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ffm

Member since Jun 2012 • Last active Apr 2021

Most recent activity

  • in Complete bikes and frame & forks
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    I have one of these as my dadbike, built up a bit like that. It's my favourite bike paint job ever.

  • in Components, clothing and miscellany
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    27.2 x 350mm seatpost

    @konadefer ?

  • in Components, clothing and miscellany
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    Also, pictures of the Simplex post:

    That's been pretty drastically cut down. There's no way that minimum insert line is still safe.

  • in Miscellaneous and Meaningless
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    T cut is a slightly abrasive car polish/rubbing compound that can restore very light scratches in paint.

  • in Miscellaneous and Meaningless
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    I've used it a few times with no ill-effects. I've also found that turtle wax works well for keeping things hydrophobic. You could always test the inside of a chainstay if you're concerned.

  • in Frame Builders
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    Could you epoxy in a long seatpost shim as a sleeve? The lip on its top would hold the broken seat tube down. If you wanted to get technical you could put a length of threaded rod down to the BB shell and use that to hold the whole thing in compression while it cures. It wouldn't be as solid as a long seat post down past that joint, but it would retain its ability to clamp the seat post properly, albeit with a smaller seat post size.

  • in Frame Builders
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    Although I'd err on the side of caution, is that definitely knackered given that the crack is above all the welds? Other than the issue of keeping the seatpost at the correct height, what would happen if you just used a super-long seatpost that went into the frame well below the junction of the top tube, seat tube and seat stays? Incidentally, how long is that seat post?

  • in Mechanics & Fixin'
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    The physics of bicycles and motorcycles are essentially the same but with more speed and power in the latter, the effects are going to be magnified

    I'm not sure about "magnified", I think having the power available to spin your back wheel and make it drift sideways is something that just doesn't happen on a bike other than in really specific conditions

    . I don't think that's the cause of all, or even most tank-slappers on motorbikes, but it's worth considering that the physics of those is potentially qualitatively different from similar-looking problems that you might get on a bike.

  • in Mechanics & Fixin'
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    That video's really interesting, the slow motion makes it look like the progressive worsening of the front wheel oscillation is partly due to the rear wheel losing traction and the rider having to counter-steer to negate that. On a bike that's obviously not going to happen, since you wont get the rear wheel to break sideways so easily, so the physics might be different. I have seen speed wobbles on bikes, in fact I managed to snatch mini_m off their bike before one took them into a pillar.

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