There's hardly anyone doing this, possibly because there are so many variations of folders and forks that each job would be like a prototype, with the commensurate high costs and problems. That's almost certainly why C H White won't retrofit customers own bikes.
The only services I know of are the C H White conversion of a new bike, the Electrobike Brompton-Nano conversion, and those fitting the Heinzmann motor, like Kinetics of Glasgow. That last company does undertake some difficult conversions, but the costs are high and the Heinzmann motor and kit are really a bit heavy for folding bikes that have to be carried and lifted. It's also very expensive due to it's high quality manufacture.
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The only services I know of are the C H White conversion of a new bike, the Electrobike Brompton-Nano conversion, and those fitting the Heinzmann motor, like Kinetics of Glasgow. That last company does undertake some difficult conversions, but the costs are high and the Heinzmann motor and kit are really a bit heavy for folding bikes that have to be carried and lifted. It's also very expensive due to it's high quality manufacture.
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