700c tyres are to small?
If 700c is too small then it will be 27" x 1¼, which was the standard British tyre size. Rim diameter about 8mm greater than 700c.
Another bloody wheel standard.....
Another bloody wheel standard…..
Don't knock it, that 8mm bigger wheel made a massive difference and the bike rolled so much faster. Or that is what they would tell you today based on all the BS in MTB wheel sizes.
Ideally we need a new size in between the two so it has the advantages of both.
Can still get decent tyres from Schwalbe and Continental, either that you can fit fat tyres on 700C rims.
Fat tyred 700c work really well.
But you will need long reach callipers.
Replace the wheels with ordinary 700c and use long reach calipers. Should work fine.
Replace the wheels with ordinary 700c and
use long reach calipersreplace the frame with a new disc compatible one. Should work fine.
FTFY. Situations like this should be seen as an opportunity to buy a new bike.
Swapping to 700c might not work! As I found out once.
If wheels are decent just buy new tyres.
Why would you go to the expense of changing wheels and brakes and tires.*
What odd logic
Change tires if required and ride .
*It's a 70s British road bike. Even with gp5000 black chilli it's gonna ride like shit
Well I was working on the logic of there might be some 700cs kicking round.
based on the fact that from memory the OP has some sort of shop/social enterprise thing going on.
aditionally the rims might be steel ditch finders/broken or it might not be his bike and the requests of customer might be "get this biek working at all costs".
I have a tyre you can have, will PM you some pics. (just a single tyre)
Why would you go to the expense of changing wheels and brakes and tires.*
What odd logic
Not really. 27 tyres are as thin as anything, 700C adds comfort. Most brakes (or at least the Weinmann ones I have on both my old bikes) have the reach and if not it's not exactly going to break the bank to get longer calipers.
Plus what Josh said.
An old bike like that is fine for touring or just pootling, we don't even know what it is so could be anything from a Raleigh shitter to a decent lightweight. Im struggling to imagine how frame design has changed so much that it would "ride like shit".
Ridden much from the 70s .
Toe overlap wasn't really considered a problem back then.
It went from a 30 quid job to a £120ish for a pair of wheels and a pair of brakes +tires. assuming the freewheel transfers across if not another 20 quid.
My pub bike is an old (probably late 60s) Sun "racer" and has 27" wheels. Late last year I managed to get a pair of Continental Ultra Sport 32s, one from Wiggle the other from BikeInn. The BikeInn ones are the new pattern too but both were new stock (no perishing). They ride very comfortably. If I need to pop to the shops after a 50 mile road ride on my "good bike" it's the Sun I choose.