Author Topic: CB400 Bolt Pitch  (Read 297 times)

Offline waffey

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CB400 Bolt Pitch
« on: March 13, 2019, 03:34:52 PM »
Hi,

Q1. might be a stupid question but are all the bolts around the frame and fixtures all a standard metric pitch? I was thinking of buying a bagful or two before the build so I have the various sizes to hand.

Q2. Zinc plated or stainless

thanks in advanced
Bikes:
Suzuki Address 110 Scooter
Suzuki TL1000s
BMW R1200GS LC
Honda CB400 F2 1977 (to be restored)

Offline Oddjob

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Re: CB400 Bolt Pitch
« Reply #1 on: March 13, 2019, 04:22:22 PM »
6mm are 1.00 pitch
8mm are 1.25 pitch
10mm are 1.50 pitch which is different than most, called fine pitch. Most are 1.75mm I think.
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Offline Nurse Julie

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Re: CB400 Bolt Pitch
« Reply #2 on: March 13, 2019, 04:47:04 PM »
A1) Would it be possible for you to have the bolts that were fitted re zinced? There are soooo many different sizes and lengths and also some special bolts, it just may be a cheaper if not easier way of you getting what you need. A2) Zinc.
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Offline PatM

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Re: CB400 Bolt Pitch
« Reply #3 on: March 13, 2019, 04:59:30 PM »
Hi,

Q1. might be a stupid question but are all the bolts around the frame and fixtures all a standard metric pitch? I was thinking of buying a bagful or two before the build so I have the various sizes to hand.



I read this and remember with horror when many years back- 25 probably- I put the wrong lower engine-bolt - ie , too long- and it picked up the captive nut but then with my enthusiastic tightening- drove it right through the lower casing/crank-case!! (LH side, if yourve wondering..)
Now, I know this is slightly off-topic, but I thought Id mention it because in those days, there were plenty of scrap 400/4 motors around for £30-50 quid, but now, not so!

Offline mike the bike

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Re: CB400 Bolt Pitch
« Reply #4 on: March 13, 2019, 06:42:07 PM »
Yup, I did the exact same thing.  The starboard bolt is 2mm shorter than the port side.  Don't forget the washers either, otherwise the effective bolt length will be too long.
« Last Edit: March 13, 2019, 06:44:26 PM by mike the bike »
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Offline K2-K6

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Re: CB400 Bolt Pitch
« Reply #5 on: March 13, 2019, 07:09:23 PM »
Honda routinely use more or less bespoke bolts on many applications,  you really have to be quite careful if you are to replace any.

Friend had an XR500 that had one (or two) 9mm bolts in the head!

You sometimes get odd things from very competent engineering designs though.  Mercedes cars fitted with alloy wheels and steel spare used to need shorter wheel bolts to fit the spare.  If you used the "alloy" bolts they would trepan a neat groove in the brake caliper from extending too far through the hub.

And Peugeot have used five sided bolts on their brake calipers to prevent tampering in the past.

Just sometimes a specific accuracy gives rise to a unseen fault that the designers didn't spot.

Offline waffey

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Re: CB400 Bolt Pitch
« Reply #6 on: March 14, 2019, 07:11:25 AM »
Thanks for the reply's,

I am definitely planning to use the same engine bolts etc.

So lessons learnt are, use the originals, get them zinc plated, make sure I check the correct lengths for the correct item.

I see on the fiche for the frame there are some odd size's. Here is a list I compiled.

Hex - 5 x 20
Flanged - 6 x 25
Screw - 6 x 20
Flanged - 6 x 20
Hex - 6 x 20
Flanged - 5 x 20
Hex - 6 x 8
Hex - 6 x 12
Hex - 6 x 16
Hex - 8 x 16
Hex - 6 x 14
Hex - 6 x 15
Hex - 6 x 22
Hex - 6 x 25
Hex - 6 x 28
Hex - 6 x 36
Hex - 8 x 25
Hex - 8 x 28
Hex - 8 x 32
Hex - 8 x 45
Hex - 7 x 54
Hex - 8 x 80
Hex - 10 x 80
Hex - 10 x 32
Hex - 8 x 40
Hex - 8 x 50
Hex - 5 x 20
Screw - 6 x 20
Flanged - 6 x 25
Hex - 6 x 16
Bikes:
Suzuki Address 110 Scooter
Suzuki TL1000s
BMW R1200GS LC
Honda CB400 F2 1977 (to be restored)

Offline Trigger

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Re: CB400 Bolt Pitch
« Reply #7 on: March 14, 2019, 09:03:15 AM »
You should not go by the fiche. I was putting a front mudguard on a Honda yesterday and the fiche size was M6x 16mm and when i measured  the depth, it was only 12mm. If i tried to get the 16mm in i would of broke the lugs on the fork  :o

Offline mickwinf

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Re: CB400 Bolt Pitch
« Reply #8 on: March 14, 2019, 09:04:16 AM »
Oddjob the 10mm bolts are 1.25 pitch on Hondas, the standard pitch on generic bolts is 1.5mm
Love the 500/4 and 550 own 2 at the moment.

Offline TrickyMicky

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Re: CB400 Bolt Pitch
« Reply #9 on: March 14, 2019, 10:25:53 AM »
Hiya, with regard to 'which bolt in which hole', when I removed the cam-cover from my 400 many years ago, (1991!), not being an engineer I did not have the faintest idea how to identify bolt thread pitches etc.. (still haven't). So I obtained a nice piece of flat cardboard and used a marker pen to draw a full size outline of the cover, then as each bolt was removed, it was pushed through the cardboard in its respective location, then carefully stored. When the rebuild commenced 13 years later, (you can't rush these jobs), my simplistic brain was not overtaxed when it came to replacing the bolts into their correct locations. Maybe if you are deft of hand this system could be advanced to other fixings. Remember, K.I.S.S. Regards, Mick.

Offline mattsz

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Re: CB400 Bolt Pitch
« Reply #10 on: March 14, 2019, 02:41:13 PM »
Hiya, with regard to 'which bolt in which hole', when I removed the cam-cover from my 400 many years ago, (1991!), not being an engineer I did not have the faintest idea how to identify bolt thread pitches etc.. (still haven't). So I obtained a nice piece of flat cardboard and used a marker pen to draw a full size outline of the cover, then as each bolt was removed, it was pushed through the cardboard in its respective location, then carefully stored.

I've done that with engine work on other bikes, works a treat!  Difficult to replate them stuck in the cardboard, though...  ;)

Offline billywingnut

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Re: CB400 Bolt Pitch
« Reply #11 on: March 16, 2019, 06:24:02 PM »
I would like stainless bolts for the front brake caliper as it catches the weather and debris but the the pitch is non-standard.

Offline ka-ja

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Re: CB400 Bolt Pitch
« Reply #12 on: March 16, 2019, 07:25:06 PM »
« Last Edit: March 16, 2019, 07:29:04 PM by ka-ja »
nice bike,nothing in the bank

Offline Oddjob

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Re: CB400 Bolt Pitch
« Reply #13 on: March 17, 2019, 09:21:32 PM »
Oddjob the 10mm bolts are 1.25 pitch on Hondas, the standard pitch on generic bolts is 1.5mm

Yeah thought it didn't sound right when I typed it, hence why I also described it as metric fine.
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Offline moorey

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Re: CB400 Bolt Pitch
« Reply #14 on: March 17, 2019, 10:23:59 PM »
Not only that when you get up to 10mm there are 3 different pitches for fine.  1.25, 1,  0.75. not that you see the later often.