GPS Speed Accuracy, Di2 Upgrades & Taping Helmet Vents?! | GCN Tech Clinic

GPS Speed Accuracy, Di2 Upgrades & Taping Helmet Vents?! | GCN Tech Clinic


(swooshing) – Welcome back to the GCN Tech Clinic, where we help answer and
solve your bike problems so that you can get back
out on your bike again, riding and enjoying the sunshine, or the rain, depending
on where you come from. Anyway, let’s start then, shall we, with the first question this week, and that is from Anton Litvivstev, who says, “Dear Jon, it’s
me again with the question, “Can I use Force 1 levers with an “XX1 rear derailleur?” Now hi, Anton. I actually like your idea here. A little bit of a hack or
a bodge to do something, I don’t know what. Sadly though, you cannot, because the road one by 11 components use an exact actuation cable pull ratio, and the mountain bike version uses an X actuation cable pull. So I’m afraid there are two
different amounts of cable being pulled there from the
actual gear lever itself. So that hack or bodge
that you were planning is not going to work, I’m afraid. Next up is a question from Liam Sangaku, who is a very popular
commenter on the videos. And Liam asks, “Should I grease
my quick release skewers? “Will it allow my wheels
to roll smoother?” Right then, Liam, so if you were to grease your quick release skewers, I’m afraid it won’t make any difference to the actual rolling
resistance of your bicycle. The reason being, nothing
actually turns on them, per se, because all they’re doing
is a very important job. But what they are doing
is actually holding the axle in place into your drop outs, then in turn, the actual hub bearings are turning on that axle. Now, a way in which you could
possibly apply some grease to those quick release skewers for benefit is to actually try and reduce
any creaking or clicking. Because in the past, that has been known to cause a few problems there. But if you want to make sure that your wheels are rolling smoother, basically you’re gonna have
to look at the bearings. That’s where the rolling resistance differences are gonna come from. Now we’ve got a question from VELOBAR+, who asks, “My rear
wheel has a DT Swiss hub “on which I can change the end caps. “Now I use five-millimeter
quick release axles. “If I were to change the
end caps to use 10 by 135 “quick release axle, would
it still fit in the frame?” Right, so to just to let
everybody know out there, those DT Swiss hubs, basically
you can change those end caps so that they’re compatible on different styles or
different widths of frames. So it’s a really, really versatile hub. Now, without knowing the
exact model of that hub that you’ve got, I’m afraid
I can’t answer that question. But essentially, I don’t see a problem with you actually being
able to do that at all, providing, of course, that your hub is able to accommodate
that 10-millimeter axle. Now we’ve got a question from Greg Brown, who asks, “What’s the best way to clean “brake tracks of carbon wheel sets? “Not just road grit and grim,”
grime, I think they mean, “but brake pad residue.” Right, Greg, well, you are gonna need some of that good old fashioned
Jon Cannings elbow grease, which people have asked
in the past where they can buy it from, but I’m
afraid it’s not for sale. The best thing to do here is get yourself a bucket of warm, soapy water, remove the wheels from
the actual bicycle itself, and then with a sponge, simply apply a decent amount of pressure
onto the brake tracks of the rims to remove any of that residue. There’s no easier method, not
that I know of, certainly. And whilst you’re at it as well, actually clean out those brake pads too, because sometimes they can get a little bit gummed up with road grime. And also some of those
compounds of brake pads do actually melt down a little bit, and sometimes they can block up the grooves that are inside of the brakes. Next up we have a
question from Marwan KMS, and I love this one. “I don’t know if I must use
#askgcntech or #hack/bodge.” Well, just use #askgcntech,
then I’ll be able to help out. “But I’m quite tempted to tape “my helmet vents to get some aero gains. “I know some rider did it in
a time trial a few years ago, “and some triathletes are doing it too.” Is it UCI legal, what
are my thoughts about it? Yes, the old taping up vents trick. Well, I’m afraid it’s
not allowed by the UCI. There’s actually a rule against that. So there we are. It could mean you would
get a little bit hot-headed if you were to tape up those vents, but more importantly,
you could land yourself in hot water too, if the
UCI were to catch you. Now, I actually tried
to make a helmet cover about six or seven years ago
now, using some fiberglass. And embarrassingly, the
results are onscreen right now. It wasn’t a particularly
good effort, I must say. But hey, I had some spare time on my hands so I thought I’d do it. And I actually never
used it in a race either, so it was basically a Saturday afternoon not very well spent. But yeah, you cannot do that if you are gonna race in a UCI race. Now Shriram S asks, “Awesome
show, daily viewer.” Wow, what’s not to love about that? “What do I need to upgrade “from Ultegra Mechanical to Ultegra DI2? “My bike manual says it’s DI2-compatible.” Right, well, you are
gonna need DI2 levers, DI2 cables, a battery, a junction box. Get yourself a charger too,
that’s pretty important. Now, I made the change to
DI2 many, many years ago, and I’ve never looked back since. Absolutely love it, so
good luck with that one. Next up is a question from John Rodgers, who asks, basically they’re following up to a speed sensor
question a few weeks back. “Do you really need one at all? “Is speed from GPS as accurate?” They had one before and now they don’t, and their Garmin still reads speed. Right then, John, well,
