Talk to me about Mullets

[Mikerb]

depends how you ride and what are you looking for.
Suspension travel, geo etc. could be more important than just one wheel size.
That Whyte E180 RSX - looks like it weights 26kg !
Doesn't matter wheel sizes, the weight will be the biggest factor here
(comparing to other ebikes ~23kg)

Agreed but when looking at weight of a bike, ........
in terms of stability weight is a positive

in terms of manoeuvrability total mass is less important than where the centre of mass is positioned both fore and aft and how high or low the centre of mass is on the bike.

In terms of acceleration a heavier bike will be slower to overcome inertia

in terms of momentum a heavier bike will maintain speed better and gain momentum with the help of gravity but lose momentum quicker if going uphill.

A heavier bike invariably enables better use of long travel suspension

So a bike optimised for gravity riding does not necessarilly benefit from being lightweight

At the end of the day the overall mass of a bike is dominated by the weight of the rider!!

 

[steve_sordy]

There is a change in bike geometry for a 29er that has been mulleted to have a 27.5 rear wheel. In that case the BB will be lower, and the design compromised. Unless of course, some sort of user adjustment has been provided for in the original design to allow for the prospect of mulleting and to restore the BB height.

A bike designed from the off to be a mullet will have the designed for BB height.

That seems obvious to me, but some of the posts above are unclear on that point.

 

[Waynemarlow]

You tend to find those loving their mulleted bikes are from a motorcycle background where wider back tyres and smaller diameters are the norm together with larger diameter but skinnier fronts and longer front travel reign from over 100 years of development.

Ask someone coming from a purely analogue background and those same attributes are looked at with almost that of heresy to the bicycle. Least we forget that we are now motorised and that quest for maximum efficiency to us humans with skinny back tyres can be traded for low pressure “fat” 2.8 - 3.0 tyres that will maximise grip on the uphill sections that we humans never really bothered to ride before.

 

[rzr]

Agreed but when looking at weight of a bike, ........
in terms of stability weight is a positive

in terms of manoeuvrability total mass is less important than where the centre of mass is positioned both fore and aft and how high or low the centre of mass is on the bike.

In terms of acceleration a heavier bike will be slower to overcome inertia

in terms of momentum a heavier bike will maintain speed better and gain momentum with the help of gravity but lose momentum quicker if going uphill.

A heavier bike invariably enables better use of long travel suspension

So a bike optimised for gravity riding does not necessarilly benefit from being lightweight

At the end of the day the overall mass of a bike is dominated by the weight of the rider!!

Exactly...
and for these reasons, i don't enjoy few black trails (still gravity orientated) I have in my area (on my Levo that weights ~22.5kg) ...
they are slow and technical/trickery (considered as blacks for some reason ) trails, on an analog bike - it'd be a difficult challange, difficult but doable.
Maybe with WAY MORE experience on an ebike i'd enjoy them ...

 

[rzr]

At the end of the day the overall mass of a bike is dominated by the weight of the rider!!

I can't agree with that. maybe because i weight only '73 kg'. but riding my Sentinel (15-16kg?) and Levo (23kg?) is VERY different. and i'm not talking about only turns but also braking etc.

 

[KnollyBro]

There is a change in bike geometry for a 29er that has been mulleted to have a 27.5 rear wheel. In that case the BB will be lower, and the design compromised. Unless of course, some sort of user adjustment has been provided for in the original design to allow for the prospect of mulleting and to restore the BB height.

A bike designed from the off to be a mullet will have the designed for BB height.

That seems obvious to me, but some of the posts above are unclear on that point.

But how much of a change are we talking about? For instance, my Levo SL which comes stock with a BB height of 348mm, is within 2mm of the Kenevo SL at 350mm. After setting the flip chip to HIGH and putting on a reasonable fork (Ohlins 170mm), the BB height remains fairly close at 344mm. If one of the most important issues about mulleting a bike is that the BB height is affected, I am not seeing it as I am not affected by it when I ride DH. I started riding on a 26" wheel bikes so I know how to ratchet. Pedal strikes are not an issue as we generally have dedicated climbing trails which are not beat to sh!t.
My BB reference to the effects of mulleting a bike is from my Knolly Warden 168, which is designed as a 650b bike. It also has a BB height that is similar at 347mm. The chainstay lengths on Levo SL, Kenevo SL and Warden range from 447mm on the Kenevo to 431mm on the Warden. The Levo SL falls in the middle at 437mm. The Kenevo SL has the longest wheelbase at 1258mm and the Levo SL is the shortest at 1185mm which I find the most interesting. The Kenevo SL and Levo SL weigh within 2 lbs of each other at 42- 44lbs. The Kenevo is not as easy to ride on the steep and technical trails on the North Shore and Squamish as it takes more effort to "move it around" when trying to pick lines. The Kenevo SL feels better at Whistler, at speed and on jumpy trails. I firmly believe that body position can correct most things that braking can not.
I just bought a set of these wheels for my wife. Some will call it a fashion statement. My wife just looks at me like this

