Experiences with Tern Castro models?

[Kell]

From memory, the weight limit was either 90kg or 95kg.

At the time I would have been on or about that weight. Maybe 98 tops.

Add clothing, water and an extra set of clothes (to change into at work) and probably over 100kg.

TBH I didn’t diagnose the problem very quickly.

As mentioned in another thread, I had huge problems with the wheels - the spokes kept coming loose and the back end just felt ‘squirrelly’.

But I kept checking the spokes and they were OK this time. Yet it still felt very odd.

In hindsight, obviously what was happening was that the top of the seat tube was moving side-to-side and making it feel similar to a very loose wheel.

On both bikes they cracked (rather than snapped) on the seat tube.

A longer seat post and they might have been ok.

This is a pic of the second one. I did have a pic of the other one but I’m not sure where.

 

[ExBrit]

From memory, the weight limit was either 90kg or 95kg.

At the time I would have been on or about that weight. Maybe 98 tops.

Add clothing, water and an extra set of clothes (to change into at work) and probably over 100kg.

TBH I didn’t diagnose the problem very quickly.

As mentioned in another thread, I had huge problems with the wheels - the spokes kept coming loose and the back end just felt ‘squirrelly’.

But I kept checking the spokes and they were OK this time. Yet it still felt very odd.

In hindsight, obviously what was happening was that the top of the seat tube was moving side-to-side and making it feel similar to a very loose wheel.

On both bikes they cracked (rather than snapped) on the seat tube.

A longer seat post and they might have been ok.

This is a pic of the second one. I did have a pic of the other one but I’m not sure where.

View attachment 688765

That's a gut-wrenching photo.

 

[Drago]

I'm North of 120kg and I buy very carefully, with one eye in the weight limit and the other on the guarantee. Don't want that happening to me!

 

[tinywheels]

I'm 98 kilos.
Never had a problem with a brompton, despite off roading,bumping on and off kerbs. Buy British, our craftsmen are superb.

 

[Drago]

I'm significantly above the weight limit of the Brompton, totally nekked near on 30 kg more than your lightweight, lo cal, streamlined self. Add clothes and gear to the sum and we approach the point where small items moving at sufifcient speed actually go into orbit around me.

While Bromptons are no worse than anyone else they do occasionally break and its a lot of money to spend only to risk being left with no cash and no usable bike if it were to fail and they caught sight of how big I am, which is quite difficult to hide.

The ones i've ridden aren't up to to job of managing that sort of load and flop and flap like more like a cross trainer than a bicycle with me aboard, giving me zero confidence that I'd escape a breakage for long, not to mention making it horrible to ride even if it didn't break.

The finish is lovely and the fold gives me a semi every time I see one, but if its isnt up to the job then it's inaccessible to me. If they made one for the husky gent with 451 wheels and discs I'd be up there like a shot. Hell, id probably even do without discs. Until then their superb craftsmen will have to stick to serving the little people and im forced to look at the few folders with 130 or 140kg load limits.

 

[tinywheels]

I'm significantly above the weight limit of the Brompton, totally nekked near on 30 kg more than your lightweight, lo cal, streamlined self. Add clothes and gear to the sum and we approach the point where small items moving at sufifcient speed actually go into orbit around me.

While Bromptons are no worse than anyone else they do occasionally break and its a lot of money to spend only to risk being left with no cash and no usable bike if it were to fail and they caught sight of how big I am, which is quite difficult to hide.

The ones i've ridden aren't up to to job of managing that sort of load and flop and flap like more like a cross trainer than a bicycle with me aboard, giving me zero confidence that I'd escape a breakage for long, not to mention making it horrible to ride even if it didn't break.

The finish is lovely and the fold gives me a semi every time I see one, but if its isnt up to the job then it's inaccessible to me. If they made one for the husky gent with 451 wheels and discs I'd be up there like a shot. Hell, id probably even do without discs. Until then their superb craftsmen will have to stick to serving the little people and im forced to look at the few folders with 130 or 140kg load limits.

Have you considered more time on the bike?
Failing that idea if you live anywhere in East Sussex, I could get my dog to chase you for a couple of hours per day,he hates all things wheeled.

 

[Drago]

I have a 35 year old weightlifting habit. A bit of lettuce won't help a 54" chest.

 

[arnop]

A longer seat post and they might have been ok.

I agree. A seatpost that does not cover the full length of the tube greatly increases the stress for the latter.

