e-Brompton after thousand of miles

cwah

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Jun 3, 2011
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My motor rim is getting really BAD!!

I didn't really try to fix it initially, but the rim bent once more and now it looks like this:


The protuberance is getting so big it kept rubbing against my brake.

Here a picture from far:


It's so big I don't think turning the spoke nipples would change anything. I tried a bit with a hammer to knock it down but I'm afraid to destroy anything.

Any idea how to solve that? I don't get how that can happen!!! Maybe LondonA Deadly potholes at 30mph :(
 

Scimitar

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Jul 31, 2010
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From the pics it looks like your rim brakes have worn a deep groove in the rim (that's normal with lots of use) and there's not much strength in it. Rim (with rim brakes) are a service item, unfortunately, so you'll have to bite the bullet and replace them.
 

cwah

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Jun 3, 2011
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:( :( :(


But how it happened? I hammered a few times before so maybe that's why it worned out. Anything I can do to save the rim????
 

103Alex1

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Sep 29, 2012
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That rim has had its day - definitely time for a new one - it's not worth trying to save it (imho). It's not just the bulge - braking at high speed lots will wear rim (and brake pads) - and that rim has LOTS of wear. Maybe best check your brake pads too (!) - if brakes failed going fast ....... sometimes not a pretty outcome ...
 

jerrysimon

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Aug 27, 2009
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Yep time for a new rim. My guess is you hit a kerb or as you say a pot hole. I I would love to see the rim brakes as I don't see how they would work the the rim edge bent out like that ?

I am also surprised the tyre is not damaged. Its clearly not a good idea to ride it like that at any speed.

Jerry
 

cwah

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Jun 3, 2011
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I've already worn out few brake pads. I also lost few ones due to loose bolt.

So my pads are quite new now, as I changed them recently.


I can still brake as usual, except I hear a "TAP TAP TAP TAP" louder when I brake... and when I cycle faster!


I'm quite annoyed because the rim is less than 1 year old... and I already have to change it. It's a CR18 rim 36H that is NEVER in stock.

If there's anything I can do to save it, I'd be quite happy... otherwise... I either have to send it back to Catsnapper to relace it or try it on my own :(


ps: Surprisingly, my rear tyre has never been damaged on my brompton. I NEVER had a puncture on the rear wheel. The marathon plus tyre was a real pain to fit to my wheel, but this hard work worth it :)
 
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jerrysimon

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Aug 27, 2009
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The bent rim is hitting the brake block hence tap tap tap when you brake and must be riding over the bent rim.

I now try to get all my Brompton hub motor with 28h drilling so I can use their stock rims.

Jerry
 
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cwah

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Yes but for my motor I think I need strong rim.... Anyway now I have to do some magic to find these CR18 349mm 36H rim...
 
D

Deleted member 4366

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One thing that you can try that might make it a bit better.

Take the tyre and rim tape off; heat up the damaged area with a blow-torch 'til nearly red hot; use mole-grips or similar to tease the rim back to where it came from. You'll find it moves easily for a bit and then stops. Don't force iit. Heat it up again and do a bit at a time until it's back in position. If you try and move the metal too far in one go, it'll snap - the same if you do it cold.
 

MikeyBikey

Pedelecer
Mar 5, 2013
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If rim puckered once, it'll probably do it again once its that thin :-(
Its usually the rear chain side rim that goes first, coz oil attracts dirt and grinds it down.
is that your front or rear wheel? Could 28h rim go on 36h hub by 'skipping' some spokes?
I've often wondered if:
Dual box rims are really stronger than single box, or are they just more rigid?
Wear indicator groove weakens the rim, or are they thicker to compensate? (inside or outside?)
Are Koolstop Salmon brake blocks any easier / less wear on rims?
Cheers, Mike
 

jerrysimon

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Aug 27, 2009
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Agreed a new rim is what's required. He's using a rear motor and a powerful one at that with a total 36h count flanges. Not a good idea to lace it with 28 spokes.

I have seen rims laced with less/missing spokes, but if I was to try it I would only do it on a front wheel.

Either disk/drum brakes or this is the best answer to no rim wear :p



But then with this coaster brake hub you would have to put your motorised hub on the front wheel.



Jerry
 
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cwah

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That is damn annoying... It's on my rear wheel motor and it has a lot of torque. Enough to climb any slope and start faster than any car on the road ;)

It did wear on the chain side, as you said, good insight!


For the koolbrake pad I have no idea how is it against rim. Bacause I'm not using them.

It's also probably the reason this rim has been quite stressed.


I'm in touch in catsnapper but he does not longer lace electric motor... So I probably have to learn how to do it!
 

