Nyah

This is a safety issue. My front brake shoes start contact with the rim when the lever is pulled only about halfway to the handlebar while the rear does this when lever is much farther in than that. I want them to engage at the same pull distance, or, with the rear engaging even before the front (i.e. the opposite from how it is now).

It took me awhile to track down the difference between the two brakes and this is what I've come up with: The brake shoes on the F brake are 5mm farther away from the pivot than how they are on the R brake.

How can I address this discrepancy, which is apparently the cause of the problem? On one of the brakes, should I try a different set of holes for the pins on the return-springs, and if so, which one?

The calipers are V-brakes setup with identical distances between the arms. The spring pins are each in the middle hole of their respective mounts. The mounts on the frame and fork are identical distance apart.

The levers are long-pull for drop-bars (Tektro RL520).

All parts are new and matching, including the rims.

dedhed

https://www.parktool.com/en-us/blog/...-brake-service

Nyah

Alright, thanks. I'll try taking out some slack on the rear cable.

Andrew R Stewart 

With the shorter cable length, and often the more direct path it takes, a front brake will pretty much always have less mush once the pads make contact with the rim. So even with the initial pad contact happening with the same amount of lever pull the rear lever will seem to need more pull amount. If the bike has cable length adjusters (often found on the levers and actually adjusting the cable casing length) one can play with the lever pull amounts while one rides. Andy

dsbrantjr

As Andrew Stewart points out, getting very different braking systems to act identically is going to be a tough job. Just having them both work well is sufficient for safe operation.

Bill Kapaun

When under severe braking, just about all your weight transfers to the front and the rear is likely to just skid anyway.
Think of a near nose stand just as the rear wheel is leaving the ground.

FBinNY 

First of all ---- There is no safety issue here.

Secondly, you're obsessing over nothing and wasting your time "fixing" what ain't broke.

Third, it helps to understand how human controlled braking works.

We humans operate using biofeedback rather than fixed programming to control motion. By example, if we reach out to pick up an apple, it doesn't matter where the apple is, we simply reach out until we touch it, then close our hand until we have grasped it tight enough to move before lifting. We have no idea we're doing this because it's a fully automatic subroutine of our motion control system.

Looking at your braking "imbalance" issue, I suggest you think back to the times you crossed a street on a hill. In that situation one leg was closer to the ground than the other, and you barely noticed, and didn't consciously make any effort to compensate. The same would apply to the unmatched braking. Each hand quickly squeezes it's respective lever until registering contact, then increases grip force until it has the desired effect, while also modulating to maintain control without excessive brake force. All that happens in micro seconds, without conscious attention to the process.

You learned this a long time ago, the same way you learned to ride a bike in the first place. So there's no need for you to try to make a reliable, fully automatic control system "better" or "safer: It works now, has worked in the past, and can be relied on to work in the future.

Note, since nothing was said otherwise, I assumed you were dealing with a typical two brake, two lever system. OTOH - if dealing with two brakes on the same lever, please disregard most of the above,

Joe Remi

You can squeeze the rear arms together, loosen the cable anchor bolt a bit, pull the cable through a bit, tighten the bolt, release your hand from the arms. This will leave your pads a little closer to the rim and your braking will start sooner in the back.

BUT..I set my bikes up like yours is now. The braking force all shifts to the front, so it's easier to lock up the rear if they're set identically and I pull both levers the same distance. I prefer that my rear brake feels "softer", I have to pull the lever way back to lock it up.

Schweinhund

If you want them "right" and the same, then I would suggest starting over from go.
Remove the brakes from the mounting posts, and use a bit of steel wool on the mounting posts to remove whatever may be there.
Do the same to the bushing inside the brake.unscrew the leveling screw (pre-tensioner) put a bit of light grease on the posts and reassemble making sure the brake springs are in the same location on your.mount. Do them one pair at a time so parts don't intermingle.
Practice makes perfect.

LesterOfPuppets

Indeed. I typically prefer my rear to be slightly "detuned" so I don't lock it up as much.

Andrew R Stewart 

My front brake lever is on the side that my dominate hand is on. Being righthanded this means that my brakes are not CPSC acceptable. The reasoning I decided on way back in high school is that the hand that has better fine muscle control is the one I want to use to save my life with (should I have to stop suddenly, which I have "tested" too many times since). The BS reason was when riding two bike at the same time (I believe ghost riding is the current term) I would not want to stop too quickly as with only one hand on the bars of the bike I was pedaling the chance of steering abruptly when that weight shift happened. Having a less effective initial braking force reduced this chance. That my bike was then set up different from almost all others helped me to think I was unique, so important when young Andy

FBinNY 

It's kind of funny how things change over time. Back in the sixties, I set my bike up with LH front brakes. Even though I'm right handed, my left hand is stronger, and has always been the steady holding hand, with the right doing the detail work. So, when riding with only one hand, it's always the left, and I decided I'd rather always have front brake control.

