What is a Top Tether and what is it used for?
When you are choosing a seat, you may come across the words "ISOFIX and Top Tether installation" in the description. What is Top Tether and how does it affect safety? Which seats utilise this additional anchorage?
What is a top tether?
The Top Tether is an extra anchorage for the seat to the vehicle structure. Its purpose is to prevent the seat from moving in the axis of rotation of the ISOFIX attachments. In simple terms, it prevents the seat from pulling away from the backrest in a frontal collision and the upper part of the seat from flying towards the front of the vehicle. This would result in the child's body suddenly decelerating and thus jerking its head. There is also a risk of the head hitting the front seat. This is extremely dangerous and directly translates into a risk to the child's life and health.
This is perfectly illustrated in the video below:
Most forward-facing seats, mainly in the 0(9)-18 kg weight range, have an extra support leg, which has the same purpose - when pushed against the floor of the car, it does not allow the seat (or Isofix base) to move forward too much. Forward-facing seats, especially from the 9-36 kg range, usually do not have an extra leg for practical reasons; this is taken over by the top tether.
What does the Top Tether look like?
It is a long belt at the back of the seat with a carabiner. It can hang loosely on the seat or be hidden under the casing.
Does my car have a Top Tether mounting point?
It depends. Cars manufactured for the European market, from 2013 onwards, are i-Size approved and must be fitted with the appropriate attachment. In older designs, unfortunately, there is no such standard.
Example car interior showing possible TopTether anchorage points (Mercedes B200):
Where to find the Top Tether attachment point?
The connector for the upper tether strap is usually located at the rear of the vehicle, on the boot side. Most often it is on the back of the seat back or on the floor of the boot. Occasionally, however, you will find this attachment point on the ceiling of the car or on the side wall of the boot.
sufit-ceiling
tylna półka-rear shelf
tył oparcia-back of the backrest
podłoga-floor
ATTENTION: Not every metal eyelet that can be fitted with a Top Tether carabiner is a suitable attachment point! Many vehicles have luggage anchors that are not suitable for child seats. To be absolutely sure that the attachment point you find is the right one for your car seat:
- - an appropriate marking must be next to it, for example:
- - or the vehicle handbook indicates this location as being suitable (particularly in older vintage cars).
Sample manual, Citroen C4 Picasso 2014:
How to anchor the seat correctly?
In accordance with the manual. Every child seat comes with a manual on how to install it correctly. Most seats also have stickers with pictures showing the correct installation for the various weight groups.
General guidelines:
- ensure that the belt is not twisted;
- The belt must run in a straight line from the seat to the attachment point;
- each upper anchor strap has a system indicating when the strap is correctly tensioned;
- if you have any doubts, please refer to the manual or contact us.
For example, a snippet of the Joie Bold car seat manual:
