I'd revert to a 23mm tyre. I know the larger tyres are said to be better now but there is little difference between those two sizes and we all rode quite happily on 23s for years before we were told it was wrong.
Lovely bike by the way, far too good to start buggering about with the frame.
Many thanks for the compliment, I do agree that it would be a shame to mess with it to that level. The issue I have is that the Fulcrum 5 rims have a minimum tyre size specification of 25mm. I would rather not have to change wheels as well...
Another tyre I have been reading that comes up with a lower profile is the Vredestein Fortezza Senso All Weather. I could buy a new pair of Veloflex's but I only got a couple of rides out of the originals. Maybe they were old, the tyre wall started to come apart so am not so keen on those, especially as I am riding this bike in the winter months.
Some tyres are wider/taller than others. I'd go back to 23c - that's way too close.
The issue I have is that the Fulcrum 5 rims have a minimum tyre size specification of 25mm. I would rather not have to change wheels as well...
When considering whether to attempt this, bear in mind that the seat tube typically has a wall thickness of less than 0.7mm.
Nearly all steel frames have a seat tube of 28.6mm outside diameter. The seat post's diameter is = the inside diameter: 27.2mm. The wall of the tubing is 0.7mm thick at the ends and even thinner in the middle (the Omega looks a nice frame).
And the paint will suffer abrasion if you leave it with minimal clearance (first image) when the tyre picks up grit.
However, I see the new '25s' are Contis. What model? The 4000s come up wide (and tall) and the GP4s come up narrower than spec. Measure those tyres (sample the width at several points and take the largest reading).
Unless you're a lightweight (which presumably (two clues) you're not
), 85psi is low for a rear wheel (@25mm).
That is really helpful thank you, I knew the frame tubing wall would be thin indeed. I wonder if a "fillet" could be welded in, that was my thinking, but it is a lot of work for someone.
The new tyres are Continental GatorSkins, I have another bike I could use those on, so they won't be wasted. Interesting to read that the GP4s come up smaller than spec. Assume that GP4 is referring to "Continental Grand Prix 4 Season"? They sound like a definite contender to solve the issue, as well as being durable. It is a pain to keep buying tyres to trial and error, but is necessary, I could always use them on another bike I have. As above, another tyre that I read has good all weather performance, puncture protection and come up slightly smaller than spec is the Vredestein Fortezza Senso All Weather - have you heard of these?
(and yes, I am not a lightweight unfortunately ;-) )
Do you know anyone running 25c tubeless tyres? If so you could try their wheel as You can probably run them at 85psi.
I recently switched tubeless and seem to have a little bit more mudguard clearance fo the same tyre size.
Lovely looking bike by the way.
Thank you for the compliment there.
I don't know anyone running tubeless unfortunately, but that is an option for sure. I would need to check if the Fulcrum 5s can run tubeless. Interesting, out of the box take, on the problem. Thanks.
I really like your bike. I'm going to guess that frame was made to accommodate tubs and sprints. I had tubs and sprints back in the day on a Bob Jackson titanium frame - that frame couldn't accommodate clincher tyres either.
I hanker after tubs and sprints for my Emonda at the moment, and I'm intending to go down that route in the spring, funds permitting.
If I was lucky enough to own that bike, that's the way I'd be going. The Bontrager R4 320tpi tubs are well-regarded for being fast and smooth riding so that's where I'll be looking. Each to their own, I'm a pretty capable engineer if I say so myself, but I wouldn't try to modify the frame in that way, just doesn't seem right.
Cheers for that, it is a lovely bike.
Seems a shame to ride it in the winter, but it was my size and represented good value to money so why not! I know what you mean about modifying the frame - it does not sit that well with me to be be truthful. But somehow I would like to get the frame, wheel and 25mm tyre combo working. I think really the answer is to find some 25mm tyres that come up with a slightly lower profile, as the rim specs state 25mm minimum.
Go back to a narrower tyre. There's only one way you can gain clearance without distorting the shape of the seat tube, and that is to file a tangential slice off the rear of the tube then weld in a flat oval shaped filler piece to close up the hole. It could be done neatly by someone good at sheet metalwork but even then the heat input will still destroy the paint job.
Thanks, this is the sort of thing I was thinking. I am aware that the paint would be damaged, but not sure to what extent. I did think that the section that has had work could be masked off and painted black - hopefully not that noticeable if partially hidden by the tyre.
