gnz

Hi, well I am so frustrated right now, I just finished putting together the bike to start my tour tomorrow and noticed the frame has a crack at the derailer dropout. See pictures below.

I need some expert opinion... do you think the frame will break all the way if I ride the bike loaded? I found no trace of the crack on the other side of the derailer dropout attachment hole, it seems it is only on the thin side... Right now I'm thinking that I will take my chances and just ride carefully.

I am in Portugal right now and headed towards Spain, When I reach Sevilla I will look for some aluminium welder place to have a bar soldered and reinforce the frame...

Any opinions / advice is greatly appreciated. Thank you.

Garthr

I would not ride it, unless you like hospitals! Cracks do not repair themselves. As far as I know, Al is not repairable. Just welding it will not make it better, as it will further weaken it....... it's not steel.

Sorry for your loss.

127.0.0.1

you already have other cracks starting

that entire dropout is junk.

note: that piece is weldable. get the right talent behind the torch
and that is fixable

garage sale GT

It will undoubtedly break; the only question is when. It may take the crack a little while to propagate.

Say, does anybody know if they heat treat Al frames? It may not be possible to restore full strength with welding.

UnsafeAlpine

Aluminum certainly is repairable. It most likely won't be as strong as original, but it will be fine. Get a good, certified welder, remove the hanger, let the welder at it, drill and tap the hole and you'll be good as new.

Shimagnolo

On a positive note, the crack was stopped by the hanger bolt hole, and can go no further.
I would look into repair or replacement, but I don't think there is really any risk of catastrophic failure.

zzyzx_xyzzy

+1

There are different kinds of aluminum use in frame -- If it's 7005 aluminum you should be able to get it fixed by a skilled welder without much loss of strength, whereas 6061 aluminum frames often have the whole frame heat treated and will lose strength when welded.

redtires

I'll agree with the opinion that the crack can go no further as it is in a rather unusual, isolated area. I will also agree with the opinion that because of it's location, there is most likely a rather low risk of catastrophic failure of the dropout. How long is this tour you are doing, and is it all paved? I have to say, I've seen a hellova lot of broken drop-outs during my time as a framebuilder, but that is in one of the oddest places I've ever seen. It kinda looks like the hanger bolt was extraordinarily torqued, and/or the hole in the drop-out is not the correct size and it stressed that area. Generally, catostrophic failures are seen when a crack propagates at the chainstay/seatstay weld or braze area. The other question is....are you SURE it wasn't there before? If not...who knows how long you've already ridden it that way. Personally, I would do the tour and then replace the frame when I got home.

Torchy McFlux

It's only a matter of time before it fails completely. What are you going to do if you're in the middle of nowhere with all your stuff and the bike is unrideable? Seriously, you need to ask yourself that.

Crank57

another +1. The best way to stop a crack is to drill a hole at its most advanced point. Your hanger bolt hole was in the path so that crack is stopped.

Caution though, the bracket is now weaker and another crack can always start on the other side of the hole or any where else that there might be a scratch or nick or inclusion to give it a start point.

Aluminum is bad stuff from the failure mode perspective. It tends to fail suddenly and completely; not as forgiving as steel which would tend to stretch and bend quite a bit before giving up.

A good welder should be able to fix this but will have to know what alloy of aluminum he/she is dealing with. My guess is one of the 6000 series which is good news as this series is clasified as easy to weld.

I think I might ride this carefully till I could get to a welder. Depends on finances and investment in the trip etc. but I might also look for a shop that would exchange frames.

As a last ditch resort I might even try to find a thin stainless steel fender washer about 30mm to 35mm O.D. Grind off all the paint from the face of that dropout and scab the washer on with epoxy. This patch would hold a surprising load; I know because I have done it. Just depends on how desperate the situation. Caution though. This patch would make it almost impossible to weld up the crack because it will contaminate the metal.

Garthr

https://au.answers.yahoo.com/question...7180656AAKzMHl

If this doesn't get through to you..... nothing will. Al frames are always a risk, this one has failed.

You could also try asking this in the frame builder forum ..... see if you have any takers. I hope not for your sake.

cbchess

you need a new frame
sorry!

JohnDThompson 

It's already broken. What brand of frame? Is it covered by warranty?

Road Fan

I was thinking perhaps the insert or the bolts in that hole have been overtorqued, and combined with that the several thermal shock cycles due to air flight. It can get real cold in the cargo hold at high altitude.

The crack has gone all the way through the d/o at one side of the hole. Any stress that area was carrying (drive forces would place it in tension, road shock could place it in compression) is now on the other side of the hole. As you ride with that crack and the stress cycles, the fatigue cycling of the remaining part of the dropout is accelerated, so any tendency toward a fatigue failure on the "good" side of the hole is increased. The tendency for the rest of the dropout to split is increased. Is it increased enough that it will break on the tour and leave you in the lurch?

I don't know, redtires could be right, and it will be ok. Or maybe not.

Road Fan

gnz

The other 'cracks' are just paint scratches, after finding the crack I did check the whole bike thoroughly.

gnz

It is 6061 ... yes I had thought about the heat treatment that might get spoiled if I have any welding job done now. I'm thinking about my options.

gnz

The tour is open ended, I'm planning to spend at least one year touring in Europe... The bolt tightens against a nut, not against the frame, so the damage wasn't caused by overtightening.

Im like 98% sure the crack wasn't there... I rode the bike and I also noticed a new crackling sound when the rear wheel is on high stress (ie. while climbing on a low gear) I checked the drivetrain and concluded that the noise is being made by the two sides of the cracked frame rubbing against each other.

gnz

Yes, I'd go for replacing the frame if I was at home but unfortunately I am already far from home and the options are more limited.

gnz

It is a New Zealand made avanti frame that I bought in 2001... I am almost sure the crack appeared with the last plane flight, It must have been dropped at some point. I'm not sure if the manufacturer would cover something like that.

I could see about it with the airline, but I'm already too advanced in my trip, it is more than three weeks since the flight now and I no longer have any receipts for the flight or luggage so I think my chances are slim there.

gnz

Interesting theory about the thermal stress... The screw and the dropout hanger were both out and packed along with the deraileur at the time of travel.

Thanks for your insight.

gnz

Okay, thank you everyone for your input. Here's the current report:

I rode 300km with a load of some 35kg luggage plus me 75kg. I did notice two new and alarming things: a crackling noise coming from the rear part of the bike when under stress (ie. when climbing on a low gear), my guess is that it is both ends of the cracked frame rubbing against each other, and the other is that the rear tire is now almost rubbing against the lower right-side part of the frame which suggests that the frame is bent. What I'm thinking I will do now is try to arrive in Sevilla Spain and 'settle' for some time there while I can mail order a new frame, I have the time as I work and travel at the same time.

Thanks all for your suggestions and comments.

DMF 

What, they don't got bikes in Spain? I bet you can find a decent, possibly used, frame there. Steel this time.

Cyclist0383

This place has some of the cheapest frames I've found in Europe. I believe that they are the retail end of a large distributor. I've found their CS to be quite good, although they can be slow in getting some parts in. If you give them a call and explain your situation I'm sure they can tell you which frames can be delivered relatively quickly.

https://bike-components.de

gnz

Thanks, At first glance it seems they don't have a steel frame for v-brakes and 700C but I'll email them...

gnz

Yes, I guess I should just reach Sevilla and have a tour of the bike shops to see what they've got.

thanks.