Originally Posted by
polymorphself
That makes enough sense regarding the frame pump.
I will likely start my own thread about this bike but since im here right now:
This is an ‘83. Is the flexibility issue when fully loaded on these as bad as a few posters have made it seem here? Is it remedied enough by packing low riders up front?
If I swap this to 700c should 32mm and fenders fit fine?
My partner has a 1986 Miyata 210 but this 720 is like new with a few upgrades (indexed shifting, Deore dx drivetrain) and it fits her. She also prefers the look of it. We can only keep one and I’m sure it will be the 720 but there is some concern about fully loaded performance with the reports of it being too flexible.
I think after a while the only way to answer the flex question is to personally observe or experience it. Everybody has different levels of sensitivity and ability to discern, and no one is listing weights or placements of weight etc. Sure, a guiding principle that a thinner tube over a longer distance will be inherently more flexible is true, but if your partner is anything close to the average woman, the stress she is putting on the frame by herself, and even if loaded, is still very likely less than just me on a much larger and more flex-prone (due to size and my weight) 720 (my '82). I wouldn't worry about it unless she is a super packer
and a track sprint specialist.
I'd ask for photos, but in lieu of them being provided, looking at the OP's 720
with 27" tires, I see acres of room for fenders. If those 1 1/4" (32mm nominal) tires are accurate, add about 4mm more in height and width in 700C form (of which there appears to be plenty of accommodation) and I'd say there's plenty of room for true 35mm tires and fenders, which will net anyone with a phenomenal ride (provided the tires are something along the lines of Soma Supple Vitesse or Compase/RH, or at least Pasela 35s).
Ultimately, it's up to you to experiment. I will say that some basic measuring of present clearances on your part will go a long way to you personally answering your own questions regarding clearance. You have the bike and the ability to do this. You likely have other bikes with 700C wheels and larger tires with which you can easily and (crucially!)
immediately swap on to this 720. The '83-85 720s were designed around 27" wheels, standard 27" tires, and fender usage. Only 1982 was designed for 700C wheels, and it will fit 32mm tires and fenders, though it's a little snug. Later 720s are bowling-with-bumpers-up easy to fit tires and fenders on. The only Trek/bike they'll be outdone by is a 1985 620 which will fit 40mm actual tires
and fenders if you play the game perfectly. It's insane, which is one of the reasons I keep that bike as well.