When Should You Replace A Road Bike Tyre? | The GCN Tech Clinic
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When Should You Replace A Road Bike Tyre? | The GCN Tech Clinic

October 22, 2019


– So this week is a very special edition of the GCN Tech Clinic
because, what can I say, I’m on location here at the Dubai Tour. Now I don’t have my toolkit with me, so I can go too in-depth, but I still reckon I can
tackle your questions. Let’s see. (ambient music) First up this week is
a question from Sophie, who’s got a braking problem. Yep, nobody likes braking problems because, well, they help you stop. So, the problem is that
they’re pulling the lever, and despite re-greasing the
cable, replacing the cable, it’s still not working well. So the first thing I
would check is make sure, if you’ve ferrules on the
end of your outer cable, is make sure they’re fully
pressed all the way on. But also, importantly, is that
the end of the outer cable, before you put the ferrule on, is to actually make sure it’s
a very clean cut, very flat, then put that ferrule
on fully, all the way. That way, you’re not gonna
get any slight movement of the ferrule on the
end of the brake cable. So making sure there’s no gap on the end, and you’re not braking,
effectively, in the air, if that makes any sense. So make sure of that. Another thing to also
check is to make sure that the callipers and
levers actually match up. So Shimano and Shimano, SRAM and SRAM, Campagnolo and Campagnolo. Reason being, they actually have a different lever pull ratio to the brake. So that’s really important to remember. Right, now next question is from Mark, who wants to know when to replace a tyre. Mm, well, like you say,
obviously if there’s any nicks or cuts in the tyre, then sometimes it’s time for a new tyre. Then other times, you can actually just fill those holes in with super glue, just to actually try and
prolong the life of the tyre. Now as for indicators,
to let you know when to replace the tyre, actually Continental, who do supply us with tyres here at GCN, they have two little indicator
holes on top of the tyre. Now, they’re not obviously
holes all the way through. Those holes, they go just a couple of mil beneath the surface of the rubber. And essentially, once you
can’t see those holes anymore, you know it’s time to replace the tyre. So that’s one brand in particular who are doing something about that. Another thing to keep an eye on, make sure the tyre still has a rounded profile across the top. Once it goes flat, basically,
the tire’s not gonna do its job properly when you’re
going around a corner. So just keep an eye on those things, and you’ll be good to go. Next up is lonewolf, even
giving me a name check. Thank you very much. Problem with a rim flexing
against the brake pads when they get out of the saddle
for the first few strokes. Now if your wheel is in straight, actually check the spoke tension because there could be some flex in there that when you’re putting a bit of weight through the front end of the bike, that rim is just moving over
and touching the brake pads. Also, maybe you’ve just
got your brakes set very, very close to the rim. So naturally, you’re gonna
get that bit of movement. Okay, so Stuart wants to know,
how long do gear cables last? It’s a great question because
I honestly don’t know. But do take care of them, so
when you’re washing the bike, make sure you don’t use
any harsh degreasers that are gonna get in there and wash out any grease from the cables. Obviously, use as well,
once you’re finished washing the bike, a good
water-displacing spray, so that you’re removing any
of the water from inside, and then preventing any rust of the inner and also the inside of
the outer cable too. Keep a good eye as well to
make sure that the cables aren’t frayed where they’re
clamped into the derailleurs. Obviously, on this bike here,
I’ve got electronic gears, so I can’t show you that exactly. But also inspect the outer cable too. So where there’s any sharp bends or where the ends are a
ferrule, make sure that there, the outer cable casing
is not cracking at all. But who knows? They could last up to two or three years, I guess, maybe longer, maybe less. It all depends on the riding conditions. Right, Christian wants to
know, does vinegar help grip on tyres or reduce
the chance of punctures? That is a brilliant question,
’cause you know what? I actually know the answer
to this, or kind of. Firstly, I’m gonna let you know, it’s not the vinegar that you
put on your fish and chips. It’s actually white vinegar,
and I’ve seen this done by the Great Britain mechanics
inside of a velodrome. They actually did it using
a Dugast tubular tyre, and that was one of the pink
ones, which from memory, it’s quite a while ago now,
is a latex-treaded tyre. So essentially, they
got that white vinegar, coated a sponge in it,
then went around the tyre, and then the riders went out and rode. Did it improve the grip? I don’t know, but there
must be some logic behind it because they were brand new tyres. And sometimes brand new tyres on a velodrome are quite slippy. Whether or not they reduce
the chance of punctures, can’t tell you, I’m afraid, because inside of
velodrome, it’s pretty rare we actually see anyone get a puncture. But try it, and let me
know how you get on. Next up is this question from Hitesh, who wants to know, how often should you replace a bike helmet,
and does foam degrade? This is a great question, actually, because I used to work for a
helmet brand and manufacturer, so I’ve got a little
bit of inside knowledge. However, most helmet brands,
in fact, none of them give a definite answer
when you should replace it. Obviously, the outer shell,
so that polycarbonate shell, can get damaged by UV rays, especially if you’re somewhere like this in Dubai. Obviously, in the UK, we
don’t get that much sun. We get a little bit. But, yeah, it can degrade the foam and the polycarbonate shell, But what’s also important to remember, if you do drop your helmet,
even from a very small height or very gently, it can
still damage that helmet, and essentially render it
useless because you may well have some tiny, little hairline
cracks in amongst the foam. But basically, the
helmet has done its job, even if you weren’t
wearing it at the time. (man whistles)
(upbeat music) (moves into tense music) – No! – Also, take care and try
and keep the helmet clean. I actually give mine a good
old scrub in the shower. I use some shower gel
just to clean it off, and I don’t use any harsh chemicals at all because you don’t know what
that’s gonna do with the foam. It may well react to it. Also, remember those pads too. Take them out, and give ’em a good clean with some shower gel. Rinse ’em out thoroughly
because afterward, if you start sweating,
you don’t want some soap to come down into your eyes. Final question this week is from Dan, who is thinking about
changing to tubeless tyres. But what are the pros and cons? Well, let’s tackle the pros, first of all. Obviously, there’s gonna
be less rolling resistance ’cause you’re removing the inner tube, and then, essentially,
you’re reducing that friction in between a tube and a tyre. Although it’s not a lot,
there is still some there. Also, you’re gonna do
away with a high-risk of pinch punctures because there’s no tube in there to pinch. You can also run the tyres
at a lower pressure too, which is quite a trendy thing or even scientifically proven
to be a little bit faster. And finally, one of my
favourite pros about it, is that you can put some sealant in there, when you’ve set them
up, and essentially, if you get a bit of thorn
or glass in the tyre, once that’s out, the sealant does its job and seals that hole, so
you can continue riding, which, for someone who
doesn’t like to stop at the side of road
and change inner tubes, that is pretty important. Now the only cons really for me is actually the tyre choice
and the tyre availability. At the moment, there’s not
a huge range out there, so if you’re particularly fussy about your tyres and treads and brands, then maybe it’s not the thing for you. But I’m sure that as we
see tubeless tyres continue to develop and evolve,
we’ll see more brands manufacturing and releasing
different types of tyres. Right, I hope you’ve enjoyed that, and I’ve helped fix your bicycles. Remember as well to
leave your tech problems for me down there in the comments. I love reading them, and most importantly, I love getting you back out on your bike. There’s no excuse because
Jonny Tech is here. Now, remember to like and share this video with your friends, and
for another great video of why the pros choose their
stem length, click here.

