Staggered Wheels (Reverse Mullet) on Gravel bike

Hi everyone,
I have recently rediscovered my joy for off-roading and have taken out the Gravel Bike on any occasion possible.
I have laced my bike in 700c x45c Pirelli Cinturato Gravel H, one of the fastest gravel tires around.
The downside of that is grip, it could have a little more traction, but also steer a little better in loose terrain.
I have an MTB set of 27.5 wheels flying around, and wanted to put Conti RaceKing Protection on there 27.5 x2.2), which are apparently among the fastest rolling MTB tires. They are probably not the most treaded for a MTB tire, but definitely more grippy that the Pirelli.
During the process of building up the 27.5 wheels, I stumbled across the Reverse Mullet wheels on gravel bikes. A fast rolling 700c on the rear and a 27.5b on the Front. The former for rolling fast, the latter for steering wheel.
This will likely not help with traction, but probably improve steering in corners.
The 27.5 is quite a bit smaller in diameter, so the bike is a Little tilted forward.
I have yet to ride it but maybe this is a unnecessary inconvenience, because it might be doomed to be bad.
That’s why I am asking you guys.
Narrower faster tire on the back, fatter knobbier tire on the front on a gravel bike: does that make sense?

  • Yes… wide front, narrower rear is super common for BMX (many decades of that as a standard practice) and something I continued for MTB setups.
  • As a rule for off-road setups, I tend towards having more traction on the front with less in the rear.
    • This can be covered via width with similar treads on both ends.
    • Or it can be done via different tread patterns on both ends (smoother rear, grippier front).

To your specific issue, the basic concept is fine and will lead to better traction on front from the width, all things considered. But, as you note, the smaller diameter front wheel will lead to changes that may be detrimental to handling.

  • Lower front axle will steepen head tube angle, which might counter the grip you gain from the tire, by making the front end more twitchy and fast steering.

  • Trail will likely decrease as well, which will lead to a faster steering bike with less “centering” action at the bars.

  • Lower front will also lead to more weight load on the front tire, and lower hand position relative to the saddle, assuming you don’t touch any other setting on the bike.

  • Bottom Bracket height will drop a tad too. Maybe not enough to cause crank clearance issues, but still worth a look.

All this is theoretical, and hard to pin down without actual diameter differences. The real numbers may lead to a relative non-issue.

Also. keep in mind that measured difference without loading (tires sitting loose) is not representative of under load (you on the bike). So if you want to really know the differences, it’s best to measure axle height when on the bike with appropriate pressure in each tire.

As a general idea, a reverse mullet is not a direction that I would consider using.

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Very interesting insight! Thanks a lot.

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I’ve set up my gravel bike like this in the past. Although not as extreme as what you are thinking with the 27.5 and cross kings up front.

I think there are a decent number of fat gravel tires, with more aggressive tread, for 700c wheels that you could use. Eg wtb riddler, panaracer graveling ext, teravail Rutland.

So no need to compromise the geometry of your gravel bike to get a more aggressive tire up front.

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Just something interesting I found. It’s not really staggered wheels, but Schwalbe has „interviews“ on their website, where people recommend tires and they all recommend going less treaded on the back and more treaded on the front.
https://schwalbe.com/gravel-your-style/

I am really not an MTB guy, absolute noob actually. What I am wondering though is, is this fast tire on rear, grippy tire on the front model really feasible in gravel? For flat roads „yes!“. For Mountainbike Trails, especially going up 20% inclines with loose stuff or even mud on it, which is likely the most difficult thing to ride I‘ll ever face, I just don‘t know how much sense that makes.
Opinions welcome!

As with anything, there is a range. A “less grippy” rear tire doesn’t mean minimal grip.

  • It’s possible to run a slick on the rear and mild traction like a file tread on the front.
  • But it’s also possible to run a medium knobby rear, and a very aggressive front.
    • This still gets you a “more grip up front” differential, but is not what I would call a compromised “minimal tread” setup.

It all depends on what you are considering for main terrain to start. I would have a tendency to start with the rear tire selection, based upon what you want for grip in the “worst” condition you expect.

  • Some people are willing to nurse a slightly under-traction tire in bad conditions.
  • But if you are on the fence and questioning ability, I’d go for a more aggressive tire at the rear.
  • In either case, move to the front tire selection after the rear, and chose an even more aggressive tread if you want the differential.

All that said, there is no real magic in a staggered tread setup. I feel it pedals a bit easier since the rear tire supports more mass, and is the one we use for propulsion. But plenty of people run a matched front and rear too.

agree with this.

Faster in the rear has been a thing in MTB for ages. I used to run 26x2.1 rear with 26x2.3 front. Rear can also run less aggressive side knobs as it’s easier to control a rear wheel drift than it is to manage it on the front.

The 700c in rear with 650b front is new, but I’m not sure if it’s better. The wider tire is nice, but it’s marginally wider. The rollover angles are better with 700c.

Since „getting up“ steep and loose climbs is a bigger concern for me than cornering hard, I think my current set up with 27.5x2.2 RaceKing is already slippery enough.

If the trail is that steep and loose, you might be better with a mountain bike. N+1 :grin: