Bicycle Mechanics - Thicker Pads = Worse Braking?

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I just picked up a pair of V-brake pads (rim brakes) at the LBS. They are made by Tektro. The pads are way thicker than the ones i took off. Therefore i had to set my brake arms out wider to clear rims. I went for a quick test ride and it seemed like i didn't have that much stopping power.
The pads are aligned properly according to Park. I just wonder if having the arms farther apart results in less leverage?
mtbikerinpa
01-03-05, 04:37 PM
Position of the pads on the arms can effect leverage, not so much the spread. Cantilevers were notorious for that though.
If I recal, Tek pads were a llittle on the hard compound side, I like the Avid rubber better.
Probably a difference in the pad material.
Less travel in the brake lever also reduces the amount of pressure you can exert on the brakes.
mtbikerinpa
01-03-05, 09:54 PM
In a practical sense, I disagree. The position of the brake lever engagement can affect the mechanical advantage your hand can exert on the cable but it has little relation to the force brake arms themselves can apply. In an indirect sense, larger pads can alter the position needed on the arms to achieve contact. This would then influence the mechanical advantage of the arm, but that too is not always the case nor is it a real big concern, as it can be compensated with the spacers(or has already).
Just in an off handed thought...are the brake arms parralell or roughly so?
In a practical sense, I disagree. The position of the brake lever engagement can affect the mechanical advantage your hand can exert on the cable but it has little relation to the force brake arms themselves can apply. In an indirect sense, larger pads can alter the position needed on the arms to achieve contact. This would then influence the mechanical advantage of the arm, but that too is not always the case nor is it a real big concern, as it can be compensated with the spacers(or has already).
Just in an off handed thought...are the brake arms parralell or roughly so?
Yes they are parallel. I do notice that there is less hand movement in the brake lever. IOW, I can't squeeze it as much as before. I assume this is because of the thicker pads.
mtbikerinpa
01-04-05, 10:52 AM
Im surprised I hadn't asked before. How dramatic is your toe-in? The way they used to do it at my first shop was to stick a rubberband under the rear side of the pad and push the arm on the rim, then tighten. A little odd, but it usually worked. Park makes a toe in tool as well, but its simple enough to make one. It should generally be about 1mm +_ a little. If its too little the pad is not engaging all the way/ and/or squeaking. Too much and the lever will feel mushy and the pad can't contact all the way either.
roadfix
01-04-05, 10:59 AM
Are the spacers installed correctly?
Upon further inspection my right arm is out a bit. I took this pic and started wondering....Can i take out the "spacer" indicated by the arrow? Sorry i can't get a better pic. It is sleeting outside so i am inside with low light. Also i have a rack and trunk bag etc. blocking my view of the brakes.
http://xs10.xs.to/pics/05012/zzz.JPG
http://xs10.xs.to/pics/05012/zzztext.JPG
http://xs10.xs.to/pics/05012/zzz2.JPG
Here you can see the spacers.
http://xs10.xs.to/pics/05012/toe.JPG
http://xs10.xs.to/pics/05012/toein.JPG
roadfix
01-04-05, 11:43 AM
Your V-brake assembly usually includes thin and thick sets of cone/cup spacers. Make sure you're using the thinner spacer between the pad and lever. The thicker set of spacers should be installed on the outer sides of the brake arms.
jeff williams
01-04-05, 12:07 PM
Your V-brake assembly usually includes thin and thick sets of cone/cup spacers. Make sure you're using the thinner spacer between the pad and lever. The thicker set of spacers should be installed on the outer sides of the brake arms.
With my thin Jagwire pads I reverse the spacers. I find the v-s work more spread, so I run the spacing reversed. :)
Looks like I need to move the spacer that is on the inside of the brake arm to the outside and vice versa. I think that will help a bit. Still those pads are way thicker than anything I have ever had. My LBS only had one set of V-brake pads on the premises. Back to the internet i go next time.
As hard as i try to deal with our only small LBS it usually requires sacrifice of some sort to do business there. :mad: NOt because they are bad people but because they have like zero inventory.
matheprat
01-04-05, 12:28 PM
Let them bed in. I would say that they will start working much better after a bit of use
BlastRadius
01-04-05, 12:28 PM
Did you give the new pads a light sanding before installation? That would likely help a lot as new brake pad surfaces are pretty hard and slick.
Actually my braking is pretty decent. I used them for 20 miles this morning and i am ok with them. I just know that i could have better mechanical advantage/braking if i could get more travel out of my brake lever. Right now there is little. I think swapping the spacers will help some.
Yeah those pads aren't huge by any stretch of the imagination. Swapping the spacers will help immensely
jeff williams
01-04-05, 01:51 PM
http://www.jagwire.com.tw/js935c.htm Rear cartridge for me. Higher carbon.
http://www.jagwire.com.tw/js909t.htm Front block (still long, narrower) softer pads.
I've been running this setup for a 2 months works very well, no noticable wear problems.
I'm recommending them as an alternative to Koolstops...which are fine pads as well.
I like the longer, narrower pad, and the cartridge system.
I run these front and rear. Not cheap but worth it in my opinion. My wet stopping is much improved with these.
http://img111.exs.cx/img111/255/JagwirebrakepadsTrizone.jpg
jeff williams
01-04-05, 02:32 PM
Ya, I would have had to order them. I'm going to replace the block front with the Tri-Zone when it wears out.
Give them a try anyway.
I checked, both my wide spacers are inside.
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