Only registered users can comment.

  1. Regarding the replacement of gear cables: This mostly depends on the particular shifting system. Some systems like Shimano Alivio 3×8 and Campagnolo Veloce 3×9 may not require any gear cable replacement at all (unless damaged in a crash or gunked up beyond ugly). On the other hand many riders made the experience that the rear shifter cable of a Shimano Ultegra 6800 groupset will snap inside the shifter regardless of the cable model used after 5000 – 10000 km. The reason lies in a very tight bend inside the shifter, high cable tension required by the system and increased friction due to (badly designed) internal cable routing inside the frame.

  2. Jon, I live in Iowa and ride me bike to class year round. During the winter it is below 0F/-18C (the other day was -12F/-25C) nearly every morning. Is my helmet less protective at that temperature?

  3. #gcntech I just recently switched to tubeless tires, another pro is that if the sealant failed, you can always put a tube in there. But I see that now I have to inflate my tires more often… Is this common or maybe there's a tiny leak (1/ week vs 1/2 weeks with clinchers, and obviously always before an important ride, like races…)

  4. #gcntech I want to upgrade to a pair of Zipp 404 Carbon wheels for my road bike but I dont know wether I should get clinchers or tubulares. Clinchers are easy to fix if you get a flat, but the people in my team and group/club ride use tubulares with tubeless sealant and never get flats, what should I do??

