filing lugs / shaving off parts
#1
Junior Member
Thread Starter
Join Date: Jul 2011
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
filing lugs / shaving off parts
Hi all,
I've been using the bike forums for the answers to all my cycling questions but this is my first post. I searched and found a little on what I'm asking but not much, so here it goes...
I'm restoring a 1982 peugeot ph10. Several components were missing so I just recently purchased another peugeot for parts. Having the extra frame, I figured it would be a great opportunity to build up a clean fixed gear (though typically I'd prefer to restore than completely alter/potentially ruin a bicycle, I just can't get over the look of a super clean simple machine and I have no emotional connection to bicycle I just purchased .
Anyways, I'm in the process of removing/filing down the brake housing guides and extra nubs here and there but I was wondering about the lugs and fender bosses (not sure if that's the proper name, I'm talking about the threaded nubs near the front/rear dropouts where a fender/rack could be attached). For the lugs, I was wondering if I would damage/cause structural issues if I filed them down so they smoothly transitioned to the tubing - is this possible? I've seen frames where the lugs smoothly transition but am not sure if this is possible after the fact - especially on a 30 yr. old frame. I wouldn't file the entire lug down; the transition would start from the tubing into 30-40% the lug. If ill-advised, is it at least sound to bevel the sharp edges or round out the points? For the fender nubs, I just want to clean cut them off and was wondering if this could weaken the frame. Since I'm not concerned for the original finish (I'm repainting), I'd like bring the frame down to a most minimal form. Thoughts?
Thanks!
Bernardo
I've been using the bike forums for the answers to all my cycling questions but this is my first post. I searched and found a little on what I'm asking but not much, so here it goes...
I'm restoring a 1982 peugeot ph10. Several components were missing so I just recently purchased another peugeot for parts. Having the extra frame, I figured it would be a great opportunity to build up a clean fixed gear (though typically I'd prefer to restore than completely alter/potentially ruin a bicycle, I just can't get over the look of a super clean simple machine and I have no emotional connection to bicycle I just purchased .
Anyways, I'm in the process of removing/filing down the brake housing guides and extra nubs here and there but I was wondering about the lugs and fender bosses (not sure if that's the proper name, I'm talking about the threaded nubs near the front/rear dropouts where a fender/rack could be attached). For the lugs, I was wondering if I would damage/cause structural issues if I filed them down so they smoothly transitioned to the tubing - is this possible? I've seen frames where the lugs smoothly transition but am not sure if this is possible after the fact - especially on a 30 yr. old frame. I wouldn't file the entire lug down; the transition would start from the tubing into 30-40% the lug. If ill-advised, is it at least sound to bevel the sharp edges or round out the points? For the fender nubs, I just want to clean cut them off and was wondering if this could weaken the frame. Since I'm not concerned for the original finish (I'm repainting), I'd like bring the frame down to a most minimal form. Thoughts?
Thanks!
Bernardo
#2
Decrepit Member
The dropout fender/rack threaded eyelets can be removed without affecting the structural integrity of the frame.
Lugs are often "thinned" by filing them down as the lug approaches the shoreline with the tube. This reduces the potential for stress risers at the tube to lug interface. It's not a good idea to file the edges of the lug so much that the lug "feathers" into the tube as that removes too much meat from the lug and could compromise strength.
See "So how does finishing the lugs add strength?" HERE.
Lugs are often "thinned" by filing them down as the lug approaches the shoreline with the tube. This reduces the potential for stress risers at the tube to lug interface. It's not a good idea to file the edges of the lug so much that the lug "feathers" into the tube as that removes too much meat from the lug and could compromise strength.
See "So how does finishing the lugs add strength?" HERE.
#3
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,363
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,664 Times
in
2,497 Posts
I would leave it alone myself. Especially the chrome bits. I don't know your model of bike, but Peugeot usually spot welded the "braze ons" on.
I'm not a big fan of cleaning up lugs after the fact. Who knows what you might reveal? There are bound to be voids under those lugs; to completely fill them would have taken longer than it was worth for Peugeot. A pressed steel lug almost always has gaps where the metal was bent and welded. The welds were crappy enough that it would be very difficult to fill them without adding another step to the process. One look at these bikes will tell you they didn't take any unnecessary steps.
If you clean up any stray filler, make sure not to cut into the tubes.
