Author Topic: How much to replace a rear dropout? (Read 9613 times)

Blodwyn Pig · « **Reply #25 on:** 11 March, 2014, 06:16:51 pm »

' if it can be welded reasonably well'!!!!!!!!!!!!!!!, If you're out, and it fails .... catastrophically,.....is the welder going to come to your funeral then? I would rather hang it on the wall as it is, as a project, and get a new dropout fitted when funds allowed. If you come off it and ...well... you can't ride a bike very well with only one leg. This , IMHO, is a silly conversation now, and I'll be off.

LittleWheelsandBig · « **Reply #26 on:** 11 March, 2014, 06:20:51 pm »

As someone who has ridden bikes to a stop after breaking various bits of their frames and ridden bikes with repaired dropouts, I'd get it fixed and ride it without a qualm. YMMV

robgul · « **Reply #27 on:** 12 March, 2014, 08:29:15 am »

Quote from: Blodwyn Pig on 11 March, 2014, 06:16:51 pm

' if it can be welded reasonably well'!!!!!!!!!!!!!!!, If you're out, and it fails .... catastrophically,.....is the welder going to come to your funeral then? I would rather hang it on the wall as it is, as a project, and get a new dropout fitted when funds allowed. If you come off it and ...well... you can't ride a bike very well with only one leg. This , IMHO, is a silly conversation now, and I'll be off.

Have to say I'm in this camp too ... fitting a separate hanger (see up thread) would enable you to fit the wheel and rear mech to look the part for display/vanity purposes.

Having had a frame break in half at the BB shell (waaaay back when I was about 15) it was not much fun - the risk from the bodge welded dropout would be a greater risk IMHO

Rob

Bicycle Repair Man · « **Reply #28 on:** 12 March, 2014, 11:16:23 pm »

Campag dropouts are forged low carbon steel. If welded by a competent frame builder with full penetration the join will be at least as strong as the original probably stronger if the adjuster hole is dispensed with. I have repaired more dropouts by welding than most people have had hot dinners (switch exageration mode to OFF) and none of them have broken. Ignore the ill informed naysayers !!!

Cheers

Dave Yates

jsabine · « **Reply #29 on:** 13 March, 2014, 01:14:20 am »

Quote from: robgul on 12 March, 2014, 08:29:15 am

Quote from: Blodwyn Pig on 11 March, 2014, 06:16:51 pm
' if it can be welded reasonably well'!!!!!!!!!!!!!!!, If you're out, and it fails .... catastrophically,.....is the welder going to come to your funeral then? I would rather hang it on the wall as it is, as a project, and get a new dropout fitted when funds allowed. If you come off it and ...well... you can't ride a bike very well with only one leg. This , IMHO, is a silly conversation now, and I'll be off.

Have to say I'm in this camp too ... fitting a separate hanger (see up thread) would enable you to fit the wheel and rear mech to look the part for display/vanity purposes.

Having had a frame break in half at the BB shell (waaaay back when I was about 15) it was not much fun - the risk from the bodge welded dropout would be a greater risk IMHO

Rob

Scare mongery gorn mad, I*M*HO.

If the 'bodge welded dropout' did fail catastrophically, the wheel would pull forward, the mech would most likely go into the spokes, the wheel would jam and skid, and you'd almost certainly limp to the side of the road cursing fluently.

If you didn't go out of your way to get it bodge welded, and simply went for normal welding, I'd be astonished if you had anything to worry about.

Quote from: LittleWheelsandBig on 11 March, 2014, 06:20:51 pm

As someone who has ridden bikes to a stop after breaking various bits of their frames and ridden bikes with repaired dropouts, I'd get it fixed and ride it without a qualm. YMMV

Quote from: Bicycle Repair Man on 12 March, 2014, 11:16:23 pm

Campag dropouts are forged low carbon steel. If welded by a competent frame builder with full penetration the join will be at least as strong as the original probably stronger if the adjuster hole is dispensed with. I have repaired more dropouts by welding than most people have had hot dinners (switch exageration mode to OFF) and none of them have broken. Ignore the ill informed naysayers !!!

Goodness, I'm agreeing with people who know far more about it than I do.

Torslanda · « **Reply #30 on:** 18 March, 2014, 10:15:26 am »

. . . and it's done

Tig welded and the HAZ kept to an absolute minimum.

CAMRAMan · « **Reply #31 on:** 18 March, 2014, 10:35:23 am »

Oh, the lovely lilac.

The weld's not bad, either!

Polar Bear · « **Reply #32 on:** 18 March, 2014, 10:39:13 am »

Now all you need to do is paint match.

jsabine · « **Reply #33 on:** 18 March, 2014, 11:03:19 am »

That is very neat work.

Vince · « **Reply #34 on:** 18 March, 2014, 11:30:07 am »

This is going to be heading slightly OT.

Am I right in thinking that with a weld the penetration is the 'merging' of the filler metal with the original metal, with the result being as strong as the original metal, but with brazing, there is no penetration and it is effectively like using a glue? In other words is a welded repair like this stronger than the join between the drop out and the stays?

BTW. Nice neat job and a lovely colour too.

CAMRAMan · « **Reply #35 on:** 18 March, 2014, 12:38:00 pm »

Quote from: Polar Bear on 18 March, 2014, 10:39:13 am

Now all you need to do is paint match.

