So my current commuter is an old trek mountain bike. Since I am not heading up any mountains on it , i was thnking of putting some skinnier tires on it and making it more of a hybrid.

Would there be any problems with slapping on some 700 size tires? i have the set that used to be on my road bike before i upgraded...

would any skinnier tire work on it?

The brakes probably won't hit the 700C rims. The rear hub may also be a different width.

Just get some narrow MTB rims (the ones that came on my Trek are really quite narrow) and get the skinniest city slicks you can find. I think I've seen 1.5 size. Pump them up hard. They make a huge difference.

The hub will almost definitely be an issue. MTB rear hubs are 135mm while road hubs are now generally 130mm. If it's an older road bike, the hubs will be even smaller, 126mm or so. But, if you have the rims, slap them on and see if it works. I went the other way and got a 130 rim on a 126 spaced frame and it does the job.

Get skinny 26s, around 1.5 or smaller, and like Mike said, pump them up. It's not going to be ideal and you may find yourself really spinning on downhills, but it will work.

Slicks make a huge difference.

yea, i might see if i can find some hybrid bike tires around. there are lots of abandoned bikes on campus, i just need to go harvest, but i will try out my road tires first

Road tires (700c) will NOT work on 26" mtb rims, end of story.

And road rims won't fit in a mtb frame, at least not very well or safely.

3rd the recommendation of getting slicks 1.25-1.5" or so.

Depending on your intended usage, you can get something like the Ritchey Tom Slicks, or if you ever wanna ride on moderate to easy trails, you could get some Ritchey Cross Max tires (they are harder to find these days, but I got some cheap online someplace, I wanna say for like $15 a pop) which have an inverted tread, so they roll decently on roads, yet are still somewhat useable on trails.

I did just this many moons ago on my old Rockhopper mtb, and then also got a 48t big ring for it, so I got less spun out at higher speeds, and it works reasonably well.

www.qbike.com is a good site to shop price online, and of course if ya find a particular tire ya like, Google is your friend as well.

just out of curiosity, did we not have the EXACT SAME CONVERSATION like three years ago, with the same protagonists and the same statements?

btw. Mike. Congrats! that Ironman finish is astounding. I offer my kudos to the pile.

nope couldn't have been from me, i just got the mtn bike this summer

stupid question, but where can i find the size of the tire?

front wheel i know is 26" by 2.0 or something like that,

but i swear the back wheel is bigger. it is a new tire and couldn;t find the marking on it

Besides, three years is far too long for the same stuff to be rehashed on this site. It was about 11 months ago, I remember it like it was yesterday...

So, anyone know anything about crossfit?