precad

hello world,

Mountainbike, specialized stumpjumper, all original circa late 90s - super grabby brakes. Installed new pads on the front for now, same issue. Its literally unsafe to ride. I can totally lock up both wheels and send myself over the bars/endo.

whats the fix? I can theoretically loosen the cable way out so my levers will touch the bars, but thats no way to ride.

any trick to toe in pads? Different pad material? Anyways, why are these so powerful?

thanks!

willtf

What kind of brakes are these? Are they so strong you can't brake lightly? Most of the time, it's a good thing to have enough potential braking power to throw yourself over the front if you're not bracing yourself with your arms.

Loosening the cable may give you a little more modulation/make you squeeze a bit more to get strong braking.

Bill Kapaun

Do these have the Avid Speed Dial brakes?
I have no experience with them, but supposedly you can adjust the leverage.

precad

Hi again, below is a pic of what I have - I was mistaken, its Specialized hard rock, but same deal. At this point its just a bike to commute on. It is unclear what the brakes are, does not say. Anyways, I am telling you as a very experienced rider, I would be either flying over the bars or skidding my rear immediately. For whats it worth, i race high level road, cross, used to race cross-country a bit. Its just plain unsafe to ride in an emergency - car pulls out, dog runs out, rolling child after rolling ball, squirrels drivers idiots etc. My hunch is that I have to toe them way in? This is where I need your advice on what to do, as I am not really a mechanic with lots of experience, especially with V brakes.

Thanks!

GravelMN

V-brakes are very reliable so I'm just going to throw out a few ideas:

- clean your rims with a scubbie pad dampened with rubbing alcohol
- you already mentioned new front pads. Did it help? If so, replace the rear pads as well.
- if they grab at certain spots or pulse, check wheel true and examine wheels for damage.
- make sure pads contact the rim squarely centered over the braking surface and start with about a mm of toe in. You can experiment with toe in but it shouldn't require you to toe them "way in".
- make sure that the levers you are using have the proper pull for v-brakes.
- it never hurts to try new, good quality cables and housings.
- lubricate your pivot points and make sure they move freely.
- check that your brakes are properly centered so that the pads contact both sides evenly.
- MTB brakes can have a different feel than road brakes and the braking geometry is different and can make you feel more prone to going over the bars as you typically are more upright. If you are new to MTBs, give yourself some time to adjust.
- if your fork is puny or doesn't have a lockout, the excessive front end dive can make your brakes feel grabby. If you are just commuting, lock out the fork if you can.
- if your no-name brakes are suspect, consider switching to Shimano Alivio which are inexpensive but still perform very well.

Good luck. I hope you find a solution. I've got a couple of these old MTBs with v-brakes and find them very safe and controllable from a light feather to a hard stop. Grab a big handful of the front brake without getting your butt back and flexing your elbows and they can launch you.

If you are still having trouble, post close up pictures of the brakes and the brake levers.

Bill Kapaun

Hard Rocks were non suspension at least up to 2000.
A close up pic of the brakes might be useful.
From the fuzzy pic you posted, it looks like the front pads are set too low.

CliffordK

Would Cantilever brakes been standard on a 97?

A short pull brake lever will mean that you have much more leverage, but the pads need to be adjusted close so you don't run out of pull.
A long pull brake would mean less leverage and less movement of the levers. It would mean it takes more strength to stop.

Are you a road bike rider, or a MTB rider? I would assume that most road bikes have the wheels trued more precisely than the average MTB, so you might set your road bike to 1mm or 2mm of brake clearance, and the MTB to a few mm of clearance.

jimc101

Hers'a a link to the OP's bike, with a better photo, and info from when sold 2 years a go. Specialized Hard Rock for sale! | Bath Bike Workshop Specialized Hard Rock for sale! | Sales, service and bicycle renovation

The brakes are defiantly linear-pull, from the look of them, they (the arms) aren't Avid Speed Dials, but suspect the levers are.

