What is the recommended PSI for bicycle tyres?

Look at the side wall of your tyres and you will be able to read the minimum and maximum PSI or Bar you can inflate your tubeless tyres or inner tubes up to.

Try to maintain the correct inflation pressure in your tube to lower the risk of punctures. Pump your tube to the pressure within that range.  If you are aiming for speed, you can inflate your tube right up to the maximum PSI indicated as that will help to reduce the rolling resistance of the tyre.

For better grip, you can let out some air for a more comfortable ride, especially when it is raining. Remember not go below the minimum PSI range recommended as the inner tube can get pinched between the rim and the tyre which can cause punctures. Also, it will be harder to ride a bike when the tyre pressure is too low.

If you enjoy riding your bicycle downhill, during descents, use your brakes in an on-and-off fashion to prevent the rim from been heated up as that could expand the air in your tube and cause a tyre blow-off. That is a good reason not to over inflate your tube.

If you visit Schwalbe’s website, you will find a tyre pressure chart calculated based on body weight and tyre width.

At Silca there is a link to "Tire Pressure Calculator". You can click on it to enter the information required, which includes the terrain you ride on, in order to calculate the PSI you need to inflate your tyres up to.

Some companies supply their pumps with a PSI chart attached. Based on this chart from PumpKing, for tyre size 700X28C, it is safe to pump your tube right up to 73 PSI if you are not able to read the markings on your tyre. 

Over time you will discover the perfect tyre pressure based on your personal experience and adjustment.  To make adjustment, you can start at the lower end of the recommended range and gradually add a few PSI after each ride, up to the maximum PSI recommended.  You can then stick to the inflation that provides you the best comfort and less resistance during rides.

Are there bicycles suitable for overweight cylists?

I noticed that customers who are overweight tend to fear looking awkward on the regular bicycle with narrow tyres. They have a tendency to worry that the wheelset cannot withstand their weight and will break down on them while they are out cycling.

This anxiety can distract them from enjoying the ride and make them feel clumsy on their bikes. Moreover, most of them prefer larger saddles which will look awkward installed on a regular bike.

So, based on the questions asked, I tend to recommend that they get a fatbike.

A cyclist needs to pump his bicycle tubes around once every week or once every fortnight if he does not ride as often. However, for a very heavy rider, he may need to inflate his tubes more often as the tube need to be pumped to the maximum pressure stamped on the sidewall. It can look embarrassing for a larger rider to be cycling on a bicycle with tyres that look flat. So, this can a hassle.

Fatbike runs on 26x4″wheelset. The wider width tyres provides better balance for an overweight person. The air in the tubes is best pumped to the maximum pressure if it is ridden on paved road. You should let some air out if you are cycling it off road. Then the tyres will act like a suspension fork, making the rider feels like he is riding on a 2 wheeler monster truck. This eliminates the requirement to pump air in tubes more often for heavy riders.

Fatbike is not that common yet in Malaysia and this is a feedback from an overweight customer who took my advice to get a Fatbike. He said that it gives him a sense of pride. People are looking at the Fatbike and not him as an overweight rider. Strangers tend to approach him and asked him about his experience on his Fatbike. This encourages him to ride out more often which helps him to reduce some weight.