Mullet/MX bike – who’s ridden one?

Have you ridden a mullet bike for any length of time?
Not many OEMs about, so what bike did you mess with?
How was it?
What was good?
What was bad?
What type of riding was it used for? (or where did you ride it sort of answers similar thing).
Would you get or try another?

Just intrigued as to whether people think it has any merits and will grow to be a decent part of the bikes available from OEMs. I’ve had one and really liked it. Just hope that OEMs start including them a bit more so the geometry compromises that a DIY bike inevitably end up with are ironed out.

Don’t a lot of trail type motorcycles run bigger front wheels, I know my old xl500 had 23″ front & 18″ rear so there might be something in it 🤔

I’ve been riding Singular Hummingbirds for years and before that various others (Trek and Carver 69ers plus homebrewed stuff).
Obviously I like the concept…

Specialized Status for about 6 months.
At 5’9″ I think it works well for me.
I ride in Aberdeenshire where the trails are mostly fireroad up and enduro type trails going down.
It’s probably a little too slack and low for these trails, even in its high setting and the back end really can’t keep up with the front, I’ve improved this slightly by getting rid of the boat anchor NX cassette and reducing the size of the spacer in the shock.
I’m not the greatest rider, but this thing has me manualing out of corners and actually jumping stuff.
I’d definitely by another that was maybe a little less like a park bike and a little more refined.

2.4 29er on the front and 2.4 27.5 on the back has worked well for me on a Ritchey p29er and Jones Diamond for a couple of years. Occasionally with a Chronicle on the front. Mainly trails with the odd bit of twisty singletrack though the woods. Always rode rigid 29ers and this feels like the set up with the best balance for climbing, rolling over stuff and handling.

Hairyscary (Matt?) – saying you’re not the greatest rider is being a little humble! From what I remember you’re definitely good. Always needed a burly bike to cope with your full on style.

I just wish someone would build a better value version of an Orange Switch, but with a water bottle cage ability and maybe a pair of little tool roll attachment bosses. Inevitably means Taiwan, but that’s fine. Single pivot for easy maintenance and year round mud bombing in a mullet style that seems to offer an excellent fun bike for messing in the woods. But not extreme with the geo – Goldilocks please, nice and balanced, 150mm front and rear.

Starling do a mullet bike, they take a water bottle on the underside of the TT, I believe.

I’ve owned a couple of mullet-ed bikes myself – one homebrew FS bike and another HT with B-plus rear sometimes. Both were a lot of fun, amazing at cornering, slightly slower on the flat. Best for “winch & pummet” riding IYKWIM.

I would consider one if starting from scratch, but I have too many 29in wheels & tyres now. And I really like full 29in as well, especially the ground-covering ability.

My write-ups…
http://unduro.co.uk/mtb/behold-the-frankenthumper-aka-project-279/
http://unduro.co.uk/mtb/review-cotic-solarismax-mk-2-a-hardtail-for-all-occasions/

Starling Twist – meets most of that criteria.

I’ve not ridden a Twist, but I ride a Murmur and my GF rides a Swoop. They are amazing bikes! I can only guess a Twist would also be awesome.

Geometron G1, mine is currently in hybrid/mullet/mx mode.

Bike corners better, it’s easier to turn in if you are late on the brakes, with full 29 the bike will stand up in the corner if you brake, with hybrid it’s less.

For straight line bombing and all day xc, will be full 29 for me. So FOD/Shropshire will be hybrid, then peaks would be full 29, find the 29 climbs a bit better as well.

Starling Twist would be wonderful, but budget won’t reach that far hence requirement for Taiwanese built, good value frame.

Might just have to do this myself in a Pinkbike Grim Donut way.

Bike corners better, it’s easier to turn in if you are late on the brakes, with full 29 the bike will stand up in the corner if you brake, with hybrid it’s less.

That’s exactly what I said about 29er’s in general in the other thread. Glad it’s not just me.

Haven’t ridden a mullet yet. Mostly because the price of decent forks makes me physically sick.

