dr1445

i have a 1972 puch, for which i have a set of 27" alloy wheels and a set of 700c. 2 x the inner width = 26mm, so i suppose a 28mm wide 700c is feasible. at around about 190 lbs am i better off with a 27 x 1 1/4 tire like the marathon for general road riding or the 28mm 700c. i might see a dirt road once in a while.

Velo Dog

I assume there's enough adjustment in the brakes that you can interchange the wheels--I can do that on my old Trek, but not on my other bikes. If not, you might as well set up for 700c (slightly smaller in diameter, requires a longer reach brake) to get a wider tire selection. 27s are getting hard to find.
I don't think rim width will be a factor, though. I forget the width on the Trek (somewhere around 24, I think), but I've used tires from 23 to 41mm without any problems at all. I have 35mm Panaracer Paselas TGs on it now, and i like them a lot. They're available from 25 to 37, I think. Good tires.
Before you buy, make sure there's room between the fork blades and under the brake arches for bigger rubber. Shouldn't be a problem if you use the 700s. Most bikes from those days had plenty of room anyway, but it's worth checking.

dr1445

it seems either a 27 or 700c tire is just a click away on the internet. so i am not sure why it is said the 27's are hard to find. certainly the selection for the 27 tires is smaller. my 27's still have some life left on them, since the width is not an issue i will go with the 700c x 28mm tires, the present 700c are long past the disposal point.

Velo Dog

You can certainly FIND 27-inch tires. Even my local supermarket sells them, 45psi Kendas for $6.99 each. But there's nothing like the selection you can get in any bike shop in 700, from super hard 19mm to fat, cushy 41s you can run at 60psi, and a whole range of cyclocross tires besides. My point was that if you have to choose one or the other, seems to me it makes more sense to spend the money to move to the new standard rather than going back to one that's disappearing.

Esteban32696

https://www.niagaracycle.com/index.php?cPath=131_167 for tires

dr1445

since i already have both 27 and 700 wheel sets my question was directed towards the tire width and the 190lbs. since the inner width of the 700 rims is 13.34 x 2 = 26.68mm i was limiting the 700 tire choice to 28mm for a good fit. with the 27 i could go wider about 32mm. the 28 x 700 are on order, the original 700 tires were 20mm.

DieselDan

If the brakes will reach, go with the 700c/622mm wheels, as there is an exponentially larger selection of tires then 27"/630mm wheels.

zonatandem

Your weight is not an issue with either size/width of tire.

jhud51

Just out of curiosity where did you get the Puch? I had one made in the mid 70's with 27 inch tires. It came from Sears and was sold with the J.C. Higgins name brand on it. It was a pretty good crusing/touring bike but I gave it away to a mission group and it went to Honduras where the bicycle is a way of life. Sort of wish I still had it but it would have to be refitted with all new components.

dr1445

i got the puch new in 1972, i used to ride it but it has been sitting in a corner of the garage for many years. it needed tires as the 700c tires on it were shot. the local dumpster supplied the 27 alloys with decent tires and so i am back riding. basically i mounted the 27 wheels adjusted the brake pads, cleaned and lubed the chain and was off and riding. the bike is no light weight at 28 lbs with some tools onboard, but it sure gets the job done for exercise. the 28x700 tires will be in the end of the week, i doubt i will notice a difference with the 27 but time will tell.