pbass

The most common mullet config seems to be a knobbier tire on the front, and a slicker one on the back. I ride in SoCal on loose over hardpack, lots of steep climbs. If anything, it's my rear wheel that loses traction, not the front, as I try and launch myself up over some pitchy section. I know technique is a big part, but that aside, what is going on with the mullet set up, and what am I missing? Is it not about climbing traction?

unterhausen

I'm sure I don't know anyone riding a bike like you describe, but it could be tire clearance issues in the back. This seems to be the motivation for most mullet systems on other types of bikes.

Toadmeister

Less weight in the front = less traction. A knobbier and wider front tire can help with that especially in speedy turns.

Steve B.

Typical mullet I’ve seen is a mix of 27.5 and 29 wheels on a mt. bike. I don’t get that either.

DorkDisk

Bigger front tire for more float and traction is a MTB thing. Front does most of the braking, tracking, and bump absorption.

Rear slipping can be mitigated by spinning, we thought slicks were a terrible idea when they first came out. After learning how to keep the rear tire engaged, we realized how faster they were.

pbass

Yeah, I'm aware of the bigger up front, smaller out back approach. But I've been seeing some gravel folks with a knobby front, smooth rear, same or very close tire size (for example, a WTB Sendero 47 front, Byway 47 back, or similar). Currently I use Ventures and if I stay seated I can get up most anything on my local terrain without the rear sliding out (which wasn't true when I ran the slicker ByWays). But I was just wondering if the added knobbies up front really did much in a climbing context. Sounds like it's more about hooking up in other ways--cornering, etc...

trailangel

I'm running a 2.35 on the front and a 2.25 on the rear, but the same tire/tread pattern on my 29r XC. Larger front will float over softer areas better. I would never run a slick on the rear... IMO that's just stupid for the dirt.

unterhausen

Did someone already say all gravel is local? I don't think I would run a slick around here because the tread would be shredded pretty quickly. I have lived in places where dirt roads were smooth and beautiful to ride on. Anything knobbier than slicks would be overkill.

It's all kind of moot right now for me, all the forest roads have 15 inches of snow on them
I have had occasion to wish I had a bigger tire on the front of my fat bike.

tyrion

When turning and/or going downhill, traction is more important in the front. Losing traction in the front is more catastrophic than losing traction in the rear. Of course going uphill traction is more important in the rear.

A a slicker, less knobby, rear tire increases efficiency.

vespasianus

Mullett is the term when you use two different sized wheels (27.5/26 or 27.5/29). The point of the gripper and fatter front tire is that it helps you carve turns and deal with downhills better. Loosing traction going uphill could be because of lots of situations. A gripper front tire won't do much to help climb. Sounds like you need a grippier rear tire.

pbass

No, as I say, with the Ventures I'm running I'm totally fine on my terrain (650bx47) - they hook up great. It's not that I'm having a grip issue (I was previously with Byways, but that's a different story) - I was just curious about the config I've seen some people calling a "mullet" when it's the same size front and back, but knobby on the front/slick on the back, and if the idea was that helped with climbing traction somehow--I couldn't see how it would. I gather now it's more about other aspects like cornering, etc.

MAGAIVER

As far as I know,Mullet on a gravel bike is mixing SRAM AXS Road and MTB components, a road crank and shifters with an MTB cassete and rear derailleur. Mullet on a mountain bike is a 29 front wheel and a 27,5 rear wheel, I've never heard of mixing wheel sizes on a gravel bike before.

AdkMtnMonster

I thought all gravel riders had mullets, beards, flannel ****s and major body odor? I'm surprised this is even a question.

fourfa

Unfortunately I’ve seen mullet used to describe three totally separate things in cycling: mixed wheel sizes in MTBs, then drop bar bikes using drop bar sram shifters with MTB sram derailleurs, and now mixed tread type on gravel bikes. Despite the OP being crystal clear in their question, people cannot help but post about one of the other uses.

The reason here is that with a gravel bike there’s a reasonable chance that you might ride 20 miles of tarmac to get to the dirt section. Of course the slick or semi slick rear is going to be worse in dirt, no one will argue otherwise. But it might be a lot better for rolling resistance and squirm on pavement. It’s about the best overall compromise for mixed rides that really truly are mixed. Maybe you suffer or walk some in the dirt in exchange for suffering less on the ride to and from.

Most MTBers I know drive those miles so they might have little idea how awful full knobbies are on long road rides (especially those flirting with mullet setups for more exxxxxtreme whatever). And the AXS ‘mullet’ shifting setup, again I’ve mainly seen this on bikes that are really drop-bar mountain bikes.

As a matter of fact on my current 650b gravel wheel set I have a WTB Venture front and Byway rear. However IMHO WTBs are ass and I’m looking forward to replacing with one of the recent file-tread tires (Pirelli, Spec, Vittorio etc) that roll better than the semi slick WTB on pavement and outperform it in dirt to boot, with the same tread front and rear.

Darth Lefty 

and they drink kombucha tea

shoota 

Not everyone lives in California. Crazy, I know. There's almost no steep, loose-over-hard climbs anywhere around the Midwest. What little there are we ride seated. Knobs don't help when standing anyway.

Darth Lefty 

It’s really going to irritate you when this thing shows up

https://www.mtbr.com/threads/surly-g...ppler.1154577/

sloppy12

I have a Raleigh Lorry super reverse mullet 26" rear 20" front. pretty good for hauling stuff. lol

chas58

IMHO, that is like asking why not put a shock on the rear instead of the front?

I sometimes ride with a wider front tire. This gives me
- better flotation, and steering in soft conditions
- a little bit of suspension up front. (riding at below 25psi will smooth out a lot of bumps).
- more trail and stability for a rougher route.

People address some of the above by using a front fork, or a shock absorbing stem, or even more exotic stuff with Trek & Specialized frames.

I like a smaller faster tire on the rear, because 70% of my rolling resistance comes from the rear tire - and my bike is very smooth riding in the rear.

Maybe work on your technique? I don't have traction problems with a slick or near slick on the rear (except muddy slick/wet conditions). Pick the right tire pressure, have a smooth pedal stroke, a little body English. When racing, I'll ride up stuff on near slicks that others are walking up.

tdilf

Use what works for you