Resistance vs Mass

CramCycle

I was reading up on a set of tyres, specifically the new GP5000, both clincher and tubeless versions.

There are alot of ways to get them close to each other but the undeniable fact is that the weights are different and I am trying to see what the lower rolling resistance offers, and is this justified by the increased weight or are they both similar out in the real world.

Model Grand Prix 4000S II Grand Prix 4000S II Latex Tube Grand Prix 5000 Grand Prix 5000 latex tube Grand Prix 5000 tubolito tube Grand Prix 5000 TL
Specified Weight (g) 225 grams 225 grams 215 grams 215 grams 215 grams 300 grams
Weight of tyre/sealant (g) 100 75.00 100 75 40 30
Total weight (g) 325 300.00 315 290 255 330
Rolling Resistance 100 psi (Watts) 12.2 11.10 10.7 9.737 9.737 8.9


So most of the numbers are taken from bicyclerollingresistance.com. I have estimated the latex tube effect for the Gp5000 from the percentage reduction in the GP4000S range.

Its been awhile sine I done the maths on rotational weight (probably 20years nearly), so there is increased resistance for the Tubolito tubes, but they are looking like they are 75g lighter, and that is with being very conservative with the sealant. Admittedly Continental claim you can run them sans sealant which would make the saving only 45g and the assumption has to be the increased weight is due to increased puncture protection and stronger side walls, thicker rubber etc. etc.

In the real world, for someone like me, I doubt there is any discernible difference and my choice would have to be on convenience, but my question for those who may know better is this. All else being equal, in a race/TT/commute home, with equal effort put in, which is going to be the fastest of the last two or which is going to be more beneficial, a reduction in rolling resistance of 0.837Watts vs a decrease in weight of 75g rotational mass.

or do they balance each other out and their is no difference?

magicbastarder

i may be wrong on this, but the mass should just affect acceleration, yeah?
once you're up to speed, it should be resistance you're fighting, not mass?

JimmiesRustled

The answer is not one you'll be thankful of but as with everything in cycling, it depends.

The same discussion is had, albeit in a slightly different guise, when talking about wheels. Aero vs lightweight. It's the same principle. Lower rolling resistance in this case is the aero equivalent in tube talk/tyre talk.

There's still a question out there about rolling resistance and the trade off between lower rolling resistance and lower grip. It would make sense that the lower rolling resistance the lower the grip of the tyre but that's not really what you asked.

CramCycle

magicbastarder wrote: »

i may be wrong on this, but the mass should just affect acceleration, yeah?
once you're up to speed, it should be resistance you're fighting, not mass?

I suppose bar a solid TT track solo effort, your always accelerating up and down with bumps in the road etc but your not doing it from a standing start each time so maybe it is not that big a deal

CramCycle

JimmiesRustled wrote: »

The same discussion is had, albeit in a slightly different guise, when talking about wheels. Aero vs lightweight. It's the same principle. Lower rolling resistance in this case is the aero equivalent in tube talk/tyre talk.

Makes sense, hence why you want light weight wheels for hill climbs but aero ones for anything close to a relatively flat TT

CramCycle

Another follow on Q is about as you, where it was long thought higher tpi equals lower rolling resistance. The numbers above imply the opposite with regular being 110tpi vs 60tpi on the tubeless.

I suspect that the tests are biased and don't account for real world variability on the road. Would love any insight.

ED E

The tests are bench tests and really have limited application to real riding.

Either 5000 is nice, wouldn't worry about the miniscule difference between.

CramCycle

ED E wrote: »

The tests are bench tests and really have limited application to real riding.

Either 5000 is nice, wouldn't worry about the miniscule difference between.

Probably going to go with the regular ones once my stock are run through for racing and either go with Tubolito or Latex tubes.

The idea of faffing about and having to remember to refill sealant isn't worth the hassle for the amount of road time they are going to see.

Lumen

IIRC the most credible bicycle tyre tests are from the German TOUR magazine.

I doubt they've done the 5000 yet as it's such a new tyre.

