Originally Posted by
zas117
...The tires are 32H Alloy/WTB ThickSlick 700x28...
There's your culprit. ThickSlicks are mostly used by fixie riders. The thicker, tougher tread lasts longer with skid stops (or skidding just for fun). But the ride is harsh. Another popular choice by fixie riders in my area is the Conti Gatorskin, especially more cautious riders who don't skid stop much or skid for fun.
At a minimum, try a more supple tire on the front wheel, which rarely skids and is less vulnerable to wear and punctures. Most of the perceived comfort issues are related to the front wheel/tire/tubes. Almost any tire, other than Gatorskins, would be more comfortable than ThickSlicks.
Latex tubes can really tame the jolts and vibrations too. Pricey, a bit fussy to install correctly, but a pleasure to ride. I use 'em on my road bikes, but not on my hybrids.
Or go tubeless. With just liquid sealant all you'll feel is the quality of the tire. The better the tire, the better the ride.
Regarding riding on the sidewalk, it's no big deal as long as you're riding as safely as possible. Be aware that drivers won't be watching for you. They don't even watch for pedestrians on sidewalks. There are more blind spots -- parked cars, trees, shrubs, etc -- so even attentive drivers might not see you until the last moment.
The entire paved portion of our multi-use path is just a sidewalk. For years it was standard suburban width, around 4', with cyclists weaving around pedestrians, and passing each other at combined speeds upward of 40 mph. Only recently did the MUP authority widen some of the paved segments, mostly in the higher traffic areas used by recreational riders and pedestrians. But it's still just a sidewalk made of segmented blocks of concrete that will eventually rise and fall with the soil and be a mess to ride on.
So while we don't deal much with motor vehicles on the MUP (although very fast electric motorcycles and mono-wheel skateboards are becoming a nuisance), it is just a sidewalk with all the attendant drawbacks. Yet I rarely hear any Elite MUP Strava Triatholon Aero Bar-riding Kings and Queens griping about that particular sidewalk.
Except for me. I gripe about it at the slightest provocation.