Classic & Vintage - Bike frame weight question

Hi,
I've got a question about frames. I have two that I'm considering using for a tourer for a friend. One is a standard Carbon Steel frame from a Raleigh 3 speed roadster, the other is a Reynolds 531 road frame.
Trouble with the 531 frame, is that the clearances on the tyres are a lot tighter for tyres and fenders. The roadster frame has more leeway, but weight is a prime consideration, as we'll be flying with the bike.
Can someone tell me how much difference there will be weightwise between the two frames. I'd just weigh them, but the frames are still bikes, and I don;t fancy stripping them both to the metal to find out.

Thanks

If you are flying with your bikes, then the size of the carrier you put them in is probably going to be more critical than the weight of the bike inside it. I cannot say I have ever weighed a carbon steel frame as you describe, but I cannot see the weight being that much different for the same size frame. All that said, if weight is the primary consideration, you need to determine if the 531 will work as a tourer and go from there.

I know there can be a lot of second-guessing on these boards, but....

Weight isn't the prime consideration. Sure, you're flying, but 99% of the time you'll be riding. Maximize the utility while riding. If the 531 frame can fit 30 or 32mm tires, fenders, and still have clearance for mud or if a rim gets out of true, then use it. If 28mm tire and fender barely fit with no room for mud and the wheel must be absolutely true to not rub, then forget it.

The frame weight difference will not be huge enough to matter, people fly with full-suspension mountain bikes. You might have to pack lighter things around the bike, but otherwise I wouldn't worry about it. Maximize utility while riding.

Of course YMMV depending on tires you want to use and if raceblades rather than full fenders will work for you. Good luck.

As long as you replace the stem, handlebars, bottombracket, brakes, and every other part on the bike with lightweight stuff, the frame itself shouldn't add more than a couple pounds. I got a sports down to 29 pounds fully accessorized, with the old pedals/cranks/bottom bracket. If you went crazy, I bet you could get it to 25 pounds.

Thanks for that, chaps, much appreciated.

If embarking on a tour the first consideration should be "what could go wrong?" If this is to be a loaded tour I would think twice about both frames... One might be a lightweight racing frame with no braze-ons and have to have everything clamped so You'll have to carry spare clamps and it might not be able to fit strong wheels, you really want a good set of wheels... with the raleigh what size of wheels does it take? Will you be able to put a strong set of alloy wheels on it?