CramCycle

So I got the 5000 and tubolito tubes. And here is my incredibly biased but as best as I can manage, fair review after two days.
First of all the GP5000. They feel weird to the touch, probably unfairly, just different to the GP4000S II I am used too. The big difference is the width. The former 25c were way wider than these on my wheels, to the point that these look like the GP4000S 23c in regards width. So that means continue.may have corrected their size descrepancies, or I just got an off batch. Road feel and rolling resistance, I couldn't tell the difference, certainly were not slower but also were not faster. Easy to pop on until the end and took a bit more force to get the last bit over the rim than the GP4000.
Secondly, tubolito tubes. Very weird. They come rolled up so small, at least half if not a third the size of normal tubes. As such, noticeably lighter. They feel like some weird throwaway plastic wrapping. A little more messing putting on, you have to orientate and pre inflate the right way but nothing major. Remember to take off the black ring that is to hold out water. One is now on the inside of my tyres as I simply never noticed. They definitely feel different to butyl tubes , even sound different on the road IMO but they don't make the ride quality worse or better, and in this regard, if your aiming to shave off weight, they are a pretty sound investment.
Overall, my opinion, GP5000 need more time to test but unlike the GP4000, I won't be making them commuter tyres for the moment. I do not like that they have changed to GP flag to a German flag, I think I would be faster with a fiNish line flag. As for the tubolito, I really like, too expensive for commuting but they will be my race choice over regular tubes.

Alek

So that means continue.may have corrected their size descrepancies, or I just got an off batch.

The GP5000 version comparison confirms your findings re: sizing. A pity, I was hoping for the 32mm version to be 35mm, while its just as wide as the 28mm version of 4k

lennymc

did anyone else be reminded of growing up, with your ma trying to get you to go to mass, but you offering ressitance, or was it just me.

this post is completely useless.

CramCycle

lennymc wrote: »

did anyone else be reminded of growing up, with your ma trying to get you to go to mass, but you offering ressitance, or was it just me.

this post is completely useless.

So was going to mass for me, alot like my cycling career, it's all in my head without anything to indicate it's worth the hassle.

Cee-Jay-Cee

Have you used latex tubes before and if so are you able to offer any comparisons with the tubolitos? I was close to buying them a month or two back but when I started researching reviews, one thing put me of abd that was the rolling resistance. Tubolitos have slightly higher RR than regular butyl tubes. I’ve been running the same Vittoria latex tubes with GP4000’s for the last two years and love how they feel and sound and more importantly I’ve had no punctures in that time.

From the Roling Resistant website it appears the GP5ks have slightly higher RR compared to the 4000s II so I think for the best all round performance GP4000’s with latex tubes beats 5000’s and tubolitos.

CramCycle

Cee-Jay-Cee wrote: »

Have you used latex tubes before and if so are you able to offer any comparisons with the tubolitos? I was close to buying them a month or two back but when I started researching reviews, one thing put me of abd that was the rolling resistance. Tubolitos have slightly higher RR than regular butyl tubes. I’ve been running the same Vittoria latex tubes with GP4000’s for the last two years and love how they feel and sound and more importantly I’ve had no punctures in that time.

From the Rolling Resistant website it appears the GP5ks have slightly higher RR compared to the 4000s II so I think for the best all round performance GP4000’s with latex tubes beats 5000’s and tubolitos.

Which site are you using, I run at 100psi and GP5000 with Butyl compared to GP4000 with Latex is has slightly resistance from the site i was looking at. Every site I look at says they have lower RR than butyl but higher than latex.

In fact the 5000 was only slower at lower pressures, and only versus 4000 with a latex tube.

The general feedback I see is that Latex is still more comfy and faster, but leaks quicker, the tubolitos are not as comfy or as fast but better than butyl, the only place to say they are not is, quite interestingly, Tubolito on Facebook.

So at the minute for tubolito:
Positives: Orange valves, weight saving (and it is noticeable)
Cons: I may have been sold a pig in a poke and they offer no real advantage over my butyl tubes

For 5000:
Positives: They are apparently better, lower RR in general
Cons: That stupid German flag as opposed to the GP flag which was cooler, they are slightly heavier

saccades

JimmiesRustled wrote: »

. It would make sense that the lower rolling resistance the lower the grip of the tyre but that's not really what you asked.

WTF!


No, absolute no.


The low rolling resistance tyre rolls the wheel better as the tyre deforms to inperfections in the road surface. You reduce the energy wasted bouncing up and down, you also get increased grip as you can run lower pressure therefore more rubber in contact with the road gives more grip.


