In this article I’m going to delve into the biggest differences between skinwall vs gumwall tires.
Tires are a big part of your restoration project. Especially tires which aren’t all black have come back into sway after disappearing from the scene at the turn of the millennium.
I’m a great Cannondale fan and have written a blog containing all Cannondale catalogs. Starting from the year 2000, none of their mountain bikes were outfitted anymore with tires than weren’t completely black.
Tan wall tires are reminiscent of the older style bikes and a such I’ve dedicated an entire article on the subject.
But before we dive into the subject of which one is better, let’s first clarify exactly what constitutes a skinwall tire and what a gumwall tire.
Different tires serve different purposes
A bicycle tire isn’t just one piece of rubber molded into the form that resembles a tire. If it was it wouldn’t last very long.
It’s made up of several layers that each serves their own purpose, with the most obvious outer layer that makes up the tread pattern.
Different tires serve different purposes. Obviously a downhill mountain bike tire will look and feel different from a tire to beat the hour-record. One has to be sturdy, the other has to be fast.
Long distance tourers will favor a tire that might contain an extra layer specifically designed for maximum puncture protection.
The layer on top of which the well-known tread pattern resides is called the tire casing. This casing is a mixture of either nylon or kevlar threads with rubber in between them.
Where rubber is heavy, the threads are not. In other words, the higher the number of threads the lighter the casing is going to be.
TPI / threads per inch
The number of threads in your casing is denoted by the TPI or threads per inch parameter.
Because the manufacturing process of a high TPI count is complex, it means that those tires are more expensive from a casing perspective than low-TPI count tire. Especially when kevlar is used, since kevlar is more expensive than nylon.
Mountain bike tires have a lower TPI count in general than road bike tires. That’s because a high TPI count results in less rubber being used, making the tire lighter, which is a more important factor for road bikes.
A higher TPI count also makes a tire more supple and less stiff, so it conforms to the road or trail more easily with the same amount of tire pressure.
Skinwall vs gumwall tires
A true skinwall tire is a tire where the casing is visible at the sidewall area. A different color rubber is used for the casing, so the sidewall of a skinwall tire contrasts sharply with the black rubber compound used for the tread pattern.
A tire that mimics this difference in color but isn’t a skinwall tire, meaning the treaded casing isn’t covered in a layer of rubber, is called a tan wall tire.
Hence a tan wall tire is a gum wall tire which has a different color for the sidewall.
Advantages of skinwall tires
At first glance it looks like skinwall tires come with a number of advantages and they do.
One of the key advantages of skinwall tires is weight and suppleness. That’s the reason why these types of tires are more the area of road- and cross-country bikes, because they benefit more from lighter tires than, let’s say, downhill or endure mountain bikes.
Reduced risk of tire wobble
From personal experience I can also state that a skinwall tire’s suppleness will lower the risk of tire wobble. It has led to me returning a Schwalbe Nobby Nic when it started rubbing against my rear brake booster. And staring at a front tire wobble annoys the heck out of me.
A trait more noticeable while riding on rough terrain with bigger tires, a skinwall tire can achieve a more supple ride. The thinner sidewall deforms more easily than less flexible non-skinwall versions, which means it helps with adjusting to the terrain.
In other words, the tire functions better at taking out the bumps in the road.
Using skinwall tires for a bicycle instantly create a vintage look-and-feel, making it an obvious choice to spruce up a retro build. For almost all of my restoration projects I’ve used skinwall tires.
Disadvantages of skinwall tires
Skinwall dry rot
Rubber has a certain shelf life before it starts degrading. The maximum shelf life is about 10 years when stored in optimal conditions.
It doesn’t mean older tires are useless. And you can definitely buy tires that are much older than 10 years. But it does mean that the tire runs a much higher risk of its rubber being compromised.
A common issue with skinwall tires is dry rot. The rubber dries out, starts cracking, and becomes brittle. Tires which are exposed to UV light are significantly more prone to show signs of dry rot.
Because the more delicate casing is exposed to the outside, this may result in the rubber coming loose entirely, leaving holes in the sidewall, with only the threads staying in to place.
With nothing to protect the threads they are very prone to tear, which may result in a tire blowout. This can be very dangerous for obvious reasons.
I’ve yet to come across true skinwall tires I do not consider premium. Because in general they are geared towards performance, instead of longevity, the tires are relatively expensive. E.g. you’ll never see them mounted on a budget bicycle straight from the factory.
Prices from these tire manufacturers range from €35 to just shy of €100 a piece.
Hard to find
No matter how you slice it, skinwall tires are hard to find. I’ve made up a list of the best 26 inch tan-wall tires and you could count the number of skinwall MTB tires on one hand.
The Nobby Nic on that list is not a true skinwall tire. And there are several slick or semi-slick tires on it as well.
Final thoughts on skinwall vs gumwall tires
In the matchup between skinwall vs gumwall tires it might seem that skinwall tires are the winner. They’re not, and the fact that their rarity and the lack of skinwall tires in the competitive scene speaks volumes.
Tire manufacturers have found other means to reduce weight, and introduce suppleness into their tire lineup. This has led to gumwall tires with a paintjob for the sidewalls to cater to a market who wants the aesthetics and vintage look-and-feel of skinwall tires.
Unfortunately for bike restorers like myself, barring the reintroduction of the classic Panaracer Smoke and Dart combination, it means that skinwall tires are still a niche market.