Doctor, you promised!!!
#1
...
Thread Starter
Join Date: Oct 2021
Location: Whitestone and Rensselaerville, New York
Posts: 1,512
Bikes: Bicycles? Yup.
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 481 Post(s)
Liked 1,586 Times
in
735 Posts
Doctor, you promised!!!
Can the broken Centurion be revived?
Chief Surgeon scarlson is masked and prepared for hours of detailed work. Attending Physicians BTinNYC and southpawboston have reviewed their bullet list of witty banter topics and are ready to support Dr Carlson.
Is this everything we need?
Post Op
Thank you scarlson, many times thank you. I had a great time in the lab with you and soutpawboston...and I learned a lot.
First ride on the reborn 1989 Centurion Prestige yesterday, and it's lovely. Mostly 105, Ultegra cranks and DA brakes.
Last edited by BTinNYC; 04-26-22 at 08:36 AM.
Likes For BTinNYC:
#2
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
Likes For ThermionicScott:
Likes For easyupbug:
#4
...
Thread Starter
Join Date: Oct 2021
Location: Whitestone and Rensselaerville, New York
Posts: 1,512
Bikes: Bicycles? Yup.
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 481 Post(s)
Liked 1,586 Times
in
735 Posts
scarlson would weld for 2-3 seconds, stop, inspect, file, clean, file, inspect, clean, inspect, file, clean, then weld for 2-3 seconds. It reminded me of the only other detailed metal work I've seen up close, gunsmithing on fine old firearms. I guess the total weld time was around 25 seconds.
Likes For BTinNYC:
#5
2k miles from the midwest
Join Date: Feb 2005
Location: Washington
Posts: 1,964
Bikes: ~'75 Colin Laing, '80s Schwinn SuperSport 650b, ex-Backroads ti project...
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 525 Post(s)
Liked 931 Times
in
446 Posts
I have a nice old mystery frame with the same failure.... but chromed dropouts. I'm guessing it'll be easier to replace the whole dropout in my case.
#6
Senior Member
Join Date: Dec 2020
Location: Wake Forest, NC
Posts: 5,790
Bikes: 1989 Cinelli Supercorsa
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 3511 Post(s)
Liked 2,926 Times
in
1,775 Posts
Glad to see the patient and dad are doing well.
#8
Senior Member
Join Date: May 2012
Location: Point Reyes Station, California
Posts: 4,528
Bikes: Indeed!
Mentioned: 92 Post(s)
Tagged: 0 Thread(s)
Quoted: 1507 Post(s)
Liked 3,478 Times
in
1,132 Posts
Brent
#9
Senior Member
Join Date: Dec 2005
Posts: 17,158
Mentioned: 481 Post(s)
Tagged: 0 Thread(s)
Quoted: 3810 Post(s)
Liked 6,702 Times
in
2,612 Posts
Hey, I've been in that workshop! @scarlson is the man with the tools! And his beer is still in my fridge!
#10
Space Ghost
Join Date: Oct 2017
Location: NYC
Posts: 1,762
Bikes: Bridgestone, Fuji, Iro, Jamis, Gary Fisher, GT, Scott, Specialized and more
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 292 Post(s)
Liked 412 Times
in
318 Posts
“ I love it when a plan comes together! ” - John “Hannibal” Smith
Likes For mprince:
#12
Senior Member
Join Date: Feb 2002
Posts: 1,177
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 117 Post(s)
Liked 71 Times
in
51 Posts
scarlson would weld for 2-3 seconds, stop, inspect, file, clean, file, inspect, clean, inspect, file, clean, then weld for 2-3 seconds. It reminded me of the only other detailed metal work i've seen up close, gunsmithing on fine old firearms. I guess the total weld time was around 25 seconds.
#13
...
Thread Starter
Join Date: Oct 2021
Location: Whitestone and Rensselaerville, New York
Posts: 1,512
Bikes: Bicycles? Yup.
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 481 Post(s)
Liked 1,586 Times
in
735 Posts
mig IIRC.
Hopefully Dr C will chime in with some reality.
It was "a trip" for me, so I don't remember everything, but as soon as I walked into the shop the smell of turned cutting oil put me at ease. Very unusual circumstances to be in Cambridge MA, let alone in the basement machine shop of a very elite graduate studies building talking with two interesting smart gents.
Hopefully Dr C will chime in with some reality.
It was "a trip" for me, so I don't remember everything, but as soon as I walked into the shop the smell of turned cutting oil put me at ease. Very unusual circumstances to be in Cambridge MA, let alone in the basement machine shop of a very elite graduate studies building talking with two interesting smart gents.