I can't see why this would be correct. Most builders don't do this because it's not what people want nowadays, but the UK builders from back in the day would feather their lugs, and there were plenty of U.S. builders that did it as well. I imagine feathering was mostly done after the fact because otherwise the lug would be hard to braze.
I'm not a big fan of cleaning up lugs after the fact. Who knows what you might reveal? There are bound to be voids under those lugs; to completely fill them would have taken longer than it was worth for Peugeot. A pressed steel lug almost always has gaps where the metal was bent and welded. The welds were crappy enough that it would be very difficult to fill them without adding another step to the process. One look at these bikes will tell you they didn't take any unnecessary steps.
If you clean up any stray filler, make sure not to cut into the tubes.
I can't see why this would be correct. Most builders don't do this because it's not what people want nowadays, but the UK builders from back in the day would feather their lugs, and there were plenty of U.S. builders that did it as well. I imagine feathering was mostly done after the fact because otherwise the lug would be hard to braze.
Last edited by unterhausen; 07-19-11 at 12:44 PM.
#4
Senior Member
Join Date: Sep 2008
Location: Collegeville, PA
Posts: 1,352
Bikes: Ruckelshaus Randonneur, Specialized Allez (early 90's, steel), Ruckelshaus Path Bomber currently being built
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
I can't see why this would be correct. Most builders don't do this because it's not what people want nowadays, but the UK builders from back in the day would feather their lugs, and there were plenty of U.S. builders that did it as well. I imagine feathering was mostly done after the fact because otherwise the lug would be hard to braze.
#5
framebuilder
It has long been a tradition that the best of the American builders file lugs thinner. We don’t taper the thickness so the edges blend into the tubes but we do thin them so they end up to be about a mm thick. This comes from a couple of influences. The first is that the father of American builders - Albert Eisentraut - did this and got a lot of publicity in American bicycling magazines in the 70’s. It became the defacto standard of judging quality. The second reason was that when we got back from our apprenticeships in Europe, we needed to visually show why our frames were better than our European competition (we didn’t compete against other at that time). Our spiel was that we not only took time to make frames look better where you could see it but also with alignment and mitering where you couldn’t.
There is plenty of meat on your Peugot lugs to thin them some, just don’t get carried away. I would start by evening the thickness all the way around. Pressed lugs are always uneven in thickness. Then you could evaluate whether you wanted to thin them more.
Start on the sides of the lugs first where it is more awkward to get a decent length file stroke. Be careful not to let the file slip off the lug onto the tube. This rounds the edge (the mark of an amateur). The top and bottom lug tips should be done last because it is easy by comparison to motor those down. Use a bastard cut file to hog off the offending bulk. Next go to a fine cut file to remove the file marks left by the bastards and then polish with 80 grit emery cloth to give a final smooth finish.
There is plenty of meat on your Peugot lugs to thin them some, just don’t get carried away. I would start by evening the thickness all the way around. Pressed lugs are always uneven in thickness. Then you could evaluate whether you wanted to thin them more.
Start on the sides of the lugs first where it is more awkward to get a decent length file stroke. Be careful not to let the file slip off the lug onto the tube. This rounds the edge (the mark of an amateur). The top and bottom lug tips should be done last because it is easy by comparison to motor those down. Use a bastard cut file to hog off the offending bulk. Next go to a fine cut file to remove the file marks left by the bastards and then polish with 80 grit emery cloth to give a final smooth finish.
#6
Member
Join Date: Oct 2009
Posts: 45
Bikes: Winter Bicycles
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
I'd leave any bike boom lug alone. I've seen plenty of bikes held together entirely by the spot weld on the bottom of the tube/ lug. I recently saw an older French bike that I could actually see day light through the gap (not crack) between the ST and BB socket- it just never had filler added there. Lug thinning presupposes tight miters and good filler flow/ internal fillet. If you don't now that is there (and it likely isn't) then leave the thick lug to act as the structural member it has been for the last few decades.
Last edited by Eric Estlund; 07-20-11 at 10:56 AM.
#7
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,363
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,664 Times
in
2,497 Posts
having fixed many bike-boom European bikes, I have to agree with Eric. You never know if you have a bike made by the new guy after lunch on Friday. It's typical to find major flaws in the construction in these bikes.
BTW, modifying a vintage bike is frowned upon by a lot of people. Not that it's anyone's business what you do with your bike, but it's a consideration.
BTW, modifying a vintage bike is frowned upon by a lot of people. Not that it's anyone's business what you do with your bike, but it's a consideration.
