decosse

Hi all- I've been having problems with my front rim brakes being noisy- rubbing sounds, sometimes almost grating. I've lightly sanded the rim braking surface with 400 sandpaper. It helps for the first couple of stops, then it's back. Today I removed the front wheel and took a good look, half expecting to find something on the pads, but nothing. The pads were both smooth, evenly worn, and free of debris . The only off thing is the non-drive side is noticeably more worn than the drive side. Anyone have any idea why, and what to do about it? Its not been dragging. (I check regularly) The rim is not showing any real wear, and they are both aligned correctly. I realize this may be a simple thing, and I have done a search, but really couldn't find anything useful.
The bike is a 2014 Lapierre with a complete Tiagra Groupset -4600 I think, dual pivot rim brakes.
Thanks!

Bigbus

You're confusing me. You begin by saying both pads are smooth and evenly worn and then in the next sentence you say the drive side is noticeably more worn... I'm confused, which is it? Either way, you just need to center the brake assembly. They move off to one side or another all the time so it's something you might want to learn how to do. It's really simple

decosse

Sorry, I didn't do enough proofreading, . Should have said they each wore smoothly, but one was worn much more than the other. Yes, you center the brakes by pivoting the brake assembly. I did mention I checked that they were aligned. Probably an unclear term- align meaning centered. Checking the centering was one of the first things I did.

Thanks for taking the time

Geepig

Do you have pictures?

If the bike is six years old it might have been through a little or a lot, so being able to see the rim, calliper and pads might help us see something. When I was a mechanic the hardest jobs were always the squeaks the owner lacked the time to demonstrate

AeroGut

If you watch the brakes while pulling the lever, does one side move a lot more than the other at first? Could be one of the pivots is stiff so one pad is contacting much sooner and you’re braking with one pad a lot.

cxwrench

Pull the lever and watch the center of the tire. Is it being pushed a little to one side? If so there's your answer.

Andrew R Stewart 

Agree with the "centering" AFTER pad contact with the rim. Since the two caliper arms have differing leverage their arc of movement that the pads goes through are also different. The gap between rim and pad will be slightly different, side to side, when the lever is not being pulled. Andy

decosse

Thanks for taking the time to have a look. It's hard to see the difference in photos. A couple of things- the pads look glazed, not sure if that's a thing, and these brakes get a workout on part of my normal ride. I climb 1100 feet in 12 miles, a bit of zigzag route. The return is those 1100 feet straight downhill in about 10. With about a dozen stoplights, so I'm hauling down from 25-30 mph to a stop at about half of them (doing this on a phone, so please excuse the mess)

decosse

I'm wondering if you may have hit on something. I've been pivot/adjusting them so that the gap is the same side to side when the lever is not being pulled. Before today's ride, I moved the less worn pad closer to the rim than the worn one.
AeroGut , cxwrench , thanks for the help!
Near as I can guess, the bike has at least 5000 miles on it. I have over 4000 recorded, but there were quite a few times I didn't bother or forgot the app-or it didn't work. There were also a couple of 6 month periods I didn't ride due to injuries.

Ferrouscious 

If you want improved braking and reduced noise (read: no scraping sounds), get pad holders/cartridges and use kool stop salmons inserts. Your rims will thank you.

Andrew R Stewart 

When the pads are centered, at the moment they contact the rim, there can be a soft whack sound sometimes. That is what I aim for.

When one pad contacts first the wheel has to warp over to the other pad a bit. This can make the feel at the lever mushier. Andy

Geepig

Well, you have certainly given those pads a workout!

I am interested in the glazing on the pads, as they maybe trying to handle more heat than they are capable of. When you cleaned up the rim, did you do the same for the pads? It is a very long time since I last deglazed any kind of pads, probably when I was karting in the 80s, but if you remove them, place a sheet of fine abrasive sheet on a flat surface and then carefully and lightly caress the pads across the sheet. If you have a nail file you might just take off a tiny bit of the edges, especially the leading edge.

Or just try a different type of pad.

cjenrick

check to see if your front rim is dished properly.

or flip the wheel around and see if the other pad starts to wear quicker.

Iride01 

How long did these pads last you? If these are original pads on your six year old bike, then maybe not worry too much. Though if you do find an obvious issue, fix it.

But will the cost of new pads every six years be a budget buster?

decosse

I am seriously going to look at that option. Wet is not an issue, so I think I'd look a their Dual Pads. I'd rather replace pads than rims

Agree- I was concerned there was an issue with the brakes, but yes, replacing the pads is in the works-they are the originals, I'm going to consult with my LBS about which route to take.

I'm going to deglaze the pads as you suggested, and touch up the leading edge. Temporarily, then replace them with an upgrade. Yes, they do get a workout. I'm pretty tall for a woman-5'10" (178cm) and have what we call the covid-15 (gain 15 lbs weight ) And I don't just coast downhill, I pedal, lol.

Thank you all