  5. Question for #gcntech – if buying a cross/gravel bike would you choose a different size/geometry to your road bike? Is a smaller frame going to be more maneuverable off-road? And what about reach/stem? How is handling going to be affected? Thanks!

  6. If you let your shift cables go too long without replacing, the cable can break off inside your right STI shifter (because you use it 10 times more often). If this happens, it may be very hard to extract, AND you may get small pieces of wire stuck inside your shifter……Change the right one every year or two. (No more than 10,000 miles)

  7. be careful with Vinegar, its an acid, and there were fatal cases eg. a men poured it on its shirt by accident in some shop warehouse, then hours later even doctors couldn't help him..

  8. #gcntech Can you tell balancing wheels (especially carbon without joint for balance to nipple), is it really problem? what doing tech in pro teams with that issue? Thanks!

  9. Regarding helmet lifetime: there was a study not so long ago showing, as far as I remember, that damn old helmets are as good as brand new ones, as long as not damaged through a crash. At least there is no reason to buy a new one after 3-5 years. Now I just need to find the reference…

  10. The vinegar burns aways the lacker that comes when they take it out the mould, just helps with grip for the first few of laps

  11. Fresh tires ( bike or car ) tend to be greasy. To avoid slipping during a first ride in wet conditions you need to degrease them. Vinegar does the job better than dishsoap which leaves a slippery film.

  12. Jon, I have a bit of rough/slow returning rear brake feel on an emonda SLR with Dura-Ace 9000(internal cable routing). Any tips to smooth it out. I haven't yet torn it apart, but am thinking that perhaps the cable housing end isn't cut clean or the end opened up. I find it hard to believe that Trek designed it this way.

  13. Hi Jon, I've had my road bike for about a year now but the thumb shifter on the hood for the front rings is really stiff, especially when shifting from big to little ring. Is there anything I can do about this?

  14. Good job Jon, you are getting more and more confident at this presenting thing. 👍 Also, would love some ideas for cleaning a bike in a little flat, where I cannot possibly take it outside, so I have to solve it with less mess. (At the moment it sits on a trainer, an old towel under it, and try to use as little water as I can. Maybe someone has a better solution for this. 🚲🚿)

  15. Regarding the use of white vinegar it's so that when you have new tyres, you can remove the moulding agent (which is not that grippy) from the rubber. Ideal at velodromes or if you have to put on new tyres and start in wet weather.

  16. How about winter beater bike care? Here in Ottawa, winter means riding through snow, slush, and salt spray for months on end. Not to mention extreme cold thrown in. It is torture on bicycles!!

    I buy a used bike in the fall and it’s a rusty mess by spring.

  17. Hey Jonny tech, I'm getting tubular tires soon and does it matter which width size I go with. I am going to be doing crit and mostly flat roads with many hill climbs. Which size would suit me. Thanks

  18. If youre going for a new wheelset make them a tubeless compatible one. You can still run them with clinchers and tubes, but you also have the option of tubeless. Like Jon says, the industry is still evolving around tubelessness but this way youre future-proofing your bike.

  19. The newer Shimano shift levers have a very acute bend inside the lever for the rear derailleur. It will fray and eventually brake at that bend. I had one fail on the road just short of 2 years old. It’s probably a good idea to change cables once a year. Jag wire has a nice complete cable set at around $50 which includes brake and gear cable including housing. Make sure you have the proper cable cutting tool before taking on this job. If brakes are hanging up or shifting is poor, check the inner cable. They can have barely perceptible kinks that will hang up inside the housing

  20. Hi there,
    I have a problem with my rear brake. It is shifted to the right, so that on the left side it always touches the wheel and on the right side it has too much space between the braking pad and the wheel. How can I adjust this?
    Thanks in advance:)

  21. I've often wondered about the cable replacement issue. I built up a custom bike to my spec when I was a teen. Working in a bike shop, my boss gave me great deals or just gave me some very good parts for the project. The drive train and brakes were particularly high end. It has been 35 years and astonishingly those cables are still doing splendidly. All that I've done is replace the outer cable guide just for fashion sake. The brakes were from Suntour, their Superbe line, the cables were very finely braided that flexed so nicely. Maybe I just took care of them very well. The drive train also was Suntour and came with similarly excellent cables and again still are original. The spare Suntour cables are still in their original packaging awaiting the day they may be needed.

