am0n

Just bought my first road bike and it has a few things that I didn't feel were deal breakers but wanted some opinions on.

When braking, I noticed a periodic sound and inspecting the front wheel I found a ding on the brake track. Doesn't seem to impede the braking, but slight annoyance coupled with brake wear concern. Anyone have thoughts on how to "smooth" this out?



The front brake seems stiff when I try to manually close it, but it still functions fine. I did see a video on GCN on how to clean them, so I'll give that a go. That said, the front seems to require I pull a lot more than the rear to engage. Might be simply cable, but how do I know if there cables need replacing? Owner had no idea when that happened last, but did have it in for a tune up recently.

The rear cassette seems brand new, and the small ring seems barely used. However, the big ring seems to have some wear. Looking at the replacement, some teeth look asymmetric even brand new, but does this appear excessively worn to anyone?

Link to brand new
https://www.jensonusa.com/Shimano-105-5750-Chainring-Black-50T-110-BCD?pt_source=googleads&pt_medium=cpc&pt_campaign=shopping_us&pt_keyword=&gclid=Cj0KCQjwrMHsBRCIARIs AFgSeI1I1WfpFnvoxIoR5-w6AIoxPjcZTYR3bUExjN_Gmv7xflySR3IX0T0aAvzvEALw_wcB

le mans

Try a fine tooth flat file on the damaged braking surface

I have one on stand by when building a secondhand wheel, any dags i'll file it smooth

am0n

Do you just smooth out the entire area? Or try to smooth between the ridges? Any example of before and after so I can get a better sense of what to do?

le mans

You just smooth it so it doesn't damage your brake pads, or hear any weird noises when braking, so i wouldn't go crazy with it IYKWIM

le mans

This rear rim had corrosion on the braking surface, made a scraping noise when braking.. so i just sanded it with 600 wet n dry

le mans

As for your front brakes, disconnect the cable on the caliper, grab hold of the cable and try the brake lever see if it's a cable problem or not

Your large chainring does need replacing BTW

HillRider

I disagree with le mans. Yes the big chainring is worn but probably not to the point of replacement. As you observed some of the teeth are asymmetric and shaped even new and that's intentional.

It's hard to tell from the photo but it appears the front derailleur is too far above the big chainring. The outer cage plate of the derailleur should only be about 2 or 3 mm above the teeth of the big ring. Adjusting that should improve front shifting a lot.

As recommended a fine flat file or sandpaper on a support can be used to just remove the raised metal on the rim. Just get it flat with the rest of the brake track.

xiaoman1 

Same as above but deflate the tire first so you don't damage it with your file...just take enough off so that the bur is gone...don't go too far or you will create another problem.
If the rim is slightly bent you may want to use a block to lightly tap the side of the wheel back into shape..if it is dinged it could also cause a little vibration when braking.
Good Luck, Ben

JoeTBM 

I would try a very fine stone dremel bit like this
Take your time and work slowly

am0n

Thanks for the replies. Some background that may help.

It's a 2011. The guy I bought it from was not the original owner. The original owner is a colleague of his. He bought it from his colleague about a year and a half ago thinking he was going to get into cycling and decided that he wasn't comfortable on a bike and felt running gave him more of a workout for his available time, so he just wanted it gone.

The original owner, according to him, basically bought it, hooked it up to an indoor trainer and rarely if at all took it outside. I can believe this for a few reasons. Both tires are original (so almost 9 years old), but the back tire is very worn (the tread in the center is almost entirely smooth and no grooves from the pattern). The front has wear, but in comparison it is minimal (still grooves in the tread). The brakes look almost brand new, with very deep "cuts" in the pads to suggest they haven't been used much. The brake tracks, beyond the one ding, seem in pretty good shape, just dirty from likely being almost never cleaned. The small ring looks untouched, just the large, which also makes sense if he was on an indoor trainer and rarely moved out of the big ring. The cassette looks brand new. The second owner said he hadn't done anything to the bike, but I have to imagine with the wear I see on the back tire that the cassette would have noticeable wear on at least one cog, so I am assuming the original owner replaced it prior to sale, just not the big ring. The chain seems good, too. Bit greasy, but I did the big ring pull test and it didn't move much (not scientific, I know). Everything else seemed fine. Did pull tests on all the bearings and they seemed fine, no damage, even scratches, to the frame, just a lot of dirt. Only marks I could see were on the wheel rim, and a small mark on the tape on the same side, but he said it never fell, so if I take his word it's probably from just resting on something in his shed.




What am I looking for when I grab the cable and pull the lever? Just that the cable moves and doesn't have a "deadzone" or something similar?

