Folding Bikes - Help Removing the Rear Hinge on a Brompton
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The rear hinge on my Brompton is worn after about 6500km. This means the rear triangle is a bit loose so I decided to replace the hinge. I have the repair kit with bushes, washers etc. However I can't get the screws that secure the tiangle to the hinge pin to open. According to the manual the screws are torqued to 10 Nm and held in place with threadlock. I've applied a lot of torque, enough to twist the hex driver I used without shifting either screw. Any ideas?
Willo in Dublin
Try some fine lub, and possibly use a cordless screw driver on the lowest torgue setting and working the setting gradully upwards. This should help apply the torque gradually, and in the correct vector
03-07-09, 04:42 PM
I read somewhere that the threadlock they use to keep the bolts in can be a pig to loosen, but the application of a little heat can help when trying to remove and replace them. How you do this without ruining the paint is less obvious - maybe think 'hairdrier' rather than 'blowtorch'.
This link may help: http://stein.dommel.be/brompton/chapters/Maintenance.html#removing_rear_triangle
More detail can be found in this PDF:
Thanks everyone for the help and advice. In the end I had to drill our the screws which wasn't as unpleasant as I had expected. No damage to the frame of the bike. Brompton do seem to use a lot of threadlock so it doesn't look like there really is an alternative to drilling.
Removing the two bushes is a bit of a pig too but I got there in the end.
03-08-09, 03:54 PM
If it's any consolation I had to drill one of mine out when I swapped out my steel rear for a Ti one. I'm sure there's a better way to engineer that hinge - seems a bit oversimplified and neanderthal to me -very hard to get a fit that doesn't have some give in it.
I had just looked up this information myself as I was contemplating repainting my frame and also doing some modifications or buying a new bike to replace it. I don't have any replacement parts so it is useful to know that at least the screws will probably need replacing.
Let us know how you go putting it back together.
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