"Crunch" Noises From Rear Hub

[The Critic]

After doing my normal chain degreasing and lubrication this morning, I took my bike for a quick spin around the block and heard a "crunch" like noise coming from the rear of the bike. I got off the bike, lifted it up, and gave the rear wheel a spin. It appears as though the "crunch" like noise is coming from inside the rear hub.

I assume that this means my rear hub needs to be repacked with new grease?

The bike in question is a '04 Specialized HardRock Sport that is ridden occasionally. I've probably ridden it less than 1000 miles total since I bought it.

Any tips/suggestions on correcting this problem are greatly appreciated. I'm new to bicycle repair.

Thanks in advance!

 

[Pablo]

Could be needing grease....or the bearings may already be munched.

Take 'er apart!

 

[The Critic]

Originally Posted By: Pablo
Could be needing grease....or the bearings may already be munched.

Take 'er apart!

It's strange how there was no warning whatsoever.

How do I take it apart? What tools do I need?

 

[Pablo]

Ping me when I get home. I have a cool DIY bike site link. Basically you take the wheel off and remove the bearing retainer nuts......

You aren't a small guy and that's a decent load on pretty small bearings....lousy or no lube or slightly defective parts....just go bye-bye.

 

[The Critic]

I found this site during a google search:

http://bicycletutor.com/overhaul-wheel-bearings/

It mentions needing a cone wrench. I don't own one--can I substitute with something else?

 

[Pablo]

Found this:

http://www.instructables.com/id/Properly-packadjust-bicycle-hub-bearings/

Not the one I was thinking of.

 

[gomes512]

I use to try to adjust the preload without cone wrenches. Never doing that again, cone wrenches make it so much easier. I typically find that a common size for front and rear is 13 and 15 mm, respectively. If that is your case then go on ebay and get a park tool dcw4 double end with 13 and 15mm ends. Should run your no more than $8.

You can substitute with a piece of sheet metal and using a grinder to grind gap to size. I've done it before when I didn't have the correct size, kind of tedious.

 

[wantin150]

Definitely recommend cone wrenches. As for re-packing, it's an easy job. Just make sure you keep track of all those little silver balls!

I remove the axle just to the point where the end starts into the hub and blocks the hole. Using a Q-tip, I pop out all the bearings. I kept mine side specific but it may not really matter. Then remove the axle and do the other side. Clean everything out really well (Q-tips work for the bearing races)and pack both sides with grease. With one greased side up, load the bearings. The grease will hold them in place. Slide the axle into the hub, just far enough so that the axle blocks the hole. Load the other bearings and seat the axle and nut. Then get the preload right. One trick was to tighten both nuts. Then, while holding the outside nut, loosen the inside (effectively tightening it against the outside nut). As long as the wheel spins freely, you're good to go. Any binding and you have to start over, same with slop. It takes a time or two to get it right.

 

[Bill Kapaun]

You can get by with ONE cone wrench and a regular wrench of the proper size.
You can buy a Park DCW series for about $6 at the LBS.
I have DCW-1, 2, & 4.
13 & 14, 15 & 16 and 13 & 15mm respectively.

I can buy new BB's for $.05 ea at my LBS. You'll need 18 1/4" ones for the rear. 20 3/16" for the front.
It's much simpler AND faster to replace, than to clean & inspect.

 

[The Critic]

Thanks everyone for your help.

After my original post, I took the bike for a quick ride around the block. When I came back, most of the noise had disappeared for some reason. Maybe I originally got some water into the bearing? :dunno:

I went ahead and repacked the rear hub anyway. I used a 17mm socket and a 17mm boxed end wrench. I didn't need a cone wrench, or was I supposed to use one? I didn't remove the cassette either. Supertech Multi-Purpose grease from the tub (red color) was used, not sure if it's the correct stuff though.

All of the bearings appeared to be in good shape. I reassembled everything and took it for a ride. It was much smoother and all of the crunching noise is gone, but now I notice some chain noise.

