Yet Another Cycling Forum

General Category => Freewheeling => Topic started by: andyoxon on 21 February, 2019, 11:09:13 pm

Title: Grazes through clothing?
Post by: andyoxon on 21 February, 2019, 11:09:13 pm
or more specifically getting grazes in a fall, through lycra/clothing - which remains pretty well undamaged (as happened today to me).  What exactly is happening?   Simply a friction burn and lycra is more elastic than skin?
Title: Re: Grazes through clothing?
Post by: hellymedic on 21 February, 2019, 11:25:15 pm
Suspect Lycra is 'harder' - resists abrasion - better than skin. It is also more elastic and has greater tensile strength - skin tears more easily.

I reckon you could scratch yourself with a dinner fork through Lycra clothing (if you are silly enough to try).

Methinks this is simple abrasion, not burning.
Title: Re: Grazes through clothing?
Post by: Kim on 21 February, 2019, 11:29:17 pm
I can confirm that you can scratch yourself with a cat through Lycra clothing without substantially damaging the Lycra...
Title: Re: Grazes through clothing?
Post by: andyoxon on 21 February, 2019, 11:42:12 pm
Would the claw tip go between/puncture the lycra 'weave', in the way a flat/rough surface would not?
Title: Re: Grazes through clothing?
Post by: hellymedic on 21 February, 2019, 11:59:08 pm
The other thing I think occurs, is that the tarmac or whatever adheres to the Lycra, which detaches from the subjacent skin.
Title: Re: Grazes through clothing?
Post by: rafletcher on 22 February, 2019, 09:20:34 am
Grazes like that are common. The lycra "sticks" to the road surface, and the skin rides across the lycra.  A more dramatic version is when you come off a motorbike, and your waterproofs act in the same way. That led to a small hole in my trousers, no visible damage to the waterproofs and a patch of skin of visible depth being rolled off my knee.
Title: Re: Grazes through clothing?
Post by: Cudzoziemiec on 22 February, 2019, 10:34:39 am
Yep, I've had the same, crashed a motorbike in leathers with woolly jumper underneath, no damage to leathers or jumper but lost a lot of skin from my elbow.
Title: Re: Grazes through clothing?
Post by: hellymedic on 22 February, 2019, 01:04:26 pm
Experiment:

Equipment
One stone
Old Lycra Garment

Method
Wrap stone in Lycra from old garment.
Rub wrapped stone on skin over several joints which have bone close to skin. Use multiple joints and levels of pressure to increase validity of results, recording all variables.

Results

Conclusion
Title: Re: Grazes through clothing?
Post by: Cudzoziemiec on 22 February, 2019, 01:14:03 pm
I are not a scientist but I'm not sure the method is reliable. In the experiment there will be minimal movement between fabric and stone but lots between fabric and skin, in real life it's the other way round.
Title: Re: Grazes through clothing?
Post by: citoyen on 22 February, 2019, 01:15:44 pm
Grazes like that are common. The lycra "sticks" to the road surface, and the skin rides across the lycra.

Sounds about right to me.

Also worth remembering that if you dust yourself off and continue your ride, by the time you get to the end, it's possible that your lycra will have become stuck to your road rash, making getting undressed almost as painful as the fall itself.

DAHIKT
Title: Re: Grazes through clothing?
Post by: andyoxon on 22 February, 2019, 01:34:13 pm
I only saw blood when I got to work about 30mins later, fortunately still unstuck to lycra.  In my saddle bag of goodies I have a few antiseptic wipes so used those to clean up...
Title: Re: Grazes through clothing?
Post by: hellymedic on 22 February, 2019, 04:12:53 pm
So long as you have a change of clothing (and preferably a waterproof bag or two), it might be an idea to enter the shower wearing the Lycra and removing it when wet.

