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Old 09-25-06, 09:22 AM   #1
Phantoj
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My Avid BB7 Road brakes don't. Help!

Don't brake, that is.

I just picked up a 2003 OCR Touring to be my commuter - to be my bike - through my first Pacific Northwest winter. Looks like the right bike for the job.

But so far, I've been very unimpressed with the braking. I turn the red knobs on the brake until the pads are just starting to rub, but when I squeeze the levers, I can squeeze them to the bars with only a modest amount of braking. Actually, the rear brake is OK; I can brake enough to skid it, but the front is just a little too weak.

Braking is important to me because I live at about 450' higher elevation than my workplace, and all this elevation must be gained or lost in a mile or so. My typical route to work has me screaming down a hill at 35+, then jumping on the brakes to stop for a red light at the bottom. The hill was scary in the wet with my road bike, but I think this Giant is even worse, although I haven't tried it on a rainy day.

I wiped down the pads and rotor with alchohol, no real effect. When I pulled the pads out, they looked very thin and worn, so I'm guessing the next step is to clean the rotor really well, pop on some new pads, and re-align the caliper. What kind of pads to get? Regular Avids? Or the new organic Avids? Or EBC, Kool-stop, some other brand?

I hear that discs are supposed to be great stoppers. What's going on? My cables are Jagwire.
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Old 09-25-06, 09:29 AM   #2
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With my BB7s it took a few days of commuting before they really started to bite. Try going downhill while using the brake. That should brake it in, so to speak.
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Old 09-25-06, 09:38 AM   #3
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Quote:
Originally Posted by Ziemas
With my BB7s it took a few days of commuting before they really started to bite. Try going downhill while using the brake. That should brake it in, so to speak.
Well, I've done that - that's how I figured out the braking performance was unacceptable. This is a used bike, so the brakes should be broken in. Actually, the pads are looking pretty thin, so I think I'll put on a new pair and re-setup the brake.
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Old 09-25-06, 12:31 PM   #4
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You are saying that the levers go all the way to the bar ? Maybe you have some slack in the cable, such that there is free play in the brake lever before the actuator arm on the brake body starts to move. I have the BB7 road brakes with Ultegra brifters, and they are excellent stoppers. My levers move only about halfway to the bar when adjusted properly. I have barrel adjusters on both cables.
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Old 09-25-06, 01:01 PM   #5
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Yes, all the way to the bar. Not without resistance, of course. But I don't think it's cable slack; I checked that. I am going to get new pads (current ones seem worn) and set up the caliper again. I wonder if the caliper is not true relative to the rotor. I have seen the Avid tech sheet detailing how to set up the brakes and I'll try that procedure.

Last edited by Phantoj; 09-25-06 at 01:11 PM.
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Old 09-25-06, 02:47 PM   #6
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You are correct that something is not right. I have BB7s with 105 brifters. They are excellent in the rain. I'm going to have a hard time going back to rim brakes. I'll be interested to see what you find out, but it seems strange that you can get all the way to the bar with your brakes. I'd be over the handlebars well before then.
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Old 09-25-06, 03:01 PM   #7
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Well, this is all good news to me. I'm using 105, too. I bought this bike for good wet-weather braking. Here's my plan: First, new pads, clean rotors, set up brake again.

Then, unwrap bars and make sure there's nothing flexy or badly routed in the cable run.

Third, buy a new caliper and rotor off Ebay for ~$75 or so...
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Old 09-25-06, 03:02 PM   #8
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My guess is that since the bike is used that the brake pads were contaminated with lube or something. Once that happens, they must be replaced. No amount of cleaning with alcohol will do.

Get new pads, perform an initial set-up to make sure that the calipers are square with the rotors and perform the necessary break-in. They'll work.

You might also want to inspect the cables. Is the housing damaged? Look for bulges or kinks. If one of the inner flattened coils of the housing gets out of alignment then the housing will collapse upon itself. It only takes a millimeter or two of sponge to completely ruin a brake's effectiveness.

Inner wire? Typically, when the inner wire gets mashed at a cable anchor, this increases a wire's "stretchiness". Remove the wire from the housing and look at it. Any strands broken? Kinked? Is the point where the wire is anchored utterly mashed flat? If you find any of these, replace the inner wire.

Given that this is a used bike and it's over three years old, entirely replacing the brake cables might be in order.

Good luck.
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Old 09-25-06, 04:19 PM   #9
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Thanks for the tips... I'll be getting the pads tonight, along with some fenders... forecast is for a week of sun, so I'll try to get thing ready before the rain hits again! Future bulletins as events warrant!
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Old 09-25-06, 04:20 PM   #10
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Only question is black or silver for the fenders, and P35 or P45 SKS/ESGE Thermoplastics. But maybe this is the wrong forum for style questions...
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Old 09-25-06, 07:29 PM   #11
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My mtn bike has the avid cable brakes and then are fantastic stoppers.

A couple of thing come to mind:

1. avid made the calipers specific for road levers or mtn bike levers. appears that the amount of throw is different. Any chance th ewrong ones were installed?

