Brake cable broken.....Aaargh!

Got a question maybe somebody might have had experience with. I was attempting to take the rotor off of the alternator and was applying the rear brake to hold it in place while I cranked on the nut holding it. Naturally, nothing ever goes to plan and the brake cable snapped :evil:

While I wait ever so patiently in the mail for a replacement cable, I was wondering if this was something that:

1. Was fortuitous because my brake cable was weakening and is better it happened now than out on the road
2. Happens once in a while and there's nothing I can do about it
3. There might be another way to keep the rotor from turning

Obviously, the nut is on pretty damn tight. I'll try and use penetrating oil while the part gets shipped in case that's an issue, but there's lube splashing around the primary case all the time, so I doubt that's the problem. I was putting all my weight on the brake, which is kind of dumb when you think about it, but the rear brake on my bike isn't the strongest thing you've ever seen, and I was trying to keep the rotor in check.

Does anyone have any ideas so I don't go broke buying brake cables?

slupdawg said:

1. Was fortuitous because my brake cable was weakening and is better it happened now than out on the road

Click to expand...

I'd say you were lucky it broke when it did.

If the cable breaks while you are riding, then the pedal swings down and digs into the road surface which can throw you off the bike!
I suggest that you and other pre-MkIII owners fit one of the Norvil type safety springs, if you/they haven't already got one?


http://www.norvilmotorcycle.co.uk/064172SS.jpg

064172SS

SPRING - BRAKE PEDAL SAFETY - REAR - DO NOT RIDE WITHOUT IT! ******

slupdawg said:

Does anyone have any ideas so I don't go broke buying brake cables?

Click to expand...

I put a piece of wood between the lower run of the primary chain and clutch housing teeth, then when you apply force to the crank nut, the piece of wood jams the assembly and stops it rotating.

hi slupdawg,not sure about another way of locking everything up besides using the back brake,however better for the cable to break then than out on the road,have you got the safety spring fitted to the rear brake pedal(it stops the pedal dropping down and digging into the road)another thing to try is shocking the rotor nut loose with a mallet on the end of your spanner hope this helps

Indeed lucky, usually my cables break when I need them the most: IE in an emergency stop, I must add that leaving the bike unattended for a while increases the chances of a cable braking as if my Norton was possessed and wanted to get even.

That being said, if you ever use the back brake to stop something from turning, make sure the transmission is in 4th gear, this puts less torque on the rear brake so you don't have to stomp on the pedal as hard.

Jean

Thanks for the replies-the wood block worked great. I was thinking of jamming something in the gear also, but never thought of something forgiving like wood. I didn't want to use metal.

Now, here's another question, just to totally change the direction of the thread. I removed the old alternator to install a new 3-phase model. Two problems:

1. The rotor and stator are not in alignment. The stator is butted up against the studs and will go no further due to the greater diameter of the untapped interior portion of the stud, while the rotor is fully recessed.

2. The directions tell you to put the stator wires to the outside at a 2 o'clock position, but this is impossible as the closest I can get is almost at 12 o'clock

I copied a pic of an earlier post showing what my current setup looks like, but imagine the stator turned 120 degrees anti-clockwise, putting the wires near the top of the case.

http://www.nortonfastback.com/images/electrical/sparx.jpg

Should I shim the rotor to put in alignment with the stator? This assumes the whole assembly fits within the primary case. What position should the stator be in, 12:30 or 4:30 position?

I love how this works! Try and keep your battery charged and end up with a broken brake cable........

Try again:

Thanks for the replies-the wood block worked great. I was thinking of jamming something in the gear also, but never thought of something forgiving like wood. I didn't want to use metal.

Now, here's another question, just to totally change the direction of the thread. I removed the old alternator to install a new 3-phase model. Two problems:

1. The rotor and stator are not in alignment. The stator is butted up against the studs and will go no further due to the greater diameter of the untapped interior portion of the stud, while the rotor is fully recessed.

2. The directions tell you to put the stator wires to the outside at a 2 o'clock position, but this is impossible as the closest I can get is almost at 12 o'clock

I copied a pic of an earlier post showing what my current setup looks like, but imagine the stator turned 120 degrees anti-clockwise, putting the wires near the top of the case

http://www.nortonfastback.com/images/el ... /sparx.jpg


Should I shim the rotor to put in alignment with the stator? This assumes the whole assembly fits within the primary case. What position should the stator be in, 12:30 or 4:30 position?

I love how this works! Try and keep your battery charged and end up with a broken brake cable........

slupdawg said:

1. The rotor and stator are not in alignment. The stator is butted up against the studs and will go no further due to the greater diameter of the untapped interior portion of the stud, while the rotor is fully recessed.

Click to expand...

Apparently that's not unusual.

If you attempt to shim out the rotor, then the rotor nut could touch the primary cover?

slupdawg said:

2. The directions tell you to put the stator wires to the outside at a 2 o'clock position, but this is impossible as the closest I can get is almost at 12 o'clock

Click to expand...

I get the feeling that the "2 o'clock position" recommendation is actually intended for installation on a Triumph twin?

I'd position the rotor with the wires as it is shown in the photo link, and that's probably where your old stator wires were I'd guess?

What's important is that the stator is positioned so there are no sharp bends in the wires, and that the wires are positioned where they won't be cut into by the primary chain thrashing about?

hi again, i dont think it matters too much what position the stator is in so long as the wires dont come into contact with the primary chain,looks like to get it at 2 o,clock you would have to fit it with the wires on the inside (reversed)

The 4 o'clock position as shown in the photo should be fine. Don't install with the wires facing in - a friend of mine did that and the chain was able to saw through the wires, leaving him with no charging and a dead battery in the middle of nowhere.

Shimming out the rotor doesn't seem to be necessary. Every one I've seen is like that and they seem to work fine in that position.

Now, my question:

I bought a Sparx kit for my 850 and was test fitting it today. The rotor doesn't fit very well - the bore is too small. The rotor is a very tight fit on the crank and the sleeve nut doesn't fit at all. I think I've heard of this before but couldn't find anything when I searched. I'm wondering what to do - seems like I need to have a machinist hone the ID out a little?

Also the sealing grommet doesn't fit over the wiring bundle, which is considerably larger in diameter than the original. So what to do, squirt a bunch of silicone sealant where the grommet used to fit? One solution would be to fit a belt drive so I wouldn't have any oil to leak out. Unfortunately that's not in the budget right now.

Debby

A thin piece of sheet copper can be used to check alignment. Put it in where you would insert your feeler gauge to align it before you tighten it down. Make sure it is big enough to pull back out and long enough to go all the way around.

If you are talking about not being able to adjust the stator for correct clearance it may be necessary to remove the studs and waist them to get enough movement. If your stator and rotor just won't have enough clearance anyway, phone the folks who made the custom bit. They may need to trim the part for you, seems to me this would be on them,

Debby, the early Sparx rotors came undersize, it was corrected for later runs but looks like you have been given old stock. The fix is to machine out the rotor to a sliding fit or return to dealer for later rotor.

I contacted Sparx about that and the reply was:

"the rotor should be a 4 thou interference fit
you can ream it to 3/4" if you want the normal lucas style sloppy fit
Thanks
Andy"

Riiight. No way I'm gonna hammer that thing on. Still haven't found a machinist to open it up so it fits "sloppy".

That "recessed" rotor is perfectly normal, as I found out when researching the issue when I had the same question!

Ahh, so you mean fit on the shaft? I never saw that problem. It still seems to me that good customer service would be too open it up for you.