More than just making your motorcycle look cooler, an aftermarket cooling system hose’s job is to better what comes as stock. So just hold fire on ordering that cheap set of cooling system hoses you’re eyeing up…
It’s all about thermodynamics. The idea of a silicone hose is that you replace the standard hose of your cooling system so it doesn’t expand and get hot under pressure. When heat is generated, it expands; water is heated and the hose of your cooling system is there prevent excessive growth as the pressure rises, so your running pressure is reduced.
You brand-new motorcycle, say an Yamaha YZF-R1, has OEM hoses that are brilliant. Manufacturers recommend you replace them every four years as rubber breaks down over a period of time. As the rubber breaks down, it gets softer, so subsequently your engine gets warm, the water expands, the hose expands and pressure inside it reduced.
As the system pressure reduces, water temperature and boiling points rise and you’re more likely to overheat. The bottom line is, there’s nothing wrong with standard cooling system hoses – providing they are in good working order.
Silicone aftermarket cooling system hoses are a lot firmer and don’t expand as much. That’s why you see them on race bikes – they’re there for a reason. In extreme conditions, expect extreme components. You wouldn’t have a motorcycle that’s had a very expensive radiator fitted without having quality hoses on. You’d be a fool to run without them.
As with anything, be wary of buying cheap silicone cooling system hoses because we’ve seen some bad quality ones that actually expand more than standard hoses, and therefore cause overheating issues. Just because it’s silicone, it doesn’t mean to say it’s better than an OEM hose. If you have a top-self branded silicone hose, Samco for argument’s sake, the effect of the hose expanding is greatly reduced, but they are expensive. That’s the decision.
It’s purely price and financial reasoning why we don’t see silicone on standard production motorcycles. 99 percent are handmake in a jig, not injection molding like they are with OEM items. Eventually we probably will do our own, but at the moment it’s too expensive. If your motorcycle is over four years old – or in a higher state of tune – it’s a cracking investment.