Back Brake Stuck! How Unistick?

Elisa Francesca Roselli said:

Flyzipper's up to his tricks again. No blow-outs, touch wood, but today
I noticed a continuous plaintive whine, half mosquito, half baby, as I
was wheeling him, and a kind of grinding hesitation in the rear
quarters. He also seems considerably slower and heavier to ride.

On closer examination back in the garage, I find that the back brake pad
is squeaking against the rim of the wheel on its left side. As I move
the bike back and forth, I can see a little bit of light between the
wheel rim and the brake pad, which then disappears as the squeaking
starts. So not only is the brake not behaving properly, but perhaps the
wheel is off true.

What can I do about that?

Your description sounds a bit more dramatic than a rubbing brake block.
However, the "disappearing bit of light" certainly suggests a wheel
out of true. It's quite easy to fix, but it sounds like you'd rather
not do it yourself, in which case - off to a bike shop.

Before you do that, just in case it's a lesser problem, try carefully
lubricating the brake mechanism (I don't know what kind of brakes you
have) a little including the brake lever and the pivots at the back.
This might free up any sticking and allow the block to clear the rim
when you release the brake.

--
Brian G

in message <[email hidden]>, Elisa Francesca

Roselli (') said:

Flyzipper's up to his tricks again. No blow-outs, touch wood, but today
I noticed a continuous plaintive whine, half mosquito, half baby, as I
was wheeling him, and a kind of grinding hesitation in the rear
quarters. He also seems considerably slower and heavier to ride.

On closer examination back in the garage, I find that the back brake
pad is squeaking against the rim of the wheel on its left side. As I
move the bike back and forth, I can see a little bit of light between
the wheel rim and the brake pad, which then disappears as the squeaking
starts. So not only is the brake not behaving properly, but perhaps the
wheel is off true.

Don't panic! This one is easy.

OK, the simplest answer may be just as you say - the back wheel isn't
installed correctly into its drop-outs. In which case, with the bicycle
upright, loosen the quick release and/or nuts which hold the back axle,
apply a little weight to the saddle just to make sure the back wheel
sits down properly, and retighten the axle.

The other possibility is that the brake has been knocked squint. This
does happen. Looking at the Dahon website it seems you bike probably has
Promax V brakes like this:
http://www.dahon.com/components/deluxe/promax.htm
- there is a boss welded on to the seat stay on each side of the rear
rim, about two centimetres down from the rim. Pivoted on each of these
is a long arm which sticks up above the tyre, and the outer cable comes
into a bent which is attached to one of these arms. The inner cable goes
through the tube and is finally attached to the other arm. If you brake
does not look like this, please post us a picture of it.

V brakes are less likely to get knocked than caliper type brakes, but it
can happen. So once you've satisfied yourself that the wheel is properly
in its dropouts as described above, if the brake is still dragging you
need to adjust it.

On each arm there is a small screw located just above the pivot which
sticks out to the side of the bike. Adjust these screws half a turn at a
time, or even less. on the side which is dragging, tighten the screw
(clockwise). On the side which is not dragging, loosen the screw
(anti-clockwise) exactly as much as you've tightened the other. As I
say, do this half a turn at a time, after each adjustment spinning the
wheel to see if it still drags.

There's a picture on this page, third picture from the bottom, which
illustrates this adjustment:
http://www.parktool.com/repair/readhowto.asp?id=21

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Q: Whats a webmaster?
A: Like a spider, but nowhere near as intelligent.

Elisa Francesca Roselli wrote:
[snip]

Quoted message said:

On closer examination back in the garage, I find that the back brake pad
is squeaking against the rim of the wheel on its left side. As I move
the bike back and forth, I can see a little bit of light between the
wheel rim and the brake pad, which then disappears as the squeaking
starts. So not only is the brake not behaving properly, but perhaps the
wheel is off true.

First, check that the wheel hasn't shifted in its dropouts - that could
cause both issues.

What type of brakes are these - caliper or cantilever? Calipers
sometime rotate and get stuck - a bit of lube on the pivot(s) and some
'working' of the brake by hand is usually enough to get it to recenter
automatically.

Cantilevers stick too, and you usually have to remove the brake arm
(with an allan wrench), clean (with emery paper) and lube (with grease)
the pivot post and reinstall the brake arm. This doesn't affect the
adjustment of the brakes, so is actually fairly easy to do.

As to the wheel being off true, a mm or so isn't a big deal. If you
feel serious pulsing through the brakes, get it seen to. (It's actually
quite easy to do on the bike, too, but a bit fiddlely.)