  22. I disagree with the dropped helmet tip. If there's nothing in the helmet then the foam won't be doing it's job because it's not being compressed by the weight of your head. It's the compression of the foam that saves your brain from further injury.

  23. I had a similar problem with the brake cable, my problem was I was using Shimano cables in a Jagwire housing. The Jagwire cable is actually thinner than the Shimano and the housing was rubbing on the cable, not letting it release.

  24. If your caliper brakes still feel spongy after going through all of Jon's recommendations consider the brake calipers themselves; Sometimes the spring recoil can be gooey or have just lost the spring in their step. Consider new calipers. GCN Tech Clinic, awesome.

  25. On brand new tires the white vinegar was most likely to remove any residual mold release or other manufacturing residue from the tire.

  26. Hi there, I would like to ask if it’s wise to set up a road bike setup (with dropbar) on a TT Frame or should I just stick to a road specific frame as im trying to make my bike as aero as possible. #torqueback

  27. So Jon, Tour Down Under, Tour of Dubai, are you just lucky enough to escape the winter weather in the UK or did the others just want you out of the office for a while?

    Nice vid, thanks for your insight.

  28. Have you heard anything about sunscreen damaging the helmet? A youtuber in Australia who has the hairless look finds the sunscreen eats away at the padding?
    Comments?

  29. I think you might have glossed over some of the cons running a tubeless system (tolerances & fit, and that you still need to carry spares). Else loving this series 👍

  30. On the tyres, tubulars you take some sandpaper or vinegar and clean the surface of the rim tape to get that glossy sealant off that they spray on the tyres! Thats what gives them that shiny look! I just do it around the (rimstrip) area that I'm gluing tyre up with! For the track I definitely could see why you would do that!

  31. Pretty certain the vinagre is used to remove mold wax from the manufacturing process which is what improves the grip without compromising he rubber properties

  32. Coming back on when to replace a helmet: I've had a crash, but I've never thought about it of replacing my helmet. When I checked it properly, I saw a couple of coves (3-4 mm deep) and a deep and large one (at least 7 mm deep). Do I need to replace my helmet on this occasion?

  33. Last time i had a problem with my braking ( with no visable reason) i replaced the cables and hey presto. ( cable was kinked inside my top tube )

  34. Hi Jon, I have a question. I ride a lot on Zwift and I sweat a lot-A LOT. I am always worried about sweat eroding the carbon frame or handle bar. While I always remember to wipe off the sweat after a ride, how often should I take my bike for an actual wash assuming that I ride everyday for at least 1 hour per day.

  35. You failed to mention an important detail regarding brake compatibility: Shimano have changed their brake cable pull ratio at least twice during the last 15 years or so: both the amount of cable pulled, and how the cable is pulled throughout the throw of the lever (from regressive to progressive pull).

  36. So if I am not changing to tubeless tires, what about just using a tube sealant? I commute in the Canadian winter and don't want to be stranded in the -20c storm. Does the sealant plug up the valve stem when you go to add air?

  37. Is there anything Jon doesn’t know?… “What was Fausto Coppi’s preferred chain lube?” Jon: “Funny enough, when I worked as Coppi’s mechanic in 1947…”

  38. vinegar on track tyres is just to clean the tyre so you're not contaminating the track, it also helps with grip to a certain extent by not having oil etc on the tyre on the potentially very slippery surface of the velodrome. On the road its just not relevant

  39. the gear cables on my mtb where 16 years old when I had to replace them because the coating on them had turned to dust , I use un coated cables now so I might never have to replace them again

  40. I’ve got a cuestion. I have a pair of bontrager aeolus 3 and the back wheel seems to be a bit unbalanced. I don’t feel it on the road, only when i lift the bike and spin it manually. I’ve noticed that the anbalance is on the valve side and located the sensor magnet in the opposite side but the “problem” remains. Is this a normal thing?
    PS best channel ever!

  41. The reason why they vinegar new tyres on a velodrome is to remove any potential release agent on the rubber from when the tyre was made. You will usually find track riders will sand their tyres and vinegar them. If you dont, you will fall off hen you go on the bank. The other trick rider will do is ride 4/5 laps of the cote, as this helps scrub the tyre in.

  42. hi Jon, do you recommend putting grease before locking the cassette? I noticed that some videos have them but never saw mechanics in different bike shops put grease in the hubs before locking the cassette. #askgcn

  43. I think the vinegar was to clean the new tyre as they often have a bit of release agent on them from the moulding process as it is slippery stuff.

