Bolt on the chainstay has sheared

emdiesse

I have no idea what this bolt is and how I can replace it, or whether I need to replace it! A while ago I hit a root with my cassette and snapped it, so I bought a replacement eventually! Then my dad told me he noticed a loose bolt on my bike and tightened it for me but it had sheared right off, I have no idea what it even is.

I have a Specialized Hardrock (2006 I believe) It has a Shimano Deore rear derailler if that helps with the diagnosis.



I can't remember exactly where it was from now I have reached lunch break at work!
However a dig on the internet and I found a picture which I believe shows the bolt in question.

http://s3.postimage.org/9hgajqtuz/Bike_Bolt2.png

Any ideas?

Many thanks

nicklouse

mech hanger retaining bolt.

you can use a inner chainring inner bolt and a SS outer chainring outerbolt.

or just ask your LBS.

emdiesse

Probably the bolt at the top of this picture



Can you even buy this as a spare part, is it a common part?

nicklouse

if it is part of the mech then new mech.

but untill we see actual pictures of your issue who knows.

emdiesse

nicklouse wrote:

mech hanger retaining bolt.

you can use a inner chainring inner bolt and a SS outer chainring outerbolt.

or just ask your LBS.

Ok, cheers.

I asked them and they just shrugged

Probably went on the wrong day at the wrong time and got the shelf stacker :roll:

I trust your diagnosis though, sounds right, searches on the internet yield the same sort of problems.

http://www.bikeradar.com/forum/viewtopic.php?p=16055069

Cheers

stu8975

emdiesse wrote:

Probably the bolt at the top of this picture



Can you even buy this as a spare part, is it a common part?

Yes you can buy that part, if its the part you need, but determine whether you need a mech hanger bolt (short chainring bolt) or rear mech bolt (B-axle assembly for shadow mechs as in the pic).

emdiesse

Ok, looking at the price of the bolts anyway i'm probably better off just driving out to a different bike store and buying them there since i'll be able to match them up properly before buying anything! It's a pain because I have the bolt here, the thread appears to be of 7-8mm diameter (Probably 8, since I have heard of M8). With the head held in place the bolts about 1cm long.

These chain ring bolts look to be what I am after, the right sort of proportion and counting the number of turns on the thread, 9, I see some chain ring bolts that match this. Then I see there are inner and outer ring bolts, what are the difference asides from one has a female part to it.

If I knew the diameter of the bolts thread i'd probably buy them since I guess eventually they may come in handy, are they used for anything else on the bike at all?

Chain Reaction Cycles has some RaceFace Inner/Outer ring bolts, question is are they the right diameter and length and do I need Inner or Outer ring bolts. The bolt I have has no female part and the place where it goes is threaded which leans me toward thinking inner ring bolt is what I need.

stu8975

mech hanger bolts are male/female, inner chainring bolts are male only as they screw directly into the spider on a crank, as opposed the 'clamping' action of male/female on a mech hanger bolt or middle/outer chainring.

Have you determined whether you need a mech hanger bolt?

The bolt I have has no female part and the place where it goes is threaded which leans me toward thinking inner ring bolt is what I need.

it should do, cant say ive seen a mech hanger that mounts directly to a threaded part of a frame.
Do you have any pics of mech hanger/frame and rear mech?

nicklouse

emdiesse
pictures please as none of what you are saying actually makes sense.