Likes For BTinNYC:
Likes For bamboobike4:
#15
Senior Member
Join Date: Jun 2010
Location: Medford MA
Posts: 2,089
Bikes: Ron Cooper touring, 1959 Jack Taylor 650b ladyback touring tandem, Vitus 979, Joe Bell painted Claud Butler Dalesman, Colin Laing curved tube tandem, heavily-Dilberted 1982 Trek 6xx, René Herse tandem
Mentioned: 80 Post(s)
Tagged: 0 Thread(s)
Quoted: 964 Post(s)
Liked 1,451 Times
in
723 Posts
I'm so happy you got the bike put together and everything is working! Thanks for posting the pictures! It was great to meet you and host a little impromptu get-together of the east-coast C&V community. I had such a good time with you guys.
MIG! It's faster, so less total heat gets put into the thing. Also, I knew I'd be adding a ton of filler, and MIG has that built-in. TIG is always good for something a little bit less ghastly. These broken dropouts are best welded like oil pipelines: grind, weld, grind, repeat. I learned stick and MIG welding from reading pipeline welding documentation. I read a lot and watched a lot of videos when I was learning to weld, and the pipeliners were the guys that made the most sense to me.
I'm not a doctor - yet!! Hopefully within the next six months I'll defend my PhD thesis and THEN I'll be a doctor! I will invite you to virtually attend my thesis talk.
It was a bit of a trip for me, too! I'm always happy to make new friends and have a little fun fixing a bike in the process.
Harvard has four machine shops (that I know of and have access to) and that shop is my favorite.
You forgot to mention the lovely Talisker single malt you gave me afterwards. It was lovely having a drink and chatting after the job was done.
I am drinking some right now along with with a San Pellegrino seltzer.
MIG! It's faster, so less total heat gets put into the thing. Also, I knew I'd be adding a ton of filler, and MIG has that built-in. TIG is always good for something a little bit less ghastly. These broken dropouts are best welded like oil pipelines: grind, weld, grind, repeat. I learned stick and MIG welding from reading pipeline welding documentation. I read a lot and watched a lot of videos when I was learning to weld, and the pipeliners were the guys that made the most sense to me.
mig IIRC.
Hopefully Dr C will chime in with some reality.
It was "a trip" for me, so I don't remember everything, but as soon as I walked into the shop the smell of turned cutting oil put me at ease. Very unusual circumstances to be in Cambridge MA, let alone in the basement machine shop of a very elite graduate studies building talking with two interesting smart gents.
Hopefully Dr C will chime in with some reality.
It was "a trip" for me, so I don't remember everything, but as soon as I walked into the shop the smell of turned cutting oil put me at ease. Very unusual circumstances to be in Cambridge MA, let alone in the basement machine shop of a very elite graduate studies building talking with two interesting smart gents.
It was a bit of a trip for me, too! I'm always happy to make new friends and have a little fun fixing a bike in the process.
Harvard has four machine shops (that I know of and have access to) and that shop is my favorite.
You forgot to mention the lovely Talisker single malt you gave me afterwards. It was lovely having a drink and chatting after the job was done.
I am drinking some right now along with with a San Pellegrino seltzer.
__________________
Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.
Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.
#16
verktyg
Join Date: Jul 2006
Location: SF Bay Area
Posts: 4,030
Bikes: Current favorites: 1988 Peugeot Birraritz, 1984 Gitane Super Corsa, 1980s DeRosa, 1981 Bianchi Campione Del Mondo, 1992 Paramount OS, 1988 Colnago Technos, 1985 RalieghUSA SBDU Team Pro
Mentioned: 207 Post(s)
Tagged: 0 Thread(s)
Quoted: 1036 Post(s)
Liked 1,238 Times
in
654 Posts
Beauty Is In The Eye Of The Beholder!
IMLTH artistic opinion, not pretty but VERY functional, especially the part about the care taken to get good weld penetration...
I picked up an early 80's Bertin SSC Reynolds 531SL frame a number of years back. When I finally got around to building it up, upon close inspection I noticed what appeared to be a scratch in the DS dropout. Scraping away some paint, I realized the it was a crack!
I took the frame to Ed Litton to see what he thought about replacing the dropout. While we were discussing the problem, he'd already started grinding a 30° chamfer into the crack. As he started on the inside the crack broke through, probably residual stress. He TIG welded both sides and was all done within 20 minutes including a shot of primer! Not pretty bu functional!
Those Shimano UF dropouts had a reputation for cracking/breaking in the area!
I was being extra vigilant in my inspection... Previously that same week I found a Stronglight crank arm with laminar cracking due to a defective billet.
Also I had a brand new Nitto Pearl stem that when admiring the workmanship when I spotted what looked like a scratch. At 200x it was clearly another crack! The good news is that I contacted Nitto in Japan. They sent me a replacement stem from Japan OVERNIGHT!!! Also a shipping container to return the defective one! Talk about product support and service.
Anyway, nice work on the Centurion repair.
verktyg
I picked up an early 80's Bertin SSC Reynolds 531SL frame a number of years back. When I finally got around to building it up, upon close inspection I noticed what appeared to be a scratch in the DS dropout. Scraping away some paint, I realized the it was a crack!
