Tyre rub/ clearance issue?

I've UTFS but not found an answer to my precise problem.

I've got a 700C bike which came with schwalbe blizzards (25s), and after a stupid number of punctures, I decided to swap for something really puncture resistant after getting a massive one on the towpath one day. I went for 700X25 Marathon Plus and though they are not super for acceleration, I haven't had a puncture since - which is nice. This weekend, I pumped my tyres up to pressure and the front tyre started rubbing the brake quite badly - not consistently though. It's never done this before and I have had the tyres up to full pressure. It looks like the tire might be seated slightly unevenly. I've tried deflating it, worrying at it to re-seat it, and then pumping it back up, but once I get above about 60psi, I have the rubbing issue.

Anyone had a tyre that used to fit and suddenly doesn't? Any tips on getting the tyre seated really evenly and keeping it there as I inflate it?

it does sound like you have got a bulge in your tyre, how old is the tyre and does it look worn?

have you tried another tyre on there and does it still rub?

if you have tried another tyre and it doesnt rub maybe its time to buy a new tyre?

Rubbing where on the brake?

thanks for the suggestions!

Tyre is less than 6 months old, doesn't really look worn. Does have a couple of cuts but that's it.I haven't tried another tyre yet, but I was thinking about swapping back to the blizzards which I still have knocking about, if I can't work out how to fix this. It's rubbing on the brake right in the middle, in the apex of the horse-shoe shape formed by the brake arms (dual-pivot). It basically looks exactly like the tyre just doesn't have clearance, except that it's always been fine in the past, even up to 115psi.

I also wondered if it might be wheel true. The wheel looks as if it might be a tiny bit out of true side-to-side, can it also go out of true in-to-out?

try another tyre before you do anything else. it sounds like you have a really tight clearance if its catching when its a little un-true.

there is no up and down movement in your wheel is there?

Is the wheel sat in the drop outs right? Try pushing it all the way in so it is even on both sides.

Silly thing to say I know but the amount of time I've messed up brakes and then realised it's because I installed the wheel slightly off.

Yes you can get a wheel out of true vertically but enough to rub a tyre on the brake would be pretty extraordinary and easily visible to naked eye (spin wheel and look at rim edge)
What frame are we talking here and are you sure its for 700c? Even the tightest racing forks have enough room for a 23c and a mudguard like Crud road racers.

Marathon plus whilst 25c across probably much taller with the thick layer of puncture protection.

I haven't noticed any up-and-down movement in the wheel, though the tyre does seem to rise and fall slightly as I spin the wheel. I'll try another tyre when I get home.

I'll try putting the wheel in again, it seems straight but I may be mistaken.

The frame is a Foffa Prima (I know) and though clearances are tight, it does fit a 700C - and 25s normally fit fine, though the marathon pluses have admittedly always been a couple of mm from the fork crown, tops.

My current new build is an old Falcon frame, originally for 27"s so I should have plenty of clearance in future! It's going to be a while before it's ready though.

I've had a Marathon on my rear wheel for a while now - it has caused me nothing but grief. Not great resistance to punctures, and an absolute bitch to get to seat correctly on the rim. I probably lost 3 or 4 inner tubes due to the tyre popping off the rim once pumped up to pressure.

Install tyre, try and get it seated correctly with a few psi in the tube, pump up a little more and check all seated on the rim properly, leave for a bit, check again before fully inflating, pump to pressure, check again for bulges etc, and hour later BANG!!! tyre off the rim and tube in bits.

Had another look at it and I'm pretty sure it's the tyre seating - it's kind or rising and twisting slightly around the valve area. I guess that I just have to deflate it fully and see whether I can get it to sit straight, and stay straight as i pump it up.

Though I tore fingernails getting the tyres on in the first place, this is the first time I've had a serious problem with the Marathon Plusses. I did have one blow off the rim on one of my fiancee's bikes though, with my head about an inch from the bubble too! Different size completely, though.

All these sound like user error. Have you considered cycle maintenance training?

When fitting the tube, push the valve UP into the tyre so that they tyre bead will then seat in the rim properly.

Cool tip, thanks! I'll try that. And yes, user error is about right. I am going to Hackney Cycle workshop when I can, trying to learn that way.