Would you ride a bike with a 1cm nick in the BB shell?

[Steve Austin]

Looks very terminal to me......

 

[ttcycle]

As I suspected, buggered and with an alu frame not much you can do to bring it back not for the cost anyway....careful you don't put too much force into the pedal stroke if you are going to try it out as that may weaken and worsen the nick...meaning an off the bike moment.

Good luck sourcing another frame.

 

[Ivan Ardon]

Where you've touched the weld between the seat tube and down tube with the grinder doesn't look much worse than some frame welds I've seen on new bikes. I'd expect that frame to fail by the bottom bracket working loose on that side, rather than it fail catastrophically.

Not that I'm recommending that you do it, but I'd be tempted to clamp a suitably sized, good quality jubilee clip around it and keep an eye on it.

Maybe even glue the bottom bracket in with Araldite or JB Weld on that side then apply the jubilee clip.

 

[Globalti]

FFS just take the frame along to a welder who can do aluminium and ask them to drop some weld into the cut then tidy up with a file. You might need to get a LBS to re-cut the threads and outer face as well.

You'll find welders in Yellow Pages. Some years ago I got some deep chain suck gouges filled in on the RH chainstay of my titanium Kona Hei Hei frame and it went on to give faultless service. The chainstay is certainly more stressed than that area of your BB, where the stress is spread by the internal part of the bearing anyway.

 

[02GF74]

I see the pictures - doesn't look that bad - is it cut all the way thorugh to the cup?

if it was on the underside, then it would be more of a worry.

whats the worse thing that can happen? the crank parts with the frame and you are left pedalling air - I cannot see that the frame will collapse under you.

ideally you want to have that TIG welded and then have the threads for the BB recut.

I am guessing that would set you back about £ 50 or so.

there is this stuff - lumiweld and technoweld - that is worked like solder for joining aluminium piece together that is worth a try except that it needs heat to melt the stuff and that would affect any heat treatment the frame had.

so just ride it and see what happens and check it often.

 

[Bodhbh]

Okay, I will have a look into the weld and get threads recut option. Like I say, it's only 60 quid for the frame, but I hate just buying something and wasting it like that. And then I have put some time into building it up already.

 

[BentMikey]

I reckon that's new frame time, personally.

 

[Chamfus Flange]

When throwing the frame away, make sure the angle grinder goes too.



.

 

[Globalti]

Okay, I will have a look into the weld and get threads recut option. Like I say, it's only 60 quid for the frame, but I hate just buying something and wasting it like that. And then I have put some time into building it up already.

Quite right. Too often nowadays people are ready to condemn something that can be repaired, either in the interest of an easy life or more sales of new kit. That BB shell is a strong cast piece of steel or ali which will behave in a different way to a straight tube where a point of damage will introduce a stress riser. Admittedly there will be downward pressure on the shell and yes, it's a relatively brittle casting so a crack could start but what have you got to lose? Get the gouge filled with weld and re-finish the BB and I bet you'll have no problem with it. The bearing shell is screwed tightly into the BB so it will be distributing your pedal effort evenly around the circumference of the shell.

FWIW I got the gouges in my Ti frame repaired by 'phoning around local welders until I found someone who could do Ti. I went along at lunch time and handed the frame to a rather spaced-out looking bloke, thinking he would either be a genius craftsman or a muppet. Happily he was the former and the following day I collected the frame, beautifully finished and handed him £20 for his lunchtime's work.

PS: Just looked again at your pics and I see that it's a welded frame with no cast lugs but much of what I wrote above about stress distribution will still apply.

 

[Trevrev]

This may have been said already. Get someone to put an aluminium weld across the "nick" then file it down.

Yes....It has been said !!!! LOL
Thats what I'd do.......Only cost a tenner if that !!

Don't throw the frame !!! It's fixable !!!
There are some clever people out there !!!! Don't throw the angle grinder either........Great tools to have !!!

 

[Steve Austin]

I wouldn't ride it ever again. I'm all for saving bikes, and reusing them but that looks written off to me.
The action of the crank BB oscillating in the shell will stretch that crack and split that BB shell within a month of riding. As for welding it, it will kill the frame.

I'm for being proved wrong. but IMHO its knacked

 

[Rhythm Thief]

I wouldn't be happy riding that. I'd be spending all my time worrying when it was going to break.

 

[02GF74]

As for welding it, it will kill the frame.

by the loks of it, that is not a top notch supre lightweight butted thin tube heat trated frame but bread and butter frame put together by a 6 year old chinese orphan so TIG welded and thrown into the paint tank - no heat treat ment. I reckon a blob of TIG without any heat treatment will sort it out ... .but the amount of heat will take off some of the paint but then why do halfords and paint spray cans exist?

maybe we should have a pool to predict what would happen.

there is always ebay of you are unsiure of riding it!!