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Discussion Starter · #1 ·
I've noticed here and there that many bikes (most notably FS) have a wider tire on the front and a narrower tire and the rear. Why? Mine is like this also and I can't think of a reason other than trying to save some weight. Is there an actual traction purpose to this, or..... :confused: Way back when I always tried to buy the same size tires because I didn't know any better - or did I? I'm looking at new rubber soon and found this more confusing than which tire to buy. :p (nice to see Panaracer is still around ;) )

Anyone?

PATIA!
 

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MTB Rider
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Running in muddy conditions ...

AndrewTO said:
I've noticed here and there that many bikes (most notably FS) have a wider tire on the front and a narrower tire and the rear. Why? Mine is like this also and I can't think of a reason other than trying to save some weight. Is there an actual traction purpose to this, or..... :confused: Way back when I always tried to buy the same size tires because I didn't know any better - or did I? I'm looking at new rubber soon and found this more confusing than which tire to buy. :p (nice to see Panaracer is still around ;) )

Anyone?

PATIA!
The wide front end floats better over terrain. This is important because the last thing you want your front wheel to do is dive into the mud.

On the rear, many people feel that the smaller contact patch "bites" better and has lower rolling resistance. It is common knowledge that thinner tires on the rear are better in wet conditions because the DO NOT FLOAT. They dive through the mud down to solid ground.

Myself, I'll take big on both front and back because I'm not a great climber and I need all the traction I can get. Panaracer Cinder 2.25. IT's a great tire.
 

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Bad Case of the Mondays
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AndrewTO said:
I've noticed here and there that many bikes (most notably FS) have a wider tire on the front and a narrower tire and the rear. Why? Mine is like this also and I can't think of a reason other than trying to save some weight. Is there an actual traction purpose to this, or..... :confused: Way back when I always tried to buy the same size tires because I didn't know any better - or did I? I'm looking at new rubber soon and found this more confusing than which tire to buy. :p (nice to see Panaracer is still around ;) )

Anyone?

PATIA!
Here's my reasons....

Big on front doesn't really affect rolling resistance since you don't have much weight on it. Also having a big meat up front helps cornering (and braking).

Smaller on back to minimize the rolling resistance. Your back tire has more traction due to your weight being largely supported by it, so a smaller tire can still track up climbs.

I've actually just moved away from smaller in the rear as I was slipping on loose, technical climbs. So now I've got a big tire in the rear too which can certainly be felt in the rolling resistance (its a Nevegal StickE though) but man does that thing climb! I made it up some stuff that I had never been able to clean last night because the Nevegal hooked up.
 

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So bigger in front...

will improve cornering traction? I have a 2.0 Hutchinson Python Airliet with Stans and was thinking of a 2.1 RR with stans for the front...maybe I should go with 2.2 RR in the front?
 

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carpe mañana
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I run 2.25 or slightly larger in the rear and 2.5 up front.

The big front tire gives you more control on the downhill, it hooks up better on corners, is more stable at speed, has big air volume, which translates to ability to run at lower psi, which translates to a really big foot print and even more traction. The large contact area to the ground improves braking performance, tromendously, since the weight shifts forward. Like it was said above, since there isn't much weight on it during climbs or on flats, it doesn't inflence the rolling resistance very much.

The rear tire is a compromise, because, again, as it was stated above, rolling resistance is a major consideration. At the same time, the bigger the tire, the more traction you have on climbs. When running in deep mud, there are two schools of though, one is to float over, ie, big tire, the other is to sink in to the bottom, for best contact, ie, super skinny. I don't personally know which works better. Finally, large rear does help in braking, although the benefits aren't as huge as they are with the front. It also helps cornering.

There have been some people, who are into motocross, and swear by large rear, small front for the bicycles, but what they don't realize is the reason mx bikes have larger rears is because of the tromendous power that needs to get transfered to the ground when the engine is revving up.

_MK
 

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Because you CAN ...

Another reason to run bigger up front is because you simply CAN. Fork clearence is typically larger than chainstay clearence. I'm maxed out on my rear at 2.25. There is just enough clearance for a little mud and a little flexing. Anything more, and I'd probably be rubbing.

Up front, I could probably fit a 2.5 tire.
 

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It depends on what you're doing ...

MCF said:
will improve cornering traction? I have a 2.0 Hutchinson Python Airliet with Stans and was thinking of a 2.1 RR with stans for the front...maybe I should go with 2.2 RR in the front?
If your running relatively flat and straight trails, you're probably OK. If you're doing a lot of technical downhills, you would probably benefit from more rubber up front.

Believe it or not, there is a trend to actually use a larger WHEEL up front than in the back. Some downhillers are now using 24" rears and 26" fronts. Some people are putting 29er forks on 26 inch frames. Same idea, more rubber up front means easier rolling, better traction, and better braking.
 

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Discussion Starter · #10 ·
(smacks himself in forehead) Well, crap, all that just makes too much sense. :eek: :rolleyes:

Okay, some great info when i'm buying. THANKS guys!
 

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"El Whatever"
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Once we are enroled on this topic...

What you think about a Motoraptor 2.4 F / IRC Mythos 2.1 rear for climb/descend kind of riding on varying terrain??

I'm running the full mythos setup (it came with the bike) but I have a set of Motoraptors 2.4 collecting dust. I know I don't want a full 2.4 set-up (not much technical climbs but rather lots of climbing) but the 2.4 at the front is in the back of my head.
 

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carpe mañana
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how about you just throw it on, since you already have it and form your own opinion and report back? ;)

_MK
 

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"El Whatever"
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Ride Report....

I put the Moto 2.4 in front with the worn Mythos 2.1 at the rear.

What a killing combination!!! The Moto made its way thru anything I could throw at it. You don't notice much the size of the tire when climbing but you REALLY do at pedaling over flat terrain. Once at speed it's all butter.

It allowed me to just point and shoot (I ride a Giant Warp which has some STIFF headtube).

It was muddy from day-before rains and the Raptor just hooked up. It came out the ruts with ease. Where it didn't performed so well was over wet roots thanks to the rather hard rubber but still it was waaayyy better than the previous Mythos 2.1F.

The rear Mythos was a poor performer in these conditions. It rolls good but stalls too easily and was continually whipping my rear end (actually, the bike's rear end!! :D Mine was just on the saddle). But to the credits of IRC my rear tire is worn. It should work better with more thread left.

So. I will keep the Moto 2.4 up front or even try with a slightly smaller (2.2, 2.3) tire and get something like a Velociraptor 2.1 or a similar tire at the rear.

I understand the reason why different tires now. It might not be a good idea if your terrain is mostly rolling. But if you climb and descend a lot or if you go thru some techie trails is well worthy.

Edit..... The larger contact area of the front tire will give your brakes a "boost". Your front brake will brake better and will allow your rear brake to work a bit less. Worth of a try.
 

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here today
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Gore and mud

Wait ?!? Under really muddy conditions (read not somewhere in CA) I'm not sure I want a "floating" front - My Bulldog looses all traction and dumps me - repeatedly ... It just packed up became really slippery - probably due to both tread and width.

I actually would have liked the wheel to 'dive into the mud' and touch some solid ground underneath, ie most of the mud tires seam to be thinner... but what would I know, I just drink it by the liter :(

Still don't know the real answer to your question ...but from sheldonbrown.com :
A wider front tire makes sense in many applications ... when handling and ride comfort are considered. A wider tire will generally provide better cornering traction than a narrower one, assuming appropriate inflation pressure.
 

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"El Whatever"
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zenmonkey said:
I actually would have liked the wheel to 'dive into the mud' and touch some solid ground underneath, ie most of the mud tires seam to be thinner... but what would I know, I just drink it by the liter :(
[/I]
Well... for that mud that can be seen on the pic you rather use a narrower tire with deep spikes that cut thru the mud and bite the soil underneath.

My ride was not really muddy and in some conditions you would prefer a tire that float. For example when you have a wet, hard surface (like the kind of surface you get after a normal rain at the singletrack which travels under trees).

As a general rule... the wider the tire, the less pressure it puts on the ground. On loose surfaces it can be good... but on mud and wet pavement you'll want more bite (less area).
 

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zenmonkey said:
Wait ?!? Under really muddy conditions (read not somewhere in CA) I'm not sure I want a "floating" front - My Bulldog looses all traction and dumps me - repeatedly ... It just packed up became really slippery - probably due to both tread and width.

I actually would have liked the wheel to 'dive into the mud' and touch some solid ground underneath, ie most of the mud tires seam to be thinner... but what would I know, I just drink it by the liter :(
Yup. When it gets deep and sloppy I prefer narrower tires. They cut in to find traction and maintain directional control.
 
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