Best lightweight inner-tube (presta) for 700x25 tyre?

[thatsnotmyname]

That would equate to a weight saving of 65g per wheel, and 130 gram of revolving weight saved will be noticed on a brisk hilly ride.

Rotating weight is one of the least relevant weight savings, unfortunately. According to Newton's laws of conservation of momentum, anyway..

Either way, 130grams equates to emptying just over one fifth of your 500ml water bottle. Don't tell me you can notice that...

[Debs]

…..New tyres are Conti GP4000 700x25

Wheels are Bontrager Paradigm Comp (tubeless ready) rim brake.

Some tubes of a given weight are that weight because they are thin walled, others because they are narrow and they have to stretch to fit inside the tyre. [Since working hysteresis (for small deflections) varies in different rubber compounds, and varies in the same compound depending how strained it is, this means changes (in a way that I don't fully understand) in the Crr depending on what tube is chosen and how it fits.]

I would only make the decision when I'd seen just how tight the blessed things are on the rims; GP4000 are often a pretty tight fit and so are many tubeless ready rims; it could be a 'bad combination'. If the tyres are very tight this

a) may influence your choice of tube; a narrow tube, that stretches to fit, is most likely to puncture in the first place (and when it does the air may come out faster) but is less likely to pinch during installation.
b) you may conclude that changing a tube by the roadside, with that rim/tyre combination, is going to be a major PITA, or even basically impractical, and (from the POV of punctures on casual rides) you arguably might be (and I can't believe I'm saying this) better off with tubeless, relying on the sealant to deal with small punctures and the 'phone home' approach for bigger ones. [but are the tyres in fact tubeless-compatible...?]
c) if you decide to run tubes and yet don't fancy dealing with a roadside puncture, there are other options such as carrying a small canister of aerosol sealant which might get you out of the poop without a massive struggle.

FWIW I have usually been at pains to be sure that when I'm running lightweight tyres the fit of the tyre on the rim is not too tight, so that punctures don't become a nightmare to deal with. Thus for a long time I was very happy with Mavic Open Pro (now open pro C) rims, thin rim tapes, and some types of Michelin tyres, which I knew to be an easy fit, such that tyre levers were not required in many cases. Conti GP4000 (and its successor GP5000) is a nice tyre in many respects but it is a sufficiently tight fit on most rims that I'd probably avoid it if I didn't want a wrestling match with the tyre every time I punctured. IIRC with GP4000 I need tyre levers even on the easiest rims and with (non tubeless) rims that are a bit tight it soon gets into the 'no thank you' range. Tubeless-compatible rims are often tighter than that, well into the 'sore thumbs when fitting, risk of tube/tyre damage during fitting/removal' zone (along with 'are my tyre levers going to break?').

NB one of the issues with tubeless-compatible rims is the lip on the inside which retains the tyre. You need this to be there so that a tubeless tyre doesn't unseat when it goes flat (which it often will do if it isn't pumped up every week). If the tyre fit is tight enough, folk (even with normal hand strength) can find it very difficult to push the bead past this lip and unseat the tyre.

So bottom line; I'd assess the tyre fit (from your POV, with your priorities in mind) with any old tube and then decide what best to do.

cheers

Thanks for your thoughts, Brucey

My priority in this is the reduction of revolving weight, hopefully without sacrificing reliability.

I really don't want to entertain the fitting of tubeless tyres to these wheels, TL tyres tend to be heavier, the fluid is extra weight, so it would probably end up heavier than an inner tubed tyre. Would be faff and expensive to do too, also their are stories around of people struggling to get tubeless tyres onto Bontrager's TLR rims, and even giving up trying!

I hear what you say about TLR rims preventing easy fitment of some tyres [ to include GP4000 S II ], what i could consider is another pair of Bontrager R3 tyres that are fairly easy to get on and off, plus are a very good tyre all things considered. Although that still leaves me with the choice fo a good lightweight inner-tube...

[Debs]

That would equate to a weight saving of 65g per wheel, and 130 gram of revolving weight saved will be noticed on a brisk hilly ride.

Rotating weight is one of the least relevant weight savings, unfortunately. According to Newton's laws of conservation of momentum, anyway..

Either way, 130grams equates to emptying just over one fifth of your 500ml water bottle. Don't tell me you can notice that...

This is only your opinion, which is very wrong!

[thatsnotmyname]

That would equate to a weight saving of 65g per wheel, and 130 gram of revolving weight saved will be noticed on a brisk hilly ride.

Rotating weight is one of the least relevant weight savings, unfortunately. According to Newton's laws of conservation of momentum, anyway..

Either way, 130grams equates to emptying just over one fifth of your 500ml water bottle. Don't tell me you can notice that...

This is only your opinion, which is very wrong!

Not sure if you're joking or not (sorry if I missed it), but it's not my opinion. It's one of the laws of physics.

