Is my Cinelli style fork trashed?
10-27-08, 07:52 PM
#1
Senior Member
Thread Starter
Join Date: Jul 2008
Location: Melbourne, FL
Posts: 53
Bikes: 1988 Miyata 512 (retired), 2003 Specialized Stumpjumper, 1990's Bob Jackson ser#20602 (Messina, I think)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Is my Cinelli style fork trashed?
Well, I bought this great Bob Jackson, used, this summer. Since then I've noticed very strong "speed wobble" except it happens even at like, 10 mph. Blazing fast, I know.
I thought maybe the frame was too noodly or I was too fat. Today I read somewhere (maybe something from Jobst Brandt?) and someone mentioned they had a cracked fork and it made that type of wobble worse. Then I definitely read something by JB that said Cinelli-style internally lugged forks can crack. Then I'm thinking about how it sounds like my stem has been creaking/popping when I stand up to pedal...
I looked over at my bike across the office...
I rode carefully home and pulled the wheel out of the front fork and here's what I saw where the right leg meets the crown:
and
I am telling myself this is just a crack in the paint, but I fear it is the leg separating from the crown.
What do you see?
If the fork is trashed, would that have been causing my wobble problem or is that more a function of the geometry of the frame and fork?
Help?
I thought maybe the frame was too noodly or I was too fat. Today I read somewhere (maybe something from Jobst Brandt?) and someone mentioned they had a cracked fork and it made that type of wobble worse. Then I definitely read something by JB that said Cinelli-style internally lugged forks can crack. Then I'm thinking about how it sounds like my stem has been creaking/popping when I stand up to pedal...
I looked over at my bike across the office...
I rode carefully home and pulled the wheel out of the front fork and here's what I saw where the right leg meets the crown:
and
I am telling myself this is just a crack in the paint, but I fear it is the leg separating from the crown.
What do you see?
If the fork is trashed, would that have been causing my wobble problem or is that more a function of the geometry of the frame and fork?
Help?
10-27-08, 08:51 PM
#3
Procrastinateur supreme
IMHO it looks to me as if the fork tube on that side wasn't brazed or silver soldered all the way around - surprising on a JT, but it can happen. The tube end fits into a protruding tang on the crown, and metal has to be fed into the joint with care. The crack you see is at the very end of the tube as it meets the crown fork tine seat. The crown itself is not cracked here ... take it to a framebuilder with a good reputation. It may be that the fork blade only needs to be sandblasted and rebrazed/silver soldered. Again, skill is everything here. No amateurs need apply.
10-27-08, 08:55 PM
#4
Procrastinateur supreme
Oh Sorry... I meant Bob Jackson but I had visualized a nice Jack Taylor...
10-27-08, 09:31 PM
#5
Afterburners...good idea
Join Date: Mar 2005
Location: Washington
Posts: 280
Bikes: Lemond Zurich
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
Recommend retail therapy vice physical therapy. The former only takes a few minutes and is easily explainable to the spouse.
10-27-08, 10:06 PM
#6
Senior Member
Join Date: Sep 2007
Location: Vancouver
Posts: 1,437
Bikes: NOYB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
Paint wouldn't crack if there wasn't movement there.
I think you've got a busted fork.
Former owner mention anything about getting it repaired/re-aligned at some point?
I think you've got a busted fork.
Former owner mention anything about getting it repaired/re-aligned at some point?
10-28-08, 07:34 AM
#7
Senior Member
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656
Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!
Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2026 Post(s)
Likes: 0
Liked 1,095 Times
in
741 Posts
I agree the fork is cracked. Your speed-wobble at 10 mph certainly says something is seriously wrong and I expect you found it. Have the fork repaired or replaced RIGHT NOW. And be grateful it diodn't fail completely while you were riding it.
10-28-08, 08:19 AM
#8
Senior Member
Thread Starter
Join Date: Jul 2008
Location: Melbourne, FL
Posts: 53
Bikes: 1988 Miyata 512 (retired), 2003 Specialized Stumpjumper, 1990's Bob Jackson ser#20602 (Messina, I think)
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
well....
crap.
I suppose I'll replace it for now so I can ride, then find out about repairing.
Thanks for the input yall.
crap.
I suppose I'll replace it for now so I can ride, then find out about repairing.
Thanks for the input yall.
