[t4t3r]

got this set of disk brakes on my 04 kona blast. they've worked pretty well so far, just needed to tweak them a bit here and there after a fall or two. recently ive been storing the bike in my backseat when heading to the trails so ive been using the quick release for the wheel a lot. the caliper/pad always seems to be slightly off when i mount the wheel for the ride, but a few adjustments with the tightness of the quick release and its fine.

well today was different. one of the pads (one that doesn't seem to be able to be moved at all - pad thats farthest away from the rotor/wheel) is right on the rotor when i mount the wheel. no matter what i adjust it seems to rub the whole time. i havent noticed it like this before, because the rotor was always just about in the middle of the two pads not touching either except for braking (what i assume is the correct position). is there something i'm missing here? can the caliper itself be moved to the right or left to help correct this, or can only one of the pads be moved? im trying to avoid a trip to the LBS by learning how to do what i thought was pretty routine and easy.

can anyone help and/or lend some advice? thanks

 

[Wombat]

You may have moved the cable when the front wheel was off and it is now not seating properly on the caliper. In effect the cable has pulled the caliper's lever so the brake is slightly on.

According to the Shimano site you adjust the outside pad by turning the adjuster bolt at the lever or the caliper. I guess you know that you adjust the inside pad by turing the allen screw.

Here's the pdf.
http://www.shimano-europe.com/cycling/phpimages/productserie/service_pdf/SI-8C90B-EN.pdf

Wombat

 

[Warp]

After reading the PDF I realized these are equal to the 515's.

Like Wombat said... You moved the cable some how. Maybe you turned the barrel adjuster (or somebody did it for you) or something.

My advice... go thru the full (cable and pads) set-up again. You can use a bussiness card instead of the spacer but a 0.2mm feeler gauge will work wonders. Also check the pads are seating properly. They may hardly go out of position but who knows....

 

[t4t3r]

thanks for the help. i tried most of the suggestions but it actually seems worse now there seems to be a lot of play in the cable, which from the adjustments ive made to the two places on the cable, doesnt seem to help. when the lever is depressed and returns back, there is actually another 1/4 - 1/2 inch of travel left which causes the outside pad to almost touch the other pad. i can't seem to figure it out. i'm going to take it to the LBS tomorrow (twice in 2 weeks, last time was a loose headset, they are going to question my intelligence im sure ) to get it fixed and try to see what they are adjusting/fixing.

 

[Warp]

Follow this...

1 - Place the bike upsidedown and release the QR and retighten it again.
2 - Loosen the cable fixing bolt.
3 - Place barrel adjusters more less halfways (with a bit more travel to turn them out)
4 - Loosen the caliper fixing bolts. Back them off a bit. Then pull out the one on top and apply some blue loctite put it in but do not tighten it yet, leave loose enough so the caliper should move. Repeat with the second bolt.
5 - Now, insert a 0.2mm feeler gauge (a bussiness card will do fine) between the outer pad and the rotor and now squeeze them by moving in the inner pad until the rotor is firmly squeezed.
6 - Now you can torque the caliper fixing bolts (by this I mean the ones that fix the caliper to the IS adapter... not the ones that bolt together both halves of the caliper nor the ones that fix the IS adapter to the fork). Tighten them a little each one as indicated by shimano on the PDF mentioned)
7 - Now, back off the inner pad just two clicks and pull out the 0.2mm spacer or card
8 - Now pull the cable thru the cable fixing bolt with some pliers (not too much just to remove some cable slack) and then tighten the cable fixing bolt as indicated in the PDF.
9 - Remove any cable slack by turning the barrel adjuster at the lever.
10 - Now adjust the pads as indicated in the Shimano PDF. Turn the barrel adjuster at the caliper to move the outer pad and the inner pad with the 5mm allen wrench as needed.

DO NOT FORGET TO:
- Check pad wear.
- Check rotor trueness
- Check for rotor fixing bolts torque (improper torque can make you to break the bolts and cause rotor warping)

The instructions are in the PDF. Make a copy. The instructions are pretty straightforward, you shall have not problems then.