What makes it a bit ironic is that back then I got tons of grief about my bike set up wrong, and it was 10 years later that the CPSC tossed a cold and made me right.

IMO, while left [edit ]front is SOP for new bikes, there's no wrong way to set up your own bike

Andrew R Stewart 

"IMO, while right front is SOP for new bikes, there's no wrong way to set up your own bike" Francis

I think you mean left front.

Agreed that for one's own bike there is no wrong way to set up brakes/levers. But when a right front would come into the shop and I was doing the service write up and the situation looked like the rider didn't chose I often (being human I can't say "always") asked if this was intentional. If the customer wished to retain the right front set up I tried to make a note on the service ticket. Andy

FBinNY 

Thanks for correction, I wentback and fixed it.

You're right that it's best practice to keep a bike the way it's owner is used to it, especially if he owns multiple bikes.

OTOH I'm not convinced it makes any difference, except maybe for the first few minutes. 99% of bike control is via the autopilot at the base of our brains, and it adapts unbelievably quickly.

Personally, I've never registered any difference riding bikes with brakes configured opposite my own.

79pmooney

I wished I'd grown up with right lever - front brake bikes, being very right handed. Until I had my head injury with its right side motor skill loses. Now, my left hand still wasn't very "bright" but it was far more capable than my right which had to re-learn everything.

To the OP - adjust those cables until your brakes work best for you. What the rest of us say doesn't matter one hoot until they need to ride your bike. (Then they can lay down the law. "I won't take one pedal stroke on your bike until you adjust those brakes to ...!"

Trakhak

Agreed. My current go-to track bike has the front brake lever on the left while the rest of my bikes have the front brake lever on the right. After the first few minutes, I'm used to whatever the configuration is.

Kontact 

Considering that the OP's rear brake lever doesn't engage until it is almost to the bar on a largely unworn brake, there could be a bit of a safety issue. He's not very far from having no rear brake power.

Kontact 

I don't know if anyone actually addressed your concern about the location of the pads.

On most V brakes, there are splined "washers" that are used on each side of the slot in the brake arm. One washer is thin, the other thicker. By swapping the location of those washers you can set your pads further or closer to the brake arm/pivot. So you might check how those washers are set up - since it is common to have the rear brake bosses narrower than the fork bosses, the brakes may have come set up different front and rear.

Something to look at.


I'm talking about the matte aluminum conical washers you can see in this picture. The outer one is half as thick as the inner, but you can mount them either way.

Schweinhund

If you ride a motorcycle, the clutch is the left and the ft brake is the right lever.
I don't have any trouble processing the difference when I hop on a motorcycle.

sweeks

Many years ago I swapped the brake levers on all my bikes L-for-R because they were that way on my motorcycles. I also like having my best brake available in case I need it when signalling with the hand that's most visible to traffic. I've also never had trouble riding bicycles set up the standard way.

Nyah

Nineteen days ago I was riding downhill and had to make an emergency-stop. My rear tire lifted off the pavement and I went OTB.

Indeed it is a typical two brake, two lever system. The only thing unique about it is that brake pivots on the fork are a different distance from the rim, than they are are on the frame. This means that the brake shoes on one brake must be moved farther away from the brake pivots in order to properly contact the rim. This amounts to a leverage discrepancy between the two brakes.

Both brakes had the same amount of cable between the arms. Since my 2nd post though, I've pulled more cable out from between the rear brake arms. Now the rear engages first. It does tend to skid more now than before. I figure though, during a downhill emergency-stop, if I were to skid it would be just minimal, because my front brake will take over the stopping function and prevent me from losing control.

Nyah

I appreciate you addressing that. However, my issue is not that the brake shoes are farther from the rim. My issue is that one rim is farther away from the V-brake pivots than it is on the other. In order for the brake shoes to line up with the rim, they have to be moved farther up the brake arms, which then changes the leverage of that brake.

Bill Kapaun

10 minutes of panic stop practice in an empty parking lot would have apparently erased the perceived reason for this thread?

There's no such thing as an all condition ABS on bikes.
Learn to use your brain to react, not think about it. You don't have time to analyze until afterwards.

Nyah

I'm sorry, but "practicing panic stops in an empty parking lot" is not the same as preparing oneself for handling emergency-stops. Practicing is not reacting and reacting can be disasterous if your brake setup conflicts with common sense.

This IS afterwards.

Bill Kapaun

Ignore list.
To prevent any future.