iambaytor

Hi there,

I was wondering if anybody could save me another trip to the bike shop on the weekend. I bought a bike for my six (now seven) year old daughter from a local shop that sells second hand bikes, I have bought about four or so from here with no issues. But, with this bike, the brakes seemed to start coming open within the space of a week and I had to take it back to the shop to be fixed. It's been okay for a few months but my daughter went out on it yesterday and came back screaming the house down, saying that the brakes failed. And yes, they are both wide open and, when the brake levers are pressed in, the brake blocks don't connect with the wheels. I have attached pictures of what the brakes look like both open and with the brakes engaged. The front brake issue I've had in the past with other bikes and have been able to stuff it back in, but as you can see from the picture "front closed", it's impossible to get the two parts to meet, which is odd. [edit: apparently I can't post pictures unless I have ten posts, so if anybody needs pictures, I'll try to find another way to post them]

The brakes say Tektro on them, if that helps.

I'm sure it's a simple fix but I'm not sure what it is so if anybody could point me in the right direction I would appreciate it, thank you.

HillRider

What's the Tektro model number and are these V-brakes, cantilevers or calipers?

dsbrantjr

Without being able to see anything, I suspect that you have V-brakes (AKA direct-pull cantilever) and that the noodle (curved metal tube that carries the cable to the brakes) has come loose. It also sounds like one of the cable housings has come out of its stop, making the housing effectively too long to put the noodle back. I would suggest that you check the entire cable run an see if this has happened and re-seat the housing, then you should be able to replace the noodle. https://www.sheldonbrown.com/canti-direct.html

iambaytor

Thanks for getting back to me, I'm going through the articles now. When you say replace the noodle, I take it you mean buying a new one?

dabac

Probably not.
The noodle is supposed to be easy to unhook/reattach at the hinged bracket it sits in at the top of the brake arm as a means of getting some extra clearance for wheel removal.
If it's only come out accidentally w/o any further damage, you shouldn't need to replace it. They tend to last for years. Pull the rubber boot down towards the brake arm (if it hasn't slid off already)where the cable is clamped and the tip of the noodle/clamp should slide right in that sort of keyhole-shaped slot in the hinged bracket and allow the noodle to seat itself safely.

iambaytor

Ah, that's good to know. I'll take a look when I get home and if all else fails I can always take it to be fixed on the weekend...

iambaytor

Okay, they are V brakes but I couldn't say what the Tektro model is.

Concentrating on the back brake, I noticed that part of the noodle had come out of its housing on the frame of the bike itself, so I put that back in but still when the brakes are applied the blocks don't touch the wheels.

I thought I could then unscrew the bolt attaching the brake cable to the caliper and pull the cable through, tightening it up a little bit - but this has ended up meaning that, when the bicycle is steered, the cable can get tight and it effectively puts the brakes on when you turn! I remember this happened when I did this to keep tightening the brakes when we bought it.

Now I've restored the cable to the slack it originally was at the caliper bolt.

However, I have noticed that, when the bike is steered, it still pulls on the cable and causes the brakes to move in and out, so how do I deal with this and how do I get the brakes to actually connect??

WizardOfBoz

Keep posting replies and you'll be able to directly add photos. But you can add links to imgur or googlepics that we could look at.

iambaytor

Okay, so pics of the rear braking system:

m.imgur.com/a/IbbmJzl

So, as you can see, I managed to get part of the cable/noodle tightened up by putting it back it its holder on the frame, but turning to the left opens the brakes and turning to the right closes them. I remember this was an issue from before....

iambaytor

And, like I say, squeezing the brakes doesn't cause them to connect (from a "straight ahead" position on the handlebars anyway, it might work if you're turning right sharply!)

Bill Kapaun

Sometimes looking at another bicycle with the same parts can be educational in determining how things fit together.

jimc101

The 3rd picture down shows your issue, with the cable outer not being inserted correctly into the frame guide.




Cable out of guide


That this can come out is concerning, and as you don't appear to have any real knowlage of fixing bikes, and this if your daughters bike, would take it to a good LBS and thinking that is probably not where you purchased the bike from, if this was how they supplied it.

You need to identify why the cable outer is comming out of the frame guide, as correctly set up, and under normal conditions, this should not happen. the handlebar is a mess as well, cable look to be out of their guides.



Messy cables

sweeks

The cable housing is tight around the head tube, possibly mis-routed. When the bike is steered to the right, this pulls the cable housing out of the frame's cable stop. The next application of the rear brake will not be successful.
Get thee to a cyclery (a *good* one).

Wilfred Laurier

Above is correct. The mis-routed cable, though, may just be hung up on the handlebar-mounted reflector, or twisted around another cable (which is definitely hung up on the reflector).

iambaytor

Hi all,

Sorry I couldn't reply sooner but forum restrictions meant I couldn't post for 24 hours. Well, I would've hoped to sort it myself but it's the weekend now anyway so i'll take it to another cycle shop tonight. I can't see any other way for the cable to go in the frame... also, the cable looping round the reflector on the handlebars was something the bike shop did. But i'll get it serviced properly at another shop I used to go to. thanks for all your help anyway

JoeTBM 

It looks to me like the fork may be turned an extra 360 degrees, turn it in the other direction 360 degrees so the housing unwind from the steerer tube.

Housing routing should be smooth without any sharp to tight bends

dabac

Spend a little time thinking about how the system of cable + cable housing works.
For extra merits, do a net search on "Bowden cable" and educate yourself.
Basically, to be able to transfer a motion w/o simply pulling the cable tight between the end points, the cable housing has to have something to brace against.

Now look at the pic in post #12(by jimc101). In the left of the pic, just below the last "S" in "Abyss", the cable housing is simply floating freely away from the frame.
It should be anchored into a frame-mounted cable stop, just as it is in the middle of the pic, at the rear of the top tube, right below the welded reinforcement between seat tube and top tube.

W/o the housing having something to brace against, pulling the lever will simply try to tighten the cable between the end points.Something which doesn't work out well when that distance will change as you turn the bars.
Get the housing back into the stop and your odds of returning function to the brake will be greatly improved.

Also, at the very least, unhook the cable from the reflector. Check that the fork hasn't been spun around. The cables should go in smooth bends and not wind around anything.

(disclaimer: BMXers sometimes run/ran the rear brake cable in a lazy spiral around the head tube or stem to be able to do a few bar spins w/o the brake binding up. Nowadays, people wanting to those kinds of tricks will either run gyros/detanglers, or ride brakeless.)

dabac

This isn't right either:


The noodle has come out of its bracket at the other brake arm, and the rubber boot has slid over the fitting at the end of the noodle that's supposed to sit in the hinged bracket on the other brake arm.
Once you've untangled the twisted cables, you should have enough slack in the system to slide the boot off the end of the noodle and get it re-seated in the hinged bracket on the other brake arm.

iambaytor

Hi all

I took it to another shop as a few people suggested and got it sorted there. Now I've seen what it should all look like, maybe I stand a chance at having a go at fixing such things another time.

Thanks for all your help

Bill Kapaun

like in post #11 ?