I ran a 69er Ibis Tranny – lightweight & rigid front end. Great for milemunching and events like HONC 10 years ago. Rear wheel span up quickly, front rolled over stuff etc.

Now use a gravel bike for milemunching, and a full 29er for singletrack

That would be a pretty good cue not to brake mid corner wouldn’t it?

Banshee titan for me. I was on a Bird Aeris, but I tried 29 on a hardtail and that sold me on having it up front. At 5″7 I’m bordeline for 29ers on steep trails and I buzzed myself a couple of times on the hardtail and that did it for me. Considered a Last Coal/Glen, the Starling Twist, Geometron and a few other bikes as well, but I wanted the Banshee ever since they showed pictures and it has adjustable dropouts and room for a bottle cage.

Enjoying the bike so far, but it’s quite a different geometry philosophy from the bird so it’s going to take some getting used to. I live in south wales and most of my riding consists of plodding along up fireroads and the like to ride down something steep.

I want to mullet my hardtail, can’t work out exactly what difference it will make to the geometry though.
Been hovering over a mullet linkage for my commencal that enable you to run mullet but keeps the stock geometry

I want to mullet my hardtail, can’t work out exactly what difference it will make to the geometry though.

If you are starting with a 650 bike, you will need to go quite a bit shorter on fork travel to maintain the BB height.

If starting with a 29 bike, you will find the BB can get pretty low, as the bb drop on a 29 hardtail is usually a fair amount to start with (my cout 290 was 60mm from memory).

The titan looks nice. If I read it right it comes with the 4 types of dropout (142/148 in both compact and long)? Having the ability to use existing kit is really nice (I have a load of nice 650b kit that Id rather not replace immediately as it’s nowhere near worn). Same with the G1 (though looks like the mutators are extra).

“If I read it right it comes with the 4 types of dropout (142/148 in both compact and long)?”

That would surprise me because the dropouts are quite expensive forged pieces. My previous Spitfires both came with only one set of dropouts but I bought some shorter ones to try different chainstay lengths.

However, you don’t need different dropouts to mullet a Banshee. A 29″ Banshee can be mulleted by using a 27.5″ rear wheel and putting the dropouts in the high position – that change in axle height almost completely cancels out the 19mm reduction in wheel radius, giving a mullet geometry in high within a few mm BB height and less than 1/4 deg angle-wise vs a full 29 in low.

The standard dropouts on the 29″ Banshees are the short ones – the long dropouts are to fit 29+ or have v long chainstay lengths on 29″. The 27.5″ Banshees have the long dropouts as standard to ft 27.5 but you can go to the short ones for 26″ rear wheels (mini mullet?)

My hardtail frame a high bb, think it’s 30mm drop. It’s a Marino so I think I landed on 30mm as that was in the middle so if I ran a smaller back wheel it wouldn’t be too low to the ground. It might be 40mm at sag maybe. I’m guessing a smaller back wheel would make the bb drop slightly less? More worried about losing the seat angle than anything! My seat is slammed forward already and the front end can get wandery climbing

If I read it right it comes with the 4 types of dropout (142/148 in both compact and long)?

No, you just get a choice of one set.

“(Frameset includes, Fox Float X2 Performance shock, pre-installed headset and choice of dropouts)”.

“I’m guessing a smaller back wheel would make the bb drop slightly less? More worried about losing the seat angle than anything! My seat is slammed forward already and the front end can get wandery climbing”

If you put a 27.5 wheel on a 29 bike, with the same profile tyre, you drop the rear axle 19mm which drops the BB about 13mm / 0.5″. And it’ll slacken the angles by about a degree. So yes, more wandery climbing!

My seat is slammed forward already and the front end can get wandery climbing

Hold onto the bars properly then!

My Merida while is mullet. 29×2.6 front, 27.5x 2.8 rear. It works fine for me although I have nothing to compare it with.

2019 Stumpjumper Evo 27.5″ S3 mulleted and longshocked here.

Cascade link and long shock gives 167mm rear travel, 160mm 29″ Mezzer Pro up front.

BB height now 342 rather than the stupid 324 of stock. HA 62°, saddle slammed forward to give effective SA of 78°, reach calculated at 480mm.

