Important Information Please read before purchasing your next pair of motorcycle jeans
Observations on light weight motorcycle denims, the new PPE regulations and slide times.
We have been producing motorcycle jeans at Hood since 1998, during which time our products have never failed to protect when called upon to do so. We believe the double-layer construction used in all our jeans is paramount in achieving this record and for giving them the high level of protection that our customers demand. Over time we have seen many lightweight motorcycle jeans. One of these jeans just had a double layer of denim, whilst many were simply made with small panels of protection covering the seat, knees and hips. In recent times we have seen the introduction of lightweight ‘single layer’ motorcycle jeans. All these products are claimed by their manufacturers to provide more protection compared to a normal jean, but they should not be confused with a serious motorcycle jean – such as the Hood K7 Infinity Jean – that puts protection at the top of the list of importance.
We understand comfort is an important factor. This is why we have spent so much time over the years focussing on development of softer, more breathable fabrics. We do, however, feel the double-layer construction is an important design feature that works by increasing performance and helps bring the protection level of a man-made material closer to that of decent leather.
Multi-layer constructions work in the same way as do laminates, which outperform the individual properties of each separate layer from which they are constructed (the whole is greater than the sum of the parts). In addition, the separate layers can move relative to each other, improving flexibility. Finally, the wearer is insulated from the road surface and from shear-force injuries; the skin abrasions which occur due to the movements between the outer fabric, when it is in contact with the road surface, which causes the back surface of the material to transfer these forces direct to the wearer’s skin. Linings in garments are essential to providing “shear-force interception” and they do this by remaining static on the wearer’s skin, whilst the movements of the outer layer take place against the reverse face of the lining. Multi-layer constructions amplify this benefit.
Our work over many years has brought us into contact with many single layer materials. These have a combination of hi-tech fibres mixed with cotton; however, none have ever afforded the same level of protection as a double layer construction. The main factor for this is that any benefits provided by the hi-tech protective fibre are simply diluted by the lower-performing cotton that it is combined with to construct the denim. Some aramid / cotton denims feature a 24% aramid / 76% cotton construction. This means the single layer material contains over three times more cotton than aramid within the mix. This simply does not give the same protection level as a 100% aramid layer. The same is true with other hi-tech fibre / cotton single layer constructions. Another aspect to bear in mind is how, over time, the cotton element of the material deteriorates, just like a 100% denim (cotton) would – this is an unavoidable fact. All test samples are washed five times before testing, but what happens after a few years of washes? In general, we have found a single layer material provides around a third of the protection of a double-layer combination of denim and Hood Jeans’ k-tech aramid.
Slide times are another question we have been asked about over the past year (we guess this is because of the new PPE legislation).
A lot of brands are quoting the so called ‘slide times’ for their jeans, but the real purpose of the figures is to show how the abrasion testing machine is functioning and it is not included in the criteria for assessing whether a material passes or fails. On the Darmstadt abrasion test, it’s the pass / fail criteria is established by the size of hole (if any) when the machine comes to a halt.
Slide time, along with distance to stop, are calibration measurements for the test apparatus, to determine whether or not the coefficient of friction between the test sample and the abrasive surface is within specific parameters. One test sample may slide further compared to another, however just because it slides further doesn’t make it better; it simply means it has less drag on the road compared to a sample that has more drag. There is a school of opinion that a garment with a higher coefficient of friction might be better, because the rider will slow to a halt in a shorter distance and might avoid collisions with roadside obstacles which a garment with a lower coefficient of friction might cause them to hit. The crucial thing is, has the material passed the test and at what speed?
Please be aware of two misleading tricks we have seen from some companies; 1) the deliberate attempt to fool people by quoting test times from the Cambridge machine against ‘slide times’ from the Darmstadt machine. We have seen one company that claimed its product’s 10:00 second (higher than level 2 – EN13595 standard) test result from a Cambridge machine was bettered by an 11:00 second slide time tested on the Darmstadt machine. This is not the case and test results and so called slide times from both machines should not be compared against one another in any way. Additionally, we have been made aware that at least one test house has evaluated clothing materials using the abrasive belt specified in the motorcycle glove standard, and that the switch from the more abrasive belt used in the clothing standard to the less abrasive belt specified in the glove standard results in recorded abrasion times being up to three times higher. So, a fabric recording 10 seconds on the glove standard belt would could achieve as little as 3½ seconds when tested on the correct belt.
The combination of our denim with the K-tech and mesh lining in the K7 ‘Infinity’ Jean has been tested to the following on the Darmstadt machine;
- Test speed: 120km/h
- Release speed: 116.3km/h
- Time to stop: 5.696 seconds
- Distance to stop: 87.728 metres
This passes the AAA classification of the provisional European Standard FprEN 17092 and enables the K7 jean to be certified and CE marked in accordance with the requirements of the new EU PPE regulation 2016/425
With regard to the new EU PPE regulation 2016/425; we feel the new regulations are generally a positive move with helping to make sure motorcycle clothing for sale is fit for purpose; however, we do also feel certain brands could use the new standards to sneak poor products with inferior protection onto the market. We simply feel customers should continue to do their homework. There are many excellent certified motorcycle jeans on the market – we believe the K7 ‘Infinity’ Jean is one of these – however, we fear there will also be many garments that, though they achieve a level of classification to the European Standard and are certified, may still not provide customers with the protection they would expect from a motorcycle jean.
During our history we have collated a large amount of data and information from real crashes, our own drag tests and independent test houses. Until last year, all testing was performed on the Cambridge machine; however, with the introduction of the new PPE standards (FprEN 17092), the Darmstadt machine is now used. The Darmstadt machine does not give the actual time to failure for the material; instead it replicates a slide and tests whether perforation of the construction is smaller than half a centimetre. This means a material could far exceed the level needed, but by how much is not known. It also means a product may just reach the required level, but by the smallest of margins, yet would achieve the same certification classification as a product that far exceeds the requirement. To compound this problem, the abrasion test levels for the new PPE standards have not been set that high, this is the reason for our concerns that some poor products may sneak through and achieve certification.
For this reason we have decided to continue to test on both the Cambridge and Darmstadt machines, so we can back check data from current testing with data from that of the past twenty years.
The original motorcycle clothing standards – EN 13595 Parts 1 – 4 – were designed for professional use garments and the new FprEN 17092 test levels are set lower, as the standards are intended to be for “non-professional use” clothing. The level 1 and level 2 requirements of EN 13595 necessitated the whole garment to be fully lined with the result that this made them very heavy and very hot. It also meant most people simply didn’t buy these types of fully-certified motorcycle jeans. Some brands would claim their material passed the CE abrasion tests, but this didn’t make the jean CE approved – CE approval applies to finished products, not to the materials from which they are made – it just meant the small area where the material covered would have passed the abrasion level. We have seen the same type of thing starting to happen with the new FprEN 17092 standard – before it is even officially published! Certain brands are stating their products pass the new abrasion tests, but as previously mentioned, the new abrasion tests are not that difficult to meet. However other assessments in the new standard – tear strength and seam burst strength to mention two – are more challenging, although still not to the level of severity of EN 13595. It is the complete garment that is tested / certified so look for the CE or EU certification label sewn inside, and for the CE / EU instruction booklet and the Declaration of Conformity. You’ll find all of these on Hood Jeans K7 Infinity jeans.
For more information please don’t hesitate to contact us through our website www.hoodjeans.co.uk or on 01953 888811
Subject to our recent telephone conversation concerning the high speed accident I had whilst wearing my Hood jeans. As you