We are a small company working in Cambridge, England to improve bicycle safety for children. We want to create a sea-change in bicycle safety, by designing the first range of transportation that helps protect your most precious cargo.

Dynamic crash testing, roll-cages, ISOFIX and child seats have been standard in the car industry for many decades, we believe it is time they were available for children being transported by bicycle.

The Chestnut Trailer will, we hope, encourage many more parents to use their bicycles on a daily basis safe in their knowledge that their child is well protected on their journey.



Before Chestnut, parents must choose between protecting their child and protecting the environment, but both of these are essential. 

Chestnut is built to provide peace of mind to parents who want to do the right thing for the environment and their children. It is, we believe, a huge step forward - the start, we hope, of a movement towards greater child safety in the cycling world.


The main body of the Chestnut is an aluminium roll cage, with two very strong continuous loops.

This ensures that the child is protected by the trailer in the event of an accident.

The roll cage has been tested at Cranfield Impact Centre, UK.



The Chestnut Trailer includes an ISOFIX bar. This makes the Chestnut able to take seats from birth to four years old and allows the use of seats from the likes of MaxiCosi, Britax and Joie.

ISOFIX will hold the seat securely in place in the event of an accident and the ISOFIX points are tested to the ISOFIX standard.

The addition of a car seat can provide considerable safety benefits, including side impact protection with cushioning for shock absorption, and head, neck and back support for the child (actual benefits vary from MaxiCosi, Britax. Joli etc and from seat to seat in their range*).

*The level of protection offered by such seats may vary from the level of protection that some seats would offer when connected in a motor vehicle.



Partially recycled nylon is used for the cover, which is lightweight but still offers protection from the elements for your child.

The frame is made of welded aluminium tubing, very strong and light and readily recyclable.

The whole trailer can be disassembled and separated for recycling at end of life.

Chestnut fits almost any adult bike without modification, allowing you to make full use of the things you already have.


“Parents are making an ethical decision when they choose to transport their child in a bike trailer, and the least we can do is keep their child safe.”


Conker of Cambridge founder Crispin Sinclair is a keen cyclist and father of two young children, with a background in design and innovation.

His passion for cycling – from taking the children to school every day in the Conker Trailer (prototype) to spending three months riding solo across Europe - gives him a fantastic insight and the determination to demand a better future for his children.

When Crispin’s bike was crushed in a road accident, it sparked the beginning of the Conker of Cambridge journey, bringing innovations from the world of car safety to the bicycle world.



Bringing unprecedented safety to the cycling world. 


All aspects of all designs shown on this website are subject to change at any time and without further notice and none form any part of any contract or obligation. All rights, including copyright, in this website, are owned by or licensed to Babel Bike Limited (trading as Conker of Cambridge). Any use of this website or its contents, including copying or storing it or them in whole or part, other than for your own personal, non-commercial use, is prohibited without our permission. You may not modify, distribute or repost anything on this website for any purpose without our prior permission - which we may well grant, but please ask first.