1988 Brompton servicing - play in pedal crank

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templehead

Active Member
The sun is out, so it's time to play with my new (v. old!) toys... I've flushed the hub out with GT85 and dripped a little oil in, as was suggested in the other thread. The cables seemed OK, so I squirted PTFE lubricant down them and this has all resulted in a much nicer gearchange. However, I have about 2mm sideways play in the rear wheel... unbelievably I can still recall adjusting the bearings on the Raleigh Chopper I had as a yoof and this looks similar so I'm thinking I'll be OK with that.

The one thing I'm not sure how to deal with is the play in the pedal crank*. I don't know if the bearings therein are adjustable or the sealed type (like in the rear hub of my Dawes electric) that I'd need to replace. I can't find a Brompton with the same pedal cranks/chain wheel as mine - but the age it is I guess it could have had all sorts fitted - I don't even know how to get the pedals off! Any pointers here would be gratefully received...

*about 0.5mm
 

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Gunk

Guru
Location
Oxford
Yours looks like a Mk2 Brompton, which means it should be a bottom bracket with loose bearings, easy to take apart, clean replace the loose balls, grease and refit.

If it is a sealed BB it was a FAG ISO sealed unit, no longer available. However if you do want to replace with a more modern sealed unit, a 110mm JIS bottom bracket works with your older crankset.
 
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Cycleops

Legendary Member
Location
Accra, Ghana
@Gunk 's advice is good if you mean Bottom Bracket but when you say 'pedal crank' do you mean that or the pin that runs through the pedals?
The play in the rear wheel is likely due to the cones being out of adjustment. Might be worth removing the axle and adding new grease and adjusting correctly.
 
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templehead

Active Member
Apologies, yeah, I'm probably using the wrong terminology...

1713382274759.png


What I mean is if I grab the centre end of the pedal crank and waggle it, there is vertical play evident as per the very bad diagram above.
 
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templehead

Active Member
I would just gently clean the threads with a soft wire brush and smear with some grease just to protect the bare metal.

I did the second one straight after and, predictably, it was in a similar state! I had to grease and adjust the rear hub bearings on that one too. But the good news is that the 5-spd hub works OK, and overall they don't seem in bad nick for their age. Very pleased with my purchase, and I'm going to start using #1 next week.
 
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