# Brompton crank snapped



## Pseudo (31 Oct 2015)

About to pull away from the traffic lights and... snap! 








Anyone else had this happen?


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## shouldbeinbed (31 Oct 2015)

No, wow, manufacturing defect? or would we not like you when you are angry?


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## alicat (31 Oct 2015)

Good job they have a low top tube.


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## Pseudo (31 Oct 2015)

Well, most of the break is clean, but part of the crack is dirty, so looks like it may have been developing over time. Just the sudden stress of thrusting my foot down was obviously too much for it! Although the shop looked impressed, they did say it wasn't the first one they've seen!


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## annedonnelly (31 Oct 2015)

How old's the bike? Has it done a lot of miles?


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## Pseudo (31 Oct 2015)

Two years - done over 6,000 miles - lots of hills where I live too, so gets a lot of pounding.


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## Pseudo (31 Oct 2015)

I'm also on my third rear wheel rim, fourth rear tyre too.


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## jefmcg (31 Oct 2015)

You are strong. Like bull. 

Here's your next challenge.


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## Pseudo (31 Oct 2015)

Ouch! I do find I'm checking everything on it lately - but something unexpected will always evade detection until it fails! The bolt securing the rear brakes to the frame came loose a few weeks ago - the only warning I had was the brake lever juddering when I applied the brake.


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## chris folder (31 Oct 2015)

Hi I am a new bromptom owner your scaring me with pictures like this I will be checking my bromptom all the time now. I have been rideing dahon for years still good as new


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## Pseudo (31 Oct 2015)

I think a Brompton is designed for 2-3 miles to and from a station every day, rather than the 17 miles pounding I give it on an uphill slog home from London every day in all weathers!


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## jefmcg (31 Oct 2015)

Pseudo said:


> I think a Brompton is designed for 2-3 miles to and from a station every day, rather than the 17 miles pounding I give it on an uphill slog home from London every day in all weathers!


People do a lot more than that on a Brompton. I've seen one on a 600km audax (600km in 40 hours) and I believe there are always several on Paris-Brest-Paris (1200km in 80-90 hours)


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## shouldbeinbed (1 Nov 2015)

Pseudo said:


> Ouch! I do find I'm checking everything on it lately - but something unexpected will always evade detection until it fails! The bolt securing the rear brakes to the frame came loose a few weeks ago - the only warning I had was the brake lever juddering when I applied the brake.


My front brake assembly fell to pieces not long after buying it. A proper strip down and rebuild at home & its been fine ever since. I do minimum 15 edge of the Pennines miles a day on mine in all but proper snowy weather & I even spotted Rose Bikes (IIRC) offering 16 inch snow tyres but I think the ground clearance would be a problem picking up the grinding paste gritter spray and snow sludge so readily.

On the few niggles people report: I do wonder if Brommy are working at full tilt to grow and meet the demand over the last few years and that final touch of QC has slipped a tad, but shops are taking them on bombproof reputation & trust. A quick bit of home TLC seems to be the thing to keep them as good as public preception.


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## Pale Rider (1 Nov 2015)

shouldbeinbed said:


> I do wonder if Brommy are working at full tilt to grow and meet the demand over the last few years and that final touch of QC has slipped a tad, but shops are taking them on bombproof reputation & trust. A quick bit of home TLC seems to be the thing to keep them as good as public preception.



My Brompton dealer tells me Brommies usually come out of the box ready to go and few require much adjustment.

But I think you could be right about Brompton taking their eye off the quality control ball.

These days they seem more concerned with style, boutique shops and marketing in general.

Ramping up production of any niche product often seems accompanied by a dip in quality, so if there is a problem, Brompton should have seen it coming.


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## LCpl Boiled Egg (1 Nov 2015)

jefmcg said:


> You are strong. Like bull.
> 
> Here's your next challenge.



That's what happened to my first M3L. I had removed the seatpost and noticed the break from the inside at exactly the same place.


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## annedonnelly (1 Nov 2015)

Pseudo said:


> Two years - done over 6,000 miles - lots of hills where I live too, so gets a lot of pounding.


Ah, mines only done 4,000 miles in two years.

I'll wait a few more miles before I start to worry.


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## Brommyboy (1 Nov 2015)

The only time I have had a crank break has been on my touring bicycle, after about 75000 miles! My Bromptons have had no failures other than within the hub gears, or worn rims. I suspect that how you use your machine has a lot to do with its reliability. Mine have been heavily used for cycle-camping tours, now totalling over 12000 miles, much in hilly regions like Wales or Scotland. My total Brompton mileage is well over 37000. Incidentally, the cranks are made by Stronglight for Brompton.


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## srw (1 Nov 2015)

I've had a Brompton crank break - my best guess is that it got bashed at some stage, and being aluminium eventually failed catastrophically. As long as you're not badly hurt it doesn't matter too much - it's an easily replaceable part.


