Am I going to wreck my bike?

[swee'pea99]

I've always assumed that bikes were basically indestructible, but trashing two bikes in as many years has given me pause for thought. (Both steel: one snapped rear dropout; one broken forks.) I now commute on a Vitus 979, which I love, but now that I think about it, I routinely start/end the day by hitting speed bumps at 20-25 mph all the way to and from work - probably ten bumps each way. I stand up on the pedals as I go over, but still...

Am I just cruising for a hat trick, or should it be able to take this kind of treatment?

 

[asterix]

Don't get an aluminium bike!

The only damage I have had on steel bikes were inflicted by car impacts, the second of which didn't do me much good either.

Perhaps we need more information, like what sort of steel bikes, how much you weigh (be honest!), what is your general riding style (it is said that some people sit on a bike - or a horse - like they are a sack of potatoes), are the speed humps like cliffs?

 

[beanzontoast]

Any bike will suffer if the terrain is punishing. A commuting bike is a compromise - relatively smooth, easy ride with ability to withstand some variations in road surface. Repeatedly taking speed bumps at 20-25mph on a maybe 20 year old road bike with an aluminium frame is going to stress it considerably, so failure wouldn't be a surprise IMO.

 

[Smokin Joe]

Speed bumps are there to slow traffic down. If you drove a car over twenty speed bumps a day at 25mph for twelve months something would break. What makes you think a lightweight bicycle is going to be any stronger?

 

[andy_wrx]

Do you 'go light' over them, a sort of almost-bunnyhop where you unweight the bike as you go over them ?
Or do you just stand-up and crash your way over them ?

 

[PrettyboyTim]

I do a similar thing on my bike, although not quite as fast as you (18-22mph, I'd guess). It's a fairly heavy aluminium hybrid, and a few weeks ago the rear axle broke on it. Whoops. I don't really know whether the frame itself is being damaged though.

 

[HLaB]

I don't have as many bumps as you on my commute and I'm not as fast but what irks me slightly is there the large cushion type and I could easily go by them at their low section but there is usually lots of parked cars and I find it better to stay in a secondary or primary and go over the high section . Will that do damage my bike I'm usually only going 19-20mph on my Ridgeback Velocity, alu frame hybrid or 12-16mph if I've got a loaded pannier from a shopping trip. And Ive only got around 4 or 5 humps (I've never counted).

 

[swee'pea99]

Thanks for responses. For starters, it is an aluminium bike - and a lightweight, built for speed, stuck-together-with-glue one at that. (20 years old toboot.) Does any of that make any odds?

I'm not over-heavy - 11st give or take - and I think I have a reasonably lively riding style. Do I bunnyhop? Not really - they're too big to hop over...I stand up on the pedals and try to ease the impact, but in truth there's only so much you can do.

Why do I think a lightweight bicycle is going to be any stronger? Er, I don't. I don't know. That's why I'm posting here, in the hopes that someone else will.

(Does anyone know what would be the strongest material for this kind of regular pounding? Steel, aluminium, carbon, titanium, other? Assuming a racer....I'd really rather ride a racer.)

 

[Smokin Joe]

Slow down. Bike frames are not built with constant impacts in mind. I would not trust a 20 year old bonded alu frame for definate on that sort of ride.

 

[fossyant]

The Vitus bikes are known to come unstuck - great at the time, but aren't built for long life...

My steel bikes are over 14 years old and are ridden hard ..... the only issue you have is that the 979 is known to come unstuck - nothing to do with it being alloy, just the glue ages..... - I'd save the frame as they are a classic, and just buy another frame to use.

Any good quality frame is fine, what ever the material used.

 

[feckless]

Hmmm. Well, having discovered that steel isn't quite the indestructible wonder-material retro-grouches would have us all believe, I guess there's only one choice for you – carbon fibre

That said, there's only so long any reasonably lightweight bike will stand up to the kind of pounding you describe.

Maybe you should start to run fatter tyres at slightly lower pressure (28 or 30mm at 70 to 80 psi should be quite balloony enough I'd imagine).

f

 

[mickle]

Bonded Alans and Vituses were referred to as 'one season' bikes by the old boys who worked in bike shops when I started. They do have a reputation for coming unstuck and I personally wouldn't use one as a daily rider.

It's likely that your steel frame failed because of joint overheating when it was being brazed, a common manufacturing problem. What make was it?

 

[briank]

feckless says, "Hmmm. Well, having discovered that steel isn't quite the indestructible wonder-material retro-grouches would have us all believe, I guess there's only one choice for you – carbon fibre "

but is being SARCARSTIC - or reckless (which is rhyming, so worse).

Carbon fibre frames can stand a lot of punishment, but among the unknowables here - how steep your bumps, how 'heavy' you ride - is the one certain fact that what you're doing breaks bikes.

A carbon frame might well sustain some imperceptible damage when you hit a bump then fail totally next time you're plummeting down a 1-in-6.

 

[Mr Pig]

I think what he means is you hop onto the top of the bump so that there is no impact at all to the bike. With as many bumps as you've got you'll be ace at it in no time ;0)

I'm fat, fifteen stone, and I've used my bike off road on very rough tracks. It's an aluminium frame and it's still intact after nearly ten years. I would say that to snap bits off the bikes either there was something wrong with the bikes or your riding style is very 'unsympathetic'. Used correctly and good bike should withstand commuting, I think you just need to be more careful with them.

 

[andygates]

My Alan lasted ages, it even did some offroading. Then it got nicked.

25 mph over speedbumps? You're a boy racer. Slow down.