Absolutely brilliant. So fast, sets up nicer into turns once you know how to muscle it into a turn, then tends to oversteer rather than understeer, but 2.6″ WTB Trail Boss out back helps with that.

The bike is way more rideable than in original form 🤘🤘🤘

Not ridden one but would be interested to try it. I have a Last Glen which they make an MX link for to correct the geometry for 27.5 rear.

Pretty sure you can buy the Mk2 Glen as an mullet from the factory.

Riding two up down the downs on a Raleigh Grifter with a Puch 50 moped fork bar front wheel and brake.

Just building up a mullet/hybrid wheelset for my Geometron G15 to give it a try. Along with a 7mm longer shock, I’ve calculated the geometry should be preserved to within about 0.2deg and about 2mm of BB height. The longer stroke shock will of course sag more, but it’s a coil so will be set for about 25% sage as opposed to 30% of the shorter stroke air shock to preserve climbing position. If it’s too slack, I can always fit an offset shock bush the wrong way round to steepen the angles slightly.

The main theory around the mullet/hybrid setup seems to be that the slightly smaller rear wheel with its tighter radius and smaller contact patch, will increase the turn in speed of the bike in corners, without compromising the positive stability effects brought about by long wheelbases, slack head angles and shorter offset forks. Obviously you lose out a little in terms of rolling speed, but the benefits are probably of more concern to those riding steeper and techier terrain on a regular basis for whom rolling speed is probably a lesser concern… Either way, I plan to have 2 distcint setups to choose from, based upon what I’m doing. Longer days out in the saddle, a faster rolling 29×2.35″ tyre in the back with the 215×63 Float X2 giving 145mm. Ride spent sessioning steeper and techier trails, then a more aggressive 27.5×2.4″ tyre and a 222×70 coil shock giving about 163mm travel (fork will remain constant at 160mm between both setups) can be fitted in moments.

I ride FoD singletrack, so the MX set up makes more sense than if I was doing moorland hacks.

I run my Evil Calling as a mullet. I dropped the fork travel from 150 to 140mm and the BB height has only gone up a tiny bit (around 4mm). By leaving it in the extra low position the change is actually less than keeping the wheel size the same and swapping it to the low position. Normal x-low is 330mm, with the mullet in x-low it’s 334 and normal low is 338mm.

The head angle has reduced to around 63.5° from 65.5°. Seat angle is around 76° measured from centre of the BB to the centre of the seat, which is run forward on the rails. If I wanted it to be more forward I could turn my seatpost round. I don’t tend to worry about seat angle as there’s so much opportunity to tune it at the saddle.

It rides really well, playful but capable. I like having a bigger front wheel for thundering over stuff but with the lively feel of a smaller rear wheel.

My suspicion is that this works better turning a very low 27.5″ bike into a mullet, rather than a 29er into one. It’s just like over forking a bike.

I’d just look for a very low frame Rickos, it’d be perfect for how and where you ride.

“ My suspicion is that this works better turning a very low 27.5″ bike into a mullet, rather than a 29er into one. It’s just like over forking a bike.”

I’ve spent a while looking into the numbers on this, and mulleting does work best with either v low 27.5 bikes that normally have more fork than rear travel, or with higher 29 bikes, especially ones that have some kind of flipchip to raise/steepen them. And they all need steep seat tube angles.

I’ve done a lot of back to back riding, same bike with different wheels. I found it very interesting. In tight corners the mullet was noticeable better, also pumping it accelerated better. No surprises I guess. A big advantage with long dropper is that bit of extra space in the back for sudden gradient changes. It’s generally more playful but loses out a bit at high speed. I’d be careful with frame geometry, on mine the geometry stayed the same. Nowadays bikes are low/slack so just sticking a 27 in the back wouldn’t be my choice. Similarly bigger wheel in the front. I liked trying it without changing geometry at all. If I had a bike that was a bit older maybe and higher / steeper, if could be a great option assuming you don’t end up with too slack a seat tube.

