- There'll be a table
of these are all the times.
I don't want to use statistics jargon
even though every Pinkbike reader is an engineer.
(upbeat music)
When the UCI scrapped the rule
which banned mixed wheel sizes for racing,
a lot of teams scrambled to experiment
with mixed wheel size bikes
which have now become known
pretty much universally as Mullets.
In the early days,
most people were running either,
a 27 and a 1/2 inch bike
with a 29er front wheel and fork,
or they're running a 29er bike
with a 27 and a 1/2 inch rear wheel.
So a couple of years ago,
my colleague Mike Kazimer experimented
with using a 29er a bike with
both 29 and 27 and a 1/2 inch rear wheel.
And the results were inconclusive.
Neither bike was outright faster, but with these setups
you had to compromise the geometry to
accommodate the next wheel sizes.
If you use a 27 and a 1/2 inch rear wheel in a 29er bike
the bottom bracket height is probably going to
be a bit too low.
And if you fit
a 29er fork and front wheel into a 27 and a 1/2 inch bike
and the BB is probably going to be too high
and either way the head angle
and the seat angle are probably going to be a bit too slack
certainly slacker than what the bike was designed for.
These days however,
when people talk about a mullet bike
they're usually talking about a bike that is designed
around the smaller rear wheel.
So these allow you to have the mixed wheel sizes
without any compromises in geometry.
There are an increasing number of bikes designed to fit
either rear wheel size, such as this Geometron G one
by using flip chips, it can accommodate
either rear wheel size without changing the geometry at all.
And because on this bike, the flip chip set
between the rocket link and their rear axle instead
of between the rocket link and the shock, the leverage curve
and the suspension kinematics are pretty similar
with both wheel sizes too.
I've been testing this bike with both wheel setups here
at the forest of Dean on a couple of different tracks.
The first track starts with a series of fairly
tight corners that are quite awkward to carry speed
through before it drops into a fast action with a series
of really big roots, before it drops onto a fire road.
I know this track really well, and I did five scoping runs
on the day to get fully up to speed.
Before I got the stopwatch out
then, I did two runs on the mullet, then four on the 29er
and then two more on the mullet.
This was to further minimize the effect
of just learning the track and potentially getting faster
as the day went on. The results.
Well, I was very slightly faster on average
on the 29er where my average time was 49.5 seconds
versus 49.9 seconds
on the Mullet.
So there was about half a second in it
or 1%.
It's not statistically significant though.
So it could just be a fluke
but subjectively what surprised me most was how
similar the two bikes felt in the turns when swapping
from the 29er back to the mullet.
I did notice
that it was a little bit more willing to tip into the turn.
I don't necessarily think it's better.
It's just different.
And I only really noticed it
on the first couple of turns after swapping over.
So, I think you learn to compensate for it very quickly.
So perhaps the 29er is a bit
like having a car with slightly heavier steering in that
it takes a little bit more effort to initiate the turn
but you can go around corners just as quickly.
But the main takeaway
is that the difference is very subtle. Indeed.
In fact, in a blind test, I'm not
a hundred percent sure I could tell the difference at all
but either way
I don't think it was faster through the turns.
And that's certainly what the stopwatch suggested.
The main area where I did notice the difference was
at the bottom on the big chunky roots where
the 29er had just seemed to hang up a little less.
It felt easier to ride smoothly
and carry speed out of those routes.
And into the next section
there shouldn't come as too much of a surprise
because while some people have painted mullet bikes
as the best of both worlds, the fact is that unless you're
on the brakes about 60% of your weight is on the rear wheel.
And also the rear wheel is more likely to be dragged
through the worst of the kind of holes and bumps.
So having a smaller rear wheel is quite a disadvantage
in terms of carrying speed.
So for my second test truck, I decided to try
and find a track where the benefits
of the Mullet were more likely to shine through,
so that I could find out
if the Mullet is faster on at least some types of terrain.
I picked a short track with a good gradient
which is basically a series of nice tight corners.
There's almost no time spent not cornering.
These tight alternating turns are where
I thought the mullet was most likely to come
into its own and because the track is so short
that meant I could do lots of runs
in quick succession and get really familiar with the trail
which is really important
for noticing subtle differences in handling.
But once again, both setups felt pretty similar to me.
I really don't think in a blind test
I'd be able to tell the difference
and the stopwatch seemed to agree this time I
tasted the 29er first than the mullet and back to the 29er.
So the same ABA pattern, but
in the reverse order to the previous track
the average time was almost identical.
And the difference
between those times was very small compared to the range
of times that I recorded for either wheel setup.
So essentially there's no difference.
So this test doesn't really paint Mullets
in a particularly good light
but that's not to say they don't have their place.
One of the main advantages
of a Mullet is probably for shorter riders.
So, I'm 190 centimeters, tall or six foot three.
So I never buzz my ass on the rear tire
but for some riders, this is a real problem.
I still suspect that really short writers could benefit
from a full 27 and a 1/2 inch set up,
so that they can get their bar height low enough.
But if you're in the in-between size
where you can get the bar height
in the right place with a 29er of front end,
but you still want that smaller rear wheel
so that it doesn't buzz your ass, then I mean
That makes a lot of sense.
But when it comes to the supposed benefits
of faster turn-in and better cornering agility
I think that the difference is very subtle
at best and very easy to adapt to some people.
I know swear that there's a benefit here
and maybe they're right, but for me with the height
I am, the writing style that I have.
I really can't feel it,
nor could I tell a difference with the stopwatch
and that's despite going out of my way to try
and find terrain likely to benefit the Mullet setup.
I wonder if in some cases, people have tested the kind
of ghetto Mullet set up that we mentioned at the start
which gives you a slacker head angle.
And that gives you more wheel flop,
which might help the bike to sort of tip into the corners.
Or if they're running a smaller rear wheel in a 29er
bike that will lower the bottom bracket height
get your center of mass a bit lower,
and that could help you to
change direction more quickly as well.
But in this test, all it is really changing
is the height of the rear axle
and the weight and rotational speed of the rear wheel.
So,
29er wheels
are heavier,
but they also rotate more slowly
for a given speed on the trail.
As far as I can see this, doesn't have a huge effect
on how the bike handles after all a 29er wheel
is only about 5% larger than a 27 and a 1/2.
It's not like we're talking about Penny Farthing here.
The main difference I can feel is that the 29er still hangs
up a bit less, particularly on very rough terrain.
It's worth saying also that I've tested on both
of these tracks before back to backing things
like fork set or suspension settings or tire sizes.
And I noticed a far bigger difference
with many of those things.
Now I can already hear Mike Levy asking
but what about climbing?
And there are really did notice a big difference.
Obviously the 29er it helps a little bit
with getting up and over kind of square edge bumps.
But by far, the main difference I noticed is
that the smaller wheel gives you an easier gear.
And this is literally the biggest difference I noticed
in the whole test.
So, what do you think, are you
into the Mullet thing or do you think it's just a gimmick?
once you've had a chance to mull it over,
let me know why I'm wrong in the comments
and don't forget to like and subscribe.
(upbeat music)