noahsmonark

Once again I seem to be lost in the sea of different tire/tube sizes, markings etc.

I'm putting my old 90's mountain bike back up to spec for the winter, for short rides and sometimes forest roads and snow/ice, not heavy riding though, just casual - it's a pretty nice Finnish-made 1998 Tunturi Kayapo with some pretty decent parts. The wheels are still dead straight. It's got 26" (559) wheels with 19mm inner rim width, I wanted to support my small local bike shop and they only had a pair of 26" tires in 54 width (2.1") so I went ahead and got them anyway - Schwalbe Black Jack. I wanted something kinda bulky for this bike anyway, like I did back in my teens in the late 90's, memory lane.. I also have some inner tubes here, but their specs aren't 100% - I'd rather use the stuff I have instead of buying new inner tubes if possible, so I just wanted to see if someone could confirm the following three:

First of all, fitting a size 54 tire on wheels with 19mm inner width should still be doable? My understanding is that this is still within limits, although kinda barely.. I think the bike originally, out of the shop, had something quite wide fitted.

My Continental inner tubes (650C whatever the heck that means - but it does clearly say 559 on the box which is what my tires are) are marked for 37-47 width - but once again, they should still work right - with just an ever-so-slightly higher chance of pinch flats because I'll have to over-inflate slightly?

The Continental tubes are marked "Tour" on the box, not "MTB" - I have no idea what this means, I guess just slightly thinner material? Again - should work ok-ish?

Thank you...

ShannonM

26" (559) tires that don't suck are becoming an online / special order thing, as new MTBs have gone over to either 700C (29") and 650B (27.5"). There is no real reason for this, other than fashion. 10 years from now, it'll probably be different again, and the new hotness will be 559A, or 27", or whatever they decide to call the same rims and tires that all mountain bikes used until last Thursday, which will absolutely not be "26 inch", because that would sound old. Bike tire sizing and marketing is stupid. It has always been stupid, and it will remain stupid. Embrace the suck.

Big tires on narrow rims can be a pain to mount. They can also go on like butter on toast. Only way to know is to try. Once they're on the rims, they will work just fine.

Inner tube sizing is like hand grenade accuracy. Close enough is good enough. I've used a 26" tube in a 700c tire, when I had the wrong tube in my seatbag. It was a bit fiddly to get the tire back on without pinching the tube, but it worked. Eventually, i pulled it out and put a 700C tube in, mostly so I could have my MTB spare back. I've also gone the other way, 700C tube in a 26" tire. That's more of a hack, but it can be made to work, and is better than walking.

Don't sweat the "Tour" vs "MTB" labelling. Tubes is tubes, doesn't matter.

--Shannon

Darth Lefty 

To answer your questions, as opposed to the above,

2" tires are right for your bike.

The tubes you have may be the wrong diameter. 650c is a triathlon size, mostly, but also found on bikes for smaller riders. They are anyhow definitely the wrong width. Even if they work, you should get the right ones and change them out when you can. When you have an under-width tube it can cause a blowout when you might have had only a slow leak, because the tube is pumped up like a balloon inside the tire and a puncture can pop it instead of just holing it.

Bill Kapaun

A 650C is a 571mm BSD vs 559mm.
It'd probably work, but the ID has to "shrink" 1/2".
IF it's unused and you can take it back, I'd get the correct size.

My personal rule of the thumb for width is 2.2X the inside width, but I'm an old lady that way. You should be OK.
You can find out if it's too squirrely in short order.

noahsmonark

Ok that's reassuring.

Thanks much for the input guys.

Alright, appreciate the info.

Receipt's gone.. It does also say 559 on the box though, which is probably why I've gotten these tubes back when I did.

ShannonM

Looks like Continental made one tube to fit wide tires on several rim sizes: 559 (26" MTB), 571 (650C and Schwinn cruisers), 584 (650B), 590 (650A and 26" Raleigh), and 597 (old Schwinn 10-speeds).

--Shannon