- This is a tech followup to the 29 versus 27.5 video
I did recently on GMBN to get into the facts and figures,
but also answer some of your questions.
(drum pounds)
(knife rings metallically)
- The first thing that a lot of you pointed out
is that I got the weights wrong,
of course I did, I said 50 gramme difference,
in fact, it's 500 grammes, so you definitely
would have felt that on the trail.
Rich Piana is one of those people,
actually, almost everyone who watched the video noticed
I got those numbers wrong, so apologies for that.
Yeah, definitely 500 grammes, you will feel the difference
and of course, it's rotating mass,
so let's talk about that straight away.
When we're talking about the whole mass
of a bike and the rider, in fact,
you've got the rider, you've got the bike
and rotating mass, so the wheels, once they're spinning
is said to make only 2% difference
to the actual accelerating and decelerating of a bike.
So, it's not a huge amount, but 500 grammes
is a reasonable amount, but also rotating mass
does depend on the diameter of the wheel.
So, a 29-er is obviously bigger than a 27.5
and it's heavier, so it is gonna make a bit of a difference,
And I do think it makes a difference
to the feel of the bike, that smaller wheels
that are lighter do make the bike feel more nimble.
So, for both different wheels, the 29-er and 27.5
I ran the same model of wheels.
They are the DT Swiss M1825 spline.
They're an alloy rim, they've got
a 30 mill internal width on both sizes,
so that doesn't affect the profile of the tyre.
I ran tubeless on both sets of wheels.
There were a few questions about why I ran
the Baron's on the smaller wheels
and the Kaiser's on the bigger wheels.
Basically I went with what I thought would be
the bst set of tyres for those conditions,
so Kaiser's are super grippy,
great for enduro-style riding,
and Baron's are also, but you
can't get a Kaiser in a 27.5 at the moment,
on the bigger 2.6 I must say, in the plus.
So, that's why I went for the Baron on the smaller wheel.
It's a really good tyre for those conditions.
So, I just wanted to go for what
I thought was gonna be the fastest.
That's something I want to address
slightly, as well, in that video.
I know we have done a 29 versus 27.5 before,
but I felt this was different
because it's just one bike that can run two sets of wheels,
and for me, it wasn't all about what was the fastest.
It was about, what would I choose if that bike was mine?
Would I have two sets of wheels?
Of course, that is the more expensive option,
buying two sets of wheels.
Or would I decide that one really suited me a little bit
better, which I'll come to at the end of this video.
Let's talk about the geometry changes
when you change out the wheels.
So, it slackens off by naught .6 degree
when you put the bigger wheels on,
so the head angle does come out, but that for me
is not enough to make a difference to the bike.
I really don't feel that, if you let your rear tyre down
or run more sag on the smaller wheels
I think it makes just about the same difference.
The BB drop is something that I think you do feel.
So, BB drop is the measurement when you compare
the axles of the wheels to where the BB sits.
On the bigger wheels the BB sits lower,
so, in relation to those axles.
Obviously your weight goes through the pedals
and that feels like you can drive
the bike better over obstacles.
And I do think that does make a big difference.
Also, I've got some props to show.
If you couple that with the angle of attack,
so when your wheel rolls over a bump, obviously
a bigger wheel will roll over that a little bit easier.
If you've got a smaller wheel
that's gonna get more hung up on that bump.
So, when you've got that and the difference in the BB drop,
that's where you do feel that the 29-er
just sort of monster trucks over
those smaller bumps a little bit better.
I think that's where we saw the difference
in the times at the bottom of the track.
There's a lot of breaking bumps, it's quite rough,
the bigger wheels were just, you won't get
as much feedback to your body,
but also the tyres will roll over that little bit easier.
Let's put the times aside for a second
and let's talk about how the bike
actually feels with the different size wheels.
Well, the 29-er feels fast everywhere,
even climbing, it feels really compliant.
You don't feel the bumps when you're riding downhill,
but also when you're going up through the saddle.
It feels like a really smooth ride and it feels fast,
but it doesn't feel as agile as the smaller wheels.
I talked about in the video a little bit
where I do drag my rear tyre, my bum,
I do that quite a lot on 29-ers.
Also, just throwing the bike around,
so in corners I do feel like the smaller wheels
are just that much more aggressive.
Also, it sounds stupid, but getting on and off the bike
I sometimes swing my leg over
and on the big wheels I catch it and almost fall over.
Smaller wheels do feel like a much
more old school normal mountain bike to me,
whereas bigger wheels does feel like
a sort of trail-y, fast cross country bike,
although everyone has proved, races have proved
that they work enduro, they work for downhill,
of course, we saw that last year.
Certain courses, I think, they're gonna
feel good and they will be fast.
Let's have a look at what you guys have been saying.
Well, we had a poll on Instagram
to see how you would choose.
We've got 8,625 votes for the smaller wheels, 27.5.
But for 29 we got 5,144, so a pretty big margin
going for the smaller wheels.
I would say that's probably what we see
on the trails, especially in the UK,
if you're looking at what people are riding.