- Brian "I am not a mechanic" Huntley

Elisa Francesca Roselli said:

Flyzipper's up to his tricks again. No blow-outs, touch wood, but today
I noticed a continuous plaintive whine, half mosquito, half baby, as I
was wheeling him, and a kind of grinding hesitation in the rear
quarters. He also seems considerably slower and heavier to ride.

On closer examination back in the garage, I find that the back brake pad
is squeaking against the rim of the wheel on its left side. As I move
the bike back and forth, I can see a little bit of light between the
wheel rim and the brake pad, which then disappears as the squeaking
starts. So not only is the brake not behaving properly, but perhaps the
wheel is off true.

The wheel probably is a bit out of true, yes, but if the wobble in the
wheel is less than a millimeter, I think there's a possibility that
the brakes are adjusted a bit too close as well.

Quoted message said:

What can I do about that? The back wheel is more problematic than the
front because of all that gear paraphernalia that is on it - derailleur
plus SRAM dualdrive. I wouldn't have a clue how to take it off, and I'm
heistant to mess with something as critical as a brake.

This requires no removal of the wheel. Depending on whether you have
a dual-pivot caliper or a V-brake setup, there will be one or two
small screws that adjust spring tension to center the brake. Turning
those changes the resting position of the arm and pad. It would be
good to learn how to adjust them anyway, as fiddling with this is
something that will need to be done from time to time. It is not
rocket science.

Quoted message said:

What behaviour on my part may have brought this about? On my new way
home, I have some very steep descents, and some nasty harsh stops. Last
night, too, I was driven home by a colleague, which means that Fly got
folded to go into the boot. Now, Fly may well be a folding bike by
vocation, but my impression is that he doesn't really like to be folded
and often develops little maladjustments as a result of frequent
folding-unfolding.

This is, in fact, a common problem with many folding bikes; that's
another reason why it's advisable to become familiar with the various
minor adjustments.

If you have V-brakes, this will help illuminate the subject:

http://sheldonbrown.com/canti-direct.html

As for truing the wheel, it's fairly simple in most cases. the basic
technique is this; in the area where the wheel's rim deflects to one
side, tighten the spokes on the sides *away* from the deflection.
This is done by using a spoke wrench to turn the small sleeve-like bit
at the outer end (the "spoke nipple"😉. If you are looking down at the
wheel from above, and the spoke is pointing from the hub towards you,
the tightening direction is clockwise. Give the nipples a
quarter-turn at a time, and check to see if the wheel is acceptably
trued after at least each pair of spokes; as you approach perfection,
check after each spoke. When the wobble is no longer great enough to
see, celebrate and go for a ride. (Recheck the truing afterwards!)

It is usually advisable to true a wheel by just tightening spokes, but
sometimes it may be necessary to loosen one. Pluck each of the
spokes, and if one hits a much higher note (a soprano amongst tenors),
and that spoke is on the side toward the deflection and is in the
region that requires attention, you may want to back off on it a
quarter-turn.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Brian Huntley said:

What type of brakes are these - caliper or cantilever?

Uhhm, well the specs say:

BRAKES Dahon SpeedStop V brakes, stainless flex noodle, front power
modulator, mini brake bolts, stainless link and anchor bolt
BRAKE LEVER BioLogic V, ultra-smooth machined pivots, Kraton insert
CABLES AND HOUSING SIS housing, slick cable, aluminum cable stops

That's worse than computer speak, surely...

What kind of lubricant should I try? When I asked at a snooty bike shop
on my way home for a good lube for my bike, they said there were many
kinds depending on if it was for the chain, for this, for that... I know
some oils can melt some rubbers, so I wouldn't want to have the wrong
product that near the tyres.

Thanks, I'll see about checking that wheel-in-drops thingy tomorrow.

EFR
Ile de France

Damn, I've made it much worse. Decidedly the Gods are not with me.

I went down to see about the wheel shifting in its dropouts. It was only
possible to loosen the bolt on one side, because on the side with the
shifters the attachment is too complicated.

With the bike upended, the wheel is so stiff it will not even spin. When
I force it to turn, it will not freewheel, but takes the pedals with it.

I turned it upright and tried applying a little pressure to the seat as
described, but it did not resolve the problem. When I wheel the bike
around, I can actually _see_ the back brake squidging around on its own.

But to add insult to injury, I broke the computer, an essential
component in my fitness tracking. I tried re-folding the bike in the
hope that it might undo whatever evil had assailed it from last being
folded. When I unfolded again, the computer cable caught in the pedal
and snapped.