[Debs]

Rotating weight is one of the least relevant weight savings, unfortunately. According to Newton's laws of conservation of momentum, anyway..

Either way, 130grams equates to emptying just over one fifth of your 500ml water bottle. Don't tell me you can notice that...

This is only your opinion, which is very wrong!

Not sure if you're joking or not (sorry if I missed it), but it's not my opinion. It's one of the laws of physics.

You obviously don't have any experience in the matter.
Please don't concern yourself anymore in this thread.

[pwa]

For what it is worth, on hilly rides I have found that I make easier progress with light wheels /tyres/tubes. On flatter terrain momentum might be more of an advantage. So I'm all for avoiding excess weight on the outer part of the wheel.

[thatsnotmyname]

This is only your opinion, which is very wrong!

Not sure if you're joking or not (sorry if I missed it), but it's not my opinion. It's one of the laws of physics.

You obviously don't have any experience in the matter.
Please don't concern yourself anymore in this thread.

right

[thatsnotmyname]

For what it is worth, on hilly rides I have found that I make easier progress with light wheels /tyres/tubes. On flatter terrain momentum might be more of an advantage. So I'm all for avoiding excess weight on the outer part of the wheel.

Less overall weight is good. The point specifically about 'rotating weight' is that it cancels itself out to the point where there is no particular advantage to it when climbing, for instance.

[pwa]

For what it is worth, on hilly rides I have found that I make easier progress with light wheels /tyres/tubes. On flatter terrain momentum might be more of an advantage. So I'm all for avoiding excess weight on the outer part of the wheel.

Less overall weight is good. The point specifically about 'rotating weight' is that it cancels itself out to the point where there is no particular advantage to it when climbing, for instance.

I have heard the arguments over the years, going back to Moser's hour record and no doubt beyond, but I have found on long tiring hilly rides that I am familiar with that light rims, tyres and tubes leave me less tired after 90 miles or so of constant gradient change. I guess that what tires me could be the constant mini-acceleration with every push on a pedal as I climb, made harder by extra mass on the outer wheel. But I set against that the disadvantages that come from trying to get the weight too low, such as having very narrow tyres that don't ride over coarse road surfaces too well.

[Brucey]

one of the reasons why lighter wheels and tyres feel nicer to ride on is because wheels -especially wheels with fairly skinny tyres, attached to bikes with springy forks- effectively end up being part of the unsprung weight of the bike. If all the suspension is in the tyres and/or the road/track surface is perfectly smooth, wheel weight makes much less difference. Were it not for the non-linear variation in aero drag with speed, you would gain back on the descents what you lose on the climbs; as it is you do lose out by hauling extra weight up hill and down dale.

I guess the optimum solution is dependant on how tight the GP4000 tyres are, and how exactly you feel about that.

cheers

[boblo]

Who'd a thunk it? For years we've been chasing the holy grail of least rotational weight as we've been led to believe it has the biggest effect overall... I chase low (least) weight all over my light bikes be it me, the frame, the components or wheelsets.

Marginal gains maybe but gains nonetheless.

[Samuel D]

Marginal gains are fine, and no-one has to account for their choices to the likes of me. However, the gains from the lower rolling resistance of lighter tubes and tyres are enormously greater than the gains from their lighter weight – even while climbing.

Lower rotating mass remains an idée fixe in cycling, but the usual justification doesn’t bear scrutiny. The lighter wheel accelerates faster on the power stroke only to the extent the heavier one decelerates slower in the dead spot. The outcome is the same except the lighter one is trivially easier to carry up a hill. Cutting equal weight from your toolkit or paunch makes the same difference by stopwatch: not much.

[jessand]

Assuming you're using 25mm tyres as standard, race 28 18-25 tubes weigh 105g - according to Continental. You may have weighed them and know different. I always thought it was worth the extra 20g or so over the lighter tubes for extra durability when I used to buy them.

[Debs]

Assuming you're using 25mm tyres as standard, race 28 18-25 tubes weigh 105g - according to Continental. You may have weighed them and know different. I always thought it was worth the extra 20g or so over the lighter tubes for extra durability when I used to buy them.

According to Wiggle the 60mm Presta Race 28 / 20-25 is 85 gram (?)

The one i weighed in at a whopping 145 gram is a 60mm Presta valve length / Race 28 / 25-32

So i guess if one uses a tyre size of 700x25 and wants a lighter inner-tube it would be better to avoid the larger 25-32 size

<>

Hang on, stop press, just noticed the one i have is Race 28 (700c) Wide

There is another type that is Race 28 (700c) Light *

Why do i come over all dyslexic when reading the writing on Conti tube boxes?


* Should have put this 'Light' version in the poll

[pwa]

As someone who doesn't use deep section rims I try to avoid the unnecessary extra weight of long valves. Yet another detail to look out for.