Tubular Tyres: Tape Or Glue? | The GCN Tech Clinic


(clanking iron) – So I’m back with another episode of the GCN Tech clinic where we answer your tech related problems and questions and quarries that you may have. First up though, last
week I tackled a question from Paraic Furlong who
wanted to fit an 11 speed cassette onto a 10 speed free hub, on a Shimano RSAT wheels. I did in fact give a couple of options but Shimano have actually got back to me with another option and
it was the following the CSHT 800 mountain bike cassette, which is an 11 to 34 ratio. Basically by using a 34 tooth sprocket you reduce the chance of any interference between the rear derailleur
cage and the spokes. So there you are; however, you’re likely or possibly anyway, gonna need a new rear derailleur for
that because a 34 tooth cassette isn’t necessarily compatible with your current rear derailleur. But hey, that’s for you
Paraic, for you to decide. Right, let’s get on with it then shall we? So, a question from Russ Starke, who says, “With most of the breaking power up front “why bother with a rear disc? “Why not have a disc
upfront and a direct mount “brake in the rear, especially for pros “with in race rear wheel swaps.” It’s a great question actually
and I can’t answer obviously on behalf of the pros because I’m not one but I don’t even know. Maybe it’s been tried in the past. What’s important to remember
though is that by using a disc brake it’s not
actually for out and out power, cause that’s just
gonna result in a skid and loss of control. It’s actually for
modulation and essentially it really comes into
it’s own in wet weather and poor conditions
where using a rim brake isn’t necessarily the best option. And I think most people
have used disc brakes can agree with that. Now, I think the big stumbling point here will actually be the feel of lever hoods. So a rim brake and disc brake lever hood are gonna feel different
because there’s a reservoir inside the disc brake hood
to obviously hold the oil or fluid so that’s gonna
be the biggest challenging point I imagine because
you don’t wanna have one feeling different from the other. But, it’s certainly
for one to ask the pros when we meet them next if
they would use that option. So, I’ll keep you posted. Next up is a question from
Osman Erdogan who asks, “Hi guys I hope you’re well.” I’m fit and healthy so I can’t complain. “I’m upgrading my bike at the
moment from Tiagra 4700 set “to an Ultegra 6700 set. “Everything is bought
apart from the shifters. “The question is can they use
6700 Ultegra rear derailleur “with a 6800 Ultegra shifters?” Osman, nice bit of upgrading there. The Ultegra group set is
actually a fantastic bit of kit and great value for money. Now the internal ratchets
of the 6800 shifters are different from the 6700. So there’s a different
amount of lever movement which in turn changes the amount of cable that’s been pulled at the rear derailleur. Unfortunately, you’re not
gonna get spot on gear shifting there so you’re gonna
have to match the levers with the mex in that case because really you want to be going
along with smooth gears because you’re gonna enjoy
your bike riding more. So, make sure it matches. Next up is a question
from Kev O’Meley who asks, “Were the teams concerned
with tubular tyres, “that they would come off
the rims in extreme heat “at the Tour Down Under?” Hi Kev, great question,
I was actually at the Tour Down Under this year
and I had the sunburn to actually prove that too. I spent quite a bit of time actually there with mechanics and none of them mentioned any special procedures
or really any concerns that any tubulars would
come off of the rims. And in fact, it doesn’t
happen that often anymore. Years ago we used to see it sometimes in the mountains back in the 80’s and 70’s you would see the old tubular tyre would come dislodged from a rim probably through a mixture of heavy
braking and also the heat. In recent times though,
there’s a couple for you. 2015 there was a stage of the Tour of Oman I think it was, where they
actually had to cancel a stage because of extreme
temperatures and there was a photo going around of a tubular tyre that actually come away from a rim because of the glue melting. I’m not sure if it was
during use or if it was because the wheel was left out in the sun. Direct sun, obviously, on
something that’s not moving along, yeah, it’s not
gonna take long really for that to get up to temperature. And in 2016, I think it
was, Wilco Kelderman, he actually had a crash
during the Tour de France and that was caused through
melting tubular glue apparently and I think
it was George Bennett who assisted him with his
problem and actually burnt his hand on that hot glue. So there’s one for you. But no, I didn’t actually
hear anything about that. Continental, they actually
make a special glue for carbon wheels so when
you’re braking on carbon rims it generates quite a lot
of heat which in turn could possibly melt glue. They’ve actually got a
special compound of glue which apparently is better at resistant to the heat generated
through heavy braking on carbon rims. So there we are. So Sam wants to know,
“Tape or glue for tubs?” Right, well for those of you
