[mattsz]

I'm preparing for this job.  The nut holding the front sprocket is quite thin, I think, and the socket from the monster set I bought is "flared" a bit at the opening; the grooves which grab the nut corners don't extend all the way to the edge of the socket.  Does this make sense?  I guess they do this to make it easier to fit a socket onto a nut or bolt head?



My question is, will the socket grip as is, or should I think about grinding some or all of that flare off the lip so it might be less likely to slip off the skinny nut?

[2bikebill]

Try it first. The nut holding my sprocket on was only finger tight!
Luckily there is a lock washer preventing it coming loose.

[heloego]

The socket pictured should work just fine.
It's normally referred to as a 6-point socket. Older sockets have an even flat between points and have always been adequate, but often an over-tightened or over-torqued nut could have its points rounded off during removal.
Your socket has a shoulder between points and that shoulder is designed to grab the nut further back from the nut point. This gives a better "grab" at the contact point, preventing rounding off of the nut.
A much better design, IMHO. Too bad they can't do the same for 12-point nuts and bolts.

[gashousegorilla]

  It's not the retaining washer under the nut, which has the tabs bent up against the flats of nut giving you trouble is ? If so, just bend them down, and your socket should fit fine. Then when your done, bend them back up against the nut.  It acts as a lock washer.

[mattsz]

Thanks guys.

GHG: I'm not having any trouble - yet  .  I haven't opened anything up yet.

heloego: That pic is just an example I grabbed off the net.  The socket I have isn't a six-pointer, and it's big enough to cook a small meal in.  But the idea is the same...

I was wondering if anyone who has needed a 6-foot breaker-bar or an impact wrench (and they're lurking here somewhere!) to remove that nut has had any trouble with the socket not grabbing enough of the slim retaining nut...

[barenekd]

I needed about a 5' breaker bar. A standard breaker bar plus an old fork tube. The nut was definitely tight! Same socket, though...No problem. If I were still a young, strong pup, I probably could've gotten it off with the breaker bar, but I try not to overstress myself these days! Especially if I have something to reduce the effort, like a guy to change my tires!
Bare

[gashousegorilla]

Thanks guys.

GHG: I'm not having any trouble - yet  .  I haven't opened anything up yet.

  OH !!  Sorry Matt. You were just doing a little pre- investigatory type thing, so you don't get into trouble..... nuttin' wrong with that.

[t120rbullet]

I was wondering if anyone who has needed a 6-foot breaker-bar or an impact wrench (and they're lurking here somewhere!) to remove that nut has had any trouble with the socket not grabbing enough of the slim retaining nut...

I used a socket that was ground flat and an impact.
Don't know if the grinding made any difference but the nut looked pretty thin so we ground it down before we even started.

[Craig McClure]

I had the same situation, on a different bike, & had a machinist pal turn the flare away on a lathe. Glad I did - that bolt was mega-tight even after heating & penetrating oil. hope that helps.

[mattsz]

I've got access to the grinder I need to do the job, so I might as well do it...

[mattsz]

My big socket set has a 45mm socket, and a 48mm socket.  The nut is apparently 46mm.  Singhg5 measured the nut as 46mm, and suggests using a 48mm socket.

I trust him, but can anyone confirm this?  I'm going to grind down the 48mm socket unless I hear otherwise!

[gashousegorilla]

  Don't do it Matt !!   LOL !  A  1 13/16 " works perfectly and probably easier to find then a 46 mm. Unless you have a different size nut on the B-5.

[Ducati Scotty]

+1, that's what I used.  Easier to find and half the price.

It was a 12 point.  It kept slipping off with the breaker bar, but it also took a few seconds to come loose with the impact gun so I suspect it was quite tight.  If you're using an impact gun you should have no trouble with the flare.

Scott

[Arizoni]

I haven't changed the sprocket but if I were to do it I would leave the chain attached and the transmission in neutral while loosening the big nut.

Rather than trying to stand on the brake pedal and wrench the nut off at the same time I would tighten the rear brake adjustment nut until the brake was firmly locked.

That way I wouldn't be putting the torque from the wrench into my transmissions gear train where it might do some mischief.

[GSS]

My big socket set has a 45mm socket, and a 48mm socket.  The nut is apparently 46mm.  Singhg5 measured the nut as 46mm, and suggests using a 48mm socket.

I trust him, but can anyone confirm this?  I'm going to grind down the 48mm socket unless I hear otherwise!

Don't do it.  Use the right size socket and spare yourself and the bike from injury/damage.  You are over-analyzing this simple project.  Left foot on the brake pedal and a proper sized socket with a breaker bar works great.  I slipped a 4 foot handle from a Hi-Lift jack on the breaker bar and it required minimal effort to break it loose.  I used the same procedure to tighten and bent the lock washer back at a different spot from the original bend.