you don’t need one, per se, because you’re right, your
GPS unit is obviously a GPS, and it can track your speed. However, sometimes accuracy
is not as good as it could be, particularly if you’re
riding under thick tree cover or around tall buildings
or even through a tunnel, because obviously, in a tunnel
you’re not gonna be able to see those satellites
with your head unit. So just bear that in mind. And then interestingly,
if you have a non-direct drive-style turbo trainer, you could attach that speed
sensor onto your rear hub, allowing you, basically,
a cheap way into Zwift. So there we go. Next up is a tire question from Leigh 350. “Is it okay to run a 25 tire
up front and a 28 at the rear? “I will soon be replacing my rear tire “and would like to try a 28, “but don’t need to replace the front yet.” Hello, Leigh, 25s, 28s, why? Are you a touring cyclist
or a mountain biker? I jest. These width tires basically have become super popular over the last few years. And indeed, you can run a 28 on the back and a 25 on the front, no problem at all. This is actually something
which I do in the winter. Just bear in mind though
that you do need to make sure you’ve got enough clearance
with your brake caliper as well as your frame, to
run a 28-millimeter tire. Recently I did try and
fit a 28-millimeter tire into a fairly recent racing frame, only something which is
three or four years old, and it wouldn’t clear. So there we are, just bear that in mind. But hopefully you’ll be good to go and get a little bit of extra comfort. Next up is a question
from Ciprian, who asks, “How do I true my tubular wheel,
which has inside nipples?” Ciprian, the art of wheel truing, something which can
sometimes go horribly wrong. It certainly did for me,
the first time I ever tried. I was 14 years old, and
basically, I destroyed a wheel. When my dad got home from work, I’m surprised he didn’t kill me, because yeah, I wrote off
a perfectly good wheel. Anyway, I will explain the basics of this. You are gonna need to
remove that tubular tire, which possibly you had to
wrestle on in the first place. Maybe get a little bit of glue. In my case, I used to get it everywhere. Then you are going to need
to find the offending spoke, or however many there
are, and then basically, you’re gonna need something
like this, which is a spoke key. But it’s different to
what we normally find. This one has got four sides inside of it. And basically, that will attach then onto an inverted spoke nipple, in some cases, that you
simply tighten or loosen. Now, it’s not always four-sided. Sometimes they can be a hex shape. It all depends on what
type of wheel you’ve got. If you’re totally unsure, I would advise visiting your local bike shop, who will certainly be able to help you out with any sort of wheel building or wheel truing problems you may have. Because it’s not that easy, believe me. Next up we’ve got a
question from Toasty Bear, who does like to write into
us with a technical question. Now Toasty says they
took apart jockey wheels on a fairly low-end Shimano system, as they were feeling a bit sluggish. They admit then, it was
actually off a mountain bike. So they could’ve asked Doddy for help, but they’ve come to
me, that’s always nice. Only to discover there
was no bearings inside. It simply rotates under a metal cap. “Is it common, does it really
make that little difference? “And if so, can I just buy a replacement “jockey wheel as an upgrade?” Right then Toasty, so just to clarify, some jockey wheels, or pulley wheels, do come with cartridge bearings fitted, whereas others resemble what
you’ve just talked about there. So it’s simply a bush which goes inside the center of the pulley wheel, then has a metal cap and attaches
into the derailleur cage. Now, on yours, sometimes they
can get a little bit gunked up with road grime and
oil, that sort of thing. But they’re pretty simple to clean. So you simply pop them out,
give them a quick rubdown, add a touch of lubricant
before reassembling and then putting back into the bike. Whereas the cartridge bearings, well, they’re not really
that easy to service, but they do offer performance gains. So that’s why we tend to find them on the higher-end components. Now, you ask me if you can,
in fact, buy a replacement. You can. A cartridge bearing jockey
wheel or pulley wheel will fit exactly the same way in which the current one you have does. So it’s really a case of, if you want to spend that little bit extra to have a little bit of a marginal gain. Final question this week
is from Mark Evasion, who asks, basically they’re telling me, they’re looking to keep gradually
updating the drive train. They’ve got Ultegra 6800 rear cassette and a long/medium cage derailleur. Can they use Dura Ace
9100 semi compact with it, plus Ultegra 8000 front derailleur? “Sounds like a bit of a bodge,
but the 8000 front derailleur “is much cheaper than Dura
Ace, for a similar spec. “Oh, and I’ve upgraded the
levers to Ultegra 9070, cheers.” Hi Mark, yes, yes you can. So go out there and enjoy the ride. Now, I hope that you’ve enjoyed
this week’s GCN Tech Clinic. Remember to leave me your
technical questions, problems, and queries, anything which
is preventing you from riding, or maybe you’re thinking
about a cheeky little upgrade. Leave them down there in
the comments section for me. And remember as well to like and share this video with your friends. Give it a big thumbs up. Share it with a friend if they’ve got one of those problems we’ve just tackled. Hopefully they won’t
have an excuse anymore. Now, remember as well to
check out the GCN shop at shop.globalcyclingnetwork.com. And now, for another great video, how about clicking just down here?