Just got back from a ride and I have a dent (about the size if little finger imprint) next to the bottom bracket weld. No cracks or splits. It's an aluminium frame (Trek). I have 2 questions. Is this likely to lead to its imminent demise and if it does, are there any repairs that can/should be done now? Secondly, is there such a thing as a frame protector to protect this area/downtube? Carbon fibre shield? I regularly kick up big rocks on descents and suspect there'll be more dents to come. A quick search of the main sites has only shown lizard skin type fabric chainstay protectors.

Get a steel frame, rather than one made from bacofoil?

wiggle/crc has a frame protector made by pace which works. I have the same dent from the same cause on my fsr and it's been fine. higher up the tube would be a problem.

Is that the Pace A4 carbon armour sheet? Reassuring to hear that your frame is ok with a similar dent. I'm guessing that if it did get worse, it couldn't be fixed? Interestingly, whatever made the dent didn't mark the weld (harder?) but clearly dented the aluminium next to it. My only concern is that the thing that alerted me to it was that I had a creaking when pedalling yesterday (hollow BB) but that went after a squirt of teflon spray and I think was due to crankarm rubbing crud at BB slightly. I hope.

I don't want to worry you – as I'm sure that your frame is only dented – but if it was cracked, and made a creaking noise as the sides of the crack rubbed slightly, spraying lube on the area will make the sound go away but the crack will still be there. This is the same reason why creaks tend to stop when you ride in the wet – the water acts as a lubricant and stops the creaking noise.

If you want to check the frame, give the bike a wash by hand, and as you clean it, pay careful attention to the BB area, and maybe turn it upside down as you wash it and check underneath too. If there is a crack, you should spot it.

i have a couple of frames dented in the same area. all my mtbs now wear a bit of old tyre, cable tied on down there, to prevent this. the bb shell on my inbred looks like it's been shot blasted!

If it helps you mentally (I did this)- zip tie a piece of all bike tyre around or to the area.

I've got pretty much the same dent on my turner 6 pack. It happened on the second or third ride. That frame is almost 5 years old now. Is the centre of the dent flat or pointed?

It seems to be really common with Trek frames, i've had two EX8's which both did it, they seem to realise this and the Remedy has a seperate carbon armour guard you can attach, wish they did the same for the EX and Fuel frames.

I used thick clear frame guard tape and it seemed to stop any further happening.

Got 3 on my fuel ex, one big flat dent, 2 small deeper ones. Annoying but nothing to warrant not riding it as yet. Might look into the pace guard though, bit of old tyre looks a bit crap!

this is a top fuel rather than an EX, been ridden for two years since i did it.

I did this to my ti456 a few weeks ago. Quite annoying really, but have to expect damage really.

Thanks very much indeed for your replies and suggestions. I've just had a detailed look after washing it and there are definitely no cracks and the dent doesn't impinge on the BB at all. Not a pointed base (which I assume would be more likely to lead to a crack?). Interestingly, mine's also an…..EX8. Must have a softer underbelly than most. I like the idea of a cut up tyre and I'll try that tonight. I kich up stones the size of housebricks on one local downhill section and the tyre will help, I'm sure. I guess my main concern was whether these dents need/can be repaired and whether they herald bigger problems. Could be a market out there for an entrepreneur to market shields for these. There are 2 allen key bolts on the underside and would be ideal to bolt on a light sacrificial shield.
Slightly off topic, the dent is down to bare aluminium approx 1cm diam. There's no absolute need to paint this over is there? Was going to leave it (I don't mind battle scars as long as I'm not ignoring something that needs sorting to prevent bigger problems later).
Can aluminium frames ever be repaired or are they all scrapped when cracked?

(PS Re: eccolafilosofiadelpedale – I didn't spray the teflon on the dent, but at the base of the crank arm and a few other areas that looked to be rubbing slightly. Think it may be time for a service for the bike and some fresh grease too).

Got two frames with dents there, ride them all hard and ignore the dents, never yet caused me a problem and I'm a heavy rider. One's a Giant and one's a Coyote.