do you think I might warp the disks

[NortonCharlie]

Swapping out part on my Tigers.  I want to keep my floating disks on my front wheel.  I am getting ready to pull the wheels.  To get the bolts out you have to heat the bolts to soften up the lock-tight (I used a propane torch).  Last time I did this I was tossing the old disks so didn't worry about it.  This time I plan of swapping them to another wheel.

Do you think there is much chance I will warp the disks? 

Replacing the disks would cost about 1/2 what I am getting out of the bike.  I could just swap the tires but that isn't free either.

[Sin_Tiger]

Heat the whole disk as evenly as you can before you spot heat the screws,  if you can get hold of some tempil stick temperature indicating chalk use that as a guide.

Once you have heated the screws DO NOT try to loosen them, let them cool naturally before you try and throw them away after that. You will have changed the metallurgical structure if you get them much over 300 deg C and will probably have destroyed the chrome plate anyway. They are not cheap so check the cost before you go wading in with the propane torch 

[NortonCharlie]

I was thinking pre heating the disk a little would be a good idea,  but as far as tossing the bolts that's not going to happen, we are talking about heating to maybe 400 F just enough to soften the lock-tight and definitely loosen them hot.  We are not changing the heat treat on these bolts at all, at $12.00 a piece I am not replacing them.  If it were a bolt torqued to yield like head bolts absolutely. 

I will probably just swap tires to be on the safe side, but the wheels I am keeping have used bolts that I heated with a propane torch to loosen.  I put new wheel bearings in about 20,000 miles ago.

[rf9rider]

All the discs i`ve replaced haven`t needed heat to remove them.

Guessing i`m lucky?

[NortonCharlie]

Interesting, did  you use an impact wrench or anything special?   I've only done the one set but am fairly sure I would have stripped the Allen heads and had a real mess without the heat.  I believe the factory manual tells you to heat them to get them loose.  Come to think of it I had to  (or did at least)  heat the bolts on my Sprint RS when I swapped disks on that one too.

The more I think about it I am just going to swap tyres and keep the 78,000 mile wheel.

[Sin_Tiger]

I can see you know what you're doing so I'll shut up

[rf9rider]

Just used good quality tools, no impact wrench.

[NortonCharlie]

I can see you know what you're doing so I'll shut up

I am sorry my response sounded short.  I value your opinion and hope you are still willing to respond.  And I can see my original question could mislead someone to do some serious damage.  And all your points are valid if you are going to raise temperatures up anywhere near annealing temperatures.   Could do some serious damage to the Aluminum hub, probably burn all the grease out of the bearings and smoke the seals.

It is just a little, gentle heating to soften lock-tight is pretty standard operating procedure.  Just a little heating till you feel the bolt slip.  You do not want to get it anywhere near hot enough to discolor the nickle or chrome so care even with a propane torch is in order.  Probably done it a thousand times in the machine shop over the last 40 years.  A little warmer than you want to hold in your hand but not much.

I think the bolts were $12.00 each when I got my floating disks and I wasn't about to spend another $144.00 on my front brake job to replace what in my mind were perfectly good bolts.  So far so good after 20,000 miles.

But the manual does say "remove and discard bolts" doesn't say anything about heating them.  I just had a Triumph mechanic recommend heating them because that always works and cold doesn't.  Triumph says to remove and discard any bolts with thread sealer,  that covers there liability because the sealer is on the replacement from the factory.  I checked and the bolts are only torqued to 22 Nm, no where near yield.  So I felt comfortable re-using them.  So here again a good reason to swap wheels and keep the one I "tampered with"  so it is on me if it fails.

[Sin_Tiger]

Not offended in the slightest, in fact more embarrassed than anything. It's too easy to assume you know more than someone else and start teaching them to sup soup  :icon_wink:

Anyway, good topic and your detailed explanation will no doubt be useful for anyone with less technical experience 

[metalguru]

Used a hot air gun on mine to luke warm and soften locking agent, just a useful addition is not so much an impact driver but a light few taps with the tool just to ensure locking agent is unseated.
Bolts came out good and reusable.