Tap Set

[scotty]

Can anyone give me the details of where I can buy a 8mm x 1.00 tap piece for clearing out the threads in the front wheel when the discs are taken off. I know I should heat up the allen bolts a bit to soften the loctite and then clean the threads out with the above tap. I tried to get a tap kit at the weekend but they only had 1.25mm pitch size and I believe the BMW threads have 1.00mm pitch. Any advice on where I could get one that would be suitable for this job would be appreciated.

[julian]

Can anyone give me the details of where I can buy a 8mm x 1.00 tap piece for clearing out the threads in the front wheel when the discs are taken off. I know I should heat up the allen bolts a bit to soften the loctite and then clean the threads out with the above tap. I tried to get a tap kit at the weekend but they only had 1.25mm pitch size and I believe the BMW threads have 1.00mm pitch. Any advice on where I could get one that would be suitable for this job would be appreciated.

Scotty, I borrowed a tap set off a member here when I did mine and was surprised how much Loctite came out. My bolts were solid with Loctite and required gentle heating for about 10 minutes before they became loose enough to remove.

Also make sure that you use Loctite on assembly. I forgot to Loctite the rear ones and one of the bolts loosened after a couple of hundred miles.

I have a Screwfix catalogue next to me and they seem to offer the required size in a kit. Also try Buck and Ryan
http://www.buckandryan.co.uk/product.ph ... sn/HAN8333

I was advised to buy decent tap/dies rather than budget ones, so may be better to source a couple of good ones in the appropriate sizes.

Can anyone recommend which sizes would be handy?

Cheers

Julian

[scotty]

Cheers Julian.

I've never used one of these things so it's all new to me. I would imagine that a cheap kit would succesfully bugger the threads in the wheel as they are quite soft alloy so a good quality tap would be necessary. I tried an upmarket tool shop earlier today and they have the right size so that's a start. It's interesting what you say about the loctite though as I was'nt going to bother using any when bolting everything together but I think I will now. I've got the blow lamp last week for heating up the bolts. Christ what a palaver to just take a couple of discs off.

[julian]

Definitely use Loctite.

I Loctited the front disc bolts, torqued them, then attached the rear disc bolts finger tight, fitted the wheel and attached a reminder on the ignition saying 'torque bolts before riding - which I did a couple of days later but forgot the Loctite. As the bolt became loose and extended, it contacted the rear caliper and applied the brake gradually over half a mile - that's how I found out the bolt was loose.

[sandbar]

.........but they only had 1.25mm pitch size and I believe the BMW threads have 1.00mm pitch.

Are you sure?

sandbar

[r550s]

I'm with sandbar - afaik the thread is standard i.e. 1.25mm pitch. check your old bolt before you stick a tap down the hole...
BTW, I've just calculated that if you bought all the ebay bits that 'mumbles spares' is selling, and reassembled the entire broken bike, it would cost £1,742,000.56, plus postage of course.

[timbox2]

Did mine with the standard tap from a set so I would also think they are 1.25, mine did feel a bit wrong when I first put the tap in, probably all the gunk in there.

[Boxadog 2000]

STOP STOP STOP
The pitch is 1.25 which is standard isometric coarse pitch.

If you are going to Wales this weekend let me know and I will bring you one of mine as a loan.

If you buy one make sure that you get a second lead and use a squirt of wd40 as a lube, and ensure that you clean the tap after each thread and then clean the internal thread with some solvent.

Bob

[scotty]

Thanks guy's. So that's a fiver down the drain already. No, that's really important as I was sure it was a 1mm pitch as the bleed nipples in the calipers are definitely 1mm pitch.

Boxerdog - What the blazes is a second lead ? I know about using the WD 40 when using thes things but hav'nt a clue what you're talking about re the second lead.

Cheers

Scotty

[sandbar]

If you buy one make sure that you get a second lead and use a squirt of wd40 as a lube, and ensure that you clean the tap after each thread and then clean the internal thread with some solvent.

Bob

Bob's the man for this sort of thing.

Cutting an internal thread from scratch is a three stage process. The second lead is, I guess, the correct name for the tap used in the second stage.

However, let me throw a little spanner into the works. I have been researching this because I was going to sell a fitting kit of 'bling' disc screws to go with the new discs that I will soon have available.

I was told - by someone who knows about these things - that here is no tool that is strictly correct for cleaning internal threads in aluminium. Taps are designed to cut new threads and that is what they will do. When you use one, there will be particles of aluminium on the tap at the end. That means that it is, in effect, making the thread slightly oversize. 'Thread chasers' are no better because they are designed to restore mangled threads and are even more severe. Both taps and chasers are usually made to be used in steel and it is very easy to f*ck up aluminium with them

I still do not know what the answer is and therefore have abandoned plans for the fitting kit, for the moment. The discs themselves will be for sale - soon!

sandbar

[scotty]

Sandbar

I understand what you are saying. The problem with using a tap is that it is very easy to mangle the soft alloy threads. What's really neede is some kind of thick pip cleaner that can be soaked in solvent and then turned in the thread to clean out the old loctite. Infact come to think of it several pipe cleaners taped together would probably do the job. That combined with screwing the new bolts in and out by hand and using WD 40 as a lube should do the trick.

Actually the more I think of it a pipe cleaner could be the best tool for the job.

[Boxadog 2000]

Actually the best tool for the job is a stiff nylon bottle brush (which looks like an oversize pipe cleaner)

You can buy them in all different diameters so an 8mm od would be just great.

bob