Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Crack in Miyata at internal cable routing

Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

Crack in Miyata at internal cable routing

Reply

Old 07-11-18, 11:11 AM
  #1  
squirtdad
Senior Member
Thread Starter
 
squirtdad's Avatar
 
Join Date: Jul 2006
Location: San Jose (Willow Glen) Ca
Posts: 5,671

Bikes: 90/91 De Rosa, '84 Team Miyata, '82 nishiski, 84 Torpado super strada (Cino someday) RIP '89 Miyata 1400

Mentioned: 45 Post(s)
Tagged: 0 Thread(s)
Quoted: 633 Post(s)
Crack in Miyata at internal cable routing

This is more to share than anything, I am assuming the frame is toast and starting to look for a new frame (58 cm or so if any one has anything cool )
I have hear for a while that Miyata's with the internal cable routing were prone to cracks.....and checking my bike yesterday found this crack (it is a crack not a scatch..pic is not great) and you can see the starting point at the end of the straight part. The bike was bought new and has always been kept inside, no rust....I am clyde so it has had some stress

I am thinking the only fix would be a top tube replacement (have a shop that builds close, Silva Cycles, and will get an estimate) but probably between fix, paint and everything thinking I will look for a new frame.

thoughts? thankx

__________________
Looking for Torpado Superlight 58cm
squirtdad is offline  
Reply With Quote
Old 07-11-18, 11:38 AM
  #2  
Colnago Mixte
Senior Member
 
Join Date: Sep 2017
Location: Center of Central CA
Posts: 1,688
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 891 Post(s)
(wrong forum)

Last edited by Colnago Mixte; 07-11-18 at 02:12 PM. Reason: Added Pics
Colnago Mixte is offline  
Reply With Quote
Old 07-11-18, 07:58 PM
  #3  
TiHabanero
Senior Member
 
Join Date: Nov 2012
Posts: 1,644
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Ideally a sleeve inserted internally and brazed up should hold it, however I wonder if a wrap on the outside will give the same result in durability with a lot less work.
TiHabanero is offline  
Reply With Quote
Old 07-12-18, 08:00 PM
  #4  
Doug Fattic 
framebuilder
 
Join Date: Dec 2009
Location: Niles, Michigan
Posts: 255
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Originally Posted by TiHabanero View Post
Ideally a sleeve inserted internally and brazed up should hold it, however I wonder if a wrap on the outside will give the same result in durability with a lot less work.
Internal sleeves is how i fixed my personal bike/frame that came off my roof rack going down the highway and badly dented the top tube. I made the sleeves on my lathe (each end had a different requirement) and brazed them in one at a time. This method worked great and I am surprised it isn't more commonly done (especially on brass brazed and pinned classic frames). I choose not to replace the through the top tube brake cable routing. I had a Hellenic seat stay attachment where the seat stays pass the seat tube and attach under the top tube so there was no way to just replace the entire tube tube.
Doug Fattic is offline  
Reply With Quote
Old 07-12-18, 10:23 PM
  #5  
CliffordK
Senior Member
 
CliffordK's Avatar
 
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 20,170
Mentioned: 124 Post(s)
Tagged: 0 Thread(s)
Quoted: 7100 Post(s)
How do you access the inside of the top tube? Is it open enough through the head tube?

There is another topic about the same bike with some suggestions of an external band.

RIP Miyata 1400

And, the OP has said he is planning on scrapping the frame rather than repairing.

Oh... in the other topic, there are notes about internally splined tubing. That might foil plans to shove reinforcement inside.
CliffordK is offline  
Reply With Quote
Old 07-13-18, 06:29 AM
  #6  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 17,183
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Is the hole in the butted area?