#8
Junior Member
Thread Starter
Join Date: Jul 2011
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Thanks everyone for the replies!
I will cut off the eyelets for the fenders since there are no concerns and will proceed with caution regarding the lugs. I think first I will strip the bicycle down to raw metal to better evaluate the lugs. Most are fairly clean and actually not too thick so considering the potential poor construction I will likely just clean them up a bit and perhaps thin them down slightly to even them out.
I know many folks strongly discourage altering vintage bicycles - like I said earlier myself, I'm usually one for original restoration... which is why I'm painstakingly cleaning and fixing the '82 ph10 (cleaning/sanding/polishing heavily abused metal is a real test of love and patience!) My dream fixed gear would be a custom design I'd have built for me but considering I don't have the cash to drop for such a frame now... I'd like to build up this peugeot as a temporary vision of what could be Plus I think a tasteful conversion wouldn't be too frowned upon... no wacky colors or ridiculously deep rims. I'm thinking the Brooks swallow, shellacked cloth tape and Ghisallo wooden rims will likely be the best this frame ever saw.
I will cut off the eyelets for the fenders since there are no concerns and will proceed with caution regarding the lugs. I think first I will strip the bicycle down to raw metal to better evaluate the lugs. Most are fairly clean and actually not too thick so considering the potential poor construction I will likely just clean them up a bit and perhaps thin them down slightly to even them out.
I know many folks strongly discourage altering vintage bicycles - like I said earlier myself, I'm usually one for original restoration... which is why I'm painstakingly cleaning and fixing the '82 ph10 (cleaning/sanding/polishing heavily abused metal is a real test of love and patience!) My dream fixed gear would be a custom design I'd have built for me but considering I don't have the cash to drop for such a frame now... I'd like to build up this peugeot as a temporary vision of what could be Plus I think a tasteful conversion wouldn't be too frowned upon... no wacky colors or ridiculously deep rims. I'm thinking the Brooks swallow, shellacked cloth tape and Ghisallo wooden rims will likely be the best this frame ever saw.
#9
Senior Member
Join Date: May 2010
Location: Bastrop Texas
Posts: 4,416
Bikes: Univega, Peu P6, Peu PR-10, Ted Williams, Peu UO-8, Peu UO-18 Mixte, Peu Dolomites
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 929 Post(s)
Liked 1,595 Times
in
1,021 Posts
You taking a Peugeot frame and making it look like something it was not made to be. I guess I can see that. But is it still a Peugeot? Surprisingly I see a Peugeot frame cleaned and lugs intact even with new paint and decals as a Peugeot. Even if it is converted to a Fixy. I also see a Peugeot frame with modified lugs as a Franken Bike.
Don't get me wrong, I have added Down Tube Bosses, and brazed on Dereailluer Hangers and Cable Guides to many vintage frames. But to be sure the end result was a Franken Bike no matter how pretty it was. And I am proud of my Franken Bikes. I do though appreciate a fully restored original frame in its original configuration even it has had all of its components stripped and has been converted to a Fixy.
So I'm thinking why? In a store bought Fixy everything is smooth clean and set. In a personally converted Fixy the wheels, chain line, crank, chain and other components have been meticulously set, and often by trail and error. So in a way leaving the Lugs and Bosses on identifies the bike as your personal accomplishment. It also shows your personal respect for a vintage frame... Just Saying...
Don't get me wrong, I have added Down Tube Bosses, and brazed on Dereailluer Hangers and Cable Guides to many vintage frames. But to be sure the end result was a Franken Bike no matter how pretty it was. And I am proud of my Franken Bikes. I do though appreciate a fully restored original frame in its original configuration even it has had all of its components stripped and has been converted to a Fixy.
So I'm thinking why? In a store bought Fixy everything is smooth clean and set. In a personally converted Fixy the wheels, chain line, crank, chain and other components have been meticulously set, and often by trail and error. So in a way leaving the Lugs and Bosses on identifies the bike as your personal accomplishment. It also shows your personal respect for a vintage frame... Just Saying...
__________________
No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
#10
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,363
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,664 Times
in
2,497 Posts
I don't care to restart an 11 year old discussion. I think I'm going to split out the new question into its own thread and close this one.
Likes For unterhausen:
Thread
Thread Starter
Forum
Replies
Last Post
mnmkpedals
Classic and Vintage Sales
6
09-24-16 09:27 AM
tsappenfield
Classic & Vintage
34
12-25-12 08:09 PM