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-   -   Luggage room gorillas bent my Brompton's chainring (again) (https://www.bikeforums.net/folding-bikes/546950-luggage-room-gorillas-bent-my-bromptons-chainring-again.html)

>>ECB<< 05-30-09 08:28 PM

Luggage room gorillas bent my Brompton's chainring (again)
 
When I flew to and from Phoenix last year, I carried my M3L in a big no-name ballistic nylon bag, with no special padding. The result? On my flight back, I got a bent chainring, a tweaked stem, and a shoved-forward saddle.

In the aftermath of that trip, I got one of the Brompton soft-sided bags, and used it on my trip to and from San Francisco this week. It worked fine going over, but...coming back, the chainring got another nice bend whunged into it.

At this rate, I'm thinking I either need to get a hard-sided case, or make all of my trips one-way. :roflmao2:

Any other (potentially cheaper) suggestions?

TIA,

ECB

sfgadv02 05-30-09 09:25 PM

I would definitely get a hard case for a folder bike.
They just throw the luggage/bags around giving no special care.

Or you can put a special "fragile" sticker on it. ;) Maybe, just maybe they'll be easier on the bag.

HSean 05-30-09 09:55 PM

Make some random think that clips over the chainring, that or maybe install a bashguard? lol

havm66z 05-31-09 05:54 AM

This looks so awesome

http://img.skitch.com/20090531-8gre2...8y.preview.jpg
Click for full size - Uploaded with plasq's Skitch

http://www.calhouncycle.com/productc...idproduct=1252

cyclistjohn 05-31-09 06:37 AM


Originally Posted by >>ECB<< (Post 9012622)
When I flew to and from Phoenix last year, I carried my M3L in a big no-name ballistic nylon bag, with no special padding. The result? On my flight back, I got a bent chainring, a tweaked stem, and a shoved-forward saddle.
.....
At this rate, I'm thinking I either need to get a hard-sided case, or make all of my trips one-way. :roflmao2:

Any other (potentially cheaper) suggestions?

TIA,

ECB

That's really depressing ECB! As the chain's enclosed, any chance of pic's to highlight where it got bent?

How about a smaller, say 44 teeth chainring, just for your trips, to bring it further inside?

Another idea - I now use self extracting bolts for the cranks & it takes 3 minutes to remove the cranks now. Maybe you could pack them separately? Actually that might also mean we could get away with a smaller case anyway.

Problem with hard case is what to do with it when you get out of the airport, especially if you want to ride to hotel, etc.. I suppose you could strap 2 small wheels to it, then tow it along.

We've carried mostly Stridas by air so far, & as there's not much to bend (plastic chainwheel with belt drive) they've survived well, always in a soft golf bag style bag, but like you, we now need a Brompton case. Time to give it some serious thought.......

John

AEO 05-31-09 06:51 AM

stamp "fragile" on it and they'll make a contest to see who can throw it the farthest.

>>ECB<< 05-31-09 01:21 PM


Originally Posted by cyclistjohn (Post 9013860)
That's really depressing ECB! As the chain's enclosed, any chance of pic's to highlight where it got bent?

Sorry; I thought of taking a pic of the damage, but didn't get around to it before carting the B off to the LBS.


Originally Posted by cyclistjohn (Post 9013860)
How about a smaller, say 44 teeth chainring, just for your trips, to bring it further inside?

As it is, I probably will have to install a new ring/crank; the mechs who looked over it weren't optimistic about being able to correct the bend. :(

I'm figuring installation of a more standard spider-and-bolt arrangement would help in a couple of ways:

1) The chainring would be supported farther out from the spindle, making these kinds of bends less likely.

2) If the ring did get bent, it could be replaced separately.

Besides, I definitely would like to have lower gears than the ones the 50 T stock ring provides. A smaller chainring certainly would have helped when I was staring up the near-vertical slope of Taylor Street.... :eek: :D


Originally Posted by cyclistjohn (Post 9013860)
Another idea - I now use self extracting bolts for the cranks & it takes 3 minutes to remove the cranks now. Maybe you could pack them separately? Actually that might also mean we could get away with a smaller case anyway.

Eh--I don't much care for the idea of having to disassemble/reassemble the bike as I go from place to place. Besides being inconvenient, messy, and time-consuming, that approach seems to defeat a lot of what the Brompton's design is all about.


