Motorcycle Community London's Motorcycle Community
Est. 2004

Confused with waterproof layers

I’ve got Dainese Tempest D-Dry Motorcycle trousers that kept me dry for a few years. But now every time it rains my family jewels are swimming in a nice cold puddle. I’ve used Nikwax techwash to clean them up, and tried wash-in and spray on from Nikwax to waterproof them without any luck.

From the outside the pants seem pristine, but an inside layer has a tear. I checked the description of the pants:

  • External fabric with water-resistance treatment
  • Breathable waterproof D-Dry membrane

So, I take it the outside layer water-resistance is good enough for a drizzle. But if I want protection from proper rain, I’ll need to fix the tear in my internal layer, which I assume is this “d-dry membrane” they’re talking about?

Bonus question, I have the same issue with my Wolf Tec-Tour Outlast Textile Jacket. The shoulders are leaking. On the outside there is no damage, but the internal layer has a tear. The specs say:

  • DuPont Cordura Teflon coated outer construction
  • XTR waterproof and breathable ultra-high performance removable membrane

Exactly that, from what I understand none of the ‘waterproofs’ are waterproof as a single layer and even the most expensive kit can fail due to the internal membrane or seams failing. Don’t confuse the internal membrane with the lining most suits are made up of 4 layers outer shell, waterproof membrane, wadding, lining which shouldn’t be confused with the detachable winter lining lining.


I see. So, how would I identify where exactly is this waterproof membrane, and more importantly how do I rectify the issue?

Fit one of these. Water will stop pooling at your crotch.


I don’t know but I’d imagine its bonded to the inside of the outer shell so it allows water to sit within the outside shell but not penetrate it. You’d probably need to de-construct the lining and wading to get to it. I’m assuming that would be the case because I can’t imagine a motorcycle jacket/trouser being waterproof if the wading or lining ever became wet.

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I get it now drop liners vs wax cotton vs laminate which explains the difference between my summer (drop liner) and winter (laminate) jackets. I found this if you have 45 minutes to spare

He also explains all manner of motorcycle attire if you care to check out his other videos


Most waterproofing in biking clothing is a PTFE (commonly known as Goretex after the innovators) layer bonded to something. It is like a layer of paint.

It is very fragile and is usually backed with a scrim layer which looks a bit like a fine mesh to prevent anything touching it.

That laminate layer can either be bonded on the back of the outer layer of the garment, or as I’ve seen on some Dainese products they insert a separate garment within a garment layer consisting of the Goretex laminate backed on both sides by a scrim layer. This is some times referred to as a drop shell. This tends to be a littler harder-wearing because bonding to the outer garment suffers from creasing which quickly damages the laminate, the disadvantage being the outer garment gets soaking wet before the drop shell (hopefully) prevents ingress. Even if ingress is prevented, you have a soaked garment that is cold and clammy to put back on for your ride home.

In both cases, whether it is bonded to the outer garment or whether there is a separate liner, the weakest point is the seam-sealing which is usually done by conventional stitching overlaid with a heated-on tape sealer. These fall off with age.

If you are lucky and all that is wrong is the seaming tape has fallen off, there are various products on the market which claim to replace it. Google is your friend. Before all this technology I had good success with sealing conventional stitching using clear Bostick glue spread carefully over the stitching and allowed to dry. I made a pair of waterproof over-gauntlets this way and I could immerse them in a basin of water without leaks.

If you are unlucky the Goretex membrane has become damaged - most likely through simple wear and tear. You can not re-laminate it, lamination is a factory process.

Your solution is probably a pair of £10 over-trousers - if you don’t want to fork out for new Dainese (or similar).

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To add to that.

All biking outerwear garments come with water repellant protection. Usually referred to as DWR. This is a hydrophobic treatment impregnated into the fabric at manufacture which repels water; you can see water will form in little beads on new gear.

Manufacturers claim it is for life but that’s rubbish. Wear and tear, dirt, washing all remove it over time. You can see it in a jacket which once shed water in little droplets now gets soaked and heavy.

This is not waterproofing, not even when new and functioning correctly. All it does is helps prevent soaking water up like a sponge.

There are plenty of aftermarket products which claim to restore this. They won’t make your garment waterproof but it helps.

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That is an amazing video and deserves a hell of a lot more views than it has. I wish I watched it before shelling out £350 for my touring jacket. I also would love for them do to a similar video about trousers, though I’d imagine there would be a lot of similarities.

That’s certainly an interesting way to deal with the problem, but at least it’s cheap and could make a long ride a bit more comfortable as well.

Thank you, that is a very thorough explanation. From what I can see both the trousers and the jacket have a tear where the seal tape was originally applied, so fingers crossed I can apply new sealing tape and this will resolve the issue.

This one’s sorted. I’ve already applied Nikwax as a repellent, and the water does bead off the garments :+1: But, as you mentioned, doesn’t protect much against moderate rain.

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Great info here guys especially Michael748 and that seat cushion looks interesting, plush cheap enough to try out.

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In summer it’s great for getting air underneath you too.

Do you have one of those @me_groovy ?

How thick are they and do they add anything to seat comfort?

Less than a cm thick. Help a little with muscle comfort but it’s the heat comfort where they make the most difference. Takes longer for Betty Swallocks to visit.