China DIapers

I took my bike in for a service and they convinced me to replace my rims. After collecting it by the time I had wheeled the bike back to my office I realised the rear tire was flat so I attempted to replace the inner tube and after great difficulty trying to get the tire back on realised they had fitted my old 700*25c tires onto the new 622*15c rims.

I take it these components are not meant to work together right? But how did the shop fit them? Do they have some sort of rim tire fitting tool?

Newbie question I know and apologies in advance.

jyl

"700C" rims are 622mm in bead diameter. I suspect the rims and tires are the correct size for each other. Tires of the correct size can be difficult to mount, if you don't have tire levers or sometimes even if you do.

Doug5150

Uhhh,,,, 700c is the 622mm ISO size.
Scroll down to the table that says "French Sizes": https://sheldonbrown.com/tire-sizing.html

The "700" in "700c" is not the ISO measurement, it's taken from the obsolete French measuring system.

The next-largest tires would not hold onto the rim with a tube inflated inside them, and the next-smallest tires down would not fit on the rim at all. The new tires you have may just fit on to those rims tight, or your changing technique is not good, or the tire rubber is very grippy because it is fresh perhaps.

Paramount1973 

Some tires can be a bit tight to mount and may require tire levers to get on and off.

dsbrantjr

"Some tires can be a bit tight to mount and may require tire levers to get on and off. "

I would suggest that you figure out how to install/remove those tires and be sure you have any tools you will need with you before you get a flat on the road. By the roadside with possibly cold, wet hands is not the place to try to figure out how to change your tire. Throw in approaching darkness for extra thrill points. If you cannot manage it get different tires; I will not ride on any tire that I cannot easily change by myself.

FastJake

This is good practice IMO. Some tires are just harder to change than others, and the rim matters too. Unfortunately you can't know until you buy and try and install them.

FMB42

Ya, I base my tire purchases partly on how difficult they are to mount/dismount (the reviews often mention this). Some tires, while very good performers, are nearly impossible to mount/dismount according to reviews from experienced bicycle owner/mechanics. This may be OK under certain conditions (track bike racing, etc), but it can be a pain otherwise.

daa

According to Schwalbe's recommendation (https://www.schwalbetires.com/tech_in...dimensions#rim), a 25-622 tire fits fine on a 622x15C rim (700x25C = 25-622 ETRTO); indeed it would fit rims from 622x13C to 622x17C.

FBinNY 

While the rim is the right size, it's shape may be a factor in your difficulty mounting tires.

Obviously, the tire's bead diameter is smaller than the rim walls outer diameter. Since beads have little or no give, you have to find some slack someplace to get the tire over the rim. The amount of available slack depends on the depth of the rim's center well, which allows the tire to move over giving you the slack you need. It's similar to stacking 2 quarters, then shifting one to the side slightly.

Unfortunately, many modern rims have very shallow center wells so the amount of slack you can get is super limited, making tire mounting difficult. It's too late to change the rim, but when you shop for tires, look for ones known to mount easier, so you don't find your self stranded with a flat and a tire that's nearly impossible to change.

dsbrantjr

"Since beads have little or no give, you have to find some slack someplace to get the tire over the rim."

Changing your rim tape may allow you to get more of the tire down int the rim to create more slack. If you have thick rim tape like the VELOX cloth tape, replacing it with something like Continental Easy Tape, which is thinner and slicker, may make mounting the tires easier.

FBinNY 

This is a good point. Using thinner tape can make big difference. I use filament tape which is very thin yet does a great job. Kool Stop urathane rim strips are another thin alternative. Do everything you can to make mounting easier. My rule of thumb for rim/tire fit is that I need to be able to remount tires without tools on cold rainy nights with half numb fingers, because that's precisely when I'm most likely to flat.