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#1
02-09-2019, 09:44 AM
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(Stupid?) question about lugged steel frame modifications
This is probably a very stupid question, but here goes.
Let's say you have a lugged level top tube steel frame. Made of classic tubing and is a holy grail frame. And it's chromed. You flat out love how it rides. The frame is maybe 1cm too big, but it fits well. But the level top tube means that very little seatpost shows. So, can this be done? - De-braze seat tube cluster, top head tube lug weld and bottom seat stay weld; chop 3 cm off seat tube and turn it into a frame with a slightly sloping top tube. Can head tube lug and seat tube lug handle slight change in angles? Seat stays would intersect lower on seat tube and need to be cut. Top tube at seat tube lug might need to be cut too. Obviously a new paint job would be needed. Not sure how the chrome factors in to this. If that's doable, who could do it? Yeah, it would cost $$, but so does a new Peg or Zanc or Kirk or Spectrum... Thanks for any insight. 
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#2
02-09-2019, 10:47 AM
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Find one in your size...
The issue with the solution you have is that the angles will get wacky I like weird solutions but since I had something similar happened to me I can tell you that if you heat the lugs front and seatpost lug you could lower the whole top tube, again the result is that the angles are going crazy... the right way to do it is to take appart pretty much the whole frame, cut and put it back together. At that point unless you have money to do it, at least here in the US is a non economical solution, In south america you can get stuff like that done for fairly money. As i said before... find one in your size.
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#3
02-09-2019, 11:11 AM
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No. Just no.
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#4
02-09-2019, 11:18 AM
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What is the consequence of very little seatpost showing? Is it a standover issue? The Bob Jackson built for me in 1972 has 2" of seatpost showing but I have standover clearance. Bigger issue on fit is the long TT, so I have a 6cm stem on it, but it rides fine.
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#7
02-09-2019, 11:40 AM
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That'd be a no from me as well
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#8
02-09-2019, 12:26 PM
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Looking for insight into actual job of doing project. Let's get it out of the way that 1)yes, I'm crazy, 2)yes, I could look for another frame, 3)yes, gods would slay me, 4)etc.
Look at it this way. You have a set of really cool tubing and lugs and you want to build a custom bike. Tubing and lugs just happen to be welded together at the moment. And the geometry of head angle, seat angle, and everything else is really good, except seat tube length is taller than you want. You just want a nicer, more aesthetic looking bike. Not that anybody here is into the aesthetics of their bike... 
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#9
02-09-2019, 12:41 PM
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no, especially no because of chrome.
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please don't take anything I say personally, I am an idiot.
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#10
02-09-2019, 12:46 PM
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 ) challenge, it might be Bilenky.GL with it!
__________________
“A bicycle is not a sofa” -- Dario Pegoretti
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#11
02-09-2019, 12:47 PM
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It sounds like you want a different custom made bike. I have no specific expertise but you would likely need a different set of lugs if you are shortening the seat tube only. I think it would result in more than a slight change in seat tube angle. It will likely result in a bike with completely different ride characteristics. If you hadn’t said this was a grail bike and you love the ride characteristics I would say go for it since this bike would otherwise be a pile of tubes of no specific value to you and available for use.
Also I think the chroming of the tubes may present some challenges for re-work but that’s just a non-expert guess. Also standard request: pics!
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#13
02-09-2019, 01:10 PM
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 But I perfectly understand what's going through your head because I have gone down this path myself. Bottomline : Don't mess with it. Hopefully the responses on this thread are therapeutic enough to get you over this hump.
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 🏻* 
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#14
02-09-2019, 01:37 PM
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No.
Somebody out there might be willing to take it on, but the head tube lug won't allow that much change in its angle; higher quality lugs are quite specific to their fit (cheaper lugs used to allow a bit more flexibility/slop). If the construction quality of this grail bike matches its grail reputation, you're likely not going to be able to re-use the lugs. As I understand it, the typical method of repairing something like this would be to cut out a section of the top tube, and then heat the lugs enough to pull out the remaining bits of top tube from their respective lugs. So, the tubing wouldn't be original any more. Third, cutting down the seat tube while it's still attached to the rest of the bike is a non-trivial operation. You might well have to de-braze the seat tube from the bottom bracket. All in all, I'd highly recommend against it. If you love the fit otherwise, bring the frame to a framebuilder you trust and commission a duplicate but with a sloping top tube. It'll likely be cheaper, and you'll also still have the grail bike you began with.
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#15
02-09-2019, 03:11 PM
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Possible, but not recommendable
In order to accomplish those modifications, you'd need to remove the chrome, take things apart, use a new top tube, and it would all take much more time and some additional careful handling that wouldn't be necessary during a repair where new substitute parts are used.
This would become more expensive than a complete new frame, no matter how much sense it would seem to make if frame parts were legos. Plenty of practical voices have already chimed in to advise against this. What I have to say/add is that although it is possible to do it all, it would be more expensive, not just similarly expensive, than a new frame. You haven't mentioned why it's a frame that is special to you, but there also remains the question of whether or not it remains special once it strays from it's originality, even if someone performs a decent set of refinishing operations. Given what you've disclosed, it seems to not be a recommendable course of action.
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