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  1. #1
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    Penny Farthing/Ordinary repair

    I've been asked to have a look at a broken penny farthing that has seen better days. I think I know what I'm going to do to fix it but would still like peoples opinions.

    Before I explain any more THIS BIKE WILL NOT BE RIDDEN AGAIN

    Please excuse the photos, the batteries died in my proper camera so my phone was all I had.

    First, here's an over view of the bike and the problem

    Complete bike by 18bikes, on Flickr


    Forks and 'headset' by 18bikes, on Flickr

    First repair
    The main frame has broken where it joins the 'headset'. The headset has no bearings and runs between centres. The pointed bar in this pic is basically the headtube. I think this joint has failed due to the poor penetration.


    What I need to recreate by 18bikes, on Flickr


    How not to braze a joint by 18bikes, on Flickr

    The solid bar it is attached to appears to be a plug into the main tube. The bar is 1" and the tube 1 5/8 with a generous fillet around the join. It appears to be pinned too which will make things more difficult.


    Is that a pin? by 18bikes, on Flickr

    I see a few ways of fixing this, some I like more than others.

    1)Drill the pin out, de-braze the bar from the tube, make new bar, cross drill and braze 'headtube' in with proper penetration. I'd probably like to use a larger diameter bar with a step to slip into the tube to provide more material around the side of the 'headtube'. Would look very close to original but be safer. I view this as the proper way to fix it but it is the most effort and I'm worried about the amount of heat needed to release the joint.

    2) cut the bar off square and braze a sleeve over it with a plug in the end, cross drill, braze headtube. Would be close visually to original but not as strong as option 1. Would be much easier.

    3) Cut bar off square, drill and tap into end, turn extension for bar with threaded stub, thread together, braze the joint to stop it unthreading, cross drill etc etc. Probably as much effort as option 1 but not as strong. Even though the bike will probably never be ridden, I'd rather not do this.

    4)Clean up existing pieces so they fit back together, get as much brass in there as possible and make the owner promise to never ride it again. Deffinitely the easiest option but I'm not doing it so we can forget it straight away.

    Whichever option I go for the 'headtube' will be put in the lathe to clean the centres up. I would prefer to do option 1 but think option 2 is the more realistic choice, what would other people do?

    Second repair
    The handlebar fillets have hairline cracks going almost all the way round the joints on both sides. If you wiggle one side of the bars, the other moves, suggesting that the bars were brazed in then bent. I'm thinking a quick remelt to pull some more brass into the join is all that's required here but again I'm open to other peoples opinion


    Handlebar crack (left side) by 18bikes, on Flickr

    It's a bit tricky to see in that photo, but trust me it's there. There are some more photos in this flickr set

    Again I would like to state this bike will probably never be ridden again

    Matt

  2. #2
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    Quote Originally Posted by 18bikes View Post
    The shorelining on the face is a classic sign of fatigue failure. Why there's brass on the right side face is another story - I wonder if it was starting to crack and someone tried to get some brass in there?

  3. #3
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    That's always a possibility, it's had a long life so no-one can be entirely sure what has or hasn't been done

  4. #4
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    Bit of extra information I forgot, the owner thinks the main tube was replaced at some point in the past. I believe this is the cause of the small cracks around the pin hole on one side (you need to look on the flickr pics for that one) when too much force/not a good enough fit was used

    Matt

  5. #5
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    I had one similar to this you could unscrew one of the conical seats and remove the front end to put it in the car, mine had a radial spoked main wheel which meant it was a bit flexy
    I did fall off mine and decided it was time to sell it before it hurt me ,

    Is there enough clearance between the wheel and the mainframe tube to red rill the pointed part in a good bit of the frame ?

  6. #6
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    Very cool and interesting to see an actual ordinary bike.
    NOTHING WORKS LIKE CLOCKWORK

    www.clockworkbikes.com

  7. #7
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    Quote Originally Posted by ade ward View Post
    I had one similar to this you could unscrew one of the conical seats and remove the front end to put it in the car, mine had a radial spoked main wheel which meant it was a bit flexy
    I did fall off mine and decided it was time to sell it before it hurt me ,

    Is there enough clearance between the wheel and the mainframe tube to red rill the pointed part in a good bit of the frame ?
    Both wheels on this one are radial, the owner has broken spokes before and had to make new ones. They thread into the hub (which has no bearings, just bushes) and have no nipple, you rotate the whole spoke to adjust tension. Apparently, when the wheel pringles (which it has in the past) you can just 'pop' it back and it comes back almost as true as it was. The rear wheel has a broken spoke at the moment but he is sorting that.

    I'd rather not redrill closer as it would mess with the geometry and make it look wierd(er)

    Matt

  8. #8
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    What year do you think this work was done? How much have things changed since then?

  9. #9
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    Almost seems that it would be better to replicate and splice than to try to repair.

  10. #10
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    I realise this is an old machine so the original construction may have been simple, but the tube replacement will have been done more recently (how recent is anyone's guess) and I think it could have been done better/finished better. To be honest it doesn't really matter as it's broken now and I'd like to put it right (as much as possible)

    I would much rather pull it completely to pieces and make new parts, but, I've never put a torch to something so bulky and I'm concerned about how much heat it's going to take to pull it apart and then putting it back together. I think I could borrow an extra torch which may help but if anyone has any experience of brazing this kind of cross section it would be greatly appreciated.

    Thanks
    Matt

  11. #11
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    Matt, I would be tempted to cut about 1/2 of the protruding rod off and drill a hole thru the solid rod to see just how long it is. That knowledge will help a lot when heating it up initially and also provide a much needed vent hole (i'm sure there is allready one but we don't like surprises).

    If you can increase the hole to around a 1/2" it will make it easier to heat and it will crush flat in the vise when you crank it down to put the twist on it.

    It might surprise you in how easy it come out. Who knows? that may even just be a feeder hole and not a pin hole in the tube.

  12. #12
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    That sounds like a good plan, I've just remembered I have a 15 and 22mm drill bits so if I can get it in the pillar drill I could remove a significant amount of the material

    Time to talk to the owner about how much work he wants putting into it

    Matt

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