Andy replaced a top tube by cutting out the seat tube inside the seat tube lug. I know a lot of people just spring a new tube into the frame, that has to involve some blacksmithing of the lugs afterwards
unterhausen is offline  
Reply With Quote
Old 07-13-18, 08:27 AM
  #7  
pwyg
Member
 
Join Date: May 2013
Posts: 25
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Those Miyata's broke all the time it is a simple repair. The main thing is that the repairer should cut out the old tube and then mechanically remove the old tube from the lug, not burn it out since that will further weaken the steel tubes that are not being replaced. Putting a stainless steel guide tube is best if you are trying to keep the same concept going, but a couple of cable stops silver brazed on is hands down the strongest.
pwyg is offline  
Reply With Quote
Old 07-13-18, 12:09 PM
  #8  
squirtdad
Senior Member
Thread Starter
 
squirtdad's Avatar
 
Join Date: Jul 2006
Location: San Jose (Willow Glen) Ca
Posts: 5,671

Bikes: 90/91 De Rosa, '84 Team Miyata, '82 nishiski, 84 Torpado super strada (Cino someday) RIP '89 Miyata 1400

Mentioned: 45 Post(s)
Tagged: 0 Thread(s)
Quoted: 633 Post(s)
The amounts quoted by my shop f(not cheap, but good quality work, I have worked with same mechanic for 10 years or so), for either top tube replacement, or a colnago mixte type repair are high enough that I am looking for a new frame (am very close on one). So I am using this as a N-1, N+1 zero sum opportunity to get replacement frame that is going to be a step up.
__________________
Looking for Torpado Superlight 58cm
squirtdad is offline  
Reply With Quote
Old 07-13-18, 05:41 PM
  #9  
Doug Fattic 
framebuilder
 
Join Date: Dec 2009
Location: Niles, Michigan
Posts: 255
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
There are several huge advantages to splicing in a new piece of top tube rather than trying to replace the whole tube. 1st there is no heating involved in removing the damaged tube. And it is much easier to clean and prep for brazing. It does take a bit of care to get the ends square and some thought and investigation where the butting starts and ends. 2nd there is no mitering necessary although the 4 ends have to be cut to an exact length and be 90 square. 3rd getting out an old tube without damaging the lugs (especially if it has been pinned and brass brazed) and getting rid of any left over brazing material can be a real effort and not always successful. Cleaning up the end of a cut off tube is way easier by comparison.

Of course one has to have a lathe and thicker walled tubing to be the splices that can then be shaved down to within a thousandth of an inch to exactly fit each of the four sockets. I brazed one splice to the new middle of the top tube and the other splice to one of the ends of the frame tube. There is enough spring in the frame to allow the new tube to fit into the frame. Since I’ve been making frames professionally longer than many posters have been alive it was not a difficult braze for me to finish the other ends of the splices. Someone not as sure of how much silver should be added or have as great heat control could preplace a ring of silver inside instead and sweat it out.

I suppose it took me somewhere between 2 and 4 hours to complete the entire task not including painting. I made my frame out of 7/4/7 heat treated tubing so something heavier would be easier to do. After primer it looks indistinguishable from an undamaged frame.

Over many years I’ve repaired (including alignment) and repainted hundreds of frames (or more I haven’t counted). The Japanese made frames were some of the very best. Unlike some of the classic European builders (many who I have personally visited back in the 70’s) that were a bit sloppy and crude in their methods, the Japanese knew how to make an aligned steel frame.
Doug Fattic is offline  
Reply With Quote
Old 07-13-18, 05:46 PM
  #10  
Colnago Mixte
Senior Member
 
Join Date: Sep 2017
Location: Center of Central CA
Posts: 1,688
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 891 Post(s)
Meanwhile, my repaired 512 Competition laughs heartily at this thread. while enjoying a fine morning in the local hills.

Colnago Mixte is offline  
Reply With Quote
Old 07-13-18, 06:46 PM
  #11  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 10,781

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1468 Post(s)
I agree that a spliced in tube replacement is easier to do then a full length one. I've done a very few full tube and spliced in jobs. One difference that I will note is the customer's opinion. I have had a chance to do a few more tube replacements over the years and when I mentioned my choice to do a spliced in one I lost credibility in their eyes. As though using a lower cost method that fully retained all the joint craft that the OEM builder/brand used was somehow wrong. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service