Technical FAQ: Even more on hypoallergenic chamois and diluting Aquaseal

A dermatologist and Redd Foxx weigh in on hypoallergenic chamois pads and three tubular tire makers give thoughts on diluting Aquaseal

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I continue to receive mail on the question of hypoallergenic chamois pads, which we addressed in a column earlier this month. We ran a good deal of feedback on this on September 17 and provide a few new perspectives today. We’ll also take a look at recommendations from three manufacturers on diluting Aquaseal for waterproofing tubular sidewalls.

At the Interbike tradeshow, I spoke about this subject with Stefano Coccia, president of CyTech, which makes Elastic Interface chamois pads — high-end pads that are used in many brands of shorts. Coccia said that a critical feature of CyTech chamois pads is that they are bacteriostatic, as opposed to being anti-bacterial, meaning that an anti-bacterial surface kills all bacteria, favorable or no, but a bacteriostatic environment is one that’s hostile to bacteria, but doesn’t destroy your body’s own natural bacteria that live on the skin and fight off harmful bacteria. In this way, by not compromising the wearer’s immune system, he said that his pads are naturally hypo-allergenic.

Coccia also said that sublimation printing of chamois covers, which Cytech used to do and no longer does, is a poor idea, health-wise. Sublimation transfers ink particles from a screen-printed sheet of paper with heat and steam to the fabric. If done on a chamois pad cover, which is worn in an area of the body that is hot and humid, with sweat and friction working at the fabric, the ink will tend to migrate to the genitals, and the small, potentially toxic, color particles can be absorbed internally.

Coccia introduced me to his company’s scientific consultant, Dr. Antonio Paoli, a professor of anatomy and physiology at the University of Padova Medical School. He has studied this issue of dye absorption at the skin-pad interface and claims it to particularly be a problem with anal and vaginal mucus membranes in contact with these inks. He says that it can lead to allergic reactions and/or hypersensitivity and urges that all pads should be covered with fabrics dyed at source by the fabric’s manufacturer and certified by Oeko-Tex and Bluesign to be safe. Cytech Elastic Interface pads are colored with a dye technology called Ultrafast, which guarantees color fastness to sweat.

Testing allergic reactions

Dear Lennard,
Although John may have had ACD (Allergic contact dermatitis) to his chamois, it is much more likely to be allergic to the preservatives in chamois lubes. A recurrence of the rash, without exposure to synthetic chamois or a similar preservative, would not be ACD to the synthetic chamois. Alternative diagnoses include irritant dermatitis, psoriasis, and fungal or yeast infections. The use of topical or oral steroids to treat ACD would increase the chance of developing a fungal or yeast infection afterwards.

A patch test to a small piece of the chamois would be easily performed. A biopsy would be recommended if the rash still exists to obtain a definitive diagnosis. In addition, applying a small amount of any chamois lotion to a small circle drawn on the upper inner arm several times daily for several days (an open patch test) would likely rule out allergy to chamois lube.
—Bernie Burton, MD
Cycling dermatologist

Remember what Redd Foxx said

Dear Lennard,
I read with a bit of amusement the recent series on chamois issues. That said, a rash on the ass is no fun. I commute to work frequently and in preparing today it occurred to me that some folks may be skipping a valuable step in the pre-ride ritual. To paraphrase Redd Foxx as he once said in a routine (hey, you’re old like me so maybe you remember), “Ya gotta remember to wash yer ass.”

Now, Redd was not thinking of going out on a bike ride when he said that. Far from it. But it’s a good rule. I, too, had the sore butt issue a couple times and made it a part of my pre-ride to make sure I’m clean down there before I chamois up. So, no more issues from that. I suspect that there are a few folks who skip the step and pay the price from time to time. So, word to the wise to remember what Redd said.

Dear Lennard,
In the follow-up to your poor reader’s question about uncomfortable chamois reactions, I’m surprised that no one has mentioned sport-specific washes for cycling gear. Brands like Penguin (my favorite) are designed to get the sweat and stink out of workout wear, without leaving behind the residues, found in regular laundry detergents, that can contribute to discomfort — particularly in individuals with sensitive skin — and diminish the performance-related features of the products.

Tire makers on diluting Aquaseal

Regarding my recent column on diluting Aquaseal before applying it to cyclocross tubular sidewalls, I requested feedback from three of the tire makers who make thin, supple cotton casings that riders would want to seal with Aquaseal. These are their responses.

Challenge Tires:

Diluting Acquaseal is a very good idea. It is more my feeling and would need some testing. I have always asked riders that use it to put a thin layer on so that you do not compromise the suppleness of the tire. Also we know that this type of solvent with our glue is not so much affected. We have tried Toluene solvent in our glue, and it does not liquefy the rubber glue. No matter for how long we mixed it, it would not. The reason was that this solvent has high percentage of oil in it and this for preparing the glue is not good. Our solvent is a dry solvent with less than two percent oils in it.

In general, if you apply solvent directly to the tire, this would be dangerous, but you are diluting a material that will be applied on it and, as the reader said, it does evaporate fast.

Our casings have a few layers of latex coating so the solvent directly on the casing would probably be able to penetrate, but you would need to pour it in heavy doses; the fact that you are applying a material on it that dries in a few minutes, and solvents that evaporate quickly, means it will not contaminate the casing. Ribbon also is pre-dipped in latex to give some water protection and increase adhesion, so also the base tape should not be affected.

Aquaseal is a Toluene-based product and has been used for quite some time with no problems on the tires, but I would be a bit more concerned about thinning the Aquaseal with Toluene on Dugast or FMB tires that have no external coating [in order] to give the tires more suppleness. The solvent will be absorbed quicker onto raw cotton. In this case I see that the cotton casing might absorb some solvent and weaken the casing in the case that the dilution and quantity of solvent is high. Ours have a coat of latex and therefore would require either more time to penetrate the latex and reach the raw cotton, or a higher quantity of solvent.
—Alex Brauns
President, Challenge Tech


In Europe this is not possible, as toluene is not allowed to use anymore (it is not in the Aquasure [Aquaseal is branded Aquasure in Europe] we have here, neither in the tubular glue) because it is considered as a dangerous product. It is neither free available on the market.
—Tamara Willems
A. Dugast BV


I think Aquasure is very thick, and the application is difficult. Adding a diluent to reduce the viscosity seems a good solution for those who want to continue to use Aquaseal. The other method that I recommend is: Regularly apply a layer of shellac, it is more flexible (no loss of performance), applied with a brush that is very fast; it’s economical.
—François Marie
President, FMB

Editor’s note: Lennard Zinn’s daughter, Emily, a former contributor to, works in public relations for Challenge Tires.

An American in France

What’s it like to be an American cyclist living in France? Watch to get professional road cyclist Joe Dombrowski’s view.