that don’t know there are two methods of attaching a
tubular tyre to a rim. First up, let’s talk about tubular tape. So essentially it’s really
strong double sided tape that is applied first of all to the rim and you apply it with loads up pressure. And a little tip here, I
actually once I’ve applied that tape on, I put the
tubular on, inflate it to it’s maximum pressure,
that in turn forces the tape even more onto
the rim and then basically I go through the whole process of fitting the tubular tyre to the rim. We have actually got a
video in the description down below so you can
check out how to do that. Tubular glue, well the name gives it away. It is a glue and it is specific
as well for tyres and rims. Essentially, there are different methods. Some people don’t like
to apply too many layers of glue onto the rim
whereas others like to apply lots and lots. Take for instance cycle
o cross riders, they will put on quite a lot of glue
because they don’t want that tyre to dislodge from the rim. The reasons being, they’re
using a lot less pressure in the tyres so there’s less pressure being forced onto the rim
from the tyres based tape. So when they go around a corner, they don’t want it to fall off. With tape, it could possibly happen. Now, I’ve used both of them and I’ve never actually had a tub come off of the rim. For cycle o cross though,
I’ve never used tape. There will be people I’m
sure, who have used tape and with great success
and I’m sure they’ll let me know in the comments down below. But ultimately, it’s up to you. If you’re short of time then go for tape. If you wanna do a really
good job, make that tyre extra secure, then go for glue. Next up is another tyre question, feeling all rubbery today. This one’s from Felix
Baquedano who says, “Could you “do a tutorial on how to fit a tube “into a tubeless tyre
in case of emergency.” Well, this one is actually pretty simple. It’s exactly the same
as fitting an inner tube to a normal tyre. The only thing is that
quite often tubeless tyres are a little bit tougher
to actually put over the edge of the rim and put in place. Reason being because
obviously they’re a lot more air tight for their intended use of being a tubeless tyre. One thing to also consider
is once you’ve put it in and inflated it, the tyre
may not sit exactly right. So if that is the case,
just give it a little bit of a flex backwards and
forwards to actually try and get it to pop into position. And yeah, inflate it to
your desired pressure. Personally, I’d probably try and head home because it’s quite
unlikely a lot of the time without a CO2 canister, for instance, that you’re gonna get that tyre back into it’s original place
cause tubeless tyres can be sometimes a little
bit of a pain to fit. Next up is from Tom
Govelitz who asks, “Hi GCN “I just got a set of Mavic
Cosmic Pro SL tubeless wheels “and my question is if you
get a flat, which they did “on the first ride after
hitting a huge pot hole, ” and the sealant does
it’s job, should I replace “the $80 tyre, or did the
sealant make a permanent fix?” Hi Tom, well that’s a pity
isn’t it, on your first ride you had that happen. I once hit a pot hole so hard and deep, I thought I was gonna need
a ladder to get out of it. And do you know what? It wrecked the rim, it dented it and I got puncture so it wasn’t good. The good news is though
your sealant did it’s job. But have a good look as well to make sure the tyre isn’t damaged from the pot hole and also the rim itself
because you may have hit it hard and it might have dented it. Fingers crossed tough for you Tom, you haven’t had that happen. But just give it a good inspection, and the good news is you
didn’t get a puncture. TriRussell and this is
a very regular commenter and also Tweeter for GCN Tech. They ask, “Can non-tubeless
ready rims be run “with a conversion kit and
a tubeless tyre safely?” Basically, in my opinion,
it’s a tough one. It is really, really
tough because you have got that conversion kit and
it is a tubeless tyre but basically I wouldn’t
use it, I don’t think, from my own piece of mind. I’ve never tried it. There will be people who have and I’m sure they’ll let you know TriRussell in the comments down below. But I’m afraid I can’t
answer from firsthand experience if it is safe or not. But, if it’s not designed
for that purpose, personally I wouldn’t go for it. Next up is a question
from Can Vural who asks, “Should the inner bearings
of a BB90 bottom bracket “come out really easily? “They removed the crank
and part of the bottom “bracket was stuck to it. “They put it back in place
but it’s easy to move. “Is it supposed to be like that?” Okay, right, so just to clarify things for everyone at home. The BB90 bottom bracket
is a press fit one. So ideally, you’re actually
gonna need something like this to remove the bearing. So you go from one side
of the bottom bracket through and then hit it out with a hammer. Requires quite a bit of
force so it doesn’t sound ideal really that your
BB90 bearing was able to be removed like that. What’s worth remembering
