Hey all,

Just bought my first bike with disc brakes, a Giant Fastroad SLR 1. I bought it for a specific purpose and it fulfills that purpose very well. I like it.

However I noticed the disc brakes are prone to "chattering". Especially the front. Enough to shake the forks under hard braking. I noticed the outer brake pad seemed to be making weird contact with the rotor. Earlier this week I took it to the LBS that I bought the bike from and they repositioned the caliper position over the rotor. It seemed to help but not for very long. The chattering is back, just at a slightly different frequency. At this point, I think LBS over adjusted the caliper. I think it was too far "out". Now it is too far "in".

Any disc brakes experts care to chime in on this???

TIA

Does that bike have mechanical or hydraulic brakes and which brand?

Not an expert, but if the pads are organic and not bedded in well, there will be a difference in the sticky layer from point to point on the rotor which can lead to chatter. Also any minute contamination may cause chatter. But your LBS should have noticed if that was the issue. Then it could be just the adjustment being off. Some of them can be tricky.

I found this tip somewhere on this forum:

"You need to clean the rotors with brake cleaner. Post cleaning, go about 15mph and slow to about 7mph, do not stop. Do this about 10-15 times. This will spread your pad compound around your rotors and set a base layer of organic goo on your rotors. This will help with noise because you get vibrations (noise) when your pads slide over goo covered parts of you rotor and non goo covered parts. Once you have done this, you need another 10 or so stops from 15+mph to hard stop. This will bed your pads into to your rotor by cementing the goo you applied onto your rotors. Your LBS should have covered this with you when you bought your bike. Cleaning your rotors will help this process."

Tektro hydraulic. I took the bike back to LBS again today. We repostioned caliper again and talked about bedding in the pads and possible contamination on the rotor. Owner of LBS rode my bike and I rode his. I think we had a combination of small things that needed to be tweaked and maybe I needed to have different expectations. That being said, I plan to pick up some brake cleaner today.

Noise is one thing,but if your fork is chattering there's something wrong. Make absolutely certain the wheel is in the dropouts properly and the skewer is tight. Also check the tightness of your headset. Check to ensure the rotor bolts are properly torqued and that the rotor is true. Check to ensure the caliper is bolted down properly. Of course,all of these things should have been done by the LBS before you picked up the bike,but I've no idea what their QA procedures are.

If all of these things check out,it's possible you have contaminated pads/rotors,but it would have to be bad to cause this level of feedback. It is also possible something is amiss in the headset(bad bearings,missing parts) or even in the fork itself.

I will check the tightness of the headset. Rotor is turning the correct way and the bolts are torqued. Rotor is true. Caliper is bolted down properly. Wheel is perfect in the dropouts. The pads are contacting the rotor properly.

Last trip to LBS netted big improvements however I would like it to be better.

Tomorrow I plan to clean the heck out of the rotor with brake cleaner. It's beautiful in MN today so it looks like a boating day, not a biking day. Happy Fathers Day to all dads.

Dynaryder and ColdCase, THANK YOU for your input.

Cleaned the rotors twice with brake part cleaner. Things are improving rapidly.

I too recently cleaned my Tektro Hydro brakes. This greatly reduced the chatter I have as well.

First, the Giant Fastroad was completely off my radar and I'm shopping hybrids pretty hard right now. I read another post yesterday that raved about the Fastroad and immediately headed for my local dealer. Unfortunately, he had just sold his last one and may not get any more with the new model year approaching. Too bad because this looks like it may be the bike for me. As for the brakes, I think one of the Specialized Sirrus bikes (which I like) has the Tektro calipers. I've read mixed reviews about them and some people upgrade to Magura, which the Sirrus Expert already has. My LBS claims that at least on the Sirrus (bolt on calipers), changing out the brakes is an easy task.
Question: Did you ride and compare the Sirrus or Trek 7.7 FX?

Travbikeman, I cleaned my rotors again today and they continue to improve. I realized this may partially be my fault. Last week when I sensed a problem, I cleaned the rotors with a "generic" automotive cleaner degreaser. It did not occur to me this product would leave a residue but apparently it did. Needless to say, lesson learned.

Roadweary, I looked at Trek briefly but I knew I was not in the price range of the 7.7. I wanted disc brakes but I also wanted better shift gear than the 7.4 Disc offered. To be honest, Trek didn't make it to my short list. Specialized is an entirely different story. I looked very carefully (and rode) the Sirrus Comp Disc and the Sirrus Elite Disc. In the end I compared my Fastroad SLR 1 and the Sirrus Comp Disc very carefully. Even though the big, local Specialized LBS chain (Erik's Bike Shop) are really great guys and I would highly recommend them, I decided on the Giant. I picked the Fastroad SLR 1 over the Comp Disc for four main reasons:

1. They had nearly identical brakes and shifter gear but the Fastroad was $100 less.
2. The Fastroad frame is a new design. I thought the Fastroad frame was more "trick" and represented some newer thinking. I also though the welding of the frame was quite a bit cleaner on the Giant.
3. I noticed the Fastroad ran all of the cables inside the main tube. The Sirrus had one cable still running outside the main tube. I thought the Sirrus design was kinda weird.
4. I like liked the Giant color scheme better.

Overall, I like my new Fastroad quite a bit. I occasionally wonder if I should have stepped up and bought a carbon frame, but I am very happy with my choice. Besides, I have yet to see another Fastroad out there yet. It's an eye catcher. People ask me about it often.

By the way, I bought my Giant from Bike King in Inver Grove Heights, MN. Kip and Nick are great guys and I recommend them highly.