is anyone making/selling the head tube shells? https://www.atomiczombie.com/az-parts-drawings/?fbclid=IwAR1cFNARWMDtg1x7Gtgc2MzWUBlYON99NwI1iobSzGfrdT

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Instead of using head tubes you could use these:-


PTFE lined flanged bearings. They are 1mm thick so an 18mm o/d 2mm wall tube will use a 14x12x7mm beearing and take a 12mm bolt. I've just made these today using these and they are seriously smooth.:-

These perform the same function as the kingpins in the plans but are designed to go below the axle rather than above. This site will explain in pictures better than words. Got to Galerie / Mambo Baufotos.
 
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Try ebay. Search for "flanged PTFE split bearings". They're common enough that most bearing suppliers will sell them
 
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I can't tell by the photo if you have a ball bearing inside the tubes?
it looks like you have a piece of steel tube with a PTFE bearing on each end with a bolt and nut through all of those pieces. IF the PTFE is on the inside diameter how does that help reduce friction?
 
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No ball bearings. The ptfe is on the inside of the bearing against the bolt and on the upper edges of the flange against the upright. The bolt is designed to be stationary allowing the tube to rotate around it. There is ptfe between anything that moves.
 
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The ptfe is on the inside of the bearing against the bolt and on the upper edges of the flange against the upright.
DIDN'T REALIZE IT WAS ALSO on the flanged parts. I have used UHMW washers to similar effect in the past. Certianly easier to fabricate than what the instructions say, if I can get the right diameter tube locally. thanks
 
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Plenty of tube and other metals available on ebay in the UK. I'd assume it's similar in the US? There are postage costs but my local metal supplier is a gallon of petrol away and back so it works out the same for me.
 
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Every mag wheel I've seen has a 3/8" axle so I've never attempted them. I have no idea if they'd be stronger or weaker than a 48 spoke 20" wheel. My suspicion is weaker as the designer would never have considered lateral forces and whilst spoked wheels aren't designed for that either there is plenty of evidence to show they can cope with them. I certainly like the look of them and I'd love them to be OK but certainly the axle and I suspect the "spokes" say otherwise. I also suspect that even if the 3/8 axle would cope any "spoke" failure would be swift and catastrophic unlike a traditional set of spokes which will fail slowly enough to not have you bouncing down the road.
 
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Every mag wheel I've seen has a 3/8" axle so I've never attempted them. I have no idea if they'd be stronger or weaker than a 48 spoke 20" wheel. My suspicion is weaker as the designer would never have considered lateral forces and whilst spoked wheels aren't designed for that either there is plenty of evidence to show they can cope with them. I certainly like the look of them and I'd love them to be OK but certainly the axle and I suspect the "spokes" say otherwise. I also suspect that even if the 3/8 axle would cope any "spoke" failure would be swift and catastrophic unlike a traditional set of spokes which will fail slowly enough to not have you bouncing down the road.
at $15 each might be worth the gamble. I will certainly let the group know of my experiences if I go that route.
 
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Even if they are 3/8 you can get high tensile axles that may do a better job. High tensile ones are more likely to break than bend though. You gain on the swings and loose on the roundabouts. From memory of looking at them myself there is no chance of discs so it'll be rim brakes with those.

It's worth mentioning that one of my donor bikes has a 3/8 rear axle that is bent and that was fixed at both sides!
 
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