Riding in the heat

A few lessons I learned from riding in the hottest of conditions.

From April 2021 to April 2022 I lived in Dubai, United Arab Emirates, a city in the desert. Bordering with Oman and Saudi Arabia, about a 6-hour drive from Qatar, and looking at Iran across the Persian Gulf. It’s hot there -very, very hot. In fact, I’ve never been in a place hotter than there. I recall visiting Death Valley (California, US) back in August of 2011, about midday. We went for a quick walk in the open desert and when we came back the thermometer in the car marked 53C degrees. Dubai edges the 50Cs most of the day from about June to September. 

During these months you need to start your ride very early to get into the ‘safe temperature zone’ -past 8:30am, and the temperature will already be nearing 35C -which to me, was the ‘no go zone’. Riding later in the evening is an option for some, however the humidity was (again) something I haven’t had experienced before (and I’ve been in places like Riviera Maya in Mexico, Singapore and Indonesia) and when you couple heat with high humidity, it’s a bit like a Zwift session in the sauna.

This is a recollection of the tips I learned about ‘riding the heat’. These tips are obviously about heat and wheels, however there is other non-wheels related advice you should investigate further if you’re going to be riding hot!

Before I get to it -know these learnings apply to road cycling, and emerged from approximately 1,000kms of riding in Al Qudra, Meydan and Jebel Jais (the first two in the Dubai Emirate, the third in Ras Al-Khaimah) and the many chats I had with some of the team at Airwerks Cycles in Dubai.

 

This is Ben conquering Jebel Jais summit - it's also the border with Oman. 35km of continuous ascend, with approximately 1500mts of elevation (ride starts at base camp which is around 164mts above sea level and peaks at 1705mts, with another 230mts up by foot to get to the top at 1934mts)

 

Let's go with the tips:

1// Hubs and overall bike maintenance

Desert means sand, very thin sand. Dust-like sand. You’ll need to sweep your balcony every 2-3 days (on the 16^th floor) because it just gets filled with sand all the time. The message here: wind carries sand on an ongoing basis, something more noticeable when you are out in the dunes, of course.

Thin, dust-like sand can (and with time, will) get in your bearings, and in every crack and tiny opening it can find on your bike really. Thus, it is recommended that you increase the frequency of doing maintenance on your bike, and clean it more often, so that chances of sand getting in the inner works of your bike are reduced and with that any potential damage.

 

2// Heat on tires 

2.1 Blowouts

You finish your ride and leave your bike in the car -exposed to direct sunlight, while you enjoy that post-ride coffee (or smoothy! banana please) with your mates, and something in your car goes ‘BLAAAM’. Yeap, the tire blew out. This is surprisingly common in places like Dubai.

Long story short, don’t leave your wheels exposed to direct sunlight for extended periods of time, especially in peak heat times.

2.2 Pressure

When air temp is hot, asphalt surface is hotter. There is a study here I found about air temp to asphalt surface temp correlation; two of the datapoints they show: 32.2C Air temp is about 46.11C predicted Asphalt Surface temp, and 10C is 32.94C. There is also a rule going around (I couldn’t find any scientific evidence for this one, but if you do, please share) that says Psi = 2 x Asphalt surface temp in C degrees approximately, this means that riding on 50C asphalt will eventually take your tires to max 100Psi.

This math is only useful on its extremes. If it’s real hot out there, say +35C, and asphalt surface temperature may near the 50-55C range, there is a chance (if you ride enough time, and depending on type of tire, tire set up, wind considerations, etc.) that your tires get to 100-110Psi, which is typically near the max inflation recommended by most tire manufacturers (120 Psi).

As a final, and personal datapoint, I used to pump my tires to about 85-90Psi and come back home after a ride with about 90-95Psi on them. I usually rode early in the morning with the final hour or so at somewhere in the 30-35C Air temp range. 

2.3 Degradation

To wrap up the ‘heat on tires’ section, the last bit of advice is to watch out for quicker degradation than usual on our tires. This happens because we are exposing the tires to higher temperatures generally, both when out riding, and when the bike is stored, parked, or being transported on the racks outside the car. Heat will contribute to degrading the rubber compound faster. I definitely noted the pattern in both my Vittoria Corsa and Schwalbe One tires fading way quicker than I was used to.

You’ll be more likely to get a flat tire when riding on less rubber (degraded tire) at high pressure, plus the obvious loss in performance (less grip, less traction)  

 

3// Heat on V-brake rims 

3.1 Braking

Rims designed for a V-brake system have an approximately 12mm wide brake surface area on the outer edge of the rim where the brake pads will exert pressure every time we brake. The surface contains basalt and resins capable of sustaining high temperatures (around the 210C mark) when rubbing against brake pads designed for carbon rims.

Under extreme heat conditions, the ability of the rim and pads to cool down when we are not braking is reduced. Couple that with a long, steep and technical descend, and poor braking skills (i.e. dragging your brakes), and the risk of a tire blowout, and/or potentially, rim walls delaminating, starts becoming real. The first much more than the second.

A blowout on carbon rims on a steep descend is risky business. Once again, watch out for extreme heat conditions and if possible, avoid significant inclines during peak heat time, and if you do ride on these conditions and inclines, use intermittent braking on both rims equally at different points throughout the descend.

3.2 Brake surface

On the topic of exposing your rims to direct sunlight -the brake track of a carbon rim will gradually lose its braking power as the basalt and resins lose their braking properties. Another reason to protect your carbon rims from direct sunlight, and heat.

 

Jebel Jais / Ras Al Khaimah

4// Heat on brake pads

To close off, and directly linked with the section just above, your brake pads will degrade much faster when in contact with a higher temperature rim, or with a higher temperature rotor -this one piece of advice does relate to both rim and disc braking systems.

This reinforces the first piece of advice; general bike maintenance should happen more frequently under these conditions with sand and quicker degradation being the main two reasons to up the maintenance cycle, ensuring performance, parts longevity and overall safety are kept intact.

 

Other tips I encourage you to investigate further if you’re going to be riding in the heat!

• Hydration
• Tactics to cool off
• Keeping your water cold
• Clothing choices

 

More snaps from our ride to the top of Jebel Jais.

We ate everything these guys had to offer after our 3h 30mins ride, which wasn't much. 6 veggie and chicken Sambosaks, sodas, water, some chips... As an avid traveller (bordering the nomad), being in the middle of nowhere, in absolute silence, eating and driking mostly local stuff like there was no tomorrow (the after-1500mts elevation feel on your legs) with Ben was one of those memories I'll get to keep for the history books. Just such an epic climb in a region that has lots to offer to the riding community but that not many know about.

For the majority of the ride, the roads were in perfect condition and more importantly, had about a 2 meter wide side for cyclists on both directions - super!

This is the 'cobbles' section taking us to the final (15% gradient?) climb to Jebel Jais summit and border with Oman. I'm not going to lie -I had to walk for a good few meters, the incline was ridiculous.

 

Some data: