floats between the two shells, and in theory allows the saddle to pivot from side to side as you pedal. In use the saddle doesn’t move weirdly or wobble about, it just feels really well padded.

To reduce pressure on all your delicate parts, there’s a channel down the centre of the saddle and two widths are offered, so you can align your sit bones to the area of maximum cushioning. Ergon has also built a bit of extra girth into the nose of the saddle, again to alleviate this hot spot.

The other distinctive feature of the SM E-Mountain Core Prime is the wedge shape, or chock, at the back. It provides something to push against when pedalling hard on a steep climb, and while it’s not new idea, I found it does help keep me centred on the bike.

Ergon has really upped the plushness – the SM E-Mountain Core Prime has got an armchair ride, but at the same time it feels supportive. It’s almost like memory foam in this respect. The problem I have with it, apart from the price, is that it’s a tall saddle. And since most e-bikes have issues with dropper post insertion (the motor gets in the way) this saddle isn’t going to help that. When I’m descending I can feel it underneath more than the one it replaced.

For all that though, I’m going to switch back to a lower-profile model for the riding I do, because for me the extra clearance makes all the difference.


Widths:S/M and M/L