More Tire and Gear Questions

Brian has asked us about tires and helmets in the past and now has more specific tire questions and he is also having problems with his gears. He wants to know the best pressures for his tires and find a solution to his gearing which is not great on his higher gears; we try to help, again

Question : Hi Samuel,
Thanks for answering my previous questions on Helmets, Tires. I live in Muscat Oman, Road & MTB are big here, more road biking, different groups for each and fun.
1. My question is my road bike has Schwalbe Blizzard tires, recommended PSI is 87, I also have a pair of new Michelin Lithion. I normally fill 100PSI in my Schwalbe tires as other riders do, but on the Michelin the manufacturer has given a graph as per rider weight which shows 80kg – PSI 116, I weigh 87kg.
2. I have 9 gears which have been adjusted, from the centre to the lowest gear the shift is really smooth, but from centre to highest gear it does not shift but drop. What could be done to improve the quality of shifting gears? Pl advise. Thanks for your time & patience.

Hi Brian,

I’m glad our last advice helped. Keep those questions coming and here are your new answers.

1. The tire pressures are a compromise between comfort, speed or road friction and keeping wear to a minimum. If the tire is very hard then it rolls more efficiently and has a lower chance of cuts and punctures, but you will feel every lump and bump in the road. If you have a soft tire then it feels sluggish, it has more chance of punctures and will wear out quicker, but it should feel more comfortable. Although most people like comfort, they prefer an easier ride that allows your tires to last longer. So the answer is to ride the tires as hard as you can put up with, my advice is to ride at around 8 atom’s, which is approximately 120 psi, on a dry day when you want an edge and not worried about comfort. On a wet day or when you are just out for a ride then seven to seven and a half atom’s, which is 100 psi to 110 psi, a combination of comfort and speed.

2. Gear questions are always tricky without seeing and playing with the gears. To me it sounds like this could be a wear problem, how old is the chain and sprockets? Do you use from the middle to highest gears more? Take a look at the profile of the sprocket teeth and compare the higher and lower gears, are they of a similar shape and is the gap between the teeth, if it is worn you will need to change it and probably the chain at the same time. That’s what it sounds like, but you need to check for wear, if it isn’t that then start by re-adjusting from the highest gear (smallest sprocket) up, if it changes correctly from the smallest to the second smallest then it is adjusted properly.