How much does it affect climbing? And If it’s a mullet designed bike rather than a mulleted bike I imagine that makes a difference? Cheers

Munrobiker’s findings very much tally with mine.

I spend (well not at the moment obviously!) riding steep, off piste so mullet works well for me with a 29″ inseam but long torso/arms.

There’s quite a few 2019 Stumpy Evo frames going second hand at the moment, 27.5″ is what you want and coincidentally they’re the cheaper ones. Run a 2.6″ out back, a 2.5″ aggressive front like a Magic Mary/WTB Verdict, 160mm 29″ fork and you’ll be golden.

What bike did you convert, Doug?

Luke – I was thinking starting with a 29er might be better, but you present a good argument.

I previously mulleted a 2016 Specialized Enduro which starts out tall and steep. Adding one offset bush and the 27.5 wheel made it quite contemporary in BB height and head angle, but obviously the seat angle suffered. I have long legs and short body, so stuffed the saddle forward and it was OK.

I have mulleted my Vitus esommet used to have 170mm travel up front now 160mm 29er fork, I enjoy the bike loads & climbing not too hindered being an ebike 😂

Somebody who knows how to code needs to make a mullet geometry calculator and stick it online. I can do the geometry but not the coding!

Kind of wish I’d bought a set of those cheap Dr Swiss forks from wiggle now. From the suggestions above sounds like my pre longshot rocket might work (https://www.cotic.co.uk/product/rocket275). It’s an XL but I’m on the l/XL boundary. Can run 170mm 27.5 forks so 150mm 29er would be in a similar size range. Maybe with a slacker to slightly lengthen, relax the head angle, slightly drop the BB and steepen the seat angle.

My suspicion is that this works better turning a very low 27.5″ bike into a mullet, rather than a 29er into one. It’s just like over forking a bike.

The opposite is actually true…

Why? Well, when you fit a 27.5″ rear wheel into a 29er bike with no other changes, you drop the rear axle by 19mm (ergo typically the BB height by arouns 12-13mm), slackening the angles by approximately 0.75 of a degree thereabouts, depending on the bikes wheelbase.

When you fit a 29er front end to a 27.5″ bike, if you keep the fork travel the same, you are raising the front end by 38mm… How? Well the larger wheel raises the axle by 19mm, but the 19mm longer A2C fork (required to accommodate the larger wheel) also raises the front end height too. If you do nothing else, keep the same fork travel on your new 29er front ended 27.5″ bike, then you’ve slackened the angles by approximately 1.5deg and probably raised the BB by around 15mm.

A 29er with some kind of geometry adjust is easily the best bike to mullet. The 2 different shock positions on my Geometron G15 meant even if I didn’t mess about with a different length shock or offset bushes etc. that even just putting the 27.5 rear wheel in and changing the shock position from low to high, I would only drop my BB height about 3mm and slacken my angles about 0.2deg… With a single offset shock bush fitted the wrong way round, I could achieve identical geometry when compared with a 29er rear wheel with the shock fitted in the low position. Newer Geometrons (the G1) are designed purposefully to be able to mess around with the geometry, and have adjustable chainstay and seatstay lengths via “mutators” purposefully to be able to mess about with the geometry and wheel sizes.

I’d really only consider it on a 27.5″ bike if the bike already had a crazy low BB (330mm isn’t crazy low to be honest), a super steep seat angle (76deg isn’t super steep!), and the fork travel was already 20mm more than the rear wheel travel, so at least you could fit a 20mm shorter travel fork and it still feel balanced along with the 29er front wheel, without upsetting the geometry too much.

Can we start a list of suitable bikes? Flip chips, very low BB 27.5 bikes, etc? I’ll start –

2016 – 2018(?) Specialized Enduro 29 – compromise is slacker seat angle
2020 Evil Calling – seemingly few compromises but does end up slack in head angle.
Various Geometron models – made for messing about with geo.

Trek Slash might be alright, but the actual (rather than effective) seat angle is very slack, so dropping in a smaller wheel would only exacerbate the problem.

Add more and I’ll do a summary post now and then to bring it all together. Pros and cons of mullet version would be useful.