Gary Fisher Ziggurat 1998 - trash or treasure?

[OJAP109]

Hi folks,

I recently picked up this 1998 Gary Fisher Ziggurat, fully original as far as I can tell - even the original WTB Velociraptor tyres have survived. I picked it up simply because my dad has an early noughties Ziggurat - it’s the one he was riding when he first introduced me to MTB and it remains his favourite bike.

As you can see from the pictures, it was filthy and it seemed in need of some TLC (especially the drivetrain) but I was fairly confident I could get it in good shape again.

I got to stripping it down straight away and after removing all the components I was able to inspect the frame properly. In doing so I noticed a pretty hefty dent / bash / chip on the bottom of the down tube, where (I imagine) the bike has come into contact with a sizeable rock at some point in its past. GAH.

Naturally I was pretty gutted when I found it. I did do a general check when I picked it up but the down tube was covered in dirt so I wouldn’t have spotted it.

You can see from the pictures that it’s not an insignificant bit of damage but my question is, with this being an aluminium frame, how bad actually is it? Could it render the frame useless? How concerned should I be about the structural integrity of the bike? The picture from the side shows that it’s not a proper dent as such, it’s almost more of a large chip. It’s obviously a bad place to have any damage though, and I don’t want to risk taking this thing out and getting a face full of mud (or worse).

My gut tells me that it's probably fine, but I'm used to dealing with steel frames so I'm not inclined to trust my judgement here without seeking advice. Any thoughts from the retrobike community would be greatly appreciated!

Thanks.

 

[W7Ford]

It doesn't look horrendous, I'd ride it and just periodically keep an eye on it. Nice bike by the way.

 

[hawkhill97]

I think it should be fine. The down tube mostly takes force under tension rather than compression, so a small dent wouldn't worry me much, as any creases are effectively being pulled out rather than folded over when under force. The only big exception to this would be a direct head on collision with a large object, which could fold the down tube exactly how you wouldn't want given the location of the damage. But even then I'd expect the force to be mostly concentrated around the head tube area rather than in the middle.

My hardtail (2010 GT Avalanche with unnecessarily nice parts on) has a larger dent than that from a big rock strike on the underside of the down tube near the BB. I've ridden it for three years since that happened, and haven't been shy - done the Forest of Dean DH runs a few times before admitting they're more fun on a FS, and loads of drops on my local trails on a weekly basis - and there's been no visible change to the dent.

I have now zip tied an old bit of tyre to this bit of the frame to prevent a repeat performance though

 

[OJAP109]

Both replies extremely helpful, and reassuring. Thank you. There’s life in this Ziggurat yet! Updates promised once it is rebuilt.

 

[hawkhill97]

Cool, looking forward to seeing how it turns out!