Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: heliwilly on May 10, 2019, 07:29:17 AM
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Hi,
I'm trying to find the correct size of thread for a 77 CB400 rotor puller. Apparently the 16mm for the CB550 doesn't fit. Thanks Bill W.
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I was considering this the other day actually. I have a crank with one still attached, I will be taking it to my local hardware supplier tomorrow to ask them to try a bunch of screws in, when I get the right one I'll let you know.
You just grease it up and wind it in, right, same as a bicycle crank extraction?
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That's the problem. If you look on the internet it gives various sizes, 16mm 18mm and 20 mm. Short of buying them all, how can I find the correct one for my brothers 1977 CB400,
Does anyone have the correct answer? Thanks Bill.
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That's the problem. If you look on the internet it gives various sizes, 16mm 18mm and 20 mm. Short of buying them all, how can I find the correct one for my brothers 1977 CB400,
Does anyone have the correct answer? Thanks Bill.
18mm x 1.5 pitch
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Might be an idea to buy a cheap vernier caliper and set of thread gauges. I find mine invaluable, so much so I now have more than 1 set of each. Often a set of thread gauges is included in a tap and die set. Really useful on matric machinery and pretty well essential if you get anything British and old or Ammerican. The joys of a 196s British vehicle, whitworth, unf, unc, bsp, etc etc.get on those and it's a real headache.
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That's the problem. If you look on the internet it gives various sizes, 16mm 18mm and 20 mm. Short of buying them all, how can I find the correct one for my brothers 1977 CB400,
Does anyone have the correct answer? Thanks Bill.
18mm x 1.5 pitch
This is correct - big bolt - wind in - pops off.
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Might be an idea to buy a cheap vernier caliper and set of thread gauges. I find mine invaluable, so much so I now have more than 1 set of each. Often a set of thread gauges is included in a tap and die set. Really useful on matric machinery and pretty well essential if you get anything British and old or Ammerican. The joys of a 196s British vehicle, whitworth, unf, unc, bsp, etc etc.get on those and it's a real headache.
Agreed. These Hondas have a mix of standard and fine thread pitches so a set of thread gauges is essential. They only cost about £7 from Machinemart.
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For the purists, there is a difference between metric and imperial threads, the thread angle is 60degrees for metric, imperial 57degrees
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I got an 18mm x 1.5 for the CB400 and a 16 x 1.5 VW transporter wheel bolt ( Via Trigger) for the CB550. Bill W.
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Sorry to pedantic but as ka-ja says they are different but the Imperial bit is even more confusing BSF (fine) and BSW (Whitworth) are actually 55 degree included angle not 57. But BA Threads often found on brass elec fittings are 47 1/2 degrees and have a metric based pitch system. UNF and UNC are 60 degree thread angle and their spanners are related to the distance across the flats rather than bolt diameter. No bloody wonder people use bolts in the wrong places and spanners which ‘nearly’ fit.
Ian
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ill octopus! ;D
https://www.ebay.co.uk/itm/M18-X-1-5-PITCH-X-45-FINE-PITCH-HEXAGON-BOLT-BZP/272510162261?ssPageName=STRK%3AMEBIDX%3AIT&var=571579385136&_trksid=p2057872.m2749.l2649
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For the purists, there is a difference between metric and imperial threads, the thread angle is 60degrees for metric, imperial 57degrees
From memory:
BA used a 47.5° thread angle, Whitworth 55°, and Unified (UNF, UNC, etc.) 60°.
I have a few British clunkers, so I have to fight with these thread forms all the time.
I'll get my coat...
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And i used to pee the plant apprenticles off when they came and asked for a 10mm bolt meaning a 10mm spanner size and i gave them a real 10mm bolt!!!!
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Or send an apprentice to the tool stores for a set of footprints!
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Or a 4 inch hole! 😂
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I heard the oil filter bold is the same thread. Dunno whether is true or not I haven't tried it.
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Just been out and tried the oil filter bolt, and it will not fit, as it is 20mm. Rotor thread 18mm x 1.5
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I must be thinking of a different bike, a Superdream maybe.
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You will have more chance with the rear wheel spindle ;)
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The number of ways of describing threads and number of angles is a minefield. Thankfully our Hondas are all metric so the imperial and whitworth thread gauges are not a lot of use. The worst place to find threads that are to multiple standards is hydraulics. Old machines tools can be equally confusing. I find whitworth threads annoying for the simple reason its 55° angle is a pain to cut and tooling ends up costing more. Luckily I have quite a bit of it kicking around.
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I must be thinking of a different bike, a Superdream maybe.
One man's dream is another man's nightmare....I'd rather stay awake and ride something else! I bought one new off Ryes of Fulham and one year of dispatch destroyed it, fell to bits, full of cheapo bits!!