New tyre rubbing on seat tube...

[bencook]

Hi all, I was finding the ride on my 23C tyres a bit hard, so bought some 25C replacements (Michelin Lithion 2). With the wheel as far back as it will go, the new tyre rubs against the seat tube. The pic below is with the tyre deflated to around 30PSI, but at 80PSI the tyre is wedged to the point where the wheel won't even turn. Gutted, any ideas?

 

[grantoury]

fagpaper clearance frame, nothing to be done, I'm afraid...

 

[novocaine]

best idea, go back to 23c. the frame was quite possibly designed for 18c tyres.
I've seen a few people file out drop outs, don't do this.

 

[foz]

yep, older quality steel frames designed for racing are unlikely to take anything more than a 23, and some not even that. Go back to the 23's, if they feel too harsh then try wheels with shallow box section rims, those deep section alloy rims will not be helping to filter out the bumps

 

[jim haseltine]

^^^ what foz wrote.
It'll be the wheels - deep section rims and too few spokes. It's something of a hobbyhorse of mine - years back other than for racing we used to ride 36s or very rarely 32s (usually an old set of racing wheels downgraded for training/club runs) but when I'm out I see guys on wheels that wouldn't look out of place in a TdF peleton. I'm sure that some of them would be more comfortable on solid discs.
I've proved it to myself - after 20-odd years one of my Mavic rims gave up so I decided to follow fashion and go deep. I rebuilt the wheels with 40mm deep rims custom sprayed to match the frame colour scheme. Oh wow, yes, they draw the eye but they are certainly less comfortable than previously, to the point that for long rides I prefer the shallower rimed wheels from my other bike. Both sets have the same 23 section tyres, same number of spokes and same spoke patterns. I will at some point replace the deep rims with some much shallower.

 

[bencook]

^^^ what foz wrote.
It'll be the wheels - deep section rims and too few spokes. It's something of a hobbyhorse of mine - years back other than for racing we used to ride 36s or very rarely 32s (usually an old set of racing wheels downgraded for training/club runs) but when I'm out I see guys on wheels that wouldn't look out of place in a TdF peleton. I'm sure that some of them would be more comfortable on solid discs.
I've proved it to myself - after 20-odd years one of my Mavic rims gave up so I decided to follow fashion and go deep. I rebuilt the wheels with 40mm deep rims custom sprayed to match the frame colour scheme. Oh wow, yes, they draw the eye but they are certainly less comfortable than previously, to the point that for long rides I prefer the shallower rimed wheels from my other bike. Both sets have the same 23 section tyres, same number of spokes and same spoke patterns. I will at some point replace the deep rims with some much shallower.

Thanks for the response. Damn, the deep rims look so good! Me and my vanity...

 

[Nob]

Old school wheelset, small flange 36/36 DB spokes & stick with the 23c tyres