Why are motorcycles getting hotter?

Modern motorcycles are getting hotter and hotter which is not only an issue for rider comfort but also for reliability and performance.

But there are things you can do to fix the problem.

The reason modern motorcycles are getting hotter is the increasingly stringent emission rules.

Most manufacturers are reaching emissions targets with water-cooled engines that run leaner and therefore hotter; big fans that blow radiator heat on to the rider; and massive catalytic convertors that burn carbon emissions and are extremely hot.

Hotter bikes

Ducati Panigale R hotter
Panigale is hot hot hot

The hottest bikes seem to be V-twin and L-twin models where the top of the engine and/or header pipes are close to the rider and motorcycles with fairings that trap the heat and direct airflow on to the rider.

Perhaps the hottest bike we have ever ridden was the Ducati Panigale which not only has a cylinder right up under the slim seat, but also has a fairing that traps the heat and directs the air on to the rider’s legs.

The other notable “hot bike” is the new Harley-Davidson 750 Street Rod which has the back cylinder so close to your crotch that when you put your right foot down, your thigh touches the cylinder head.

Harley-Davidson Street Rod hotter
Hot riders on Street Rods

What can be done about heat?

There are expensive and cheap options that manufacturers and owners can employ to reduce heat.

Kawasaki has addressed the problem with its water-cooled parallel twin Ninja 650 by blowing the radiator heat down, not back.

Kawasaki Ninja 650L for sporty novices hotter
Ninja 650 blows heat down, not back

BMW addressed the problem of fan air on its F 800 models with a simple piece of plastic to plug a gap in the frame where hot air poured on to the rider’s thigh.

There is not much an owner can do about fan heat and we would advise against fitting any parts to stop hot fan air as you could be hampering the engine’s ability to cool.

Heat soak

However, there is something you can do about heat soak from cylinder heads and header pipes.

Coating the inside of the cylinder and the header pipes with a ceramic material makes the outlet flow faster, directing the heat further down the exhaust pipe and away from the rider.

It’s expensive and very few bikes have it as standard, but the new limited edition Ducat Diavel Diesel has black ceramic-coated header pipes and mufflers by Zircotec.

Ducati Diavel Diesel hotter
Ducati Diavel Diesel

They say it offers “thermal protection to reduce heat soak, avoid damage to components close to the exhaust, and potentially improve performance and reliability”.

There are places that will do ceramic coating for a few hundred dollars, but you will need to remove your bike’s exhaust and/or cylinder heads.

Manufacturers and/or owners can also reduce heat on the rider’s backside by fitting gold or silver reflective foil under or inside the seat.

Heat wrap

And hipsters have been answering the problem of header pipe heat by using heat wrap. They might do it strictly for style, but it also has advantages in reducing heat and improving exhaust outflow.

Hotter heat wrap Ellaspede
Heat wrap by Ellaspede

It’s an inexpensive solution that has been used by racing teams for years.

If fitting heat wrap yourself, wear gloves that cover the cuffs of a long-sleeve shirt as most wraps contain fibreglass that can get into your skin and cause irritation.

8 Comments

  1. Heat wrapping the headers helped on my 250cc dirt bike, the muffler was roasting the fabric saddlebags I put on, after heat wrapping that’s no longer an issue.

  2. Hi Mark, whilst Zircotec isn’t coating in Australia yet we do arrange for items to be sent to the UK for our plasma sprayed ceramic coatings to be applied & have done so for several bike owners. The other option you mention of heat shield material being applied to the underside of a seat can also be done using our self adhesive flexible ceramic heat shield material ZircoFlex. We stock this in Adelaide & post Australia wide including to numerous V8 Supercar teams.

    Anyone interested can check us out at Zircotec.com.au or give me a call on 0405 521 033.
    Cheers,
    Dan
    Zircotec Australia

  3. Having just switched to the new Euro 4 emissions compliant 650 Ninja, I can attest to the new design keeping you cooler as it directs all the heat downwards. I can hardly feel the engine heat even when the temp gauge is reading higher in traffic. I got so used to my last bike keeping my legs warm in the winter!

  4. After riding a hot Harley, I changed to a BMW1200RT with the boxer engine. the cylinder heads are down low near foot level and I actually never feel any engine heat at all now. I hadn’t considered this before buying it, but it is certainly a bonus.

  5. I’ve just paid for heat wrapping on my pipes under the heat shield on my Indian Scout & I still burn my right left when I put my foot down. I’m really ticked off that this happens & the burn is through my kevlar leggings & kevlar jeans. I’m really worried about how I will deal with the heat in summer.

    1. Hi Donna,
      The answer is … don’t stop!
      Seriously though, it is a problem and there is not much you can do when the cylinder head and header pipe are that close to your leg.
      Cheers,
      Mark

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