Bicycle Tires Max Speed

[gensem]

I was wondering if there is any speed rating for bicycle tires, like the ones we see in car tires.
I mean, are mtb tires safe to be used at 40-50mph in a daily basis?


Regards

 

[auraslip]

One of the advantages of using DOT certified tires is the speed rating is printed on them. That being said, many people use hookworms and their equivalents at those speeds, and we've never heard of a problem.

However, the selection size is very small, so this is a topic that warrants deeper discussion. I've had people mention that heat build up may be a problem with a bicycle tire operating at such speeds.

 

[amberwolf]

The average MTB tire I've seen is knobby, and I wouldn't really wanna run those on a road at those speeds. Off-road, like downhilll, I expect they could get going quite fast, but the runs will likely be short, so not like taking a hundred mile trip on a paved road at those speeds.


I haven't seen a speed rating on any bike tire so far, but I've never had "good" ones, just the cheap stuff that comes with a lot of bikes. I wouldn't run any of the ones I've had at speeds like that, for any great lengths of time. Biggest issue I can imagine however isn't tire wear, but rather the tire blowing out from overpressure caused by the heat, either of friction with the road or of braking (if rim brakes) from those speeds frequently in traffic.

They're just so small, volumetrically, with such thin walls and pliable beads, that I'd expect problems with the large amount of expansion from heat if you already run them at higher pressures to counteract the extra weight of an ebike.


I don't actuallly know that any of it would be a problem, but it seems like it oculd be.

 

[rebelpilot]

.

 

[Doctorbass]

The Hookworm - Maxxis 24" x3.0 do 112km/h no problem on the road.. and 160 no load

But generally all bicycle tires can take 100km/h+ easy.

I guess they can take 200km/h no problem since the ratio between thge width and the height is nearly 90-100% so the sidewall are pretty tough as for a bicycle tire compare to other tires.

i'll try 140 kmh on road this summer and will report you the results

Doc


Doc

 

[REdiculous]

i'll try 140 kmh on road this summer and will report you the results

Hopefully you'll be in some kind of condition to report. A crash at that speed could easily kill. Go to a track where there's medical professionals on hand, just in case....it would really suck to have an accident on some deserted road where there's no cell service, nobody around and a response time of 40mins once they finally get the call.

 

[Doctorbass]

i'll try 140 kmh on road this summer and will report you the results

Hopefully you'll be in some kind of condition to report. A crash at that speed could easily kill. Go to a track where there's medical professionals on hand, just in case....it would really suck to have an accident on some deserted road where there's no cell service, nobody around and a response time of 40mins once they finally get the call.

Back in 2009 for my speed record i had ambulance and other safety service availlable just in case.

This summer it will be on the drag racing lane again.

Between you and me.. an accident by falling off a motorcycle and a bicycle is pretty the same... guess what.. some do 350kmh on motorcycle..

as well, Everything can happen.. blowing a tire, hitting a put hole ( not probabale on a drag racing lane) wobble etc

i'll make my attempt gradually by increasing the speed step by step to ensure everything is ok as long as i push approach the max speed.

DOc

 

[John in CR]

Summer is half gone. What's the schedule date?

 

[Doctorbass]

Summer is half gone. What's the schedule date?

During august.

I need to make some tests before.

Doc

 

[dougnutz]

Tire failure due to speed is a function of heat, except for extream cases. If the tire generates heat faster than it can dissapate the heat it will eventually delaminate. For example DOT drag radials have a very low speed rating (often s or L) but they are used at every nhra event at speeds well above 100mph. The key is they have time to dissapate the heat between races. I don't know if there has actually been a study on it or not but I doubt very much that any off the shelf bike tire would fail at highway speeds for short durations. But I would expect that any of them would be subject to an increases in temp that could lead to tire failure.

 

[gensem]

I know from experience that a tire ll not fail doing hi speed for a small amount of time. Ten years ago I used to go to the beach sometimes using a mtb. From where I live to sea level there is a 800m diference and the distance (all paved) was about 70km and the downhill part was about 15-20km, my bike was doing 50-55mph going down. My el cheapo street tires did get hot, could barely touch the tires but never had problems.
What I was thinking is that I could damage the tires(or the tubes) doing this in a daily basis, and maybe after awhile end up blowning a tire at hi speed. Im saying that because now I could use a big hub motor and do 45mph+ all the time.

 

[Hillhater]

Heat is a non issue.
Road surface temperature in summer can easily exceed 60 deg C ( melting black top !).. never a tire problem.
Road race riders frequently exceed 90km/hr downhills on condom thin tires at crazy high pressure (120psi).
There are a lot worse things that can happen at speed ( and more likely to) than a burst tire !
.. think ..pot hole or rocks in the road
... buckling a rim
...spoke breakage
... idiot other road users !

 

[gensem]

Heat is a non issue.
Road surface temperature in summer can easily exceed 60 deg C ( melting black top !).. never a tire problem.
Road race riders frequently exceed 90km/hr downhills on condom thin tires at crazy high pressure (120psi).
There are a lot worse things that can happen at speed ( and more likely to) than a burst tire !
.. think ..pot hole or rocks in the road
... buckling a rim
...spoke breakage
... idiot other road users !

Your are right Hillhater, I forgot about thoses skinny road tires doing almost 100kmh.
Im realizing bike top speed doesnt matter for the tires, at least doesnt below 90km/h.

 

[dougnutz]

Heat is generated by flex in the sidewall, friction, and many factors. If you don't believe me deflate your tire to a couple psi and go for a short ride. The tire will get very hot very quickly. Road bike tires inflated to high psi don't flex much and so they don't generate heat from flex. I'm not saying it's the ony thing that will cause a tire failure but from 17 years of racing cars professionaly I can tell you first hand that low pressure= heat= early failure. There are a lot of factors involved though.

 

[Dave Sloan]

The best thing to do is get a puncture proof inner tube as this is what is holding on the tire. Nothin like seeing your rear tire fly off at 70 mph in your rear view mirror as I did years ago on my motorcycle - had smoking hot cowboy boots from that experience!