Verende zadelpen voor de bakfiets: de Ergotec PM-705!

Suspension seatpost for the cargo bike: the Ergotec PM-705!

A cargo bike is generally very stiff and offers little comfort. With a lower tire pressure, some comfort can be gained, but too low a tire pressure will cause extreme wear on the sidewall of the tyre. Moreover, this will lead to a high(er) chance of flat tires and we don't want that, especially not with a cargo bike. A suspension seatpost for a cargo bike provides a more comfortable ride. Studio Vollebak has extensively tested the Ergotec PM-705 in an Urban Arrow Family cargo bike that we still use daily to this day.


So a suspension seatpost, why specifically this Ergotec PM-705?

First of all because this seat post has a so-called parallel mechanism. A must for the less steep seatpost tubes of cargo bikes. The "normal" suspension seat posts are less suitable because the spring direction is actually not good. Apart from the lesser effect, such a seat post will also show wear sooner. An additional advantage of the parallel mechanism of the Ergotec PM-705 is that it has a relatively low body height. This is the height from the point where the saddle is mounted (clamp) to the bottom of the suspension system. With the Ergotec PM-705 this is 111 mm, which also makes the seatpost suitable when the saddle is relatively low.

Another advantage of this seat post is the security, in the form of a rubber, between the parallelogram. This prevents children sitting on the back from putting their fingers between the pearlogram.

The Ergotec PM-705 comes standard with a spring that is suitable for people weighing between 70 and 90 kilograms (including clothing and accessories). Don't worry, other springs are also available. The weight ranges are as follows:

  • up to 70 kg;
  • 70 to 90 kg;
  • 90 to 110 kg.

Less weight in a higher range is not a problem at all, only the operation is slightly less optimal. This is especially noticeable with small bumps in the road surface. However, this is common as there are usually several family members using the same bicycle.

When purchasing the Ergotec PM-705 in our webshop, we mount the spring free of charge that matches the weight of the cargo bike rider(s). This optimizes the driving comfort even further and you do not have to purchase an unnecessary spring.

Mounting this seat post is relatively easy with two bolts. The front bolt is hidden behind the rubber, here an Allen key with a round head is the easiest to use.

First open both bolts, mount the saddle and then tighten the front bolt first. On most bikes, this bolt will be tightened more than the rear one. Then you tighten the rear bolt and the saddle straightens. You will have to play with this a bit until the saddle is level, or at a slight angle if desired. Make sure that the bicycle is on both wheels and not on the stand.

Not a must, but possible: before you mount the seatpost in the bike, the tension of the spring can be adjusted as desired. First open the small Allen and set the desired tension. This can be done by turning the large Allen clockwise (tighter) or counterclockwise (looser). This is really personal preference and can also be omitted. By default, the spring is set in the middle.

Are you convinced of this product, but are you unsure whether the Ergotec PM-705 fits in your cargo bike? First of all, check the seat post diameter of your cargo bike: this must match the diameter of the Egrotec PM-705 (31.6 mm). You can usually find the diameter on the seat post of your cargo bike. Then measure the height of the saddle rails to the point where the seat post disappears into the frame. If this is more than 111 mm and less than 270 mm, then this suspension seatpost will fit in your cargo bike.

We have tested several suspension seatposts and this Ergotec PM-705 clearly gave us the best result. That is why we sell them in our shop: German quality with a favorable price tag. Still unsure? Don't hesitate to contact us for more information or questions.

A lot of comfortable driving pleasure,
Team Studio Vollebak

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