Originally Posted by cyclistjohn (Post 9013860)
Problem with hard case is what to do with it when you get out of the airport, especially if you want to ride to hotel, etc.. I suppose you could strap 2 small wheels to it, then tow it along.

I think that wouldn't be so much of a problem--I invariably end up taking a taxi/shuttle from the terminal to the hotel, so towing isn't really a major priority.

Thanks for the feedback,

ECB

cyclistjohn 05-31-09 02:03 PM


Originally Posted by >>ECB<< (Post 9015204)
...........
1) The chainring would be supported farther out from the spindle, making these kinds of bends less likely.

I don't understand what you mean there :-(

2) If the ring did get bent, it could be replaced separately.

Yes, that's partly what I was getting at in my post :-)

........


Originally Posted by >>ECB<< (Post 9015204)

Eh--I don't much care for the idea of having to disassemble/reassemble the bike as I go from place to place. Besides being inconvenient, messy, and time-consuming, that approach seems to defeat a lot of what the Brompton's design is all about.

ECB

Yes, I realise it goes against the philosophy of a folder to take bits off & refit them. The problem though is that it isn't "normal" use of a folder, is it?

I'm sure Brompton, Dahon, et al, didn't design their folders with frequent century 21 air travel in mind :-)

In "the old days" handlers would treat "baggage" with some respect, but sadly it seems that is no longer the case - I wonder why? :-/

.......


After reading your post, in the absence of any pictures, I folded my M3L to try to imagine what happened to your chainring.

Since you mentioned your saddle was pushed forward, it was maybe a glancing blow which distorted the outside of your chainring?

I wonder if the right hand pedal could be strategically placed (& "locked") to help prevent such a blow?

In the USA you have many reasonably priced options for spiders & separate chainrings.

Maybe you can persuade your LBS to take a pic' of the bent chainring?

John

>>ECB<< 05-31-09 05:58 PM


Originally Posted by cyclistjohn (Post 9015369)
I don't understand what you mean there :-(

Here's what I'm getting at:

If you measure a 50T ring, it will have a diameter of about 200 mm. This means that, if the ring is just swaged on, it will have to resist bending over a length of 100 mm--the ring's radius. (Obviously, I'm ignoring the size of the crankarm here.)

If, on the other hand, you have a 50 ring bolted to a 130 mm BCD crank, the spider's radius will basically be 130/2 = 65 mm. That means the ring will have to resist bending over a length of (100-65) = 35 mm.

The upshot of all this is that applying equal amounts of force to either chainring will be more likely to bend the swaged chainring, since the force will have 100 mm of leverage--versus only 35 mm of leverage on the bolt-and-spider chainring.


Originally Posted by cyclistjohn (Post 9015369)
...
Yes, I realise it goes against the philosophy of a folder to take bits off & refit them. The problem though is that it isn't "normal" use of a folder, is it?

I'm sure Brompton, Dahon, et al, didn't design their folders with frequent century 21 air travel in mind :-)
...

If that's the case, I find that disappointing. The B practically begs to be taken on air travel, given its small, regular shape when it's folded.

I may look into the self-extracting bolt idea, though. I would have to figure some way to "hide" the loose right arm within the folded package, while keeping it secured there; however, I think that could be managed with velcro straps.


Originally Posted by cyclistjohn (Post 9015369)
...After reading your post, in the absence of any pictures, I folded my M3L to try to imagine what happened to your chainring.

Since you mentioned your saddle was pushed forward, it was maybe a glancing blow which distorted the outside of your chainring?

...

I'm pretty sure whatever happened involved the corner of some other suitcase being dropped on the M3L's case as it was lying with the B right-side-up. After all, only the upper-left-hand part of the ring is exposed in the folded state: the rest gets covered by the front wheel from the right, and by the rear triangle from the left side.

The glancing blow thing may have happened last time: my saddle was OK this time, which inclines me to suspect a side impact happened.


Originally Posted by cyclistjohn (Post 9015369)
Maybe you can persuade your LBS to take a pic' of the bent chainring?

I could call and ask, but I frankly doubt I'll be able to find time to call (classes are starting up this week), or that the LBS would be inclined to spend time taking photos rather than wrenching.

ECB

EvilV 06-01-09 03:31 AM


Originally Posted by cyclistjohn (Post 9013860)
Problem with hard case is what to do with it when you get out of the airport, especially if you want to ride to hotel, etc.. I suppose you could strap 2 small wheels to it, then tow it along.

