ehron

So I am riding to work this morning, and all of a sudden my wheel starts thudding against the brakes. POP. I stop, look at it, and realize that I have a long walk ahead of me.

Sorry about the size. When I shrunk the pictures using irfanview the file size tripled for some reason.

Al Downie

Yep, soft alloy rims, hard compound brake blocks, and grit...

ehron

Gotcha. Local bike shop service guy said he had never seen one fail that way before. Time for a new rim I guess.

I have wanted to upgrade to discs for a while. Now seems like a prudent time for this project. Any suggestions on a wheel and brake combo? If I go with discs do I need to replace the front wheel as well?

Thanks.

Retro Grouch 

Of course you need to replace the front wheel.

1. If you switch to disc brakes you'll need a disc style front hub to mount the rotor on.
2. If you stick with rim brakes, how much less wear do you suppose is on your front rim than was on the failed rear rim?

ehron

Thanks for clarifying the hub difference. That is what I suspected, but I wasn't positive.

cbchess

get some avid BB7 disc brakes .
what ever hub you like deore disc would be cheap or LX
hope pro 2 is a good higher end hub but not too spendy.

some Sun or Mavic rims have always worked well for me.

if you want to go cheap look online - you can buy a disc ready wheelset for $100 and up. just take it to a LBS and get them to tighen up the spokes and re true it for ya if you can't do it your self.

Harry Stone

Wow, that's ugly.

melville

Where are you that your guy had never seen one blow before? Add just a touch of water to your environment and that's a regular service item, as it was for us in Seattle. I had a friend who went through three a year like that on his mountain bike. After a while, he got clued in to checking his wheels on Thursday night by inflating them to 100 psi. If they blew, he'd have time to build a new one before the race on Sunday.

If you really want to go disc do it, but by the cleanliness of the rest of the bike I'd tend to think this was a freak occurrence. Get new brake pads along with your new rim, as you must have something stuck in the old ones to cut the rim so cleanly.

cyccommute 

And tires that push outward on the rim surface like wide mountain bike tires do on narrow rims.

ehron

It was at the LBS near my office. National chain so I don't know if it is kosher to say the name as i don't want the comments of a single employee to cast aspersions on the entire company.

The bike is only 2.5 years old so it certainly surprised me. It does see water every now and then as I sometimes get caught in the occasional storm on the way to work and back.

New wheels ordered over the internet require trueing and spoke tightening? Is this because they have been shipped, or is this the case with all new wheels?

Thanks again for answering my questions.

Retro Grouch 

It's because mass marketed wheels haven't seen the love that hand built wheels enjoy.

the_tool_man

Does your bike have mounts for the brake calipers?

ehron

Yes, it has mounts. Now that I realize I have to replace the wheels to swap discs in that extra $90 I would have spent for the disc model seems like a bargain. Damned hindsight.

It is a Trek 4300. 2005 or 2006 model. This is the first real problem I have had with the bike after riding it back and forth to work 13 miles a day for the last 2 years. It is the first non-Walmart bike I have ever had...

dabac

Time for a new LBS as well. It's possible that your separation was a tad longer than usual, but in the days before lightweight disc brakes that was pretty much the most common reason for wheel failures on XC and touring bikes.
Strictly, no. But as the front brake should see the most use it'd be a bit odd to run a disc rear and a rim front.
As already pointed out by others:
- your frame and fork needs to have the mounting brackets for the calipers
- if you're going to hydraulics you'll need brake levers as well, and if you've got brifters right now you'll need new shifters too.

ThreLittleBirds

You dont necessarily need to go for discs. I would call this a fault of the particular rim, rather then the entire concept of rim braking. you really just need better quality rims, and a regular check for grit on the rims and pads. you should also make sure your rims match the tires better next time. a fat tire on a narrow rim causes extra stress on the sides of the rim, especially if you run the tires at a higher pressure.

personally I think an "upgrade" to discs wont be worth it, you will need completely new wheels and brake levers. even if you were to use identical replacements on the rims, it would probably take 4-5 failures (would take 10+ years) before the cost of the replacement rims equaled the cost of switching to discs.

which brake do you use more? if you mostly used the back then your front should be ok for a while.

