Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 01-05-08, 08:34 PM   #1
!jayho!
Member
Thread Starter
 
Join Date: Nov 2007
Location: san jose, ca
Bikes: Univega Sportour
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Question about cracks in frame

Hi folks. This is just my second post aside from my introduction, so thanks in advance for your insight! I've got a question regarding a couple small cracks that I just discovered in an older steel road frame of mine. Let me start by saying that I'm not doing any kind of serious training or racing or high performance riding or anything like that. I'm headed back to school full-time and in the process ditching the car in favor of biking and hopping on the train to do my commuting. My overall plan is to just rely on the car less and less and a bicycle more and more in life. I'm having a lot of fun getting back into biking after not even owning a bike for about 6 or 7 years. So back to this bike at hand... it's a 70's road frame and by no means a high end model -- a Motobecane Nomade Sprint. I realize that the steel used and the frame aren't to die for/top of the line, but it's a bigger bike (64cm) as I'm 6'7" (weigh about 210-215 pounds) and fits me pretty well and feels good riding. I haven't ridden it too much yet but the little that I did it was good. Plus it seems to be a great take-on-the-train-and-up-to-school-type low profile bike. The frame has got your normal nicks and scratches here and there and some slight rust in a few spots but really not too shabby. Pretty clean all around (for the most part) and in pretty good shape. Except... the thing is, I discovered some small cracks in the frame and I'm trying to determine whether the cracks make the bike "unsafe" and I should just ditch this frame and get something else, or if it's not that big of a deal and I'd be fine just riding as is for how I'm going to be using it. Specifically, the cracks are located where the seat stays meet the seat tube. See the pictures below. I noticed almost a peeling effect on the top of where these meet. I'm sure I could pull this back and break it off. And then the crack continues down and makes a slight curve toward the underside of the seat stay. It's doing this on both sides, but it's the right side where the crack is bigger/longer. In three of the pictures, the camera is just below the top tube and I'm looking back at the seat stay/seat tube juncture. In the other two pictures, I'm obviously looking down on the frame with the seatpost removed. Based on the pictures and my description, what do you guys think about the safety and structural stability of the bike in this shape? Should I continue riding it if everything else is fine, or just ditch it and pick up something else? If you want to see more pics, just drop me a line. Again, thanks in advance for your insight/opinions!




!jayho! is offline   Reply With Quote
Old 01-05-08, 08:46 PM   #2
J T CUNNINGHAM
Senior Member
 
Join Date: Nov 2006
Location: TORONTO , ONT , CA
Bikes: '86 AMBROSI / C RECORD. PINARELLO MONTELLO / FRAME, FORK.
Posts: 813
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My feeling is that you should visit a 'Bike Doctor',

before you need to see another type of doctor!


Reguards,
J T
J T CUNNINGHAM is offline   Reply With Quote
Old 01-05-08, 08:52 PM   #3
Cannondaler
Senior Member
 
Cannondaler's Avatar
 
Join Date: Dec 2007
Location: Atlantic Beach, FL
Bikes: Cannondale F600sl, Windsor Falkirk Carbon
Posts: 205
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It is a little hard to tell but it looks like the cracks are the end caps of the stays and not between the stay and the seat tube. Is this the case? It looks like the weld between the stay and the seat tube is ok but the cap that covers the tapered part of the outside of the stay is cracking off maybe. Hard to tell from the pictures tho. I would have a shop take a look at it. It could be no big deal or it could mean the stays are going to come off which wouldn't end well for the rider. The middle two pics make me a little uneasy about it tho.
Cannondaler is offline   Reply With Quote
Old 01-05-08, 08:59 PM   #4
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 29,111
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 174 Post(s)
Two recommendations:

1 Divide your postings into paragraphs. It will make them a lot easier to read.

2. Ditch the frame and get one that's in useable shape. I really can't really see how bad the cracks are but what I can see looks really serious.
HillRider is offline   Reply With Quote
Old 01-05-08, 09:00 PM   #5
!jayho!
Member
Thread Starter
 
Join Date: Nov 2007
Location: san jose, ca
Bikes: Univega Sportour
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Cannondaler, for the most part it does appear that the cracks are at the cap of the tapered part. But like you said, those middle pictures make me nervous as well, as it appears the crack has begun to actually curve underneath the weld between the stay and the seat tube.
!jayho! is offline   Reply With Quote
Old 01-05-08, 09:02 PM   #6
!jayho!
Member
Thread Starter
 
Join Date: Nov 2007
Location: san jose, ca
Bikes: Univega Sportour
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by HillRider View Post
Two recommendations:

1 Divide your postings into paragraphs. It will make them a lot easier to read.

2. Ditch the frame and get one that's in useable shape. I really can't really see how bad the cracks are but what I can see looks really serious.
Great point regarding the paragraphs, thank you kindly.

If the cracks look really serious from what you can see, I'm not too interested in taking many chances.

Thanks for your comments.
!jayho! is offline   Reply With Quote
Old 01-06-08, 06:58 PM   #7
supcom
You need a new bike
 
supcom's Avatar
 
Join Date: Aug 2002
Bikes:
Posts: 5,433
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The cracks are very serious. They are working they're way around the seat stays which will eventually fail if continued to be ridden.

I'm afraid that this frame is destined for the recycling bin.
supcom is offline   Reply With Quote
Old 01-07-08, 11:21 AM   #8
rmfnla
Senior Member
 
rmfnla's Avatar
 
Join Date: May 2005
Location: La La Land (We love it!)
Bikes: Gilmour road, Curtlo road; both steel (of course)
Posts: 6,243
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 223 Post(s)
I agree that the frame is history.

It is apparent from the hollow seat bolt bosses that it's a lower-end model so it's probably not worth trying to fix unless you feel like using it to learn frame repair.
__________________
Today, I believe my jurisdiction ends here...
rmfnla is offline   Reply With Quote
Old 01-08-08, 03:03 PM   #9
!jayho!
Member
Thread Starter
 
Join Date: Nov 2007
Location: san jose, ca
Bikes: Univega Sportour
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks to all for the comments. Knowing that this is indeed a lower-end frame, and not wanting to use this as a learning tool for frame repair, this seems like it would be a simple fix from an experienced frame repair person. Is that correct, and how much would you say this type of repair should cost? ...just saying if I did entertain this option.

Thanks!
!jayho! is offline   Reply With Quote
Old 01-08-08, 03:51 PM   #10
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 29,111
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 174 Post(s)
Quote:
Originally Posted by !jayho! View Post
Thanks to all for the comments. Knowing that this is indeed a lower-end frame, and not wanting to use this as a learning tool for frame repair, this seems like it would be a simple fix from an experienced frame repair person. Is that correct, and how much would you say this type of repair should cost? ...just saying if I did entertain this option.

Thanks!
A frame maker could repair the frame by either welding or brazing the cracks and reinforcing the area or replacing the seatstays entirely. Either repair would be worth it if the frame were valuable but too much to put into a low-line frame. I'd guess maybe $100 for the work but that's really just a guess. However, any repair would then necessitate a repaint and that will add from $2 (rattle-can DIY type) up to hundreds for a first class job.
HillRider is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 03:19 AM.