I took the frame to Ed Litton to see what he thought about replacing the dropout. While we were discussing the problem, he'd already started grinding a 30° chamfer into the crack. As he started on the inside the crack broke through, probably residual stress. He TIG welded both sides and was all done within 20 minutes including a shot of primer! Not pretty bu functional!
Those Shimano UF dropouts had a reputation for cracking/breaking in the area!
I was being extra vigilant in my inspection... Previously that same week I found a Stronglight crank arm with laminar cracking due to a defective billet.
Also I had a brand new Nitto Pearl stem that when admiring the workmanship when I spotted what looked like a scratch. At 200x it was clearly another crack! The good news is that I contacted Nitto in Japan. They sent me a replacement stem from Japan OVERNIGHT!!! Also a shipping container to return the defective one! Talk about product support and service.
Anyway, nice work on the Centurion repair.
verktyg
__________________
Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
Last edited by verktyg; 04-27-22 at 12:18 AM.
Likes For verktyg:
#17
Death fork? Naaaah!!
#18
...
Thread Starter
Join Date: Oct 2021
Location: Whitestone and Rensselaerville, New York
Posts: 1,512
Bikes: Bicycles? Yup.
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 481 Post(s)
Liked 1,586 Times
in
735 Posts
Left it solid for strength.
I've been riding the NY Empire Trailway in Westchester, Putnam and Dutchess on quiet weekdays. Easy riding paved bike trail all the way from Bronx to Poughkeepsie with maybe 2 miles of on-road.
I've been riding the NY Empire Trailway in Westchester, Putnam and Dutchess on quiet weekdays. Easy riding paved bike trail all the way from Bronx to Poughkeepsie with maybe 2 miles of on-road.
#19
Senior Member
Join Date: Jun 2010
Location: Medford MA
Posts: 2,089
Bikes: Ron Cooper touring, 1959 Jack Taylor 650b ladyback touring tandem, Vitus 979, Joe Bell painted Claud Butler Dalesman, Colin Laing curved tube tandem, heavily-Dilberted 1982 Trek 6xx, René Herse tandem
Mentioned: 80 Post(s)
Tagged: 0 Thread(s)
Quoted: 964 Post(s)
Liked 1,451 Times
in
723 Posts
Yeah, we discussed dressing it up with a couple more passes, but decided it wasn't necessary! Time better spent having a drink and a chat.
I have done a fully dressed-up/invisible repair on a French constructeur frame that shall not be named at this time. Aesthetics just weren't a huge deal in this instance, and may have even been the enemy of a job well done. Also, holy merde, if you'd seen the size of the crack I'd need to fill after I finished grinding prep! It was like the grand canyon! Again perfect for pipeline-style welding.
I wish I'd taken pictures along the way, but conversation with friends was more fun/important. I had to grind out most if not all of the adjuster hole, because the metal was so distorted and greasy in those fine threads, even after acetone and a wire brush I wasn't confident I could get it clean enough not to form voids and get brittle. I had a big gap to fill! I clamped a thick copper backing to both halves of the dropout (copper won't get involved in the weld), separated by the required a-little-more-than-10mm for the axle to slide in. The gap to fill was about 3/32" at the bottom. Laid a root pass down (tie into one side, then the other, don't heat up the copper backing!), ground, filled it up with a finish pass or two (apply more heat on the finish pass to penetrate in and tie the whole thing together), then put the copper backing on the other side and did the inside. Then I did a bunch more filing to get things flat, and we properly spread the frame using the Sheldon Brown technique with a piece of lumber braced against the seatpost. I'd forgotten my alignment tools, so I did a rough job with calipers and a crescent wrench. BTinNYC did the final alignment when he got home. A rough guide for alignment is also to feel for dropout flex when you tighten the quick release. If you feel the dropouts flex as you tighten the QR, it means they're conforming to the axle, and aren't parallel to those faces.
I think the original failure was caused by a combination of things. The wheel was spaced at 130, but the frame was spaced 126mm. The frame hadn't been spread, instead it was just sprung apart (making for a lack of alignment when at 130). I think the dropouts are pretty hard metal, and the modern axle didn't have very aggressive knurling on the end of the locknut. These factors (DO misalignment, lack of dig-in) combined to allow the axle to slip forward and diagonally, and then I think the tire caught up on a chainstay, brake, or seatstay, bringing it to a sudden stop, and the momentum of the rider was brought to bear on the bottom of the dropout, the wheel wanting to remain at rest and the rider/bike wanting to go forward.
__________________
Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.
Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.
Likes For scarlson:
#20
Senior Member
Join Date: Jan 2013
Posts: 2,679
Bikes: too many sparkly Italians, some sweet Americans and a couple interesting Japanese
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 569 Post(s)
Liked 582 Times
in
409 Posts
The chrome damage I am accustomed to with a replacement of a Campagnolo dropout.
#21
Senior Member
Join Date: Oct 2009
Posts: 1,103
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 288 Post(s)
Liked 330 Times
in
160 Posts
You earned street cred, got to bond with your new ride, and a little adventure to boot. A win all the way around. Hats off to scarlson for keeping a good one on the road!