So no bike tomorrow. On Saturday I must forswear all other activity to
get him all the way to Gif, five towns away, where there is the only
bike shop in the county willing to service him. They will keep him for
at least a week, and I shall not be able to cycle on my 50th birthday
(Monday), which to my superstitious nature is a really bad omen.

Why is this bike so fragile? I love him so, he's the only bike I really
enjoy riding, but he's like Beth in Little Women, exquisitely bedridden
and tear-jerking.

EFR
Ile de France

Elisa Francesca Roselli said:

Damn, I've made it much worse. Decidedly the Gods are not with me.

I went down to see about the wheel shifting in its dropouts. It was only
possible to loosen the bolt on one side, because on the side with the
shifters the attachment is too complicated.

With the bike upended, the wheel is so stiff it will not even spin. When
I force it to turn, it will not freewheel, but takes the pedals with it.

I turned it upright and tried applying a little pressure to the seat as
described, but it did not resolve the problem. When I wheel the bike
around, I can actually _see_ the back brake squidging around on its own.

But to add insult to injury, I broke the computer, an essential
component in my fitness tracking. I tried re-folding the bike in the
hope that it might undo whatever evil had assailed it from last being
folded. When I unfolded again, the computer cable caught in the pedal
and snapped.

So no bike tomorrow. On Saturday I must forswear all other activity to
get him all the way to Gif, five towns away, where there is the only
bike shop in the county willing to service him. They will keep him for
at least a week, and I shall not be able to cycle on my 50th birthday
(Monday), which to my superstitious nature is a really bad omen.

Why is this bike so fragile? I love him so, he's the only bike I really
enjoy riding, but he's like Beth in Little Women, exquisitely bedridden
and tear-jerking.

EFR
Ile de France

Quelle dommage (I think that's sort of commiserations in French; if I've
just written something deeply insulting, please ignore it). It sounds
like a trip to the bike shop is now unavoidable. Would the shop
hire/lend you a bike for birthday cycling? Or would that be especially
unpropitious? As an alternative, could you give yourself a book on
bicycle maintenance as a birthday gift? Or book into maintenance
classes? This is not meant to be an ironic suggestion; bike
maintenance, at least at the basic levels, is not difficult, once the
principles are grasped. It is very satisfying and it provides you with
defences against these attacks by the gods of ill-nature.

Bonne chance! (That's meant to imply good luck; again, if I've written
an insult ...) :-)

--
Brian G

in message <[email hidden]>, Elisa Francesca

Roselli (') said:

Damn, I've made it much worse. Decidedly the Gods are not with me.

I went down to see about the wheel shifting in its dropouts. It was
only possible to loosen the bolt on one side, because on the side with
the shifters the attachment is too complicated.

With the bike upended, the wheel is so stiff it will not even spin.
When I force it to turn, it will not freewheel, but takes the pedals
with it.

OK, don't panic.

The first thing is to check that it /is/ the brake that's the problem.
(Assuming V brake) the little bent piece of tube the cable passes
through clips into a sort of long stirrup which is attached to the top
of one of the brake arms. The wire then comes out of the tube and is
attached to the other brake arm. If you squeeze the two brake arms
together, you can easily unhook the bent piece of tube from the stirrup.

The two arms should now flop apart. If the brake was to blame for the
wheel binding, it should now spin freely. If it does not spin, the
problem was not the brake.

Assuming it spins, as it spins, you will be able to see whether it
appears to wobble from one side to another. If it 'wobbles' by less than
2mm, don't worry. Some degree of wobble is acceptable.

Reattach the brake by again squeezing the arms together and this time
hooking the bent pipe back into the stirrup. Ensure that it has properly
clicked into place. Again turn the wheel. Does it touch the block only
on one side, or on both?

If on both, but the wobble is less than 2mm, then I would advise
loosening the cable a bit. On this page:
http://www.parktool.com/repair/readhowto.asp?id=21
find the picture with the caption 'Use barrel adjuster to set tightness
of pads to rim'. You want to loosen the pads, so you want to unscrew the
locknut a bit, screw the barrel two or three turns into the brake lever
body, and retighten the locknut.

If, however, the brake is rubbing on one side only, there are two
possibilities:

(1) the wheel is squint in the frame, in which case looking at it you
will see that the tyre is not central between the two chainstays. If
this is the case I'm afraid you're just going to have to tackle that
axle bolt; or

(2) the brake is squint, in which case you need to adjust the brake arms
as shown in the picture with the caption 'Use centering screws to move
arms and center pads to rim' on the same page.

