Weinmann Symetric

For discussions about bikes and equipment.
Ugly
Posts: 368
Joined: 14 Jul 2009, 8:34am

Weinmann Symetric

Postby Ugly » 8 Feb 2020, 4:18pm

P1010179.JPG


Bought these recently, but I need to change the pivot on the rear brake for a longer one. There doesn't seem to be any way of taking the brake apart, nothing is hidden under the red badge and I am loath to file the two rivets on the back without replacements. Welding an extended pivot bolt on could be an option, the frame it will go on has a reinforced bridge. Any other ideas?

fastpedaller
Posts: 2277
Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Weinmann Symetric

Postby fastpedaller » 8 Feb 2020, 5:03pm

Any possibility you can use a 'long nut' eg recessed AK type?

Ugly
Posts: 368
Joined: 14 Jul 2009, 8:34am

Re: Weinmann Symetric

Postby Ugly » 8 Feb 2020, 11:32pm

Thanks fastpeddler.
Practically the brake bridge is reinforced with an internal sleeve, and ascetically the frame predates AK fittings.

tim-b
Posts: 1150
Joined: 10 Oct 2009, 8:20am

Re: Weinmann Symetric

Postby tim-b » 9 Feb 2020, 6:59am

Hi
Buy a second front brake and get the thread dies out?
Regards
tim-b
~~~~¯\(ツ)/¯~~~~

Brucey
Posts: 36646
Joined: 4 Jan 2012, 6:25pm

Re: Weinmann Symetric

Postby Brucey » 10 Feb 2020, 1:01pm

it may be possible to use the front brake as a rear and use a threaded sleeve (inside the steerer) to allow the other brake to be mounted at the front, even if the crown is drilled 6mm dia only.

FWIW I'd be worried about welding to extend the extant stud; asides from your safety being dependant on the quality of the welding, weinmann often used plastic bushes in their brake arm pivots and obviously these are liable to meltm if they get hot.

Altenburger synchron are an alternative retro brake that are vaguely similar, and IIRC there is/was at least one shimano model which worked in a similar kind of way too.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Ugly
Posts: 368
Joined: 14 Jul 2009, 8:34am

Re: Weinmann Symetric

Postby Ugly » 10 Feb 2020, 5:45pm

Thanks for that Brucey. I would leave the weld to an expert, we have one locally. I see your point about plastic. I think that filing off the rivets and replacing the bolt with a longer one is the way to go if I can find suitable replacements. I have A Veteran-Cycle Club lunch on Wednesday and will take it along, there are some very experienced restorers, cars, small engines and bikes there and plenty of out the box thinking.

Brucey
Posts: 36646
Joined: 4 Jan 2012, 6:25pm

Re: Weinmann Symetric

Postby Brucey » 11 Feb 2020, 7:49pm

to me, the threaded sleeve approach is likely to be the easiest way ahead.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~