RAL 4005 to you, sir.

aidan.f · « **Reply #36 on:** 18 March, 2014, 12:59:53 pm »

Quote

Am I right in thinking that with a weld the penetration is the 'merging' of the filler metal with the original metal, with the result being as strong as the original metal, but with brazing, there is no penetration and it is effectively like using a glue? In other words is a welded repair like this stronger than the join between the drop out and the stays?

As DY says it depends what you are joining - a chunk of low carbon steel, AKA a dropout can be welded and repaired back to the original strength.
Brazed lugged or fillet joints will not provide stress raisers leading to a point of failure, so you could say they are as strong as the tubes. You cannot weld 531 and welding any other thin-walled HTS tubing is a skilled job, lots of metallurgical things happen when you weld specialist steels, (or titanium) so if you don't know what you are doing avoid it. If you are making your frame out of steel scaffold pipe - weld it, because it will both be very hard to braze and subsequently ride on

Bicycle Repair Man · « **Reply #37 on:** 22 March, 2014, 02:14:38 pm »

Quote from: torslanda on 18 March, 2014, 10:15:26 am

. . . and it's done

Tig welded and the HAZ kept to an absolute minimum.

A tidy looking job, should last the life of the frame. Done with the minimum disruption to the frame.

The case for the defence of TIG rests

Dave Yates

Bicycle Repair Man · « **Reply #38 on:** 22 March, 2014, 02:41:20 pm »

Wunja said

Quote

Am I right in thinking that with a weld the penetration is the 'merging' of the filler metal with the original metal, with the result being as strong as the original metal,

Absoluely right, a weld is a fusion join where the edges of the parent metal are fused (melted) and a filler rod of similar composition is melted into the joint. A properly executed weld, if tested to destruction will always fail along the edge of the fillet if one exists or the edge of the welded area at a value almost equal to the yield strength of the parent metal.

Quote

but with brazing, there is no penetration and it is effectively like using a glue? In other words is a welded repair like this stronger than the join between the drop out and the stays?

"Hot metal glue" is a good description of how braze works. You must have penetration, ie the brazing material must cover and "wet" the two surfaces to be joined. A larger area is better so a repair like a broken dropout will only be as strong as the small area of the brass joint. The dropout / seatstay / chainstay joints are designed (usually) as a tang up a slot joint which has some mechanical strength and is self locating and provides a large "gluing" area. A good, well executed brazed joint will not break, the tube or components may but the joint is always stronger than the surrounding tubes. This observation is based on viewing (and repairing) thousands of frames in the last 30 odd years.

Hope that makes it clearer.

Cheers

Dave yates

CAMRAMan · « **Reply #39 on:** 01 April, 2014, 04:35:36 pm »

Here is the (almost) complete Harry: https://www.flickr.com/photos/15028720@N08/sets/72157643260694114/

I picked Little Miss AWL up from school today and I didn't die of The DETH.

Polar Bear · « **Reply #40 on:** 01 April, 2014, 05:06:47 pm »

Not public. Thankfully...

CAMRAMan · « **Reply #41 on:** 01 April, 2014, 05:09:59 pm »

Should be. If not, try https://flic.kr/p/mEhmoR
https://flic.kr/p/mEhE8r

Polar Bear · « **Reply #42 on:** 01 April, 2014, 05:16:00 pm »

No. Still asking me to sign in. Phew!!!

Vince · « **Reply #43 on:** 01 April, 2014, 05:18:18 pm »

Adult Content

Should this be in NSFW?

Deano · « **Reply #44 on:** 01 April, 2014, 05:21:45 pm »

You need to add it to the group, AWL!

https://www.flickr.com/groups/371302@N23/pool/with/12389679835/#photo_12389679835

And I can lend you an Allen key to swing those bars down a bit

Polar Bear · « **Reply #45 on:** 01 April, 2014, 05:33:21 pm »

Don't tell him ~~Pike~~ Deano.

phantasmagoriana · « **Reply #46 on:** 01 April, 2014, 05:36:41 pm »

Ooh, that's lovely. And purple.

CAMRAMan · « **Reply #47 on:** 01 April, 2014, 05:59:29 pm »

Quote from: phantasmagoriana on 01 April, 2014, 05:36:41 pm

Ooh, that's lovely. And purple.

Purple? Purple?! That's RAL 4005 Blue Lilac, I'll have you know.

Deano: Almost complete. I have sprayed the offending Allen bolt with releasing fluid to move them down. I'll add it to the group once I get onto a proper computer. The iPad isn't playing ball with Flickr.

CAMRAMan · « **Reply #48 on:** 01 April, 2014, 07:09:30 pm »

Quote from: Deano on 01 April, 2014, 05:21:45 pm

You need to add it to the group, AWL!

https://www.flickr.com/groups/371302@N23/pool/with/12389679835/#photo_12389679835

And I can lend you an Allen key to swing those bars down a bit

I'm getting this message, Deano: 'None of the items you've selected can be added to the group, because they're either already in the group, in too many groups, or they don't follow the rules of this group.' Must be the latter, as they aren't already up there.

Deano · « **Reply #49 on:** 01 April, 2014, 07:16:29 pm »

I'd guess you either have to join the group first, or cos you've somehow flagged the photos as having adult content. Or both.