Have I broken it properly this time?

[Big_Jimbo]

Last weekend I had to replace a broken spoke on my mountain bike. It was on the brake disc side of course. So I took the disc off. I know the manual says I should be able to do this without first removing the axle plate and click box, but I couldn't get it past. I undid the five torx screws and eased the click box assembly off no problem. Swapped the broken spoke and started to rebuild. This is where I hit the problem. I've snapped two of the torx screws. I don't think I was overtightening them, but there you go, they snapped.

Does anyone know how to get the broken remains of the bolts out?
I've tried gently drifting them round with a small sharp screwdriver, but to no avail. I figure I can't drill them out as dwarf would drop down inside the hub.

Anyone had this problem before?

[JimK]

ouch, that is nasty!

You might be able to drill them out safely by having the screw hole face down, so the drill bit is going up. That way the fragments will fall down, away from the hub. Yeah you really want good eye protection for that! Anyway it's just an idea. Take it slow and steady!

[triaesthete]

 How far below the head have the bolts snapped?

[geocycle]

Yes struggling to think this one through. Have you a picture?

[Big_Jimbo]

I have a picture, but not the IT skills to attach it. Can't seem to find anything in the help files.

[Danneaux]

Hi Jim!

Surely sorry to hear of your dilemma.

This tutorial should at least help in posting photos :http://www.thorncycles.co.uk/forums/index.php?topic=4313.0

Best,

Dan.

[Big_Jimbo]

Thanks Dan
The two broken studs are roughly in the two o'clock and for o'clock positions of the attached picture.
If I had a left handed drill bit, I'd risk sealing the bearings up with something and then trying to drill them out. My stud extractors are all far too large. I'm worried that a standard drill bit might drive the broken piece further in and therefore into the main bearings.

All help greatly appreciated.

[Danneaux]

Jim...

A thought: In the absence of any remaining bolt heads, are the remaining threaded shanks actually holding anything in place? Wondering if you could ease the flange off, then perhaps the studs would stand proud enough to grab with mole-grips?

Best,

Dan. (...who, like many of us, has been in a similar situation and feels for and with you in your dilemma)

[Big_Jimbo]

I'm not brave enough to slip off the circlip in case what comes undone is either spring loaded or there are thousands of tiny parts that all need to be mounted in the right order to very tight (precise) tolerances.

[il padrone]

Easyout - correct size, used with great precision




But I'd probably talk to Thorn first, and even get them to do it in preference.

[onrbikes]

The easy outs are good but you'll need to first drill the hole, and thats the hard part, because its such a small bolt.

You'll first need to get a centre punch and get a dent in what you think is the centre.
Get a smaller drill than the tap drill size.

ie. if its a 6x1 it is a 5mm hole. If its a 8x1.25 its a 6.7mm drill.
Subtract the thread pitch from the diameter and thats the true size of the hole.

So whatever size yours is go for a drill size 1mm smaller than the drilled size. Its best to use a centre drill first, as they don't wonder round.
This will allow for off centre error. Plug all holes and any gaps to stop any swarf getting in and try to set it up on  bench.

If you get the drill through the bolt, get a screwdriver and tap it down the now smaller hole and unscrew it. It should come out as the screw would virtually have collapsed.

You should have it set up on a bench.
Most automotive machine shops could easily do it. You'll need to know the depth of hole.

Failing that send it to Rohloff

[Big_Jimbo]

In answer to my own question, it appears I had.
The axle plate that the five torx headed bolts screw into can't be removed without special tools and/or adhesives. 
Fortunately Dave Whittle of SJS has fixed it (at quite reasonable cost) and its on its way back to me again.
Thanks for the advice and I hope to be back out on it by the weekend.

[Danneaux]

What wonderful news, Jim (not the breakage, but the repair)! So glad Dave was able to get it sorted for you and you'll soon be back on the road.

Best,

Dan. (...who appreciates the followup)

[geocycle]

Great result.  That would have beaten me!

[Dave Whittle Thorn Workshop]

If this happens to anyone else, its worth realising they are likely not to be seized as they are surrounded by gear oil.  And never drill into them as this will almost certainly get swarf into the gear unit and the drilling may even drive the studs further in and hit the internal casuing shiting issues and damage.

In this case I was able to use a pick and a hammer and tap the studs round to remove them.  I belive in this case they were over torqued, the screws were not Rohloff ones either... so maybe we won't see this again.

As with any Rohloff issues, i'm always happy to help, do repairs/conversions etc. just email me dave.whittle@thorncycles.co.uk