blinky

The rear lever only requires a smidgeon of a pull for rubber to meet rim - front requires roughly twice as much arc - here are a few brake tools that I have :

Would any of these tools be required
to achieve the desired result or would the trusty barrel adjuster be sufficient ?

alcjphil

What is the desired result? Are both brake callipers the same model?

blinky

A similarly , (i.e. like the rear brake lever), short pull on the front brake lever to hit the rim - as the post title indicates both brakes are Ultegra ST-R8000.

alcjphil

I would go the other way. A very short pull before the pads hit the rim leave no room for anything but a perfectly true rim and you can have brake rub from something as innocent seeming as pedalling standing up. As well you may have trouble installing your wheel after repairing a puncture unless you inflate the tire after you install the wheel. I was on a club ride a couple of years ago and one person had a flat. Even with the brake release open we had one heck of a time getting his back wheel back in place, even me who has worked as a bike mechanic and who has built up many bikes over the years. I set up my brakes so that I use about 1/4 of the brake lever travel before the brakes engage

blinky

Good points - so would any of those tools shown be good for setting more spacing and longer pull ? I'm assuming the barrel adjuster would only be used for more micro adjustments ??

cxwrench

No, just hold the pads together by hand and loose the cable anchor. Let the brake open a bit and tighten it. Not rocket surgery.

CliffordK

Most of those tools look like some variation of a "third hand" tool that has been around for quite some time.



I haven't used one for quite some time, but they can be handy to squeeze the pads together when attaching the pinch bolt to the cable or adjusting the pinch bolt.

But, as mentioned, not entirely necessary.

CliffordK

Apparently the middle tool (2nd from the left) is called a Park 4th hand, and helps stretch the cable.


It looks like it may take some of the guess work out of setting the pinch bolt. But, I'm not quite sure I'd use it. I have had front derailleur adjustments that were a bit tricky, so I might use one there.

I don't see a reason to use a 3rd hand and a 4th hand together.

Iride01 

If your brakes are the same model and series and your levers the same model and series, then your issue is likely the pads are spaced further on one brake than the other. As cxwrench said, just loosen the pinch bolt on the cable and you can squeeze them to where you need them then re-tighten the pinch bolt. You can also change that with the barrel adjust screw that might be on your brakes if it's not outside the limits of it. It'd be nice to know what brakes you have because a certain model of Shimano brakes also has a tension adjustment. Though probably not your issue.

As well, if someone was messing with the reach adjustment screw underneath the hood of the STI, it might make you think the lever travel is less in one than the other.

You don't need special tools to do what you are asking. Or is this thread just a tool show thread?

cxwrench

Not tool, other than the proper allen key to loosen/tighten the anchor bolt. It's stupid easy. Seriously.

blinky

You're too funny Iride01 - In the past , one of the things that discouraged me from continuing to do brake work was alignment after adjusting - this is mentioned very quickly at roughly time point 2:32 in the video posted above - after he gets the brake pads set he grabs the entire caliper and sets it back into alignment - a trick I learned from a mechanic was to take a large screwdriver and hammer and whack the spring on one side to restore alignment - but the guy in the video made it look too easy - isn't it possible that to restore alignment you'd have to loosen the brake fixing bolt , align , and then re-tighten ?

Yes , you can read the Shimano dealer's manual about installing and adjusting brakes and it does talk about rim clearance and the barrel adjuster but I also think hands on experience with some trial and error are important as well .

The tool on the far right is probably 40 years old and I have an old Phil Wood gizmo that had a small threaded hole in the body that would accept a tube of Phil Wood freewheel grease - you then somehow attached the gizmo to the freewheel and squeezed the tube to lubricate the freewheel .

alcjphil

8000 series Shimano brakes are dual pivot. You don't have to whack at the spring to align them. Do what the guy in the video did

Iride01 

In the 70's I never needed a tool to adjust my brakes other than simple wrenches to undo the pinch bolt and re-set the cable position if the barrel adjuster wouldn't get it where needed. If they were off center then depending on how much off center I'd either live with it or loosen the mounting bolt and muck with things until it was more correct.

With the advent of dual pivot brakes, things became even simpler, especially for centering the pads to the wheel. All that I've seen and used had an adjustment screw that moved one arm. Most if not all still required the barrel adjuster or cable to be repositioned in the pinch bolt to get the proper pad clearance on both sides of the rim.

Absolutely no special tools or banging on springs needed. Usually to set them initially I screwed the barrel adjuster to about it's mid point or a tad further, then clamped the pads to the rim with one hand while snugging up the pinch bolt with the other hand. Then if they weren't already, I'd open them up a tad with the barrel adjuster. Really, really easy for all the caliper rim brakes of mine, my kids and miscellaneous neighbors back into the previous century that I worked on.

If you have some special brakes that require something special, or you don't understand, then you really need to specify the particular brakes and shifter and exactly what you are having trouble with instead of assuming all brakes use the same tools or even need special tools.


let's have a beer each.... I'm not yelling at you. Just giving my viewpoint.

blinky

I know , you caught me going down memory lane .

alcjphil

Even back in the 1970's many side pull brakes had wrench flats so that you could align the brake using a cone wrench. The only brake I ever had to align by banging on the spring were the cheap steel side pulls found on low end bikes

blinky

My questions are focused on the front wheel and front Shimano Ultegra R-8000 dual pivot brake caliper - the brake pads appear to be centered around the rim with no rub but the lever requires more travel compared to the rear brake before pad contact - most of these discussion threads have been aimed at adjustment of the cable using hand and hex key or tool and hex key - I now wonder if adjusting the 2mm reach screw under the hood would achieve the desired lever travel - it's easy enough to try that but I want to get affirmation that it's logical .

cxwrench

You really don't understand how brakes work. The answer is most likely it's because the front pads are further from the rim than the rear pads. This is very easily confirmed by just looking at them. If this is indeed the case then adjust the brake cable length. You can do this w/ the barrel adjuster or by undoing the cable at the anchor bolt and pulling some cable/squeezing the pads together then tightening the bolt again. Cable actuated rim brakes are very easy to understand and adjust...you just need to mess with them a bit and you'll figure it out.
You pretty much have to be able to determine the difference in pad distance to the rim. If you adjust the lever reach you'll still have the same amount of lever pull it will just be closer to the bars or further away depending on how you adjust it.

blinky

Thanks CX , - All my Shimano components were an upgrade installed by the local LBS - turning the barrel adjuster both ways had no impact and this could be a result of it not being initialized correctly - I'll try the grip 'n pull and re-initialize the barrel adjuster - and I must say you do have a way with words and I'm glad you spared me , at least for now , of the now famous RTFM refrain - but I did read the Shimano DM regards brakes but I got more useful info from the boys here at the Forum .

cxwrench

Not possible unless it's screwed all the way out of the brake. You're either making the effective length of the housing longer or shorter relative to the length of the cable which doesn't change. It HAS to make some difference. When you pull the cable tighter at the anchor make sure you turn the barrel adjuster all the way in so you have the full range of adjustment for pad wear/possible wheel changes.

alcjphil

If the LBS did the installation for you (I imagine that you paid for a proper installation). Why not go back and ask them to properly set up your brakes so that front and rear brakes have similar pull before braking occurs. Seems to me that they did a substandard job. You paid good money for a professional installation

blinky

Bingo , hadn't turned the barrel adjuster enough , few more turns counter clockwise and now the pull is short and pretty much the same front and back - and point well taken about turning it all the way in when the cable is pulled and anchored ( I call that a reset or initialization) - thanks again !!

CliffordK

The barrel adjuster for the rear derailleur may be primarily micro adjustments. Half a turn? Although it may be get it close, then go to micro adjustments.

The barrel adjuster on the brakes is far more of a macro adjustment thing. Make it longer or shorter? Often quite a few turns.

I like to screw the barrel adjuster in quite a bit (but not all the way bottomed out) when I start with new brake pads, and do the macro adjustment with the cable pinch bolt. Then as the pads wear, slowly screw it back out to compensate for the pads becoming further away from the rims.