LOTS of streaming, clean water (with or without some detergent/soap/shower gel) probably cleans a wound better than antiseptic wipes.
Title: Re: Grazes through clothing?
Post by: hellymedic on 22 February, 2019, 04:15:54 pm
I are not a scientist but I'm not sure the method is reliable. In the experiment there will be minimal movement between fabric and stone but lots between fabric and skin, in real life it's the other way round.

Empirically, I disagree here. Methinks the Lycra mostly sticks to the road surface when the rider lands hard.
Title: Re: Grazes through clothing?
Post by: Cudzoziemiec on 22 February, 2019, 06:41:39 pm
It might do but it's wrapped round the person not the road. Though I note that the test for motorcycle protective clothing (might even have been here I read about this) consists of a cylinder of concrete, the garment and no mannekin or similar.
Title: Re: Grazes through clothing?
Post by: hellymedic on 23 February, 2019, 08:51:29 pm
The garment is indeed worn by the victim but I still suspect the road 'grabs' the Lycra while the victim continues forward travel.
Eventually the stretchy fabric recoils...
Title: Re: Grazes through clothing?
Post by: rafletcher on 23 February, 2019, 09:52:53 pm
Grazes like that are common. The lycra "sticks" to the road surface, and the skin rides across the lycra.

Sounds about right to me.

Also worth remembering that if you dust yourself off and continue your ride, by the time you get to the end, it's possible that your lycra will have become stuck to your road rash, making getting undressed almost as painful as the fall itself.

DAHIKT

Or after remounting you get that warm feeling along your forearm and decide exploration can wait until you get home...
Title: Re: Grazes through clothing?
Post by: CrazyEnglishTriathlete on 23 February, 2019, 11:02:33 pm
When running in the dunes near The Hague last winter, I put my foot through a frozen puddle (about a centimeter thick ice).  My lycra based running trousers were unmarked, but there was a deep graze which has left a scar which is highly visible a year later.
Title: Re: Grazes through clothing?
Post by: Cudzoziemiec on 24 February, 2019, 02:02:39 pm
The garment is indeed worn by the victim but I still suspect the road 'grabs' the Lycra while the victim continues forward travel.
Eventually the stretchy fabric recoils...
Yes, I wouldn't dispute that.
Title: Re: Grazes through clothing?
Post by: Kim on 24 February, 2019, 02:31:56 pm
Perhaps the difference between the lycra tearing/melting and not is simply the duration of the slide?  If it's short (or 'bouncy') the lycra is elastic enough to cope, but the skin isn't.

IME the canonical left elbow graze is relatively non-damaging to clothing.  Sliding on your hip/arse can do more damage to the clothing than the skin.  Knees can go either way, depending on the dynamics of the fall.

I've got a jersey with some mild damage where the shoulder was used as a braking surface against the wall of a canal tunnel.  No injury, but the scuffing looks a lot like what you get at the periphery of a hole around some road-rash.

It also occurs to me that the fabric of legs/sleeves can have more scope to move in one direction than another.
Title: Re: Grazes through clothing?
Post by: Cudzoziemiec on 24 February, 2019, 03:32:17 pm
Well if you're going to crash in a tunnel it might be best to do so against the wall rather than a Basil.
Title: Re: Grazes through clothing?
Post by: Kim on 24 February, 2019, 03:35:48 pm
Well if you're going to crash in a tunnel it might be best to do so against the wall rather than a Basil.

That's exactly why I ended up doing it.
Title: Re: Grazes through clothing?
Post by: LittleWheelsandBig on 24 February, 2019, 07:53:58 pm
The elastane in lycra gives it a quite high friction coefficient against both asphalt and skin. It might not be too hard to exceed the shear strength between outer skin layers. Potentially, the outermost layer of skin 'sticks' to lycra clothing during a fall but an outer skin layer slides on the underlying layer.
Title: Re: Grazes through clothing?
Post by: rr on 27 February, 2019, 01:00:40 pm
The friction between the lycra and the skin is stronger than the bond between different layers of skin.
Endura MT500 bibs have a double layer of the hip, claiming to protect against this.

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