Old_Dave

Esteemed Pedelecer
Sep 15, 2012
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Anything I can do to save the rim????
Substitute the word parrot for rim :p

[h=3]The sketch:[/h] A customer enters a pet shop.
Mr. Praline: 'Ello, I wish to register a complaint.
(The owner does not respond.)
Mr. Praline: 'Ello, Miss?
Owner: What do you mean "miss"?
Mr. Praline: (pause)I'm sorry, I have a cold. I wish to make a complaint!
Owner: We're closin' for lunch.
Mr. Praline: Never mind that, my lad. I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.
Owner: Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?
Mr. Praline: I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!
Owner: No, no, 'e's uh,...he's resting.
Mr. Praline: Look, matey, I know a dead parrot when I see one, and I'm looking at one right now.
Owner: No no he's not dead, he's, he's restin'! Remarkable bird, the Norwegian Blue, idn'it, ay? Beautiful plumage!
Mr. Praline: The plumage don't enter into it. It's stone dead.
Owner: Nononono, no, no! 'E's resting!
Mr. Praline: All right then, if he's restin', I'll wake him up! (shouting at the cage) 'Ello, Mister Polly Parrot! I've got a lovely fresh cuttle fish for you if you show...
(owner hits the cage)
Owner: There, he moved!
Mr. Praline: No, he didn't, that was you hitting the cage!
Owner: I never!!
Mr. Praline: Yes, you did!
Owner: I never, never did anything...
Mr. Praline: (yelling and hitting the cage repeatedly) 'ELLO POLLY!!!!! Testing! Testing! Testing! Testing! This is your nine o'clock alarm call!
(Takes parrot out of the cage and thumps its head on the counter. Throws it up in the air and watches it plummet to the floor.)
Mr. Praline: Now that's what I call a dead parrot.
Owner: No, no.....No, 'e's stunned!
Mr. Praline: STUNNED?!?
Owner: Yeah! You stunned him, just as he was wakin' up! Norwegian Blues stun easily, major.
Mr. Praline: Um...now look...now look, mate, I've definitely 'ad enough of this. That parrot is definitely deceased, and when I purchased it not 'alf an hour ago, you assured me that its total lack of movement was due to it bein' tired and shagged out following a prolonged squawk.
Owner: Well, he's...he's, ah...probably pining for the fjords.
Mr. Praline: PININ' for the FJORDS?!?!?!? What kind of talk is that?, look, why did he fall flat on his back the moment I got 'im home?
Owner: The Norwegian Blue prefers keepin' on it's back! Remarkable bird, id'nit, squire? Lovely plumage!
Mr. Praline: Look, I took the liberty of examining that parrot when I got it home, and I discovered the only reason that it had been sitting on its perch in the first place was that it had been NAILED there.
(pause)
Owner: Well, o'course it was nailed there! If I hadn't nailed that bird down, it would have nuzzled up to those bars, bent 'em apart with its beak, and VOOM! Feeweeweewee!
Mr. Praline: "VOOM"?!? Mate, this bird wouldn't "voom" if you put four million volts through it! 'E's bleedin' demised!
Owner: No no! 'E's pining!
Mr. Praline: 'E's not pinin'! 'E's passed on! This parrot is no more! He has ceased to be! 'E's expired and gone to meet 'is maker! 'E's a stiff! Bereft of life, 'e rests in peace! If you hadn't nailed 'im to the perch 'e'd be pushing up the daisies! 'Is metabolic processes are now 'istory! 'E's off the twig! 'E's kicked the bucket, 'e's shuffled off 'is mortal coil, run down the curtain and joined the bleedin' choir invisible!! THIS IS AN EX-PARROT!!
(pause)
 

jerrysimon

Esteemed Pedelecer
Aug 27, 2009
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112
Cambridge, UK
So I probably have to learn how to do it!
Always the best route if you have the patience and amplitude. Can't beat being self sufficient when it comes to building bicycle wheels :p

Jerry
 

cwah

Esteemed Pedelecer
Jun 3, 2011
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Daaaamn, is it dead or not this rim? I'm about to buy a small methane torch to bent it back to life!!!


I'm not sure if I have patience or amplitude, but I think I don't have much choice as my brompton is very custom and wear most parts much faster than normal... :/


At least I know it's kinda special :)
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
67
I'm in touch in catsnapper but he does not longer lace electric motor... So I probably have to learn how to do it!
Trust me, if I can do it then so can you ! Just needs a lot of patience, a suitable spoke wrench and a few spare spoke nipples. I sat in front of the telly doing mine over a couple of evenings... with a load of advice and a book. It wasn't as hard as it first seemed although having to dish it was a bit more than I expected on the first one.

Daaaamn, is it dead or not this rim? I'm about to buy a small methane torch to bent it back to life!!!
Let's be honest, you've very little to lose trying apart from a bit of wasted time at worst. You can always use the methane torch to make some Creme Brulees if it doesn't do the job so all is not lost !
 

MikeyBikey

Pedelecer
Mar 5, 2013
237
23
Yes, unfortunately small rims have less braking surface metal due to the shorter circumference.
And the weakening caused by cutting the indicator groove does not help either :-(
(is it what is called a 'stress riser'?)
Pity one can't epoxy on extra metal and extend their life!
Their is no incentive for manufacturers to make rims thicker, because we would buy less and also everyone looks for the lightest.

I bought a rim and spokes once, but chickened out and took it to a shop.
When I tried the recommended technique of taping the rims side by side and swapping spokes over one by one, the small diameter made the angles too acute.
Sorry, im not helping, am i? So I'll bow to those who know, but take pics of current pattern first for ref?

Cheers, Mike