YT Jeffsy 29 Custom Build: What are we riding? – Flow Mountain Bike

YT Jeffsy 29 Custom Build: What are we riding? – Flow Mountain Bike


One of the questions we’ve been asked a
few times in the comments section is what is that bike back there? It’s a
YT Jeffsy CF 29 it’s a custom build of my own that I’ve been riding
for a little while now. So why don’t have a bit of a look at it?! Let’s look at the
fork first and foremost, now this is a fork that we’ve got on test at the
moment. It is a Fox 36 2019 version with the new Grip 2 damper with both high
and low speed compression adjustment and also high and low speed rebound
adjustment. Now this fork is 150 millimetres travel which is 10mm more
than you’d have on most Jeffsys – they normally come with 140mm up front on
the two-niner version of the Jeffsy. I wasn’t sure how it was going to work – I
thought maybe the 150 fork might slacken it out too much but it hasn’t, it feels it fantastic. The bottom bracket’s a tiny bit higher which isn’t
necessarily a bad thing on the rocky trails that we have around here. The
36 chassis is just unbelievable and I think it’s gonna be hard to go
back to any other fork really. It’s so stiff, so precise and has saved my butt
on many occasion already. In terms of the damper in the fork we have been a little
bit reluctant to delve too far into it to be honest because it feels so good
with the way that we’ve had it set up already. And when you’ve got high and low
speed rebound as well as high and low speed compression it becomes a bit of a
a bit of a minefield really. You need to really spend the time to make sure
you’ve got the suspension set up correctly. You don’t just want to go in
there and start twiddling knobs all over the show. High/low-speed compression
that’s fine, that’s a concept that everyone is is familiar with or most people are
familiar with and we’ve been dealing with us for a long time on forks. With
the high and low speed rebound it is a little bit trickier – sometimes it’s hard
differentiate between what is a low-speed impact and what is a
high-speed impact and how those are going to have two different effects. So
we found a setting that works for us at the moment and we’ve only been moving it
one or two clicks either way from that setting at the moment just to see how it
goes. So a little bit confusing, but we’re sure there were going to be people
out there who will get the most out of it though. For us at the moment it’s
probably more adjustability than we personally need for our bike and,
you know, whether or not anyone really needs it, who knows? It’s a
in shock to what you’d normally find on the Jeffsy as wel.l I’ve got a Float X on
there. Now this shock has been custom tuned by the very friendly guys Mountain
Bike Suspension Center in Sydney. The reason that I wanted to get a custom
tune on it is, one; I don’t weigh very much and so I often find myself at the
extremes of the adjustability of a lot of shocks, but secondly the trails that
we have around here around Flow HQ are rocky there’s a lot of loose rock, there’s also
a lot of flat drops. So really you want a suspension setup that it’s super duper
active and is really supple over all those small choppy hits. but then saves
some in reserve and is really progressive towards the end stroke so
you’re not constantly blowing through all your travel and bottoming out on
some of those bigger hits. And that’s what we were able to do with this shock.
I really can recommend going getting yourself a custom tune on your shock. It
is not just for the pros, it is not just for people who have been riding for a
long time. When you think about the way that a bike is put together you’ve got
some brand manager who rides their local trails who gets feedback from some
riders, pro riders, his or her local crew, and from that they then decide on what
the shock tune should be. And they take that to FOX, RockShox, or whoever
and ask for the tune and that they think is best going to suit the bike. However
they can not possibly cover all bases when it comes to riding styles, rider
weights, trail styles, all that kind of stuff , setup preferences. And so there is
a lot to be gained by going and getting your shock tuned by someone who knows
what they’re doing. There’s a bunch of different places out there now across
Australia who will do it for you. I can highly recommend the guys at Mountain
Bike Suspension Center. They are fantastic, they talked me through
everything that they were doing with the shock and we will have a little bit more
up about the process that I went through there at a later date as well. In terms
of the drivetrain it is a off-the-shelf SRAM GX Eagle drivetrain. I went with
this drivetrain because I really liked the range of the 10 to 50 cassette, it’s
been great in that regard never running out of gears. A lot of people say you
don’t need a 50 tooth out back, and that’s true, you don’t need a lot of things when
it comes to all kinds of tech on a bike. But it is nice to have and if you’ve got
the gears there you’re always going to use them. And I find myself using that 50
tooth out the back quite a lot. While I really like the range of the GX
setup I found it a little bit finicky, and it’s something that a lot of people
have remarked on in the past. It is super duper fiddly to try and get it
exactly perfect when it comes to the shifting. And although it’ll make every
shift at the moment it’s got a really nice light and crisp kind of action, you
often feel like it is just on the verge of mis-shifting or skipping out, and
sometimes I’m having a little bit of trouble getting it to settle in nicely
into that down the 10-tooth out back as well despite having twiddled with it and
done some adjustment on a couple of occasions. So not all roses there but
overall pretty cool. In terms of the dropper post, I’m running a PRO Koryak
ASP dropper post. It’s not a post you would have seen too much of but it’s
been really reliable it’s only 125 millimeter drop, which is generally
okay. Sometimes I’m aware of the fact that it doesn’t drop as far as some of
the other posts out there on the market, and I’ve matched it up to a Wolftooth
dropper lever because the one that comes with it is complete crap. So you want to
really upgrade the lever if you’re going to be using one of these Koryak posts.