Much more people are riding 27.5,
although, let's talk about the 26
'cause a lot of people were starting
that in the comments section.
We don't talk so much about 26 inch wheels now,
generally because not many manufacturers
are making those bikes any more.
I guess you can still buy free ride
some downhill bikes maybe, maybe not
even downhill bikes actually,
but it's all dirt jump bikes and kids' bikes
all still come with 26 inch wheels, but when we're talking
about your higher end bikes, they all come in 27 5's.
So, I think, really, that has become the norm
in let's say the last five, six years, I would say.
But, yeah, there's a lot of people kicking
off in the comments section.
Will Mockel said, "It's funny how the vid is about
"27.5 versus 29 but the whole comment section
"is people defending 26."
Which is fine, a lot of people saying, "26 for life."
Perrocan Atakes says, "Really? Wheel size debate?
"Is that all you've got?"
I know this has been raging on
for years and years, hasn't it, since 29-ers came around,
but I still think it's a valid point.
There's still a lot of people
trying to decide which one suits them best.
I think I still am, to be honest.
There's some situations where I really do like the 29-ers,
others when I want to get rid of them,
I chuck my smaller wheels back on.
Just a couple more comments on the wheel size debate.
The Chosen Dude says, "It ended years ago,
"when cross country and enduro racers
"began widely using and winning on them.
"No one cares about downhiller's opinions.
"They were always the last and loudest
"to adopt new technology, clipless pedals,
"carbon frames, tubeless, air shocks,
27 5 wheels, et cetera."
I do kind of agree with that last statement.
Downhillers are always pretty stuck in the mud.
They do take a little while to get used to them,
but it'll soon come like we saw
with Greg Minnaar grabbing the bigger wheels
and starting to do really well on them.
The rest of Santa Cruz team, everyone else
joins suit after that and bigger wheels
started appearing everywhere.
But, I would say that Nino Schurter,
up until a couple of years ago,
always ran 27.5 wheels, so he's
the one person cross country that really
didn't want to use the bigger wheels,
and obviously he's won a lot of races.
I know he uses bigger wheels now,
but I don't think that statement stands completely true.
One last one, this is from Some Judo Guy.
"Is there still a debate about wheel size?
"Choose your ride and go and have some fun.
"It's all down to your preference.
"29 just feels too big for me, but for some, it's perfect."
And that brings up a little bit of a point,
that a lot of people say that 29-ers
just suit bigger riders, and the 27.5
are better for shorter riders
is something that I really do want to test.
I don't know if that has been completely proven.
I know there are some shorter riders,
people like Tracy Moseley, Danny Hart have used 29-ers
to a good a mount of success,
so I really want to test that out.
Get a smaller rider, put more bigger wheels.
Is it gonna limit them at all, who knows?
We need to try that one out.
A few people have asked this question,
but Jog Bird asked it, "How about a mix up?
"A 29-er on the front and 27.5 on the back."
That's something we're seeing come in with E-bikes.
I've seen quite a few people riding that.
I've not tried it yet, definitely would like to run it,
see if it works, obviously you're gonna run
a wider tyre on the back with the 27.5 plus,
and then a smaller one up front, the 2.4 and the 29-er.
Yeah, not tried, I'm really interested to try that one out.
Could it work, I don't know.
It might be the best of both worlds,
it might be the worst of the two together, who knows.
Neil Blundz raises a point, he says that,
"It's always been 80% rider and 20% bike.
"The small margins are just that...small."
Yes, it's definitely more the rider than it is the bike,
but I would say it's probably more than that.
I would say it's more like 90, 95% the rider,
'cause if you put a really good rider on anything,
a 26 inch fully rigid bike, they're still gonna be fast.
But, if we're talking about racing,
where hundredths of seconds, especially in downhill
and enduro, make a difference between
winning and coming second, then small margins are important,
but, of course, we're not all racers, we don't
always have to have the fastest equipment on our bikes.
Maybe it is down to preference.
And then Bob Brusk Fruco brings up that again, he says,
"Hi, there, actually a question to Neil:
"In this video you focused on the time
"and the speed advantages of using different wheel sizes,
"but what are your impressions
"in the case of agility, manoeuvrability on steep
"and narrow technical sections, hair pins, et cetera."
I've talked about it a little bit already,
but I'd say hair pins, I don't really notice
the difference between the wheel sizes.
It does seem to me like you would notice
that 29 inch wheels were harder to get around a tight turn,
but I don't actually feel that.
They do feel pretty, sort of,
I guess it's the grip more than anything.
You do have really good grip on the bigger wheels,
But, that's not something I really know.
It's just more about those times when I've got
to move around on the bike, so soaking the bike up.
I'll finish this video with a final question.
If I had to choose one set of wheels,
only one, which one would I have?
Actually, that's a really difficult one.
I find it really hard to decide,
but if I could only have one I
would probably go with the 29-ers.
Just feels like a really fast bike
and, according to my test, it was one second faster,
so why not, I'll have that one.
If you want to see some more videos
click up there for the original video,
down there for how tyres are made,
I think that's really interesting
that it does make a difference,
that rotating mass of the wheel.
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