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I've managed to strip the threads in one of the bolt holes in the non-driveside sliding dropout on my Voodoo.
Would a simple helicoil insert be the best fix (other than a new dropout plate)?
They're cheap on [url= http://www.ebay.co.uk/itm/25-Piece-Thread-Repair-Kit-M6-x-1-0-x-8-0mm-Helicoil-Type-/260919783495?pt=LH_DefaultDomain_3&hash=item3cc007f047#ht_2643wt_952 ]ebay[/url]
aren't the drop out plates quite thin? I would have thought they would be too thin for a helicoil as you need to drill them and re-tap them to fit the helicoil.
Could you epoxy in a threaded rod and use a nut instead? OR drill a hole in from the side and file it to a (rounded corner) rectangle so you can fit a nut inline with the old thread.
Its about 8-9mm thick, so the helicoils would just fit in.
Its my fault for not using a torque wrench, but equally, M6 bolts are a wee bit, well, wee for a sliding dropout IMO
Cheers for alternative ideas though. I've emailed Voodoo to see if replacement dropout plates are available.
could always get some cut yourself if you find a friendly guy with a laser cutter.
I guess halfords might have them listed as they stock Voodoos? I do like their frames and wish more makes did the sliding drop outs.
PS 8-9mm thick and with an M6 bolt? What is the outer diameter of the M6 internal helicoil? It must be getting on for 7.5mm surely? seems a bit close to me.
Looks about 8mm drill bit?
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could be a 20mm drill bit without anything for reference 😉 Okay, that's an exaggeration but it's just too hard to tell accurately from the picture.
Just checked up on the sizes and for M6 the drill hole is from 6.3 for a cut tap to 6.8mm for a roll tap but the nominal outer diameter of the M6 helicoil is 7.4 to 7.95 so I really don't think you will have enough material.
Any suggestions for alternative threaded inserts that might work?
they are all going to be similar tbh. Might be worth giving it a shot if you can drill straight. I guess you don't have anything to lose.
I bought one of those exact kits about a week ago to fix a stripped post mount in my fork's lowers.
It worked a treat. Very easy to install and very sturdy.
As long as your current hole is longer (deeper) than the 8mm helicoil; it will be fine.
Is the depth really so crucial? Can't you cut the coil?
People above seem te be confusing thickness/depth with width/diameter.
Hole is thru the plate, plate thickness marginally greater than diameter.
Is the depth really so crucial?
sort of. rule of thumb thickness needs to greater than diameter, ideally > 1.5 times I think.
Not ideal but will worth a try. helicoil is a good option
Don't know if it's any help but you could try this place http://www.mountainbikecomponents.co.uk/result.asp?CategoryID=193&Name=HANGERS+%2F+DERAILLEUR+%2F+GEAR+%2F+DROPOUT+%2F+MECH+%2F+FORCELLINO+%2F+SCHALTAUGE+%2F+HANGERS Hope you get sorted.
Cheers Rockape, i had a look at BETD yesterday. They don't make the dropout as standard it seems, but I guess they may be able to copy if if the helicoil fails.
Waiting to hear back from Voodoo if they can sell me a replacement.
1.5 x is to stop a thread stripping IIRC, given the greater strength of the helicoil, I smaller factor should work?
Helicoil kit ordered from ebay...
So, just fixed the dropout.
Driled the old M6 thread out no problems with the supplied drill bit. Tapped the new M8 thread no problems.
Wound the helicoil in, all good. Broke the end tang off. THEN checked it had gone in cleanly. Oh dear, it hadn't. The last half-loop of wire was cross-threaded, and I now had no way of turning the helicoil to take it out. Doh!
In the end, I managed to get an M6 tap into it which wedge in enough to push it through the hole, enough to grab the other end with pliers and wind it all the way through.
Took a couple more goes to get the helicoil in, and it had probably worn things down a bit as it was no-longer a tight fit. BUT, the 4th one has gone in and is staying in. Bolt tightened up to it, will find out if it creaks next time I ride it....