They’re really good value for money and I think it’s been really reliable and
the performance has been pretty good so far.
The tyres that I’ve got on this bike are also something that I’ve been testing
out. They are a Vittoria Morsa tyre. now we hadn’t heard of Vittoria making
mountain bike tires, obviously they’re well established on the road, but when it
comes to the mountain bike game we haven’t seen much of them in the past.
The tyre is a 2.3″ width and obviously in a two niner size, but you can get it in a
27.5 as well. What’s interesting about this tyre is that it uses a graphene
compound which is something that NASA invented in the Space Wars
and as a hair gel… We actually don’t know what graphene really is, other than it’s
a nanoparticle and it seems to be getting put into more and more stuff, but
it makes big promises about the durability and grip of the tyre. Now when
it comes to the durability they seem to be holding up very well. We’ve only done
probably five or six weeks worth of riding on this on this tyre, so far the
durability seems to be good. A bit of chewing out on the rear tyre but nothing
that’s unexpected. The grip is pretty good. It is not on par with a lot of
tyres out there that are using a super sticky rubber compound, and on dry sandy
surfaces where there’s not a lot for tyres to bite into we find them a little
bit skatey. And also wet rock, we’ve had a few hairy moments,
but they are very fast rolling the tread pattern. It reminds us of a Maxxis Rekon
tyre and they carry speed really well. The tread pattern is is great in
that regard, and in softer soils especially brown dirts, and things like
that, they bite in really hard. Loamy stuff or deeper sand, you’re going
to find heaps and heaps of traction so that’s where these tires have
been a real standout. The weight is pretty good too, around about nine
hundred and thirty grams, they seal up well, the sidewalls seem nice and tough
so far as well so there are some positives. On the on the negatives I
guess you just need to accept the fact that there’s going to be a trade-off
between your rolling speed and your out-and-out grip, so that’s probably
our only criticism of that tyre, at this stage. The brakes that I have on this
bike, and please excuse the absolute mess of cables out the front at the moment,
Hope E4s matched to The tech 3 lever. We are doing a shootout at the moment
between three different four-piston brakes. I’ve got the Hopes here, the
Shimano XT four pistons, and of course the SRAM Code RSCs, the latest version
of the SRAM Codes which is probably a little bit more of a downhill oriented
brake, but we’re still sticking them head-to-head against the the Shimano XT
and these Hopes. They are a gorgeous looking brake these Hopes. So far, this is
our first proper ride on them, they feel really lovely. Quite a different level
feels to the SRAMs which we just took off previously. Lighter a little bit
softer lever, feel but a gorgeous-looking brake and I think that is definitely
part of the appeal when it comes to these brakes. Obviously performance is
paramount, but you cannot discount how gorgeous they are. The four pistons
should have heaps of power we’ve got a 203mm rotor up front and a 180mm
rotor out back, and so we’re not expecting any worries with brake fade,
especially around here the hills aren’t that long in particular. So we think it’s
going to be just fine. That is about it, so if you’ve got any more questions
about this particular bike build, feel free to stick them in the comments
or shoot us an email on [email protected] and we will do our
best to to answer your questions about the way this Jeffsy has been performing.