FF: Forks Brampton Steering Stops

oexing

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In my setup above I have used a plastic bush for bearing, 12 mm high, the original size more or less I believe. The head lug was machined for old BMW taper roller bearings 34-51-12 mm . The lower Brampton casting just 1 mm clear of the head lug, you cannot go higher so all depends on variations in castings where parts hit their stops. Anyway I like to have defined faces for stops and not slopes for big variations of stops from tolerances. In case the Brampton sits lower you get even poorer stops. So my consequence was welding - which is not critical on the stop extensions even with cast iron. Real cast iron is welded with nickel rods basically that you can use anywhere when in doubt about brittleness. The welded stops should keep up in normal use , for tank slappers on Bramptons no argument, no ? Even so , I will fit hydraulic steering dampers to the Brampton, less so due to tank slapper anxiety but for smooth driving on bikers´roads, one handed on rough roads no troubles then. I found the hydraulic damper on the tele Horex great on rough three dimensional roads where there was some judder in the handlebar with friction damper only.

Vic
 

Cyborg

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If you or someone else has a new bearing (as in new and not NOS) that they are willing to measure, I may have an original one or two because I seldom throw out anything that is metal and round. Just have to find them.
Recently I was checking out two sets of lower bearings and both had cracks. Is it possible that later bearings had more beef in that area to reduce cracking? Who knows... it’s a long shot, but there has to be some sort of explanation for the difference.
 
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oexing

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You mean broken races from ball bearing types ? These should be strong enough for not braking ? Maybe knocked out from the head lug by brute force ? My photos in first page were made with 12mm bearing height and the lower Brampton part just clearing the head lug by 1 mm, you cannot go higher a lot. So any bearing with more than 12 mm (1/2") will make things even worse. So when not having some welding you´d have to come up with a different steering stop idea.
The BMW replacement taper roller in the Ebay link may come as a great alternative in case the head lug sizes are fu***d up or questionable. Sizes are 34 - 51- 12 mm . But this is an "interesting" machining job to get perfect alignment and parallel seats for slim size bearings.

Vic
Taper roller bearing
 

Cyborg

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Yes ball type. Not sure why they were cracked. I found the cracks when they were still installed in the UFM. Just inspecting them to see if they were reusable. Not knowing there history, I suppose they could have been cracked during installation which was at least some 50 years ago and they may be original. Once they are safely home in the steering head, I don’t see a reason why they should crack. Seemed odd that I had two different lower bearings with the same cracking.

Edit... just went and looked at one of the bearings. It’s the inner race that is cracked, so still quite possible it was cracked when installed or too much interference fit on the stem?
 
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Robert Watson

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Cyborg ---- Maybe we should get together and see if any of your cracked races line up with mine and we could make up some pairs - Oh just a minute!!!!
 

greg brillus

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If the bearing is too tight a fit on the lower stem they will crack, pays to check them and give not more than a thou interference any more is risky.
 

Cyborg

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If the bearing is too tight a fit on the lower stem they will crack, pays to check them and give not more than a thou interference any more is risky.

Good plan. This stem is scheduled for service so when I get the new bearings it’ll be out with the micrometers.
 
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