Quoted message said:

But to add insult to injury, I broke the computer, an essential
component in my fitness tracking. I tried re-folding the bike in the
hope that it might undo whatever evil had assailed it from last being
folded. When I unfolded again, the computer cable caught in the pedal
and snapped.

Much sympathy. I broke the cadence sensor cable on my own computer though
very similar cackhandedness.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; We don't just borrow words; on occasion, English has pursued other
;; languages down alleyways to beat them unconscious and riffle their
;; pockets for new vocabulary -- James D. Nicoll

Simon Brooke a écrit :

Quoted message said:

Much sympathy. I broke the cadence sensor cable on my own computer though
very similar cackhandedness.

No more cabled computers for Flyzipper. Now I'm in the market for one of
those Polar thingys that does everything by thought transmission except
make coffee.

Fly has wanted one of those since the last MeRx. I wonder if he didn't
break his cable on purpose to get a prezzie.

EFR
Ile de France

The Bicycle Angel of Paris is coming to have a look at that brake
tomorrow. If he can't figure it, I doubt the LBS of Gif would do better.

Much relieved.

EFR
Ile de France

Brian G a écrit :
Or would that be especially

Quoted message said:

unpropitious? As an alternative, could you give yourself a book on
bicycle maintenance as a birthday gift?

I've got three of those. They don't help much. Too much difference
between theory and practice and I'm too scared to force anything for
fear of doing major damage, so I never know whether something just needs
a good whack.

Or book into maintenance

Quoted message said:

classes? This is not meant to be an ironic suggestion; bike
maintenance, at least at the basic levels, is not difficult, once the
principles are grasped.

Great personal tutor coming tomorrow. I know much more about inner tubes
and wheels since his last visit, and will lilely know much more about
brakes very soon.

EFR
Ile de France

Artemisia said:

No more cabled computers for Flyzipper. Now I'm in the market for one of
those Polar thingys that does everything by thought transmission except
make coffee.

On a small-wheeled bike check very carefully that a wireless computer
has sufficient range. They are normally rated for 75cm max, and that's
probably not enough for you.

Mike

Elisa Francesca Roselli said:

So no bike tomorrow. On Saturday I must forswear all other activity to
get him all the way to Gif, five towns away, where there is the only
bike shop in the county willing to service him. They will keep him for
at least a week, and I shall not be able to cycle on my 50th birthday
(Monday), which to my superstitious nature is a really bad omen.

Out of curiousity, since you mentioned the existence of a local bike
shop ... why is the one in Gif the only one willing to service him?

-M

Elisa Francesca Roselli said:

Brian Huntley said:

What type of brakes are these - caliper or cantilever?

Uhhm, well the specs say:

BRAKES Dahon SpeedStop V brakes, stainless flex noodle, front power
modulator, mini brake bolts, stainless link and anchor bolt

That's excellent news, in all likelihood. V-brakes are perhaps the
easiest to adjust of all since their design is so straightforward and
predictable. There are several links already posted which should
help; trust me, you can do this.

Quoted message said:

That's worse than computer speak, surely...

It's not as difficult as learning English!

Quoted message said:

What kind of lubricant should I try? When I asked at a snooty bike shop
on my way home for a good lube for my bike, they said there were many
kinds depending on if it was for the chain, for this, for that... I know
some oils can melt some rubbers, so I wouldn't want to have the wrong
product that near the tyres.

In the absence of anything better, ordinary motor oil will work for
most everything on your bike, but it has the disadvantage that it
attracts dirt and makes a nasty mess as it becomes contaminated with
dust and grime; this is primarily an issue on the chain. Everywhere
else, just use it sparingly and you should have no problem. The chain
merits special consideration; since Flyzipper must be on good behavior
when seated in the back or boot of a car, it would be wise to use a
"dry" chain lube to reduce the nasty-greasy-mess problem to a minimum;
consult the bike shop for a recommendation.

Quoted message said:

Thanks, I'll see about checking that wheel-in-drops thingy tomorrow.

Bonne chance!

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Elisa Francesca Roselli said:

Damn, I've made it much worse. Decidedly the Gods are not with me.

It seems that a lot of your problems are caused by the fact that you
ride a "folder" with some non-standard components. Would it be practical
to switch to a more "main-stream" bike? It's like owning a 1939 purple
Lagonda - they're lovely, but service/repair/maintenance is daunting. I
have a similar problem with my trike - I have to maintain it myself
since no one has the vaguest idea about them around here.

