Ghazmh

Whoops, I meant Gator Hardshells. They have the tread pattern of GP4000’s and are long lasting with diecent puncture protection.

djb

aero theory doesnt fit as wider tires make no diff to stability, I've ridden at 80kph 50mph many times on 28 to 50mm tires. Tire width makes no difference, but there are a whole slew of other factors that come into play, especially at 60kph and or with varying rider experience going fastish.
Your issue was most likely how the tires were mounted, this that or the other thing, too many variables to know for sure (rider position, weight on bike, wind, tire installation, tire pressures, rider steering input, weight distribution on bike, weird bump in tire, inflation issues....so many possibilities)

is the 94 seven speed or did they get up to 8 at that point? My old '91 tourer is seven.

djb

if for commuting getting a flat and being late would be a real problem for you, then obviously a tough tire has its advantages. Ive been commuting by bike for decades and decades, and very rarely get flats, but Ive generally had good quality tires, keep an eye out of what I ride through and over, and keep tabs on pressures.
If you are someone who pays less attention to this sort of thing, and would be inconvenienced by a flat, then clearly a good tire is worth the money spent.
Ive commuted on 28s to 50s, and I do find that for commuting, wider is a bit nicer for being more comfortable over our notorious rough roads. So 35 and 38 are my favs for commuting, especially in the fall when it is so dark so early and I am riding in the dark a lot more--so hitting potholes more and not seeing what Im running over like glass and debris.

In these sort of conditions there really is an advantage to wider tougher tires, compared to nice road, nice weather, good visibility riding lets say. And why especially in the fall I prefer to use my commuter bike with 35mm regular marathons, a good compromise of width, price and flat protection.

mev

Marathon Plus 700x35 has served me well on my 2007 & 2004 model 520s. I am a heavier rider and more so when fully loaded. I will also ride gravel roads as well as pavemen. I've also used Marathon XR (discontinued) and Marathon Mondial (replacement for XR) but default is Marathon Plus. I'm not going for speed records so durability/puncture resistance is important. i'll typically ride them until the blue shows from underneath

Note on the Trek 520, but on my touring mountain bikes, I have also used 26x2 Marathon Supreme. These are lighter tires with thinner sidewall. I've had a few sidewall cuts so not always ridden until the blue - but still fairly durable.

Fredo_Adagio

The 1994 Trek 520 has a Shimano Deore LX 3x7 drivetrain with bar end shifters. She's beautiful with dark green paint. She came with light brown bar tape. The guy in the shop referred to her as the "Eddie Bauer Edition" after the Ford Explorer special edition of that vintage that had the same color scheme.

Regarding an explanation for the steering stability problem, I'm grasping at straws. The steering stability problem existed at high speed for the original tires (28 mm), but went away when I installed narrower tires (25 mm). I'm sure I checked the air pressure before going for a ride, so I'm fairly certain that wasn't the problem. I did not have the bike loaded, and I am not a big guy at approximately 145 lbs. Perhaps more weight would have made a difference.

francoisnewtown

Schwalbe Marathon Plus, 26 X 1.50.

djb

TOS, really who knows, but I'm lighter than you, 135, and have been fast with no issues unloaded on 28s, fast loaded on 28s, so impossible to find an answer here.
main thing is that wider tires have no bearing on high speed stability, bonus is the large difference in rider comfort.
May your trek continue to be stable.