aviation welding australia, any good on mtb fix

safreek

*******
ok, took the bike for a ride and it appears that the crack wasn't the cause of the noise (lucky I found it though) so where should I start in the search for the noise
 

Binaural

Eats Squid
ok, took the bike for a ride and it appears that the crack wasn't the cause of the noise (lucky I found it though) so where should I start in the search for the noise
If you previously thought it was the head tube crack, my money is on dry headset bearings that need to be regreased. It is related to pedalling or turning the bar, pulling up on it etc.?
 

safreek

*******
If you previously thought it was the head tube crack, my money is on dry headset bearings that need to be regreased. It is related to pedalling or turning the bar, pulling up on it etc.?
They are a sealed bearing, should there be grease outside it or is it just in the bearing case. Cheers for the input
 

stirk

Burner
ok, took the bike for a ride and it appears that the crack wasn't the cause of the noise (lucky I found it though) so where should I start in the search for the noise
I'm guessing the crack is your hip old man.

What are you doing when it makes the noise?
 

Mattyp

Cows go boing
If they welded over the crack, its possible that the top of your steerertube and the bottom of the steerertube are no longer in line/true, causing a misalignment and binding when you do it all back up and tighten it, which could be causing the noises. just a guess.
 
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safreek

*******
I'm guessing the crack is your hip old man.

What are you doing when it makes the noise?
Tbh I hadn't thought about my old bones or the tin foil crackling under the helmet, could be the cause.
To be serious though I have tried riding no hands, feet off cranks, feet on cranks. Only time I don't hear it is when I am in the air.
When I bounce up and down on it without moving I don't hear it so I am guessing it's not suspension related, pivots or such.
It really irritates after an hour or two, so much that I stop and go home
 

safreek

*******
If they welded over the crack, its possible that the top of your steerertube and the bottom of the steerertube are no longer in line/true, causing a misalignment and binding when you do it all back up and tighten it, which could be causing the noises. just a guess.
Maybe, but it is the exact noise as before
 

bear the bear

Is a real bear
Bottom Bracket, pedals, cleats, skewers, seatpost, seat rails, stem, headset, chainring bolts, derailleur pulleys, cassette, wheel bearings, etc etc.....
 

stirk

Burner
crack thread turns in creak thread - love it!

Isolate it.

Front brake on, rock bike back and forth, does it creak?

If yes then that isolates the issue to the front of the bike, CSU, stem, headset, fork crown.

From there you can isolate further, pull everything apart and apply loctite, repeat test, if creak persists apply grease, good luck!

My recently replaced pressfit BB has started to creak, so annoying, I feel your pain.
 

Binaural

Eats Squid
If they welded over the crack, its possible that the top of your steerertube and the bottom of the steerertube are no longer in line/true, causing a misalignment and binding when you do it all back up and tighten it, which could be causing the noises. just a guess.
Or it might have been pre-existing misalignment of the head tube - this might also help explain a crack in an unusual location. Either way, getting the head tube faced top and bottom might be a cheap way of ruling this out.

safreek - if you've ridden the bike in the rain a lot or wash the bike with a high pressure washer you can easily rinse the grease out of a "sealed" bearing. If you're going to the hassle of taking everything off to regrease and check alignment, you might as well change the headset anyway, they're about $20 for a cheapie. But following the other steps recommended for general crack finding is a great idea.

stirk - I hate pressfit BBs with the hatred of a thousand suns. Even the threaded ones squeak like mice having a threesome.
 

Binaural

Eats Squid
That's not a particularly unusual spot for a crack.
Might just be my personal experience, but I've seen lots of cracks below the head tube but no top cracks (quite a few around the seat post and BB junction). I was curious to see if there's any data out there on where frame cracks are most common, the best I could come up with Gripsport's repair album. There is one top crack in there that I could see but lots of bottom cracks. There's a few that look pretty scary.

https://www.gripsport.com.au/photo-albums/detail/frame-repairs-main-frame-sections
 

tasty.dirt74

Likes Bikes and Dirt
ok, took the bike for a ride and it appears that the crack wasn't the cause of the noise (lucky I found it though) so where should I start in the search for the noise
Sorry bud, but that is the funniest thing I have heard in a long time !!!!
 

safreek

*******
Check your seatpost. Even it needs some grease. This finally solved my creaky bike problems on the weekend.
ok, shall try that as a first thing
Isolate it.

Front brake on, rock bike back and forth, does it creak?

If yes then that isolates the issue to the front of the bike, CSU, stem, headset, fork crown.

From there you can isolate further, pull everything apart and apply loctite, repeat test, if creak persists apply grease, good luck!

My recently replaced pressfit BB has started to creak, so annoying, I feel your pain.
well I guess that's a thought, the Loctite. does every one grease the bolts before insertion/screwing.
 

safreek

*******
also was wondering why a grip welded frame wouldn't weaken in the welded area but anyone elses welding will. I have no gripe with grip but it just does not make much sense. I get that he gussetts the broken part for strength but would not welding the gusset onto the frame then weaken the frame where the gusset is welded to it. genuine question
 

Dales Cannon

lightbrain about 4pm
Staff member
It comes down to the welding process. Knowing the material and using the correct filler and pre and post treatment as required.
 

Knuckles

Lives under a bridge
also was wondering why a grip welded frame wouldn't weaken in the welded area but anyone elses welding will. I have no gripe with grip but it just does not make much sense. I get that he gussetts the broken part for strength but would not welding the gusset onto the frame then weaken the frame where the gusset is welded to it. genuine question
Simple answer is to email them with the question. They're very prompt and free with advice and information.

Johns basic response to the need for industrial size gussets is, if it's cracked once, it will crack again in the repaired area because of the original join's inherent weakness. The gusset is to reduce the damaging forces impact on the repaired joint. I'm sure there are metallurgical reasons for the repair to be weaker than the original (already weak) weld, but I'm a geological nerd, so can't be more specific.

*the views expressed above do not necessarily reflect those of a sane well adjusted human.
 
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