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trailie

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Posts posted by trailie
 
 
  1. On 7/21/2018 at 7:50 AM, stevem75 said:

    The G on the headstock more than likely was used to identify what the particular tube on the frame was to be used for.

     I've two M80 frames, one is stamped G and the other is stamped with a number 3. From my own manufacturing experience I used to think they might have been an inspectors stamp but your idea may well be more plausible Stevem75.

    http://ralphsbultaco.blogspot.com/

     

  2. Good job with the tank Manndolins. I've also got mine finished this week although I didn't do the actual painting. I did however cut it in two at one point to get rid of the old petrol sealer so its nice to see it back on the bike. 

    She had to come down some very steep stairs as well this week, so hopefully very soon I'll get a ride on her again.

     

    http://ralphsbultaco.blogspot.co.uk

     

     

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    • Like 8
  3.  I had thought of cutting the two big slots like you did but the boat repair man reckoned it wouldn't make any difference just cutting the thing in two bits. 

    Yours turned out looking really good Larry. Did you use anything inside it again afterwards. Brian was telling me he has a resin that he uses in chemical tanks that's resistant to acids, but ethanol's not really an acid, so I might go with whatever is currently the best - caswell maybe

  4.  I want to fit my front mudguard to a model 80 sherpa using the original shaped stays. I don't have any of these but I reckon I could make them easily enough with a little help.

     

    If anyone has a bike with these on it (twinshock maybe) could you do me a favour. Could someone screw them off and try to make a drawing or template with a few dimensions on it. It would give me a better idea than just working from a photo.

     

    Ralph

     

     

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    • Like 1
  5.  I started making a chainguard today for the M80. Got a sheet of 1.5mm aluminium about 18" square from a mate for free and made a folder from bits that where lying round the shed. Managed to put a nice curve on the top of it. Next it needs cut out and filed up. Maybe tomorrow.

     

     

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    • Like 5
  6. Yes indeed Larry, very easy for the spokes to snap when trying to loosen the nipples. But you'll know yourself, lathes with enough swing to accommodate the full wheel aren't as common, so most will find themselves forced into taking it apart for that reason. - A thought just came into my head, I know where there's a railway restoration yard - their bound to have big machinery - that's me sorted out next time.

    I kinda mentioned the hub distortion thing just because I'd heard it discussed here in another post somewhere and it was in my head while I was writing.

    • Like 1
  7. Have a Nice day

    Larry

    ;PS I wish someone would show & tell about brake lining truing, it must be simple tooling, if I should figure it out I will share with

    all interested.

    Larry, my thoughts initially were to bore out the remains of most of the existing steel liner and make a new new one to suit. I would have made a simple mandrel and mounted the bare hub on this, with just the bearings in it (no rim). I feel that the hub is pretty substantial and won't be pulled out of round by the spokes. (I've built several wheels for people and never had that happen). So a pretty simple set up really.

    The thing that troubled me most was deciding what fit I was going to choose. It had to be an interference fit but the precise class of fit I couldn't decide upon because I didn't have the experience of just how much the hub might expand if given a good amount of heat, and what I could get away with, if you know what I mean. The last thing I wanted was for the liner to spin inside the hub when I applied the brake.

    So I just took the lip off the edge of the old liner and went with thicker material on the shoes. When I was doing this on the lathe the hub was spinning really true inside, so I don't think you need to necessarily keep it in the rim for accuracy.

    Posted a couple of pictures of my setup on this link

    http://www.ralphsbultaco.blogspot.co.uk

    • Like 3
  8. For maximum braking power, --- put shims between the cam and the brake shoes ---- Then you should turn down the lining to the exact diameter of the brake drum.

    I should have done that - that would have been perfection :thumbup:

    • Like 1
  9. I was looking at your markings on the frame, I rubbed my frame down today and discovered a G and a P. One on the side of the headstock one on the top frame tube. It made me think these might be identity marks from the individual welders or factory inspectors. I know we worked a similar method in Shorts. I would have stamped any jigs I worked on with a T242, that was unique to me.

    The little square marks are a bit more peculiar. You say there is another set directly opposite. Almost seems like witness marks left by the jaws of a vice, although they look a bit too deep for that. Strange.

    Ralph

    http://www.ralphsbultaco.blogspot.co.uk

  10. Don't discount making the broken gear if you fail to source one. If you've still got the old one you'll find an engineer somewhere who can remanufacture it. No idea what this would cost mind you, unfortunately we don't have the facilities in our place. I once got a worn out mainshaft hard chromed and ground for not very much. This was way before the days of internet and ebay and I didn't know anywhere that I could get another one, so repair was my only option.

    http://www.ralphsbultaco.blogspot.co.uk

  11. That's a lovely wee bike your riding Woody, and I remember our M80 looking a bit "tired" like the one you had.

    When I was over in Barcelona this year I had hoped to find out a bit more about the bike but they don't have an M80 in the moto museum and the lady on the desk doesn't know much, although she's very nice about it, and the books they have are all in spanish.

    I called out at the Romero shop. The're a really nice family but on the day I was there he had to go to the hospital, so him and his wife didn't stay long. In fairness he's not really into the trials bikes. He worked in the race department so it's all TSS stuff he's into. His wife worked in the export office and she showed me photograph albums of old pictures from inside the factory and of different people working there. That would have been good if I'd more time to sit and look at them.

    I will say anytime I asked Peter what was the correct part he pointed to that cover picture from the owners manual. So it's the best thing I have to work from at the minute unless someone knows different ??

    Ralph

  12. This is a great history lesson Woody, you need to write a book sometime. I've got loads more to ask but it'll keep for another time.

    Thought I'd share a couple of the old photos I'd dug out. Me and my dad about 1977. Like most wee boys I'm more interested in building ramps and doing jumps. Notice nobody gave a toss about putting kids on motorbikes without a crash hat in those days, but back then we'd the sense not to hurt ourselves.

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    • Like 3
  13. So a nice range of answers there :) I think I'll put just the small Bultaco transfer on the side panels and the Spanish Championship '71 on top of the tank ahead of the seat, ( just because I like that wee badge !).

    I found that owners manual on ebay Woody - useful :thumbup: . Would I be right in thinking the kit campeon's were the ones fitted with lights?

    I vaguely remember the man we bought her off saying there was a tax book somewhere but he didn't know where it was or who had it, we never did need it anyway. It was a long time ago, I was only 10 at the time, I can't remember for sure, must ask my dad..

    I took the head staggers earlier and bought a mid box from frankiemountain on ebay. Hopefully it'll fit. I'll let you know when I get it. I'm still holding off on a front pipe until I see what shape I can make of fixing the dents in the old one.

    Stuart and Sparks, if you would, sometime I'll get you to post me a couple of good photos of your chain guard and the front mudguard stays. I think I could make these easily enough if I had a decent picture to go by.

    Thanks

 
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