Advisable to switch from 38 mm tires to 28 mm? I have a urban/hybrid bike ( Riverside 500 that came with 38mm tires that I don't really have complaints with except some visible cracking since a year or so (which hasn't impacted feel, air retension or anything at all) But I have been thinking of replacing these 700x38 tires.
I can go with 38, 35, 32, 28 or 25 mm tires to replace these. I am speculating about going with 28mm as of yet.
I dont do any off-road stuff , I stick to road riding and commuting mostly on great highways but the occasional pot-hole riddled by-lane does come up , so fragility or sharp feedback is best avoided .
Which size is ideal in this scenario ?
Two things to take into account.
Firstly, 28mm tires lower your bottom bracket by one centimeter when compared to 38mm tires. If your bicycle was designed with 38mm tires in mind, it probably has a quite large bottom bracket drop. With 28mm tires, you can touch the ground with pedals when cornering pedaling.
Secondly, from 38mm to 28mm is quite a large change. Are you certain that 28mm tires are what you want? They require far higher pressure and the ride is less smooth.
Considering that one of the best tires, Continental Grand Prix 5000, is available as 32mm width, I would pick this width in your case. (Don't do what I do; instead, do what I say -- I use the 28mm width of GP5000 but in my opinion 32mm may be even better for people not used to narrow high pressure tires.)
The rim width may also limit your tire options. A 28mm tire requires a rim at most 622 x 19C. If the rim is 21C, you should not use 28mm tires.