  44. I’ve used tubeless tires for over three years now and discovered that I had punctures I didn’t realize had happened when I replaced a worn out tire. Now that most international brands have tubeless selections, the only significant downside is when you get a large cut and you have to perform the dollar bill and tube fix at the side of the road. Bead tolerances on tubeless tires are so tight that it can be a pain to get the tire off and then back on the rim.

  45. Bike maintenance tip; never, ever spray your bicycle with water, yeegads! Why is that still a thing? Just wipe it down and oil the parts that need oil.

  46. Regarding tubeless (latex) tires.

    My experience isnt that good. I loose around 1.5 bar of presure before the gap is closed so i drop from 7 bar to 5.5 wich increases the risk of pinchpunctures instead of removing them. You can always bringe your tire up to 7 bar again at wich point the latex doesnt hold te gap any more but Just blows out

    Also when u get a nasty ripp or slash in your tire you will be cleaning latex offerte your bikes for about an hour

    So if your a bigger person there is a chance that when u get a flat tire ure ride will be over instead of replacing an inner.

    Im back on inners. Latex works great on mtb though

  47. By using vinegar you remove a bit of the rubbers oil therefor making the tire less sticky. This lowers rolling resistance by an unmeasurable amount. But iT is still usefull because on the Road your tires pick up less debris so less chance of flats.

  48. Tubeless tires, to me, are not worth the trouble. Most of the advantage of a tubeless tire can be matched with a light tube (latex or very light butyl) and by powdering the tire and tube with either talc or cornstarch. You don't have to worry about the sealant drying out or incurring the extra cost of buying sealant. In a blindfold test, I doubt that the vast majority of riders would be able to tell the difference between a tubed and a tubeless tire.

  49. Fill gaps in tires with liquid rubber like Shoe Goo. Much better than super glue. It can be even be used to cover sidewalls and the tire casing from super worn tread.

  50. The super glue on tires trick truly works to fix nicks and such, mine has a lot of it on there and it just keeps going (for now, anyway).

  51. I was quite surprised seeing my sisters helmet after she had a close look at a Ford Transit windscreen at 60 km/h. The helmet started to shrink. right after the collison it was normal size and only had a few scuff marks, but after 2 days i'd estimate it had shrunk 10%. The plastic outer lining was way too big for the foam.

  52. Is it possible to use tubless tires on standard rims, I saw someone use plumbers tape. I don't know if he was successful.

  53. Lol y'all have brake problems when I got 55 mph with a engine and my brakes are dollar store flip flops on the ground 😂😂😂

  54. Be very conservative judging front tire wear and damage. The front tire is how you steer, stay up on two wheels and takes much of the load under braking. ANYTHING connected to the fork CAN BECOME A SAFETY ISSUE!!
    Dont overinflate tires. Propely inflated tires are FREE PERFORMANCE!Most roadies overinflate. It makes no sense unless youre riding the track or exceedingly smooth roads. I weigh 170 and never pump tires over 70 psi on smooth roads(32c road tires)
    80-90psi for skinny tires max unless you weigh more than 220lbs or carry loads. Softer, more voluminous tires roll just as well, its been proven in real world tests. Softer tires grip better in braking and cornering. Softer tires wear longer and suffer less flats. Last , but most important, (to me)softer tires are more comfortable letting you ride longer and be fresher at the end of a long ride. Hard tires ‘feel’ faster, but its an illusion. Your body needs to absorb all those extra impacts and theres added stress in keeping the bike on track. Try to ride smoother, unweight the bike over obstacles and pick good lines.
    DONT Rotate tires on a bicycle. This isnt a car!!Rear tires wear out almost twice as fast as front tires. Remember! Front tires are a safety issue!Replace tires as they wear out or are damaged. They WILL NOT last any longer rotating. Its not worth taking safety risks to save a small amount of money in any case.

  55. the foam rubber on the inside of bike helmets degrades over time. I just had to replace an old Specialized helmet after virtually all of the foam padding crumbled and fell apart. If you recall the scene from The Andromeda Strain where the rubber hose on the pilot's helmet turned into what looked like sand, you'll know what I mean.

  56. Hey John, how about cuts and tears in your tires?? Show us some of those and chips off the tire? Also is there Teflon tape to put on the tire?

  57. Ahh, that's what the dimples are on my Conti tyres. Thanks Jon, didn't know it was a tread indicator.

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