Joshua A.C. New

You don't want to hurt the company's feelings?

They undertrain their employees. Asperse away.

HillRider

The extent of your rim failure is more than usual but I've seen, and had happen to me, several rims fail this way from wear at the brake track from grit and abrasion. The soonest was a Mavic Open 4CD rim at 12,000 miles and the longest was a Matrix (Trek house brand) rim at 18,000 miles. Other rims, ridden only in good weather, have lasted 30,000 miles and were retired before failing.

As was yours, both of my personal rim failures were rear wheels despite most of my braking being done by the front. All I can figure is that the rear rim gets a lot more water and grit thrown up on it which makes a more effective grinding compound.

BCRider

Go discs or just replace the rims. Some last longer than others but rim brakes make rims a consumable commodity. If you get new rims that use the same spoke diameter then it's not a big deal to change them. A rather good introduction to wheel building in fact. Tape the new rim to the old one, loosen the spokes off so it's all floppy then start undoing the spoke nipples and move the spokes over to the new rim one spoke at a time to maintain the pattern. Remove the old rim and start tensioning up. You can stress relieve and true them in the bike's frame using a ruler to measure for centering and a bit of electrical wire wrapped around the leg or stay with an end fingering off to use as an indicator. Read up on tensioning and truing and have at it.

But if you really want discs then that would certainly be a good way to go as well.

ehron

Thanks for all the input guys. I wanted discs from the beginning, but I wasn't sure I would ride the bike so I didn't spend the extra money. Now that I have put hundreds of miles on it I think I can rest assured it won't be a waste of money.

I have searched Google for a guide, but I have been unable to locate one. From the bits and pieces I have gathered it seems like all I need to buy is:

Set of disc ready wheels like Sun Rhyno Lite/xt 756, or Sun/deore 525 Mountain? Out of curiosity, what would make the first set worth an additional $100?

Cable mounted discs like Avids or Hayes?

And that is all for cable discs, correct? Or do I need additional parts? I have this bike:
https://www.trekbikes.com/us/en/bikes/2006/archive/4300

Jeff Wills

Thump-thump-thump-BANG!
https://home.comcast.net/~jeff_wills/...s/rites042.htm
Been there, done that, my ears hurt for an hour afterward.

dabac

XT hubs are a notch or two above Deore. For rear hubs this usually means slight better seals, for fronts I don't rightly know. Deore are perfectly serviceable, their main fault with Deore is that they're utterly lacking bling value
Avid BB7 tends to get the better reviews, but it's not like the hayes are known for sudden and catastrophic failures either.

I can see that your fork can take discs, but the rear can't be determined from the pic. Otherwise you should be pretty much OK. Disc-ready wheels, brakes, rotors, new brake cables + housings( new brakes will be further away. If you're feeling cheap you can reuse the old rear cable for the new front.)
Be aware that there are two mounting standards, post mount and IS. Depending on what you get in your kit you might need an adapter to go from one to the other.

EatMyA**

WOW 2 years into it 13 miles daily. Good for you! Thats great, most people dont last that long.

Just buy a new rim $60 tops, for good rims. your spokes, nipples and hub still work. why spend all that money (unless you like to of course).

But you seem like you really want to do the conversion to disc. either way GOOD LUCK!

roadfix

My Ambrosio road rim exploded like that with a gunshot like bang while riding. It tore off about a 15" section of the braking surface. It was not a pleasant experience. It happened in the middle of nowhere in the mountains where I had to walk for like 3 miles before I was able to hitch a ride back to my vehicle.

ElementalMojo

Ahhh! Who needs brakes!!!!

griftereck

There was a little girls bike with normal width tyres and rims at my work that had the same failure

Unlikely to have been riden hard
or the tyres inflated too hard...or even hard enough.