Is my frame beyond repair?

[LCpl Boiled Egg]

I think I already know the answer to this one, but here goes. The seatpost on my Brompton was wobbling back and forth so I bought a replacement seatpost sleeve as the old one looked worn down. After removing the old sleeve I was ready to fit the new one when I saw a worrying crack in the frame that is only visible from inside, just below the slot where the seatpost sleeve clips in.

It looks like it's a show-stopper and I need to buy a new frame/bike before it collapses under me, what do others think?

Thanks everyone.

 

[Lanzecki]

Get it to a main dealer. How is the corssbar welding to the seat post? Butted or a straight weld.

It looks like the cracking is inside the diameter of the crossbar, and so would be stopped by the welds.

But a main dealer should help.

 

[stuee147]

surely with a bit of care and time it could be welded of course you would then need to repaint

stuee

 

[Cycleops]

Might have been caused by having the seat post too far out of the frame. Should be able to weld it as suggested.

 

[byegad]

Nah. A bit of gaffer tape and give it to someone you hate on condition they ride it every day. Revenge!

Seriously needs looking at if you intend to ride it again though.

 

[LCpl Boiled Egg]

Thanks everyone for your replies. It's good to know that it may be repairable after all, as Bromptons are a lot more expensive now than when I bought this one.

Cycleops makes an interesting point. I've always fully extended the seatpost and when I bought the bike the assistant in the shop said I was at the limit of getting away without the seatpost extender. Maybe I'll buy a telescopic extender as well if it can be fixed.

My only concern about getting it welded is that it would have to be filed smooth inside in order for the seatpost sleeve to fit, but I guess if I took it into a main dealer they would make sure it could all be put back together again. It would be cheaper than a new bike anyway, as long as it's done properly. (I think it's butted rather than straight weld by the way, but I'm not sure to be honest.)

I will get it checked out as soon as I can, and definitely won't be riding it until it's been fixed or written off.

Many thanks again all!

 

[stuee147]

Nah. A bit of gaffer tape and give it to someone you hate on condition they ride it every day. Revenge!

Seriously needs looking at if you intend to ride it again though.

iv always found chewing gum better dont want to waste good gaffer tape now its way to useful lol

 

[stuee147]

Thanks everyone for your replies. It's good to know that it may be repairable after all, as Bromptons are a lot more expensive now than when I bought this one.

Cycleops makes an interesting point. I've always fully extended the seatpost and when I bought the bike the assistant in the shop said I was at the limit of getting away without the seatpost extender. Maybe I'll buy a telescopic extender as well if it can be fixed.

My only concern about getting it welded is that it would have to be filed smooth inside in order for the seatpost sleeve to fit, but I guess if I took it into a main dealer they would make sure it could all be put back together again. It would be cheaper than a new bike anyway, as long as it's done properly. (I think it's butted rather than straight weld by the way, but I'm not sure to be honest.)

I will get it checked out as soon as I can, and definitely won't be riding it until it's been fixed or written off.

Many thanks again all!

grinding it down after its welded even on the inside is easy one of them dremil type tools will have it done in a couple of minuets

 

[Lanzecki]

Grinding it down is easy, getting a welder in there unless it's arc is a problem. And with Arc the problem will be avioding blowing thru the thin metal. And then you have to paint it... ugh!

As it's at the top of the seat post tube, and within the cross bar cross section, I'd just use a longer seat post. It'll reduce the load a lot. As it's steel the frame's not going to snap, you'll get loads of warning before it gives way.

 

[Banjo]

I ride my Brommie with the standard seatpost fully pulled up. I just presumed this was ok?

 

[Drago]

On any bike too much exposed seat post and/or too little inserted seat post can damage the frame where it levers merrily away. I've not seen that many frame failures over the years, but of those the clear majority have all been in that area and all on bikes with inordinate amounts of seat post sticking skyward.

 

[Tenkaykev]

I ride my Brommie with the standard seatpost fully pulled up. I just presumed this was ok?

Same here, I've also flipped the pentaclip as that with the fully extended standard post is the perfect height for me.
Can this thread be cross posted to the Folding bike thread?
Paging @chriscross

 

[Banjo]

On any bike too much exposed seat post and/or too little inserted seat post can damage the frame where it levers merrily away. I've not seen that many frame failures over the years, but of those the clear majority have all been in that area and all on bikes with inordinate amounts of seat post sticking skyward.

The brommie is different to most bikes in that you cant pull the seatpost up out of the frame. It stops when fully extended. Seems hard to believe Brompton would have made it so that was unsafe?

 

[chriscross1966]

Bromptons are brazed. Get at it with a welder and you will destroy it. There is a way to fix it by brazing a repair piece over the crack once the crack has been stopped.

 

[Drago]

The brommie is different to most bikes in that you cant pull the seatpost up out of the frame. It stops when fully extended. Seems hard to believe Brompton would have made it so that was unsafe?

Levers are as levers do.