Bicycle Mechanics - Rear tire axle screw broken, how to fix?

so, at some point last sat when I was riding it broke!! not sure how, but I figure it might be from the abuse of mtb riding!

so, is it something that can be replaced easily?

included are some pics.

broken screw, arrows indicate where it broke.
http://img14.imageshack.us/img14/5400/p1060061medium.jpg

does anything need to be replaced from this part of the rear wheel?
oh yeah, the bearings fell out, and so I dont have any right now. can I buy them and is it easy to get them back in there and all working good??
http://img8.imageshack.us/img8/8185/p1060066medium.jpg

That's not a screw. Your axle is broken. They are replaceable.

That's not a screw. Your axle is broken. They are replaceable.

so, I should just be able to pick one up at the LBS??

how about the bearings?

Clean the bearings, if they're in good shape, you can re-use them. Here's a shopping list:


cone wrench combo, 13,14,15,16mm
Shimano freewheel removing tool
1 rear axle 10x1mm threading, measure length of existing axle 1st

You'll want to remove the freewheel, clean off the bearing races & cones and inspect for smoothless. Take apart axle, cones, washers, spacers and locknut. Pay attention to order, I tell people to draw a line on a piece of paper representing and axle and lay the parts down in the exact original position.

Install axle cone, washers, spacers & locknut on freewheel end of axle. Tighten down locknut. Apply grease to both hub cups, drop in bearings. Push through open end of axle. Install cone, washer, spacer locknut on the other side. Adjust bearings so you have a tiny bit of play. Tighten lock nut. Install freewheel and you're done.

Along with Danno's advice you may want to take a gander at the Park tool site.

http://www.parktool.com/repair/readhowto.asp?id=105

http://www.parktool.com/repair/readhowto.asp?id=48

You'll also want to ask yourself if that wheel is worth replacing or if you figure you have enough to go to a new cassette type rear wheel? Break axles like that often? Go offroading? Things to think about before you spend a big chunk of change.

You'll also want to ask yourself if that wheel is worth replacing or if you figure you have enough to go to a new cassette type rear wheel? Break axles like that often? Go offroading? Things to think about before you spend a big chunk of change.

the wheel is fine, I don't need to replace it.

and what do you mean a cassette type rear wheel? pro's and con's?

this is the first time I have broken a axle. and I do mtb once a week min.

Cassette hubs have the outer bearing closer to the end of the axle. This pretty much eliminates the type of failure you have. But you'll need a new hub to get it at the very least and will require unlacing the existing hub and rebuilding it with the new one. A new wheel with cassette hub is much simpler.

http://www.sheldonbrown.com/k7.html

Axle failure on freewheel-equipped rear wheels is a common issue. In fact, that's the main reason why cassette rear wheels (with the freewheeling ratcheting mechanism inside the hub) have replaced freewheel rear wheels for everything other than on low-end bikes.

The axle can certainly be replaced, but the job can be a bit tricky. You'll also need one large (12" or bigger) adjustable wrench - or better yet, a bench vise - to grab the freewheel removal tool. If you haven't adjusted bearings before, it'll probably take you a while to get it done. Make sure that both locknuts are very tight with their cones or the bearings will unadjust themselves quickly.

You say the wheel is fine, well, inspect the bearing races (cups) inside the hubs. If those are shot, the wheel is never gonna run smooth again. Otherwise, you can fix it and make it good again. You might need also replacement cones if the bearings races on the cones aren't smooth anymore.

Otherwise, all you need is a new axle of the proper length, and new ball bearings. Make sure to only use new ball bearings from the same batch - never mix bearings from different batches together.

As for a cassette wheel, there are no cons. Well, other than the fact that it'll cost you, and you'll need a new 7-speed cassette to replace your freewheel, and a 4.5mm spacer since you'll probably be getting a 8-9-10 speed cassette wheel, which only needs a space to work with 7-speed cassettes. Also, you need to check the spacing between your dropouts (O.L.D.) - if your bike uses the new standard, 135mm, then you'll be able to fit any new MTB wheel. If it's 130mm, you'd need to spread apart your dropouts (if your frame is steel) or modify the hub spacing and redish the wheel - making the new wheel option considerably less attractive..