Allegro

Does anyone do this? My buddy got a new bike recently and it come with 2.35 up front and a 2.1 on the rear, what is the theory behind this and does anyone reccomend it?

ed 

I run a 2.35f/2.1r on my crappy bike b/c I can't fit a 2.35 between my chainstays on the rear. I would be running 2.35f/r.

The larger casing offers:
-more traction from the larger contact patch
-more traction because you can run lower pressures w/o pinch flatting
-lower pressures = cushier ride

A good reason to run wider front skinnier rear is to keep the cornering ability and still have somewhat snappy accleration.

ca7erham

2.35's up front, 2.1's out back. I'd strongly recommend it.

mtnbiker66

I hear it'll make the frame break.

ca7erham

They also say that about putting on longer travel forks than what came with the bike

stapfam

Many years since I bought it- but My Kona Explosif came with a 1.95 on the front and a 1.75 on the rear.

Never did understand why but it was explained to me that the larger front tyre gave better steering at speed on hard pack trails.

I am in England so I fitted 1.8 mud tyres and chucked the OM tyres as they didn't work.

brendon_ak

just look at motocross for an example of this in the sense that the larger (diameter) front tire rolls over more crap and doesn't get stuck

BearSquirrel

You heard wrong.

jcook1989

I ran 2.7 Minion up front a 2.1 Weirwolf out back for a little while. Right now I'm running both 2.35s although there is nothing wrong with going a size up in the front. In some cases is can actually be advantages.

7daysaweek

^

mtnbiker66

Prove it.

ed 

Though a larger diameter tire will have a little bigger contact patch...your post would be better suited for a 69'er / 96'er conversation. The "wider" front narrower rear is more adept to frame breakage.

MaxxisMaster

What are we in the freakin 3rd grade? my dad can beat your dad up...prove it...way to be mature gentleman

10 Wheels

My grandson can beat up your granddaughter.

theextremist04

I can beat up your grandson.

mtnbiker66

Why don't you just shut up. What do you know about it anyway! My Dad runs a bigger front tire that your Dad.

sstorkel

Another reason to run a larger tire up front: it will slacken the effective head-tube angle by a fraction. If you bike is just on the edge of nervous, like mine, a bit more slack can be a Good Thing.

Allegro

I'm glad you brought this up, I am considering a 69'er SS build with my new(to me) 03 SC chameleon frame. I am thinking wider up front will def be the best bet for this setup. But it sounds like it just comes down to personal preference, I havent heard anyone say anything about making a switch and noticing much difference, but if you guys have stories like that let me know.

Thanks.

pc_1453

I'm a BMXer, but I think the theory still applies. I always use bigger ones up front cuz they have a little bit more traction from the surface area. you want you front wheel to stick to the ground. if the rear slides, you can recover it, but if the front goes, you lose control.

pinkrobe

That's mainly why I run a 2.3 in front and a 2.1 in back. I'll be going to a full-size 2.4 in front and smaller 2.4 in back this year [Conti Rubber Queen and Mountain King respectively].

TimJ

Yeah. This was the logic for doing it way back before mtbs were suspended, you want the rear to break first.

scrublover

FYI: that logic still applies today, with front and rear suspension.

kmart

Riding around some fairly sandy/gravely, and in spots muddy trails today, I immediately regretted my decision to run 2.35 rear, 2.1 front (used to be a 2.5). Sure it rolls a bit faster, but it's a lot more slippery. Too bad the front is a Panaracer Dart (front specific tire), so I can't just swap front and back.

ca7erham

What I did for my front specific tire is when I put it on the back, I just turned it around. It seems (WTB Veloraptor) to climb and have quite good traction that way.

dminor 

I turned my outside-specific rear tire inside-out on the front and now I RULE the kitchen floor.