Convergence | We Are One Composites

 

[Litehiker]

"Mullet" wheel setups may be great if you are riding faster than a crawl but my 2 wheel drive, 2 battery dual suspension E-CELLS Super Monarch Crown is for HUNTING and carrying a load of meat out so I doubt if a mullet wheel setup would help me a lot, especially since the rough terrain I'll be hunting in Nevada will be kind to a lowered pedal stroke. So maybe I'll suggest it to my daughter for her Specialized mid motor E-MTB.

 

[RustyMojo]

"Mullet" wheel setups may be great if you are riding faster than a crawl but my 2 wheel drive, 2 battery dual suspension E-CELLS Super Monarch Crown is for HUNTING and carrying a load of meat out so I doubt if a mullet wheel setup would help me a lot, especially since the rough terrain I'll be hunting in Nevada will be kind to a lowered pedal stroke. So maybe I'll suggest it to my daughter for her Specialized mid motor E-MTB.

Eh?? Thanks for that, I now know to put my bike back to 29/29 if I ever decide to randomly kill animals in the wilds

 

[cappuccino34]

Running mullet frees up the Geo options for the designer, be that shorter chainstays or a more upright seat tube for a given cockpit length etc.

For me I prefer the agility given by having shorter chainstays (allowed by a smaller rear wheel), and I'm just average height and buzzing my nuts on the rear tyre of my 29er is a regular thing. I find that (for me) the shorter rear end helps me to get my weight where it needs to be for maximum traction when climbing in the loose, more so than the traction benefit from having a longer contact patch from the larger radius of a 29rear.

The rollover benefits of a 29er front are obvious, and the front is more stable by vertu of having a larger polar moment (vs 27.5 front), ergo a 29 front is slightly less nimble than a 27.5 by the same token.

But that's ME. If you happen to be 6'7" tall then you would probably ideally want a 29er rear with a 32" front.

 

[franciscoasismm]

The 29/27 short chainstay ebike is more agile and lowers better, 29/29 climbs better and is faster

 

[edruid]

For years I rode 27.5, then I bought a E Cube 29er but I also went to large instead of medium frame size. It felt better at the time but I never gelled with the 29er. Sold the Cube and got my Whyte E150 RS with 27.5 wheels. I love this bike but am now looking at the Whyte E180 RSX which is a mullet. I have no experience with a mullet so what would I expect. It must work because a lot of peaple run this set up but how different is it. Your options and experience please.

I got a 27.5 for the rear of my 2020 140in spring 2022. Instantly felt more secure on downhill runs and quicker turning. Have changed back now it's muddy just to have the extra footprint. Changing felt good in both directions. Choose abike, don't choose a wheel combo.

 

[Seven]

It’s just a daft fashion,
Personally feels awful to me,
Tried it on my Levo and immediately changed it out for 27.5 front and rear,
Handles, jumps and flows way better without the horrible cartwheel up front.

 

[Mikerb]

I can't agree with that. maybe because i weight only '73 kg'. but riding my Sentinel (15-16kg?) and Levo (23kg?) is VERY different. and i'm not talking about only turns but also braking etc.

ie 3 times the weight of your Levo, meaning 3/4 of the total riding weight is you!!

 

[Kirk P Brosius]

Hi all,
I've been watching this thread with much interest but I'm moving in the oposite direction.
I have a gen 1 SC Heckler that I am very happy with and I am VERY interested a MX (mullet) conversion which will require a new fork (OEM 27.5 only from SC), front wheel and tire.
These parts will set me back approx. $650!
Any comments or feedback will certainly be appreciated.
Happy New Year to all of you from Wesrwen Colorado!
Regards, Kirk

 

[dalf83]

I have a mullet after 27,5 setup and then 29. My 27.5 was a hard tail. Served me well. Switched to 29. It was lovely for going to work, but I struggled personally as the roll speed felt too fast for me personally (I am control freak). The mullet setup has felt the best. I am sure there are experts with better opinions, mine is based purely on feeling. The front 29 lets me roll over large hurdles, the 27,5 lets me accelerate slower and therefore I have more control. I need to work harder when pedalling compared to my friends with only 29, but for me the control factor is worth it, and I get a health bonus for more pedalling. It definitely is more tedious to get to work with, but one of the most memorable quotes for me is „get the bike you need 80% of the time”. Try it out for yourself before you commit. There are no bad options. Bike on!!

 

[G-Sport]

It's easy for tall people to rubbish Mullets and Shorter chainstays but if you are under 5'10" they are transformative. I bought a Levo Sl in September specifically intending to mullet it. Rode it for a month and a bit and although it was nice ridden "passively" (just pointing downhill and hanging on) it was super hard work for me to ride it playfully at my 5'8" height and I nearly died a number of times when buzzing the back-wheel hard with my arse mid-drop.
So I cut the chainstays down to 415mm (which also corrected the BB height at the same time) and made the (irreversible) leap to mullet. It is absolutely fantastic. Bike feels super playful and pulling up is a split second decision rather than needing to be booked in advance with a pre-compression of the fork. Balance seems better and it does turn more easily.
I'm not really bothered that I cant switch components front to rear, I always go for a stronger rear rim and stickier front tyre so nothing was ever compatible anyway.

 

[KnollyBro]

It's easy for tall people to rubbish Mullets and Shorter chainstays but if you are under 5'10" they are transformative. I bought a Levo Sl in September specifically intending to mullet it. Rode it for a month and a bit and although it was nice ridden "passively" (just pointing downhill and hanging on) it was super hard work for me to ride it playfully at my 5'8" height and I nearly died a number of times when buzzing the back-wheel hard with my arse mid-drop.
So I cut the chainstays down to 415mm (which also corrected the BB height at the same time) and made the (irreversible) leap to mullet. It is absolutely fantastic. Bike feels super playful and pulling up is a split second decision rather than needing to be booked in advance with a pre-compression of the fork. Balance seems better and it does turn more easily.
I'm not really bothered that I cant switch components front to rear, I always go for a stronger rear rim and stickier front tyre so nothing was ever compatible anyway.

Now THAT is commitment! How/where did you cut the chain stays down to 415mm ( from 437mm)? I am looking at my carbon Levo SL and Kenevo SL and thinking you must be some kind of magician or a very confident welder if you own an aluminum Levo SL!

 

[cappuccino34]

It's easy for tall people to rubbish Mullets and Shorter chainstays but if you are under 5'10" they are transformative. I bought a Levo Sl in September specifically intending to mullet it. Rode it for a month and a bit and although it was nice ridden "passively" (just pointing downhill and hanging on) it was super hard work for me to ride it playfully at my 5'8" height and I nearly died a number of times when buzzing the back-wheel hard with my arse mid-drop.
So I cut the chainstays down to 415mm (which also corrected the BB height at the same time) and made the (irreversible) leap to mullet. It is absolutely fantastic. Bike feels super playful and pulling up is a split second decision rather than needing to be booked in advance with a pre-compression of the fork. Balance seems better and it does turn more easily.
I'm not really bothered that I cant switch components front to rear, I always go for a stronger rear rim and stickier front tyre so nothing was ever compatible anyway.

Some effort that is.
It'll have increased the anti-squat too because the chainstays with have a more upward direction. Probably got more initial bump compliance too with the more rearward initial axle path.

 

[G-Sport]

It's a carbon one. Had thought I would need to shorten both the chainstays and seatstays but when I got it all measured up and into CAD it turned out I could leave the seatstays as they were. Only complication was that the motor mounts and front sprocket clearance meant I needed to put a kink in the chainstays to keep the front clearances OK.
Yes, axle path is a touch more rearward and a few other minor changes but for someone my height it is a revelation to have a bike that comes up so well.

 

[Downhillr]

Had to look up those words on Google. But they must make mullets for a reason and not just a trend.
with my 29er I just found the wheel size just too big but with the 27.5 the bike feels part of me If that makes sense.

Have ridden 27.5 for years but I demoe’d a 29’er (Megatower) vs MX (new Nomad) which share frame and similar travel/geo.
Clearly different handling on tighter, steeper trails, found the 29’er bit smoother through chunk while MX more fun in steeps... so I bought my ebike (SC Bullit) which is MX and shares similar travel/geo characteristics with those analog bikes.

 

[KnollyBro]

It's a carbon one. Had thought I would need to shorten both the chainstays and seatstays but when I got it all measured up and into CAD it turned out I could leave the seatstays as they were. Only complication was that the motor mounts and front sprocket clearance meant I needed to put a kink in the chainstays to keep the front clearances OK.
Yes, axle path is a touch more rearward and a few other minor changes but for someone my height it is a revelation to have a bike that comes up so well.

Sounds great! I am not following how and where you cut your carbon chain stay and joined it back together. Could you post some pictures and details of how you did that? Personally, for the climbing trails and FSRs we have for riding up, the effect of shortening a chain stay would not affect me.

 

[YZDude]

Built up my frame as a mullet, partly due to my moto-sensibilities. I think the slightly smaller diameter rear still allows quicker directional changes, and you can still muscle the 29er front around with the bars to initiate turns.

 

[G-Sport]

Made a Jig to hold everything in the right place...

Sawed through and sanded ends down to taper into new material. Bonded joint with superglue to hold shape (not photographed sorry)

Did a first layer of braid to properly fix the joint for handling and check everything. Sanded this back to get another key...

Then four layers of UD carbon for the main strength and a final layer of braid. Cured at room temp for 24 hours then post cure in the oven.

Final gentle sand to prepare for paint then a hurried spray job just to keep UV off the resin and reassemble and ride ASAP.

Did slightly have my heart in my mouth cutting it, but I knew that if it all went terribly wrong I could (probably) buy a replacement chainstay and put it all back to normal.

 

[KnollyBro]

















Made a Jig to hold everything in the right place...































































Sawed through and sanded ends down to taper into new material. Bonded joint with superglue to hold shape (not photographed sorry)















































































Did a first layer of braid to properly fix the joint for handling and check everything. Sanded this back to get another key...































































































Then four layers of UD carbon for the main strength and a final layer of braid. Cured at room temp for 24 hours then post cure in the oven.































































Final gentle sand to prepare for paint then a hurried spray job just to keep UV off the resin and reassemble and ride ASAP.





















































I









Did slightly have my heart in my mouth cutting it, but I knew that if it all went terribly wrong I could (probably) buy a replacement chainstay and put it all back to normal.







Made a Jig to hold everything in the right place...







Sawed through and sanded ends down to taper into new material. Bonded joint with superglue to hold shape (not photographed sorry)









Did a first layer of braid to properly fix the joint for handling and check everything. Sanded this back to get another key...











Then four layers of UD carbon for the main strength and a final layer of braid. Cured at room temp for 24 hours then post cure in the oven.







Final gentle sand to prepare for paint then a hurried spray job just to keep UV off the resin and reassemble and ride ASAP.







Did slightly have my heart in my mouth cutting it, but I knew that if it all went terribly wrong I could (probably) buy a replacement chainstay and put it all back to normal.

View attachment 103894

Made a Jig to hold everything in the right place...

View attachment 103895

Sawed through and sanded ends down to taper into new material. Bonded joint with superglue to hold shape (not photographed sorry)


View attachment 103896

Did a first layer of braid to properly fix the joint for handling and check everything. Sanded this back to get another key...

View attachment 103898

View attachment 103899

Then four layers of UD carbon for the main strength and a final layer of braid. Cured at room temp for 24 hours then post cure in the oven.

View attachment 103901

Final gentle sand to prepare for paint then a hurried spray job just to keep UV off the resin and reassemble and ride ASAP.

View attachment 103902

Did slightly have my heart in my mouth cutting it, but I knew that if it all went terribly wrong I could (probably) buy a replacement chainstay and put it all back to normal.

Wait a minute... you not only seem to have (way) more skills than the average dude giving advice on this forum but you also have some serious cahonas to try something like that! Well done! Unfortunately, your move puts me closer to the "Mullet for Fashion" as @Mikerb calls it as I neither have the talents you possess or know anyone around here who does. Just to clarify, but not to question your ability, how do you know you have made it strong enough? Have you hit any "big" drops to flat (intentionally or on purpose) to test it? How do you test such a mod? Once again.... WELL DONE
So, when will you start taking orders?

 

[Waynemarlow]

Pretty crude but effective it would seem. Anyone considering this really needs to spend a bit of time researching aircraft building forums as much of this is perhaps a little on the ”crude” side of carbon fibre repair leaving the epoxy taking the strain in ways it perhaps it wasn’t designed to do.

But if it works and does the job, why not.

 

[irie]

I can't agree with that. maybe because i weight only '73 kg'. but riding my Sentinel (15-16kg?) and Levo (23kg?) is VERY different. and i'm not talking about only turns but also braking etc.

Weight distribution here^^^ is a key issue because ebikes are front weighted by their batteries, and cockpit setup is critical.

* coming from 10 years closed circuit motorcycle racing at Brands/Snett etc. (BMCRC).

 

[G-Sport]

Wait a minute... you not only seem to have (way) more skills than the average dude giving advice on this forum but you also have some serious cahonas to try something like that! Well done! Unfortunately, your move puts me closer to the "Mullet for Fashion" as @Mikerb calls it as I neither have the talents you possess or know anyone around here who does. Just to clarify, but not to question your ability, how do you know you have made it strong enough? Have you hit any "big" drops to flat (intentionally or on purpose) to test it? How do you test such a mod? Once again.... WELL DONE
So, when will you start taking orders?

Wasn't at all suggesting this as a DIY solution for people wanting a mullet, but aside from working out the geometry/clearances and making the jig it wasn't really a very difficult job, just basic DIY tools.
It would be awesome if companies like Specialized offered short chainstays as a mullet-ing option though, the FSR design really lends itself to this kind of change which is way more useful than a "flip-chip" in my opinion.
If you were super keen on going this way then Adrian at Carbon Wasp would probably be the person to ask.
As for strength: the original tube at this point is about 1.8mm thick top and bottom and 1.5 on the sides; my joint is 2 layers of 0.32mm braid and 4 layers of 0.65mm UD, which gives a total thickness of 3.24mm (and at a larger height and width so more material from that aspect too). Yes, the shrink tape has probably not consolidated the layup as well as a proper bladder and autoclave process would but the braid has the advantage of having no discontinuities in the fibres. So overall I am very confident that it will be strong enough. It has not had any issues with my routine local ride which starts with a 2.5m rock drop (but into a moderate downslope rather than to flat) or with casing some of the bigger jumps on A470 at Bike Park Wales which were hard enough to blow me off the pedals.
IF it were to break, there is also the comfort of knowing that most likely the back of the bike would be collapsing which is likely to be much less dramatic than any kind of front end failure.

 

[G-Sport]

Pretty crude but effective it would seem. Anyone considering this really needs to spend a bit of time researching aircraft building forums as much of this is perhaps a little on the ”crude” side of carbon fibre repair leaving the epoxy taking the strain in ways it perhaps it wasn’t designed to do.

But if it works and does the job, why not.

There is no way that this would still be together if it was just held by epoxy in tension. Although the shrink-tape technique I used is pretty low-tech you can get very good results this way.

 

[Cell4soul]

View attachment 103894

Made a Jig to hold everything in the right place...

View attachment 103895

Sawed through and sanded ends down to taper into new material. Bonded joint with superglue to hold shape (not photographed sorry)


View attachment 103896

Did a first layer of braid to properly fix the joint for handling and check everything. Sanded this back to get another key...

View attachment 103898

View attachment 103899

Then four layers of UD carbon for the main strength and a final layer of braid. Cured at room temp for 24 hours then post cure in the oven.

View attachment 103901

Final gentle sand to prepare for paint then a hurried spray job just to keep UV off the resin and reassemble and ride ASAP.

View attachment 103902

Did slightly have my heart in my mouth cutting it, but I knew that if it all went terribly wrong I could (probably) buy a replacement chainstay and put it all back to normal.

will the chain stay work hold up to the weight of the EMTB? I’d be Leary it would fail in some fast chunk or bigger drops.

 

[Waynemarlow]

There is no way that this would still be together if it was just held by epoxy in tension. Although the shrink-tape technique I used is pretty low-tech you can get very good results this way.

Yup the braid is doing its job holding the shape, possibly you should really have made a small inner sleeve to hold the shape and locate the join. Heat shrink tape works quite well and the heat sets off the epoxy. Carbon should be tapered at 100:1 if you want to do it precisely, 200:1 if you simply want to layup over the top as effectively you have done relying on the Epoxy glues strength.

From a more practical level, what you have done " works " and not all carbon repairs perhaps need to be "signed off" as the work I have done on aircraft needed. The art of a true master in carbon repairs though is when after the repair, the repaired piece weighs the same as it was before needing a repair.

A very good company to deal with and a great learning area

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