How much can a bike take before breaking?

[Andrius.B]

Just wondering how fast can I go with a commuter before the risk of it breaking because of the tensions created by the physics of going fast. Lets assume that the hybrid bike has a good quality aluminium frame + good quality steel fork.

Anyone got any data? Past experiences? What are the approximate speeds that are considered to be risky? 30mph? 35mph? 40mph? 50mph?

 

[Rickshaw Phil]

No idea but your bike will be tougher than you think. If you want an idea of how fast you can go, this thread may interest you along with this one.

 

[sidevalve]

Any decent bike will have a massive reserve of strength. Far beyond anything that can safely [or even unsafely] be achieved on the road. Other factors wiil slow you down before the bike would break. Assuming you don't hit a brick or ride down a mountain track on a road bike of course. Even an old git like me has achieved 30 [sorry, I admit it, I bottled out then but I certainly didn't have any worries about the bike, even an old beast like my Dawes can cope with that] and many on this forum have far exceeded that speed.

 

[stephen.rooke]

i've done 50mph downhill

 

[Andrius.B]

thanks for the replies.
Now I feel safer when going downhill.

 

[Lyrical]

It's something I've often wondered, for example on a road bike how fast would you need to be going where a small sized stone (say marble sized) could cause a blow out.

As for frame snapping, wheels suddenly buckling I don't think you'd be able to do it from just speed alone.

 

[Andrius.B]

Yeah, thats a good point... probably it would be better to ask at what speed would going over a small dent or stone on the road could easily lead to a crash.

 

[HovR]

Yeah, thats a good point... probably it would be better to ask at what speed would going over a small dent or stone on the road could easily lead to a crash.

That's a tough one to answer definitively, however I think it's fair to say that the riders judgement or skill will run out before the bike mechanically (catastrophically) fails.

I know descents in my area that are fine taking at 45+mph, whereas there are less severe descents that you wouldn't want to take at over 30ish due to poor road conditions.

Vary your speed dependent on your riding ability, the bikes ability (e.g. a MTB will take a pot hole better than a road bike), and road conditions. If you are nervous and feel you are going to fast, slow down! Remember it's supposed to be fun!

 

[Lyrical]

That's a tough one to answer definitively, however I think it's fair to say that the riders judgement or skill will run out before the bike mechanically (catastrophically) fails.

I know descents in my area that are fine taking at 45+mph, whereas there are less severe descents that you wouldn't want to take at over 30ish due to poor road conditions.

Vary your speed dependent on your riding ability, the bikes ability (e.g. a MTB will take a pot hole better than a road bike), and road conditions. If you are nervous and feel you are going to fast, slow down! Remember it's supposed to be fun!

But the thrill is in going fast!

 

[edindave]

When I saw the title I thought this was about HLab.

 

[HovR]

But the thrill is in going fast!

I completely agree, however I don't think it would be fun if I was constantly worrying about the bike falling to pieces during the descent! After putting many miles on my bike I'm confident it will hold steady on descents, making them enjoyable at high speeds.

 

[Nebulous]

There are two real issues:-

risk - which I think is actually quite small, even when you're going fast. The issue though when going faster is that although the risk is small the stakes if you do crash increase.

perceived risk- people believe that speed is dangerous, and therefore land up imagining all sorts of horrors, like bikes breaking.

I'm a risk-taker and absolutely love going fast on a bike. 49.9mph is my best so far, tantalisingly close to my goal to break 50, but not quite there.

 

[Globalti]

Why would speed cause a bike to break? In theory a bike could travel at 2000 mph and not break. What matters is shock loads from hitting objects, either through the wheels or impacting on the frame or handlebars. Some cheap bikes will break just going off a kerb or down a step.

 

[sabian92]

Speed isn't what kills you. It's the stopping that does the damage.

Honestly, you won't go so fast bits will fall off unless they weren't attached properly, and in any case they'd have come off at 50mph or 5mph anyway.