I measured the chain and discovered that I had 1/16" of wear. I've had the bike since 2004 and I only ride it occasionally. I still have the original tires! I even clean and lubricate the chain regularly.

Is it normal for my chain to show this much wear so quickly? Do I need to replace my chain?

Thanks again.

 

[wantin150]

It can happen that quick (heck, 4 years? How many miles!), especially if the cassette is worn. Look at the gear teeth and if they have a sharks fin look, they're shot. A new chain will quickly wear on a worn cassette so replace both.

As for your hub crunch, a couple pieces of sand past the seal is all it takes. Better safe than sorry.

 

[Bill Kapaun]

IF you have QR hubs, be aware that when you tighten the QR, you'll remove some of the "play" in the bearings.
You have to set them a bit loose. A bit of trial & error will give you an idea of how much.

 

[The Critic]

Originally Posted By: Bill Kapaun
IF you have QR hubs, be aware that when you tighten the QR, you'll remove some of the "play" in the bearings.
You have to set them a bit loose. A bit of trial & error will give you an idea of how much.

I did not know that, thanks.

How much play are you supposed to have in the bearings? Is tightening them up a bad thing? I had them very tight for the last year or two.

 

[The Critic]

Originally Posted By: wantin150
It can happen that quick (heck, 4 years? How many miles!), especially if the cassette is worn. Look at the gear teeth and if they have a sharks fin look, they're shot. A new chain will quickly wear on a worn cassette so replace both.

As for your hub crunch, a couple pieces of sand past the seal is all it takes. Better safe than sorry.

Gear teeth look OK to me. 4 years and less than 1000 miles for sure. I ride it a few times a week around the block. It still has the original tires, rotated once.

I'm still not sure how the chain is showing 1/16" wear already. My 12 year old BMX bike when measured using the same method, shows almost no wear. And I cleaned and lubed the chain maybe five times during those 12 years!

 

[huffmuds9320]

Yeah I would say its possibly that sand can get into places you don't expect it to. If you ride off road, sand can get onto derailer parts and find its way onto ball bearings. Happened to my bike and I just rinse the parts then relube them.

My 15 year old bike used to get sand easily in the crank and makes a crunching noise, I just blast it with water to get the sand out. That bike too has gone though a lot of neglect and its still rock solid.

 

[Bill Kapaun]

[/quote]
I did not know that, thanks.

How much play are you supposed to have in the bearings? Is tightening them up a bad thing? I had them very tight for the last year or two. [/quote]

With the wheel off the bike, rotate the axle with your fingers. You'll find a fine line where you can feel the bearings start to feel almost "gritty". That's too tight. The problem is duplicating the feel with the skewer clinched down. IMO, It's better to err a bit loose than a bit tight. That doesn't mean sloppy. Sideplay at the rim should probably still be < 1/64".

 

[moribundman]

Originally Posted By: lpcmidst128
Yeah I would say its possibly that sand can get into places you don't expect it to.


"I hate sand. Its rough and course and it gets in everywhere."

--Anakin Skywalker, former Boonta Eve pod race ace

 

[wantin150]

Originally Posted By: Bill Kapaun
[/quote]
I did not know that, thanks.

How much play are you supposed to have in the bearings? Is tightening them up a bad thing? I had them very tight for the last year or two.


With the wheel off the bike, rotate the axle with your fingers. You'll find a fine line where you can feel the bearings start to feel almost "gritty". That's too tight. The problem is duplicating the feel with the skewer clinched down. IMO, It's better to err a bit loose than a bit tight. That doesn't mean sloppy. Sideplay at the rim should probably still be < 1/64". [/quote]

It helps to spin a "new" wheel and try to remember that feel!

I always use this same approach. Before settling on the feel, grip the axles and try to wobble the wheel side to side. You can feel excess play there as well. It takes alot of trial and error.