Mountain Bike Tires On A Road Bike
Retrofitting mountain bike tires on a road bike can present a few challenges, especially regarding the tire width, thickness, and size. You would need to consider why you want to do this and how it would affect your road bike – but can you fit mountain bike tires on a road bike?
You can put mountain bike tires on a road bike, although this is a little more tricky than doing it the other way around. This is because road bike frames, wheels, and braking systems are made for thinner tires inflated at much higher pressures, and the thicker mountain bike tires may not fit.
The success of taking your road bike off-road by fitting mountain bike tires would also depend on the type of terrain you would be riding on; remember that your ride would be a lot bumpier than it would on a mountain bike – so let’s saddle up and see how this tire transplant could be done.
Why Would You Fit Mountain Bike Tires On A Road Bike
For some off-road riders who have road bikes, the idea of taking the road bike off-road to see how it would perform would require a change of tires, as road tires would have virtually zero traction on gravel or sand, much the same as mountain bike tires would struggle on a road surface.
Perhaps you have moved from the city to a more robust area with more sand or gravel roads than asphalt or concrete, and instead of buying a mountain bike, you are going to go the cheaper route and simply retrofit mountain bike tires to your road bike.
Find The Right Size Mountain Bike Tires For Your Road Bike
Replacing the road tires with off-road tires would give your bike the traction it needs to ride trails, but your challenge is finding the right diameter tires for your road bike. Most road bikes come with 29″ wheels, and MTB wheels can vary from 26″ to 29″, with 26″ as the standard size.
Road bike tires are typically 27,5″ in diameter with 0.9″ in width, but you can also get 29″ wheels that are 1″, 1,1″ and even 1,25″ wide, and if you know MTB tires, these are quite thin by comparison, although the diameter of the tire would fit on a road bike if they were thin enough.
The tire’s diameter is not the issue; it’s the width, as most mountain bike tires start at around 2″, which would pose a problem for the road bike as good quality road bikes have very little additional space and tolerance for tire widths.
Another consideration here is that the brake calipers are designed to fit accurately on the rim, so a wider tire would mean that you wouldn’t be able to get a 2″ MTB tire to fit inside calipers designed for 1″ -1,25″ road tires.
If you are going to fit mountain bike tires to your road bike, you need to know the tire specs and ensure you get the same diameter and width tire so it will fit, unless you plan to modify the brake cantilevers or add wider wheels to accommodate a wider tire.
Handling Will Be Different With Mountain Bike Tires On A Road Bike
Because road bikes are built primarily for speed and traction on smooth surfaces, and mountain bikes need traction on rough terrain, MTB tires are inflated to a much lower pressure than road bikes.
A road bike tire would have a working pressure of between 50-100 psi, while mountain bike tires would only be inflated between 20 and 35 psi as this would provide traction for off-road terrain and allow for braking, cornering, and control on downhills.
While you can inflate your MTB tires to this pressure for the road bike, remember that your handling, control, and braking, even with off-road tires, will not be nearly as sharp and responsive they would be on the mountain bike – but if you are doing slow leisurely off-road riding, then having mountain bike tires on your road bike will work fine.
While the softer pressure will help with the absorption of impacts while riding, the road bike frame does not have suspension, and adding it to a road bike is not an option, so prepare to be bumped and shook around during your ride.
Consider The Frame And Braking With Mountain Bike Tires On A Road Bike
While this sounds simple, remember that road bike frames are less accommodating than mountain bike frames, and even if you modify the brake system, if the tire is too wide, it may rub on the frame, which won’t last very long while riding.
Another consideration is brake durability, as you tend to brake more frequently and harder when trail riding than you do on the road, so you may have to swap out your road bike braking system for something that can handle the stresses of off-road riding.
Road bikes are usually fitted with cantilever braking systems, which could mean reduced braking efficiency if the tires fitted are too wide as it would adversely affect the stopping ability, especially o downhills.
Adding mountain bike tires to a road bike could also include changing the rims, as road bike rims are not made to manage the impact of mountain bike riding and would sustain impact damage and buckle under the greater forces involved.
Your road bike frame has thinner tubing, which means a lighter but less resilient frame against the more robust durability of the mountain bike frame. Coming downhill at speed, even with the right tires, your road bike frame could bend or even break on impact at lower speeds.
Conclusion
You can put mountain bike tires on a road bike, but the truth is, this is ill-advised as the risks of damage to yourself, and the bike outweigh any benefits. This option will be viable if you plan to do only gentle rides on light gravel roads at low speed, with no major downhill heroics.
With the additional modifications you would need to make the road bike manageable and safe when fitting mountain bike tires, you may be better off buying a separate mountain bike and keeping it where it belongs- on the road.