We've carried mostly Stridas by air so far, & as there's not much to bend (plastic chainwheel with belt drive) they've survived well, always in a soft golf bag style bag, but like you, we now need a Brompton case. Time to give it some serious thought.......

John

I agree about the problem of what to do with the hard case at the destination airport if you are touring. Luggage Lockers can be quite pricey I think if you want them for a few days or a fortnight. There has to be a 'fingers crossed' approach I suspect unless you box the bike and then obtain another box for the flight home.

I recently took my copy Strida to Barcelona. It went fine on the way out, but received a bad scratch and a smashed rear light on the way back. It could just as easily have had the front pulley broken I suppose, but maybe it is tougher than I think. The SLO was in a rather lightweight soft bag that came free with the bike. As an aside, my other luggage went missing on the return flight too and was delivered to my house the next evening about 28 hours after the flight. Had this happened at the start of the trip it would have wrecked my plans, because we only stayed in Barcelona for an hour and a half before travelling by bus to Pamplona which is a good 300 miles.

The SLO performed an invaluable service as a way of carrying two people's luggage painlessly on a walking holiday. It performed fabulously as a luggage trolley. :lol:

jur 06-01-09 03:40 AM


Originally Posted by EvilV (Post 9018361)
The SLO performed an invaluable service as a way of carrying two people's luggage painlessly on a walking holiday. It performed fabulously as a luggage trolley. :lol:

You look dumber than you are.

Not me. I would have had the other party carry both sets of luggage while I rode the bike.

elmergeorge 06-01-09 11:31 PM

I've travelled with my birdy and DTFS in the soft bag my DTFS came with. I lined it with foamcore (looks like cardboard but with a foam centre) and padded critical points with bubble wrap or clothing(socks etc.) and got pieces of high density packing foam for extra support, lucky we receive a lot of shipments at work I can scavenge from. have had minor problems, cracked latch for the back wheel of the Birdy, broken bell...but otherwise it has been ok, and I can tell that it has been whacked around each time

EvilV 06-02-09 02:54 AM


Originally Posted by jur (Post 9018368)
You look dumber than you are.


The pre-frontal cortex normally screens out such candour, but hey - I'll take it as a compliment and assume you think I have extraordinary mental powers. That way I won't have to confront the idea that you think I look stupid. It would cause me such distress that I might have to check into a clinic specialising in the treatment of mental trauma.

jur 06-02-09 03:49 AM


Originally Posted by EvilV (Post 9025459)
The pre-frontal cortex normally screens out such candour, but hey - I'll take it as a compliment and assume you think I have extraordinary mental powers. That way I won't have to confront the idea that you think I look stupid. It would cause me such distress that I might have to check into a clinic specialising in the treatment of mental trauma.

:D You look quite clever evilV old chap.

Which is why I said, "Not me", meaning I don't look dumber than I am, I AM dumber than I look! :eek:

EvilV 06-02-09 10:59 AM


Originally Posted by jur (Post 9025520)
:D You look quite clever evilV old chap.

Which is why I said, "Not me", meaning I don't look dumber than I am, I AM dumber than I look! :eek:

Oh dear - there we are then. I entirely misapprehended you and made it clear to all that I am not as smart as I look.

I'd better get away from here while the going is good.... Is that the telephone ringing? Must dash.

:D

cyclistjohn 06-02-09 11:23 AM

1 Attachment(s)

Originally Posted by >>ECB<< (Post 9016298)
Here's what I'm getting at:

...........
If, on the other hand, you have a 50 ring bolted to a 130 mm BCD crank, the spider's radius will basically be 130/2 = 65 mm. That means the ring will have to resist bending over a length of (100-65) = 35 mm.

The upshot of all this is that applying equal amounts of force to either chainring will be more likely to bend the swaged chainring, since the force will have 100 mm of leverage--versus only 35 mm of leverage on the bolt-and-spider chainring.

ECB

Something like this (110 bcd here) maybe?

puppypilgrim 06-02-09 11:38 AM

Here is what one person using reverse psychology did:

http://www.fearlessgearless.com/2008...etting-airport

Disassemble the bike. Pack everything into a clear plastic bag. The baggage handlers could see it was a disassembled bicycle and treated it gently instead of throwing it around thinking everything was boxed and protected. The stronger the case, the more the handlers thrash it.

>>ECB<< 06-02-09 09:50 PM


Originally Posted by cyclistjohn (Post 9027658)
Something like this (110 bcd here) maybe?

That's exactly what I mean. :)

ECB


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