You can take it too far and the optimum pressure depends on internal rim width, rider weight and tyre width for the road surface


The smoother the surface the less this applies, checking rolling resistance on a oil drum is pretty useless if you cycle the sally gap and the like. A perfectly smooth surface wouldn't need movement of the tyre so long as the friction coefficient is large enough you can move so minimal grip, like the historical 23c at 110psi on a 17mm internal rim.


Low rolling resistance does not equate to low grip.

magicbastarder

CramCycle wrote: »

I do not like that they have changed to GP flag to a German flag, I think I would be faster with a fiNish line flag.

they could have been clever and put a finnish flag on the tyre, but that joke probably would only make sense to english speakers.

Cee-Jay-Cee

CramCycle wrote: »

Which site are you using...

....the only place to say they are not is, quite interestingly, Tubolito on Facebook.

Yeah I got it from Tubolitos facebook page and I figured if they were saying themselves then it must be true.

Like I said I have been using latex tubes for the last number of years and did notice a distinct difference when I changed from butyl to latex.

At the moment, I would consider changing to tubolito's as a downgrade. Theyre 15g lighter than the Vittoria 19/23mm latex tubes i'm using (in 25mm tyres) which is too small to make any discernible difference.

I have two spare GP4000's for when the current tyres need replacing and if I cant get them again I will most likely buy the GP5000's but with latex tubes.

My latex tubes lose between 10-15psi over 3 or 4 days which is perfectly acceptable and takes less than 1min to re-inflate them again.

I see Tubolito are currently developing a newer version of their tube to rival the comfort/RR of latex, maybe I will try them when they are finalised but for now latex is king IMO.

harringtonp

saccades wrote: »

WTF!


No, absolute no.


The low rolling resistance tyre rolls the wheel better as the tyre deforms to inperfections in the road surface. You reduce the energy wasted bouncing up and down, you also get increased grip as you can run lower pressure therefore more rubber in contact with the road gives more grip.


You can take it too far and the optimum pressure depends on internal rim width, rider weight and tyre width for the road surface


The smoother the surface the less this applies, checking rolling resistance on a oil drum is pretty useless if you cycle the sally gap and the like. A perfectly smooth surface wouldn't need movement of the tyre so long as the friction coefficient is large enough you can move so minimal grip, like the historical 23c at 110psi on a 17mm internal rim.


Low rolling resistance does not equate to low grip.

Spot on observations which agree with personal experience. In general, grip and lower rolling resistance go together, the trade off is tyre rubber longevity and puncture resistance. Take the Gator Skin for example, great puncture resistance and they last a long time but they have (comparatively speaking) heavy rolling resistance and poor grip.

I'm out of touch with the latest on tyre rolling resistance but looked into it a lot a couple of years ago and back then came to the conclusion that the best combination was either

a) Schwalbe Pro One tubeless (very light for tubeless)

or

b) Contintental Grand Prix TT ad latex

and have ridden on both of these

magicbastarder

i've read a theory that people think high pressure = higher speed, partly because you usually will feel a more pronounced road buzz at higher speed; but that people conflate this with the more pronounced road buzz you'll also get from higher tyre pressures. so it 'feels' faster to ride higher pressures, but this does not mean you're going faster or have less rolling resistance to fight.

harringtonp

magicbastarder wrote: »

i've read a theory that people think high pressure = higher speed, partly because you usually will feel a more pronounced road buzz at higher speed; but that people conflate this with the more pronounced road buzz you'll also get from higher tyre pressures. so it 'feels' faster to ride higher pressures, but this does not mean you're going faster or have less rolling resistance to fight.

Yes going from 120 psi to 75-80 psi tubeless does feel a lot slower until you get used to it.

CramCycle

Got their first proper run this weekend. Comfort was good, ran at 100psi, probably could have run lower considering the weather. This said the grip was excellent, GP4000 were always good but these were better by a noticeable margin. Tubolito were fine, felt as comfy as the wider tyres I was used to and certainly rolled well

magicbastarder

how do you determine grip unless you take them to their limit of grip though?

CramCycle

Very unscientifically. There were a few moments, conditions as they were I would have expected to feel the bike give a little, maybe the front or rear wheel to slip a little. Barely noticeable, the sort of thing you'd correct out of habit. This time I found I didn't have to correct. It's all in my head I realise but I just felt after awhile, even more confident than usual.