While Bromptons are no worse than anyone else they do occasionally break

Can you cite an example?

and its a lot of money to spend only to risk being left with no cash and no usable bike if it were to fail

I'm more worried about lying in an ambulance with broken bones and missing teeth.
Loosing the bike would be my last worry!

But folders and heavy people don't mix very well, that's a fact.
Maybe an extra strong version of a typical model would be an interesting option .

I'm barely 80Kg, but I would be interested too, for the added margin of safety and loading capability...

 

[Drago]

My ID9 folder is fine. It rides very nicely with my weight aboard, and if it breaks (and I survive) the warranty is good.

It's not the world's best fold, being an unashamed Tern clone, but it's good enough to be usable for trwin travel.

 

[tinywheels]

can anyone cite an example of a brompton breaking?
Pictures would be helpful.

 

[Drago]

New, old, and in-between...

These are just random images from the first Google search. The same search brings up loads of chat about them, including on this very forum.

I don't think they're any worse than anyone else's wares, but they're certainly not immune to cracking, failing, or just plain breaking.

 

[berlinonaut]

Picture 1 and 3 show a break on the mainframe of the old, short wheel based version. These were not uncommon but unseen since the invention of the new mainframe with the new hinge in 2004. This is why personally I'd avoid buying a Brompton with the older mainframe. Not all break, but a unknown percentage does and while there are speculations there is no official root cause named.

Pic two shows the ear of the little wheel - this breaks due to mistreatment (sitting on the folded bike, bumping it harshly on the ground, sometimes when using skater wheels). Has nothing to do with the weight of the rider.

Pic 5 shows the seat tube. This happens if you don't exchange the seatpost sleeve in time but instead keep tightening the bolt further and further to stop the seat post from slipping. Nothing to do with the rider weight but with a lack of maintenance.

Pic 6 shows the steerer tube. This happens on ti-bikes when overtightening the stem bolt (and sometimes even when not) the cone has been changed in ~2018, since then this should be gone. Again not a totally common issue and nothing to do with rider weight.

Pic 4 shows the chain stay. A very rare occurance. In this pic it looks like a follow up failure of the chain stay rusting through inside out. This was relatively common with older bikes (mainly MK2) and is gone since about 2008. However, while the rear frame was toast then anyway this break was not a very common consequence. In very rare cases (way less than a handfull) I've stumbled upon this break w/o a rusted through chain stay as well, typically on bikes that were pushed very harshly for years including jumping cerbs with a heavy rider on top.

So of these pics only the last one can possibly be related to rider weight but only when combined with a brutal riding style.

 

[Drago]

To be fair that is not the question that was asked when the images were requested.

As aforementioned several times by my good self, Bromptons don't break any more than anyone else's tin.

But they do occasionally do so. Enough that I, who significantly exceeds the payload limit (which has been reduced once already in the models history), would rather not take the financial risk.

As also aforementioned, I've ridden a few now and with my mass aboard they flex and flap more than any other bike I have ridden with my weight aboard. If someone could explain how a frame flexing noticeably - my cross trainer analogy is only half joking - than normal is in any way a good thing then I'm open to be reassured.

I'm not suggesting they're fragile, flaky, or prone to explode when within 10 feet of a dog turd as if they've hit a land mine, because they don't. No, I believe nothing more than they're not up to the job of having the weight limit exceeded by a very noteworthy amount, which is what I would have to do.

If anyone wishes to put their money where their mouth is and buy me one I will repay them, with interest, after 7 years when the frame warranty expires if the frame has not broken.

 

[berlinonaut]

As also aforementioned, I've ridden a few now and with my mass aboard they flex and flap more than any other bike I have ridden with my weight aboard.

Probably at your weight almost any bike with a hinged mainframe will be challenged. The Brompton flexes on the mainframe hinge under a rider with normal weight already if you put serious power onto the cranks, the long stem has a bit of natural flex too, the older M handlebars do flex (and the P ones even more) and the rear frame is for my taste a bit filigree for a rider of massive weight. There's a reason why I recommended a Bernds to you.

If someone could explain how a frame flexing noticeably - my cross trainer analogy is only half joking - than normal is in any way a good thing then I'm open to be reassured.

It makes the ride more interesting?

 

[Drago]

Although my ID9 with a hinged main frame is as solid as a rock, and absolutely flies.

But even then I take nothing for granted. I always BESTCOPa my bikes before each ride but pay particular attention to the ID9's frame for any tell tall sign of impending Hiroshima level annihilation.