'92 RM Hammer bottom bracket/possible frame damage

[MartinYorkshire]

Good evening everyone,

I was hoping some of you may be kind enough to offer an opinion on the following images.

After not riding her bike, a 92 Rocky Mountain Hammer for a few years, her indoors decided she wanted to get back into it. I figured I'd better give the bike a service and started with the bottom bracket. It had never been removed since we had the bike.

Non drive side came off without any drama. Drive side however, wasn't exactly seized, just very tight on the entire removal. On closer inspection I can see thread damage, which matches in location, on both the frame thread and bottom bracket itself. The last 3rd of the bottom bracket thread is stripped, but not the frame. There was quite a lot of muck in the threads including particles.

Whats strange, is that the damage appears to be in the center of the thread overall and I can't work out how that could happen.

I'm trying to work out if the frame is done for, or if it's worth trying a new bottom bracket. I don't like the look of the damaged thread in the frame though.

I'd appreciate your thoughts.

 

[kanerdog1x1]

Re:

Nothing to worry about there. Just fit a new cartridge bottom bracket, a good one like a Shimano UN5x, and grease the threads this time.

 

[MartinYorkshire]

Re: Re:

Nothing to worry about there. Just fit a new cartridge bottom bracket, a good one like a Shimano UN5x, and grease the threads this time.

I've got a UN55 on order as of this morning, so I'll have to hope it goes in without bother. If whoever installed the original one forgot to grease it, would it cause damage like that? It seems pretty nasty.

 

[k-rod]

Re:

If you really wish to be particular with it, take the frame to your lbs and have them 'chase' the threads to clean them up nicely, before installing the new b/b

 

[2manyoranges]

Re:

Exactly that - run a bb tap through it.

Then install with copious amounts of copper-based anti-seize.

All will be fine.

 

[MartinYorkshire]

Re: Re:

If you really wish to be particular with it, take the frame to your lbs and have them 'chase' the threads to clean them up nicely, before installing the new b/b

I'll see if it will go in easily with some anti sieze. If not, I'll likely get them to do that.

Thanks everyone, its reassuring to know its not knackered. To be honest, the threads on the non drive side were so pristine its hard to believe it's a 30 year old frame. Unbelievable quality these rocky mountains.

 

[k-rod]

Re:

"made in Canada" you say,

... then it was made to last ... eh ...