The bike also has flat brakes (not really sure what they are called, but an extra set of brake levers on the flats of the bar). Do those impact the effectiveness of your normal brakes? Any good resource on how to properly tension/tune that system? If they aren't a safety concern, I'm apt to just keep them as it means I'll have access to my brakes in all (most) hand positions.



As for the chain ring, here is a side by side (new vs mine). What in particular stood out that makes you feel the big needs to be replaced? I'm not so much doubting as just trying to understand what would stood out to you.



I do plan to look over and adjust the derailleurs. Here is another picture that might be more helpful.




Thanks. I did the measure both sides of the bike to look for a bent frame and it seemed fine. I also checked the spoke tension (by hand) of every spoke and they all seem under tension. Spun both tires to look for alignment and they seemed to spin straight (had to try hard to see any wobble). I can't see anything that suggested the wheel was bent, but I'll check more closely.

As a next question, are there any tell-tale signs that brake or shifter cables need replacing? This guy had no idea what had been done beyond taking it in for a tune up, so I have no idea how old the cables/shrouds are.

mpetry912 

Hmm. I don't think that ring is overly worn, it has some fancy profiling on the teeth from the factory. it would be 7000 series aluminum, pretty hard to wear that out unless you had severe dirt / grit conditions. Are you able to measure the chain wear ?

As for that rim. That's a crack. Hard to tell what caused it. Grind / file / chew on it all you want but I think you are going to find that it's cracked and should be replaced. That said, it might last a long time before failing. Take the tire off and see if there's a crack on the inside.

Mark Petry
Bainbridge Island, WA USA

am0n

I did the chain in the big ring pull test and it seemed fine. I can grab a ruler and measure the length tonight as a second test.

What about the rim leads you to think it is cracked? I'll take the tire off tonight and look inside. What would I be looking for? A line or something similar on the inside in the same spot?

le mans

It's just that your chainring looks worn, and if your chain is worn also but it still rides OK.. maybe replace things when it starts slipping.

Yeah, Once the brake cable is disconnected you grab hold of it with one hand while it's still threaded through the brakes, squeeze the brake lever with the other hand to see if the cable if free enough, if it is then you can look at the brake calipers, squeeze the calipers in and out see if it springs freely.

Can you post a better pic of the dual lever set up on the brake caliper area?

le mans

Or is it that levers are connected to eachother, and the flatbar lever acts as an extension?

am0n

When I say the caliper is stiff, that is at the caliper. When I put my hands on the arms of the caliper and squeeze, it feels stiff, like something is rubbing. The back (and the brakes on my hybrid) don't feel this way.

There is a single cable that goes from the brifter, through the flat brake levers, then continues to the brake calipers. Is that what you are asking about? If not, let me know what you want regarding a picture and I'll get another tonight when I get home.

le mans

Nah, you explained the mechanics, I've seen them before but wasn't sure how it was set up.

OK, maybe you just need to clean and lube the calipers.

le mans

If i were you i'd take the brakes off the bike and give it a good inspection, the rim got damaged somehow so that might also have issues

mpetry912 

My point was that it looks worn on the backside of the teeth. Not the leading edge where the load would be applied.

you'll wear out many chains before a chainring wears out.

Yes, look for anything suspect on the inside of the rim. That's a crack. The force required to "dent" something there would have damaged the rim. I would not file or grind it.

Mark Petry
Bainbridge Island, WA

am0n

Thanks. I'll take off the wheel and inspect the inside for any damage.

am0n

Any suggestions on resources for tuning up that kind of brake configuration?

le mans

Tuning? they're pretty easy hey, Before you do anything screw the Barrel adjuster about half way, and make sure the pads line up, once the cable is threaded through squeeze the pads tight to the rim, pull the cable tight and lock the cable in. release your hands from the calipers and give the wheel a spin, if it rubs turn the barrel adjuster out anti clock wise untill you hear no rub.

le mans

If you mean the pivoting of the brake calipers, if it's tight i'll spray it with WD-40 to free it up

In your case i'd look for any signs of damage

am0n

Finally had a chance to take the tire off. Inspecting the brake track more and the inside, I don't believe it is cracked. It's clearly suffered an impact of some kind, but appears to have just resulted in material displacement. There is no sign of a crack or any other damage inside the rim.

I took a straight file and got rid of the raised material. I'll update again after I get to inspect the brakes this weekend.

cyccommute 

You are both wrong...Le Mans more so than you, HillRider. As you've noticed, am0n, the ring is about the same as a new ring. You can still see the machining marks on your ring. It's got years of life left on it as does the inner ring.

cyccommute 

It's not cracked. Do you hang the bike up by the front wheel? It almost looks like you hit it with a hook while hanging it. It could also be due to a rock strike or any number of other causes. Just smooth it and ride on.