Leather
There is an excellent supplement with the current edition of What
Bike? about leather jackets and jeans. I would recommend buying the
magazine.
This is an unauthorised copy of part (or all) of the original artical.
I appologise for any copyright infringement
.
The body was never designed to get hurled from a bike and land on a
hard, abrasive surface then bounce, roll, slide and hit even harder
objects along the way.
Skin, muscle tissue, nerves and bone abrade, burn, tear and
generally get ripped to shreds as they're catapulted down the road.
Would you let a friend pull you down the road on your back or
stomach at walking pace (three mph) for 20 feet? No. It would be
extremely painful, so why mn the risk at thirty times that speed
wearing...
JEANS
Bikers wear a leather jacket, jeans and boots (stereotypically). It
looks good, it's convenient and it's cool.
While the jacket and boots will help in an accident, the jeans will
not. Denim bursts open in a fraction of a second in the first two or so
feet of sliding, exposing all your delicate parts to damage. Padded
jeans are slightly better (very slightly) - don't rely on them.
KEVLAR
Kevlar-reinforced helmets, Kevlar-strengthened gloves, Kevlar
suits.. new materials sound great for advertisers and few manufacturers
can resist putting just a little, low-quality Kevlar in their products
to give them that scientific-sounding edge.
It's a load of cobblers, because in protective clothing too little
is used too sparsely. Kevlar can work, but normally at least two layers
of good-quality Kevlar are needed to give adequate abrasion resistance.
An average-standard Kevlar will tear open far too quickly to make it
worthwhile (see tear-time table).
When World Superbike runner James Whitham tested the abrasion
resistance of Kevlar on his knee sliders last year, the material burst
open almost immediately. The leather he tested stayed intact.
LEATHER
Dead cows and goats have their uses. We can eat them and then wear
the skins to give us very good protection indeed.
However, a leather suit will not prevent all injuries, especially
fractures, but in many cases it will reduce their number, nature and
severity. It will also stop you being shredded by the sharp-edged road
surface. Dead cow and goat is good stuff.
But there are many unscrupulous manufacturers making sub-standard
suits. Some of them claim that because a grand prix racer wears their
name, the product is good.
That's rubbish. For a start, while you will probably buy your
leathers off the peg, the GP boys have them tailor-made from the very
best hides (if they've got any sense). And the kings of the track are
also paid Ioadsamoney to advertise brand names. Just because Johnny
Speed wears a suit with Protectorama written up the side doesn't mean
that the mass-market stuff is any good. You can pay anything from #250
to more than #1000 for a suit, here's what to look out for:
- One and two-piece suits should be manufactured with the minimum
number of load-bearing components (panels, seams, fasteners,
decoration).
- Decorative panels should not form part of the suit, but should be
stitched over the basic structure. The maximum number of panels
for a one-piece suit are: arms, 4-6; front, 4- 10; back, 5-10;
total panels 13-26 (stretched panels not included). The reason
you want few panels of leather stitched together is simple:
seams are always the weakest areas.
- Leather should have good impact, abrasion and tear strength. It
should be a minimurnl of .2 tol .3mm thick. Any leather less than
1 mm thick is generally rubbish. Take a set of Vernier calipers
into the shop, pinch the leather tight between your fingers,
measure the thickness, halve it, and you've got an accurate
enough guide to how thick the hide is. It should have a tear
strength of 8 to12 kg and should be smooth on the outside so it
slides easier.
- Leather should be full grain split and full chromed tanned (or
the equivalent). Ask the sales people what it is, if they can't
tell you, it tells you enough about the shop and the gear they're
selling to go elsewhere.
- Dyes should never run - they can cause cancer. If you end up with
red knees and a green crotch after a damp ride - take them back to
the shop.
- Secondary protection. A second layer of leather should cover the
shoulders, upper arms, forearms and elbows, bum and hips, knees
and crotch seam should be reinforced.
- Stretch panels may be used above the knee, back of the waist and
back of the shoulders. A cut-out may be used behind the knee.
- Ventilation panels can be used on the chest, lower abdomen, inner
thigh and inner arm, and -should not decrease the perfor mance of
the suit. Holes must be not less than 9ne inch apart. A few big
holes ventilate better than lots of tiny ones.
- Lining should be good airtex nylon, cotton or-a polyester/cotton
mix. The lining should allow the body to breathe so that sweat
can evaporate.
- Seams should be well protected and~doubIe or triple stitched.
Single stitching is a total no.
- Thread should be low-twist, bonded monofilament polyamide (size
Ticket 20) at seven or eight stitches per inch. Very strong
leather can-accept a Ticket 40 thread at 1-0 stitches per inch.
Anything over 12 per inch will weaken the leather.
- Zips should be low profile, nylon, with no rough edges or raised
parts. They should be well seamed, away from impact points and
have a leather protective flap behind. Metal zips are out.
- Two-piece suits should be joined by a heavy-duty zip. Body armour.
If the stuff is made of the right material, it will reduce the
risk of injury, but many firms use rubbish foams and claim it will
help in a crash It won't. The ONLY protective foam that should
be used is called POLYNORBONENE, (brand name Norsorex) and should
be 8mm thick. You can identify Polynorbonene, beca-use it is black,
heavy and very dense. Tests prove that Memory foam will not help
protect you.
- Jackets sold with back protectors are a gimmick. Spinal protectors,
like all other body armour, will only provide soft tissue protection.
They won't stop a broken back.
The Time Table
This is how quickly some materials take to hole:
Material
| Seconds
|
---|
Denim
| 0.2 to 0.5
|
Some race gloves
| 0.6
|
Most leather gloves
| 1.0 to 1.8
|
Keprotec stretch material
| 0.9
|
Poor Kevlar
| 1.0
|
Two layers of waxed cotton
| 1.3
|
1.3mm thick cow hide
| 3.8
|
Two layers of 1.3mm thick cowhide
| 18
|
Three layers of 1.3mm thick cowhide
| 55
|
Two layers of Kevlar plain weave
| 5.6
|
Suede
| 18
|
Boot leather (generally 2.2mm thick)
| 20
|
Leather stretch panels
| 20.4
|
Contact Us
This page is based upon a post from Roger Ford (there, that should drop you in
it ).