though is that there is actually a V2 bearing available. What’s that? It’s not .1 millimetres bigger in diameter than the first edition of the bearing. So pop along to your local shop, get them to have a look inside your bottom bracket to see if there is any other reason why that bearing has come out so easily. If not, sounds like
the V2 bearing could be the answer to your problem. Now, Samuel Ljungvist asks
that, “I’m thinking about “buying a power metre,
specifically a stages. “Can you for example,
use an Ultegra crank arm “on a 105 group set or vice versa? “So if they upgrade components later “it would be nice to be able
to use the same power metre.” Great question Sam and actually that’s a really good option to use because traditionally
power metres used to be on the real high end scale of pricing. Yeah, providing if you’re
using the same style of fitting, then it’s
not a problem at all. So you’re probably talking about Shimon Holotech 2 so it uses
the same fitting type. As far as I’m aware, it
doesn’t actually change the cue factor so that’s the distance from if you take a vertical plane through the bottom bracket
shell and the distance on both sides to the centre of the pedal, it doesn’t actually change it as far as I’m aware. So importantly, keeping
you even and being able to let the power out that you can measure. Daniel Brace, “Hello guys,
I have stripped the threads “on the drive side crank
arm, is there a way “of it being salvaged or is it time “for a replacement?” Daniel, a stripped thread. That is an absolute nightmare
in nearly all cases. I think, now you haven’t said
if it’s your pedal thread or if it’s one that you
would use an old school crank puller like this, so that would be in the centre of the crank. You’d screw that in and
then wind this handle in to force the crank off the bottom bracket. But let’s assume it’s your pedal thread. The good news is Daniel,
you can salvage that crank. Essentially what you do is actually remove that thread with a special
tool and then you insert a bush or a heli coil
in there and that’s held in place with glue or
really strong lock tight. I can’t remember, I’ve never
actually done it myself. I have seen it done. It’s kind of a last resort really. So if it’s a very old
crank that you can’t find a replacement for then
that’s certainly an option. Personally I’d be tempted
to have a look around for a second hand replacement. So you can just have a
matching pair and you’re not gonna be using a glued in petal thread. Okay, next up, Ben Moore
who asks, they have one gear which they can’t use
moving from the easiest gear to the next easiest. They have to change gear
twice and it jumps a gear. Is it an indexing issue or something else? All changes are smooth. Right, first thing I
would do is have a look at where you’re inner cable
goes into the outer cable so then by the derailleur most likely, and check to make sure
that the cable there is not kinked at all because if there is that could be adding a little bit of extra resistance to pull that
cable in to the outer cable. Another thing to check is that your cables are working nice and
smooth so that they’re nicely lubricated. Also, check that the cable is clamped in the correct position on the derailleur. I have seen people do it wrong before, leading to mis-shifts. This one is gonna sound a little bit daft but have a look at your
cassette and where the gears are not working right, make sure that the sprocket is actually fitted in the right direction so the profiling or shifting ramps actually match the other sprockets there. That, well, is probably quite enough to be getting on with but finally check the rear derailleur hanger. So make sure that it is nice and straight because quite often that
can actually plague people with bad gear shifting. Let me know how you get on. Ali Yazdi wants to
know, “Can car gear lube “be used as a chain lube?” They’ve seen motorcyclists
use it on their chain. Well Ali, you could but car lube is pretty thick generally so it’s not gonna be ideal for the job
where as a bike specific lubricant is nice and
thin so when you apply it very carefully I must say
as well, it can actually get into those rollers
and pins and work better. A disadvantage really
of that car gear lube is it’s gonna be thick and so thick that it’s just gonna attract dirt and not work its way into the rollers. Yet, people have used it in the past but personally I wouldn’t recommend it. I’m quite meticulous about lubing chains and I reckon our viewers are too and they will let you
know why not to use it or maybe why to use it in
the comments down below. Final question this week
is from Yura Tolstik who says, “Can I use Shimano fishing hooks “to pin a race number?” Of those of you that don’t know, Shimano do actually make
fishing equipment too. I guess you could but you may get reeled in quicker if you
try a salt breakaway. There we are, made me laugh anyway. Now do remember as well to let me know your tech questions down there in the comments below and I’ll try and answer them here
on the CGN Tech Clinic. Remember as well to like
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helps and also check out the GCN shop, loads of goodies. Now, for a video on essential tools for your home workshop,
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