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## chris folder (1 Nov 2015)

Hi I have seen a few bromptom bikes where the sticker on the bikes frame has bubbles showing where bromptom are not sticking the stickers on properly they not sticking stickers on right the skicker should not have bubbles showing


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## Pseudo (1 Nov 2015)

srw said:


> I've had a Brompton crank break - my best guess is that it got bashed at some stage, and being aluminium eventually failed catastrophically. As long as you're not badly hurt it doesn't matter too much - it's an easily replaceable part.



I'm wondering if that's what's happened to mine. It has fallen over onto its left hand side quite a few times. And aluminium is rather susceptible metal fatigue.


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## GrumpyGregry (1 Nov 2015)

Stuff breaks. We all die.

End of, really.


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## srw (1 Nov 2015)

GrumpyGregry said:


> Stuff breaks. We all die.
> 
> *End of*, really.


Placeholder for raised eyebrow smiley, it being All Saints and all.


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## GrumpyGregry (1 Nov 2015)

srw said:


> Placeholder for raised eyebrow smiley, it being All Saints and all.


Very, VERY, good sir.


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## chris folder (2 Nov 2015)

Hi when your rideing brompton on a uneven ground or Stoney area the bumping from back wheel though rubber suspension is in a way like hitting bike non stop with a small rubber hammer can see after long use the frame cracks


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## samsbike (2 Nov 2015)

so was this covered by warranty?


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## roundthebendbromcycle (3 Nov 2015)

I had one break about 8 years ago, riding up a railway crossing in the dark, thought it was the pedal, I was so proud, but also very pissed. I used to go out for 60 mile rides, so I guess it had done perhaps 5,000 miles. I upgraded to a mountain drive system which came with much stronger cranks. Its not quite the brompton legend is it.


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## GrumpyGregry (3 Nov 2015)

chris folder said:


> Hi when your rideing brompton on a uneven ground or Stoney area the bumping from back wheel though rubber suspension is in a way like hitting bike non stop with a small rubber hammer can see after long use the frame cracks


Really though? I don't think you've thought that through...


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## GrumpyGregry (3 Nov 2015)

roundthebendbromcycle said:


> Its not quite the brompton legend is it.


Like most legendary characters the Brompton is flawed. Specifically in tow ways; slavish adherence to backwards compatibility & not so nice componentry bought in to finish the bikes, which are built down to a price not up to a specification; cranks, chainrings, grips, and in recent memory brake levers and brake callipers.

I love my B; but until I upgraded it I only liked it.


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## RMurphy195 (27 Nov 2015)

srw said:


> I've had a Brompton crank break - my best guess is that it got bashed at some stage, and being aluminium eventually failed catastrophically. As long as you're not badly hurt it doesn't matter too much - it's an easily replaceable part.



I'm inclined to agree that it probably had a knock at some stage. This is the problem with alloy - it doesn't always bend when you wack it, it can get a hairline crack that can only be picked up by x-rays or some such, but it will weaken and fail over time- I guess water can creep in (and salt in Winter), corrosion starts, then suddenly one day it goes. Did you say that part of the break on yours was dirty?

Something to remember if you buy a used car that's been kerbed hard - maybe the buckled wheel and bent track rods were replaced but not the alloy hub carrier!


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## rootes (9 Jan 2017)

Hiya came across this thread randomly

I do hope you are not claiming this clearly impressive display of strength as your own jefcmg? ;-)

That pic is actually of my first Brompton which broke on the way to Clapham Junction back August 2009!

https://www.flickr.com/photos/sitrickett/3841610383/in/photostream/

back home
https://www.flickr.com/photos/sitrickett/3842402854/in/photostream/

could fully fold for the train haha!

Brompton where good with warranty and since that age of frame the altered the design and materials in that area to prevent this failure.



jefmcg said:


> You are strong. Like bull.
> 
> Here's your next challenge.


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## rootes (9 Jan 2017)

Change to a white frame when they did the frame warranty, then this happened..

https://www.flickr.com/photos/sitrickett/4475072577/

Again the design of the crank is different these days.


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## e-rider (9 Jan 2017)

chris folder said:


> Hi I am a new bromptom owner your scaring me with pictures like this I will be checking my bromptom all the time now. I have been rideing dahon for years still good as new


I have never owned a Brompton but I've read a lot about them - It appears that Brompton have created a 'premium' brand simply by charging a high price for the product rathet than actually producing a high quality product - sure Brompton frames are strong and the folding design is good but......
Dahon on the other hand seem to have a poor reputation even though many owners only report very positive experiences?


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## TheDoctor (10 Jan 2017)

Brompton have the odd component break. Dahon have the odd frame break.
A crank is easier to replace than a frame which hasn't been made for a year...


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## jefmcg (11 Jan 2017)

rootes said:


> I do hope you are not claiming this clearly impressive display of strength as your own jefcmg? ;-)


Lol, no. I just googled it (I think - it was more than a year ago). Never meant to claim it was my work.

I have broken a saddle rail, but that with was the impressive force of my arse rather than my legs


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