i was riding a friends mountain bike yesterday and the brakes seemed ok on the flat. Then I was coming down a hill, not too quickly, into a right hand turn.Things wooulk have been fine if a family of cyclists had not suddenly appeared. I applied full brake force. I slowed down some but I had to put my feet out like the Flintsones to stop in time. Question: How can I improve the brakes. Different pads?
Improve brakes? How?
- Thread starter rshaw125
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What kind of brakes? If they're the old style where the cable splits in two and acts on two seperate levers there are adjustments that can help leverage and squeeze the pads against the wheel rim better. It depends on geometry and needs tweaking as the pads wear.
The new style with the horizontal cable does away with one angle, geometrically, but it's still possible the friend does not have the pads lined up 100% right.
You should get most of the range of travel of the brake lever; I've ridden many bikes where it's rock hard and barely moves. I can't accurately describe in words how to tweak it but with proper geometry down at the caliper the leverage and brake lever travel is greatly increased.
The new style with the horizontal cable does away with one angle, geometrically, but it's still possible the friend does not have the pads lined up 100% right.
You should get most of the range of travel of the brake lever; I've ridden many bikes where it's rock hard and barely moves. I can't accurately describe in words how to tweak it but with proper geometry down at the caliper the leverage and brake lever travel is greatly increased.
The pads look like they have a good flat contact with the rim. The design of the brakes consists of a cable coming down to a round thingy and then going left and right. Levers left and right both squeezing against the rim. I thought maybe the rim surface was too slick and not creating enough friction??
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Remove the wheel. Inspect the pads. Pick out any imbedded pieces of AL (overheated rim material). You can remove the pads and rub them on sandpaper to remove the glazing or you can use the sandpaper (fine grit) with the pads installed. If you don't have any vertical line showing on the pad, replace them. Next, take a piece of 000 steel wool or a scotchbrite pad, and carefully rub around the braking surface of the rim. Removing the tire helps but isn't necessary. When you resurface the rim, you remove alot of the built up pad material and refresh the surface.
Different pad material may help but some compounds can be very abrasive to the rim which will reduce it's life.
Mtn bike pads should be "toed" in. The front portion of the pad should contact the rim first (front tire- rear tire is opposite). This allows the leading edge of the pad to remove water and dirt before the rest of the pad makes contact which will improve braking some. This also lessens pad squeal.
You can also upgrade your brakes to a "V" brake (linear pull) which is much more powerful than a cantilever and will run you around $100 (or less) for a good set up.
Different pad material may help but some compounds can be very abrasive to the rim which will reduce it's life.
Mtn bike pads should be "toed" in. The front portion of the pad should contact the rim first (front tire- rear tire is opposite). This allows the leading edge of the pad to remove water and dirt before the rest of the pad makes contact which will improve braking some. This also lessens pad squeal.
You can also upgrade your brakes to a "V" brake (linear pull) which is much more powerful than a cantilever and will run you around $100 (or less) for a good set up.
Probably 90% of cantilever brakes I see are set up improperly. They need to be set up so that when the pads are in contact with the rim, the cable from each brake arm is at an appropriate angle to create maximum torque on the brake arm. It sounds like you have Shimano cantis with a link wire of non-adjustable length (the best straddle-cable setup for cantis), so you probably need to either move the pads out or use a shorter link wire.
That link Mori provided looks like a very good one.
That link Mori provided looks like a very good one.
Thanks for all the replies. I gave up on the bike and returned it to Target, they did not want to give me my $ back. I worked on the brakes twice and they were never acceptable. I bought another bike and the difference is amazing. It stops the bike as opposed to just slowing it down.
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The inexpensive stuff of today makes the inexpensive stuff of yesterday look like quality products. And that's not only due to inflation.
"I gave up on the bike and returned it to Target, they did not want to give me my $ back."
Why should they, if it was your friends bike? (as you stated in the original post)
Why should they, if it was your friends bike? (as you stated in the original post)
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My friend has terrible diarrhea, my friend just had an accident, my friend is in love -- and now my friend needs advice!
Could the rims have picked up moisture from weeds on the trail? Spittlebug spit?
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Spittlebug spit? Ewww!
Actually, the forward end of the pad should make contact with the rim first. This removes water and dirt from the rim before the rest of the pad contacts the rim. It also cuts down on pad squeal, which is common with rim brakes.
Actually, the forward end of the pad should make contact with the rim first. This removes water and dirt from the rim before the rest of the pad contacts the rim. It also cuts down on pad squeal, which is common with rim brakes.
The bike belonged to a somewhat timid female friend of mine. So I took it back to target for her. The new bike came from Walmart and I rode it this morning. So far it seems to be decent for the $. Stops very well.
Ride that new bike as hard as you possibly can on the trails. Give it H E L L. After breaking things a few times, you will either decide to give up mountain biking, or you will look into more durable equipment from a local bike shop. Generally speaking, any bike under $500 will not stand up to too much abuse.
Very much agreed. I try not to discourage folks from riding, even on a discount store bike, but those are best left for kids who will outgrow them in a few months, not folks looking to get into the sport. One will have a much better experience with a bike shop bike and the support which comes with it than with a discount store bike assembled by a min wage, part time, non-riding, sales associate. $150 for 6 months of hard use is a lot more than $400-500 for 2-3 years of hard use.
I agree totally. If the sport does not agree with you you have not got a $500 bike collecting dust.
Here's what you really want...
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Disc brakes work so well in wet and muddy conditions that I will never go back to rim brakes. Not to mention the lever feel is phenomenal when you have a decent setup.
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Disc brakes work so well in wet and muddy conditions that I will never go back to rim brakes. Not to mention the lever feel is phenomenal when you have a decent setup.
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I'm going to install a disc brake (I'll go with the BB5) in the front eventually, but I don't ride enough in wet conditions to ever feel I "have" to go with a disc brake. I can easily do an endo with my front V-brake.
In the rear I won't bother with a disc brake at all, because I'm not doing any serious freestyle stunts that require the rear brake to become the main brake.
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Oops, I meant to say I'll go with the Avid BB7 (Easier to adjust than BB5). I want a simple mechanical brake and not some fancy hydraulic brake on a bicycle. I'll get around to installing the BB7 when my front rim walls are worn down from the V-brake. I'm getting there pretty quickly, by the looks of the rim.
Mori,
You're right - if you don't ride in wet or muddy conditions, you don't really need disc brakes. However, I do, and they work much better in both of those conditions than V-Brakes ever will.
Good call on the BB7. As far as mechanical discs go, those are the best available! Not so sure that I would say hydraulics are any more complicated than the mechanicals. Mine came assembled and pre-bled, so I haven't had to worry about that yet. Just had to bolt them on.
You're right - if you don't ride in wet or muddy conditions, you don't really need disc brakes. However, I do, and they work much better in both of those conditions than V-Brakes ever will.
Good call on the BB7. As far as mechanical discs go, those are the best available! Not so sure that I would say hydraulics are any more complicated than the mechanicals. Mine came assembled and pre-bled, so I haven't had to worry about that yet. Just had to bolt them on.
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