Marcus Aurelius wrote: If he’s really the only person who’s views you’re trying to use, to shore up your ( very weak at best ) argument, then it says everything that needs to be said really.
You obviously have not even paid enough attention to realise that the BMJ editorial was a collaboration with David Spiegelhalter.
I don't suppose there is any point in directing you to https://www.cyclehelmets.org/
. You would not want to read anything which questions your convictions. You will find there much material, a lot by qualified scientists, assessing the evidence.
Here is the editorial board.
Accident Researcher; Past President, Ottawa Bicycle Club; Former Director, Citizens for Safe Cycling, Canada
Road Safety Activist, Reading, England
Retired scientist and policy adviser, Canberra, Australia
Shane Foran, MSc
Safety Analyst, Galway, Ireland
Cycling Skills & Safety Consultant, Cheltenham, England
Director, Institute for Traffic Safety Analysis, Arlington, Virginia, USA
Journalist and Researcher, Perth, Australia
Dr Richard Keatinge,
GP, Anglesey, Wales
Transport Researcher, London Metropolitan University, England
Dr Nigel Perry
Senior Fellow, University of Canterbury, New Zealand
Dr Dorothy L Robinson
Adjunct Associate Professor, University of New England, Armidale, Australia
Director, Head Protection Evaluations, UK
Dr Peter Ward, MB.BS DCH DRCOG MRCGP
GP Principal, Gateshead, England
Malcolm Wardlaw, BSc, MBA
Consultant on Cycling, Health and Safety, Edinburgh, Scotland