2. you can shorted the cable whether by the adjusters or otherwise to make the lever stop due to brake pad contact vice lever to bar contact. actually, you always want this to happen.

3. because the lever is bottoming, I suspect cable adjustment. But also, are the housings bottomed on their stoppers properly? worst case would be if the housing on the brifter side is not bottomed against their cutout in the brifter.

4. A seriously frayed cable can stretch a lot and it is dangerous, so you may want to remove and inspect.

hope this helps vs confuses
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Old 09-26-06, 08:25 AM   #12
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Put on the new pads and set everything up again. Now the lever feels pretty good... you don't have to squeeze it far before it starts to feel stiff. But I can still (barely) bottom the lever... perhaps I have a lot of grip strength. Anyway, they *feel* pretty good, so if they stop effectively, I'm happy.

I am thinking the new pads will cure my braking ills, but I'll have to give them a few rides to bed in. I took my "fast" bike to work today instead of the Giant because I want to do a fast group ride after work. So, I haven't had the opportunity to try them yet.

One thing I noticed is that the old pads were somewhat unevenly worn and that the bolts attaching the caliper to its mount were not very tight. So I suspect a combination of bad pads and poor setup.

Shimano should make an STI lever that can be set up to pull a larger amount of cable - this would allow lower cable forces and a less mushy brake feel, IMO. If the "disc brake road bike" really takes off, I suppose we could see a hydraulic STI lever...
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Old 09-26-06, 10:03 PM   #13
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I had disc brake problems with my (2002?) Giant OCR Touring, also. My solution was to remove the short suicide levers and all the associated cable slop. Now the brakes are set up exactly like a road bike, 3K miles and beautiful.
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Old 09-26-06, 11:05 PM   #14
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I am using the BB7 on my mountain bike. They are excellent.
Except if your pads are worn out, I am pretty sure your problem is in the cable tensioning. When attaching the cable to the brake unit (caliper), first make sure the pads are as far from the rotor as possible using the red knobs, then make sure to hold the brake unit lever (not the handle lever) tight almost to the point of having the pads touch the rotor. Tighten the cable with enough torque and then adjust the pads to be about 1mm from the rotor.
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Old 09-27-06, 07:05 AM   #15
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I am using Avid road discs on my tourer, and they are excellent (when fully loaded too). Something doesn't sound quite right.

i. As previous posters have suggested, I wonder if you have Avid mtb rather than road discs -the lever throw for brifters is different than v-brake levers
ii. pads and/or rotors may be contaminated (clean rotors with soapy water and dry with clean cloth is the first thing to try). New pads is the second.
iii. bad cable routing or bad cable (replace cable)
iv. brakes not bedded in (though you mentioned the bike is used, so that would seem unlikely)
v.. I admit to not following the Avid directions on my road discs. I found that if I slightly pulled up on the caliper lever and then tightened the cable, it was alot better than allowing for a full caliper lever extension.


Good luck!
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Old 09-27-06, 08:59 AM   #16
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It would be really strange to have MTB discs rather than road, since this bike came from the factory with discs, and the Giant spec sheet online says road brakes.

I found that the old pads were fairly worn - and unevenly worn - when I took them off.

This morning, I took my first ride with the new pads on. The lever feel is back to fairly normal, but the braking performance doesn't seem to be all there. I noticed some squealing, too. BUT... they seemed to maybe be getting better just during the course of the ride. I'm going to give the new pads a week or so to bed in before making any rash decisions. Next step will be checking the cable to be sure that everything's firm there.
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Old 09-27-06, 10:08 AM   #17
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I don't know if it has been mentioned before.

If you have rotors that are slightly warped and you set up the brake so it does not rub, you require an increased brake pad travel v. non-warped rotors with the same set-up.
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Old 09-27-06, 11:10 AM   #18
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Phantoj, something still doesn't seem right. Someone correct me if I'm wrong, but I thought it should only require about 20 hard stops for new pads to bed in. Shouldn't take a week (unless you're only using your brakes a few times a day).
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Old 09-27-06, 11:49 AM   #19
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Quote:
Originally Posted by newbojeff
(unless you're only using your brakes a few times a day).
Today was the first time I rode with the new pads.

I'm only using my brakes a few times a day. My commute is about four miles, mostly flat except for one big hill. See my commute routes here:

http://routeslip.com/map.php?map=8738
http://routeslip.com/map.php?map=8737
http://routeslip.com/map.php?map=8739
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Old 09-28-06, 08:09 AM   #20
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Last update:

After I got home last night, I adjusted the pads (with the red knobs) again. Rode in this morning - observations:

1. After putting on the new pads, the lever feel was pretty good. After adjusting them again, the lever feel is excellent. Almost no free play.
2. Squealed a little at the first stop or two, but no more squealing for the rest of the ride.
3. On the big hill, the brakes had pretty good power. Not scary.

So I'm pronouncing these brakes FIXED. They're working good! Thanks for the tips!

Last edited by Phantoj; 09-28-06 at 08:37 AM.
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