My new bike has arrived boxed and partly built. The manual is generic and unclear. The front brakes need to be widened to fit the wheel, it says to 'disengage the cable guide tube from it's yoke'. Not sure where or how and I don't want to force anything and break it.
Here's an annotated rotated version of your photo:
To get the wheel in:
- Pull the RUBBER BOOT to the right, slide it along the INNER CABLE toward the PINCH BOLT
- Squeeze the BRAKE ARMS together at the top. This allows the NOODLE to move to the left, permitting the YOKE to swing away from the NOODLE. When the bike is upside down like yours, it may need a hand.
- Release the BRAKE ARMS and they will rotate outwards a lot under spring pressure.
- Now you can install your wheel
To close the brakes back up:
- Make sure the YOKE is dangling downward, toward the tyre.
- Squeeze the BRAKE ARMS together, and hold in place with one hand. An assistant might be needed here.
- Manoever the end of the NOODLE into the hole in the YOKE. Once its seated, gently release the BRAKE ARMS and they should hold their position.
- Slide the RUBBER BOOT back onto the end of the YOKE to protect the INNER CABLE.
Do this as soon as you finish putting the wheel in - its very easy to forget and ride off with no brake otherwise !
Other initial setup tasks that will be needed:
- You need to adjust the brake pads - they're not at the same height so at least one of them won't be on the rim brake track on the wheel.
- The arms appear to be leaning to the bike's left. There will be a tension adjustment near the brake arm's pivots - either a small philips head screw, or a small hex socket. When releasing the brake lever, the two arms should move out from the wheel about the same distance.
- Also, your brake lever in the initial photo looks like its on the wrong side of the bars - brake levers should be inside your fingers, not at the base of your palms.
Most V brakes can be disengaged by the process the manual says. Anther term for this part is the cable-hook link or the cradle and the noodle. Some most-basic V-brakes do not have this feature and may require releasing the cable-fixing bolt.
The process is shown in this video
Then you will have to properly setup the tension to get the correct braking action and avoid any rub. There are many tutorials about this. Some brakes are more adjustable than others. The better ones have adjustable springs on each caliper.
One of the tutorials is here
There are two ways to assemble a new bike.
- The right way
- The way it's usually done
To answer your question:
The front brakes need to be widened to fit the wheel, it says to 'disengage the cable guide tube from it's yoke'. Not sure where or how and I don't want to force anything and break it.
It looks like you are concerned with getting the front wheel on the bike. The tire is keeping the wheel from going past the brake shoes.
The easiest way (non-technical) to get the front wheel on is to:
- Let some air out of the tire.
- Slide the front wheel into the fork.
- Squish the tire as it passes through the front wheel.
- Slide the axle into the fork slots and tighten the nuts or adjust and tighten the quick release.
- Air the tire to the correct pressure.
I would like to offer pictures of how to "disengage the cable guide..." but I don't know what kind of brake you have to get the right pictures.
In the absence of information I'm going to guess you have a bike that does not have sealed bearings and offer one small step in correct assembly.
While you have the front wheel off spin the axle between your thumb and pointer finger. Does it spin glassy smooth?
If it spins glassy smooth you are good to go.
If it feels "bumpy" or if it's smooth but the axle has play (can "wiggle") then the bearings were adjusted too tight or too loose at the factory. You need to adjust the hub before installing it on the bicycle.
Here is a step by step guide with pictures on how to adjust a front hub. For reference I'll summarize the article.
- Unlock the cone from the jam nut. Using a cone spanner (a special type of wrench that is very flat designed to fit into the slot on one side of your hub) to hold the cone use the correct size wrench to turn the jam nut counter clock wise.
- Adjust the cone so the axle spins smoothly but without play.
- Tighten the jam nut against the cone without changing your adjustment.
- Check the adjustment. Often tightening the jam nut against the cone changes the adjustment so it needs a final check. If it's too loose (the axle wobbles) or to tight (axle does not spin smoothly) repeat steps 1 through 3 again.
Some bikes are made so poorly that it is impossible to get it adjusted exactly right and you have to compromise - do the "best possible" adjustment. My personal thought is that it's better to be a little too loose than a little to tight.
The front hub is just one of four areas of your bike that needs to be checked for bearing adjustment. The other three are:
- Rear hub
- Bottom bracket
This is a small start on correct assembly. There are many articles and videos on assembling a bicycle. Some of them are good.
If you have specific questions we are glad to help. Please provide as much information as you can when asking a specific question.