The Jett forks the bike has was made from 1999-2001, if stock, that narrows the age of the bike, can't find it on Bikepedia, but it could well have been a bike not sold in the US market.

dsbrantjr

Make sure that the brake pads have not been mounted too low and developed a lip which goes under the braking surface; this will tend to jam the pads under the rim and may cause them to be grabby. Make sure that there is not excess play at the mounting studs which allows the arms to twist inwards under braking forces. Try braking with only one or two fingers.

CliffordK

Ahhh.... so it is a HardRock and not a Stumpjumper!!!!

I think 97 had Cantis, and 98 had Linear Pull, but it is probably a 98 or newer bike originally with the linear pull.

Perhaps we need a better description as to whether the brakes are surging, or just seem to stop too quickly. Without loosening up the braking, it may just take a bit to get used to the different bike.

Levers that pull a little less cable may be more comfortable.

Kimmo 

Maybe the bike came out with cantis which were changed to Vs without changing the levers?

elessar007

It sounds most likely like canti brake levers matched to linear pull brakes. The levers are pulling more cable than the brakes relative range of motion was designed for. Some proper, up close photos of the levers and brakes would be useful in narrowing down the issue. You should certainly go down the checklist of things the previous posters have mentioned in order to rule out installation and set up issues before moving on to equipment incompatibilities. Unfortunately,though, that is what it sounds like is the most likely cause based on the limited info your description gives.
If you can get some closeup photos, that could be key to solving the issue. I am virtually positive this bike is not all original equipment so simply knowing the model year is not enough to determine what levers or brakes are on it.

fietsbob

V brakes can be set up either with the pads close to the rim or a bit slacker..

for family - Cruiser-MTB, a noodle with a modulator spring is fitted, the lever first compresses the spring,
so the brakes come on softer, then with a firmer grip the spring bottoms out and the brakes push in like the regular noodle..

elessar007

The Shimano Power Modulator. Never cared too much for it myself but I never thought my brakes we're too grabby. This might work if you can not otherwise remedy the problem and if you can even find one. Perhaps a third party makes one. I suspect you could effectively achieve the same results by putting a cable donut on the cable at each housing stop as long as it doesn't then keep the housing end cap from seating properly. If it prevents proper seating of the end cap in the stop, you might be able to actually put a donut inside the housing end caps. The rubber would act as a spring to modulate the cable pull but if the donut is in the cap it will definitely increase the friction on the cable as you pull the lever because the rubber will be constricting around the cable the tighter you pull. All of this seems like quite a bode and I suspect it can be resolved by making sure they aren't canti levers. Nevertheless, that is certainly a solution that can be done for mere pennies and a bit of time.

hueyhoolihan

getting oil or grease on the pads has never failed to provide less grip for me...

Homebrew01

Yup, a quick smear of grease on the brake track will fix you up

FBinNY 

let's clear some brush and see what you have and how you can improve the feel or sensitivity.

Normal brakes open roughly 5-6mm (2.5-3mm per side) in about half the lever travel. So if your brake travel matches that somewhat the levers and brakes are correctly matched. If they open more, the levers are pulling plenty of cable, but that means LESS leverage. OTOH - if they open less than 2mm per side (in half the lever's travel), then the lever's are pulling less cable and providing more than the designed leverage. In that case you might want to go with levers that pull more cable

Now, if there's enough travel to do so, increase the toe-in to the maximum extent possible, so the open brake barely clears the rim up front. This way, when you first apply the brake you'll get some friction off the front corner, then the twisting arm will act as a force damper until it's pressed down flat, delivers full braking power. This twisting may provide sponginess and make the brakes less sensitive. The rest is simply learned behavior on your part, analogous to when a driver who never had power brakes in a car, learns to ease off pedal pressure, fairly quickly after pitching his passengers into the windshield.

jyl

Or take a sharp knife/razor and bevel the pad surface so that there is less pad to rim contact.

elessar007

Tektro makes a V-brake modulator that might help if you are still stuck for a solution.

https://www.amazon.com/Tektro-Power-M...68364&sr=1-131