Further - Happy Birthday

I hope to meet you on the road!
Triker

So, James the Bicycle Angel was here much of today. He was able to
diagnose the problem with Flyzipper's back wheel almost immediately: the
wheel was out of true because a spoke had broken. It looks as though the
wheel has taken a serious knock - James also found a nicked bit in the
tyre - yet I cannot remember perceptibly going over some big bump,
although my path to work is strewn with ugly rocks. Nothing wrong with
the brake, apparently.

Now, the spoke is a non-standardized part of a wheel off a bike that is
not supported in France. The size, 172mm x 2mm, is also very rare. I
spent about 20 minutes phoning bike shops throughout Paris and Essonne -
no hope of getting this spoke size here or of having one cut to length
(French bike vendors do not offer this service).

Luckily, I'm coming to London next week, for just a day and a half. So I
start phoning the shops in London. Bikefix don't have this spoke. Condor
might, they have to rootle through their spoke selection one by one.
Evans the Cut not only do not have it despite stocking Dahon, but say it
would have to be special ordered and that this would take at least two
weeks.

Blessed be Haywards in Cambridge. If all else fails, they will be able
to cut the spoke to size for me. This will involve a day-trip to
Cambridge carved out of what is scarcely more than a day-trip to London,
and will make for the most expensive bike spoke ever sold (somewhere in
the order of 280 Euros counting all the train fares and the
overnight). But at least I have a batting chance of having my bike road
ready for my trip in the Loiret. If I take it to a French LBS, they will
order the spoke, it will take a month to arrive and they will charge me
150€ for the repair because I am a completely captive market.

Indeed, I would like to buy a whole set of spokes, since if one dies,
very likely the remainder will start dying around the same time, but
James tells me they are not all the same size.

Anyone here have recommendations for London shops with spoke cutting
services or fully committed to Dahon maintenance? I would prefer not to
have to travel with the whole wheel (besides which James has reassembled
it so as not to lose bits and pieces).

Heigho,

EFR
Ile de France

Quoted message said:

Elisa Francesca Roselli wrote:

Out of curiousity, since you mentioned the existence of a local bike
shop ... why is the one in Gif the only one willing to service him?

-M

The nearest LBS, just round the corner, will only service bikes they
sell themselves. They have never been able to come up with a bike that
interested me in the least. I broke commercial relations with them two
years ago.

EFR
Ile de France

HANDSOME PRINCE said:

It seems that a lot of your problems are caused by the fact that you
ride a "folder" with some non-standard components. Would it be practical
to switch to a more "main-stream" bike?

I'm too far off main-stream myself.

I spent three years looking for a bike that would suit my purposes and
concluded that simply nothing available in France will do.

Flyzipper is my third bike. I found a prototype at a bike fair in
Islington and ordered him on the Internet. He was only on the market for
about 18 months or so before Dahon discontinued the model!

The other two, Myrtille and Behemoth, are in the garage, unridden,
although I sometimes go to the supermarket with Myrtille. I cannot
reliably get to work with either since they do not have enough gears and
Behemoth is too heavy, and the fact that they do not fold make them
unsuitable for taking on tours.

Flyzipper is perfect for me. We are both in a category by ourselves. It
is nearly impossible to be as obsessed with bikes as I am and at the
same time be such a weak, "special needs" cyclist. People simply
wouldn't cycle at all if they cycled as badly as I do. (Remember I'm the
one who took two and a half years just to learn to balance on a
kick-scooter - this too a special order job from Xootr in the USA.) Or
they would never dream of an upmarket bike (by the time he got to
France, Fly cost 900€). If they are willing to spend 500€+ on a bike,
it's because they are lycra types with TdF ambitions. So I constantly
fall between markets, and in a mass-production society I am simply not
cost-effective.

James says I should take a look at Moultons. They would not be any more
"standard" than Fly, and are a lot more expensive, but at least they are
an ongoing proposition.

EFR
Ile de France

Elisa Francesca Roselli said:

Now, the spoke is a non-standardized part of a wheel off a bike that is
not supported in France. The size, 172mm x 2mm, is also very rare. I
spent about 20 minutes phoning bike shops throughout Paris and Essonne -
no hope of getting this spoke size here or of having one cut to length
(French bike vendors do not offer this service).

Order it online from St John St Cycles for 30p each (plus P&P!!!) and
it will be at your home by the time you get back from London. The link
to the webpage for 172 x 2mm spokes is
http://www.sjscycles.co.uk/product-SJSC-British-made-14g-stainless-steel-plain-gauge-spokes-3145.htm

Tony