Correct Front Wheel Hub K0

[StevieWonder]

I’m hoping that my CB750 K0 has the correct front wheel fitted.

According to Service Bulletin #26 the width of the front wheel hub was reduced by 4mm for the K1.

My front hub is 65mm when measured across the outside of the top flanges as shown in the attached photo.

If I have the correct wider hub, then a similar measurement on a K1, k2 etc. should be 69mm.

Grateful if anyone would confirm.

[Bryanj]

Two things,

(1) isnt the measurement across the machined flanges?

(2) the later one is suppose to be SMALLER not bigger

[Nurse Julie]

Both our UK CB750/4 K2's have a measurement of 65mm, the same as yours. Sorry, terrible pic 🙄. But you are not actually measuring the 'overall width' of the hub the way you are doing it. The overall width is actually 110mm measured across the flanges. Service bulletin #26 relates to the brake disc mounting bolts, not the hub itself.

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[AshimotoK0]

My 10/69 K0 Front Hub Dimension

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If anyone has a spare 106 mm to sell me I have 'misplaced'    one of mine

[StevieWonder]

Marvellous, thank you all.
Yes, I got the logic wrong, the latter K1 is supposed to be smaller, but not across the spoke flanges.
I will use the 86mm provided by AsimotoK0 to measure mine though I may need to drop the wheel.

[StevieWonder]

With the help above, I have established that my front hub is of the narrow K1 type 

Moreover, the six bolts that hold the brake disc to the hub are of the long (106mm) type – Part Number: 90122-300-010, which only just clear the bottom of the fork leg as shown in the attached picture and are probably not holding the brake disc securely.

The reason for Service Bulletin #26 is to avoid just this situation.

A set of the correct bolts are available from DSS, at a little over £50 (similar price from CMS). As I purchased the bike from him perhaps a little discount can be granted or maybe a new K0 wheel 

[JamesH]

With the help above, I have established that my front hub is of the narrow K1 type 

Moreover, the six bolts that hold the brake disc to the hub are of the long (106mm) type – Part Number: 90122-300-010, which only just clear the bottom of the fork leg as shown in the attached picture and are probably not holding the brake disc securely.

The reason for Service Bulletin #26 is to avoid just this situation.

A set of the correct bolts are available from DSS, at a little over £50 (similar price from CMS). As I purchased the bike from him perhaps a little discount can be granted or maybe a new K0 wheel 

I’m pretty sure I have a nice set of the shorter bolts if you wanted to do a straight swap?

[AshimotoK0]

I found out that my UK 10/69 came fitted with K1 wheels after I bought it... the K0 wheel not only had a diffrent hub & bolts  but the axle,speedo drive, chrome cover etc and disc rotor are all subtly different. I did manage to get a K0 wheel with disc etc. from the States for £100 back when postage was reasonable and prices were generally much more realistic but the rear 2-hole hub eluded me so, I just went with the 4-hole .. I mean who would ever know anyway I asked myself ?.....  probably the same with the front hub TBH but to a lightly lesser extent. After an almost 10 year search for a decently priced/condition 2-hole hub, I laced up the 4-hole and b*gger me there was a K0 rear wheel I picked up at Newark autojumble for £15 two weeks later (he wanted £20 for the  complete wheel but I cheekily knocked him down to £15  ) Not sure that I will ever fit the hub though but I know it's there if anyone ever squawks non-originality to me.  This was followed up at the next Newark autojuble where another seller had a double-cut front guard .. not perfect but will restore nicely ..again £20 knocked down to £15. The same bloke told me he had  just sold the UK frame from the same bike on eBay but the buyer told him to only ship the headstock and V5C    This is totally non-typical of autojumbles though ... very little of our stuff on the whole but tons of Brit stuff. For example, last month there were two sellers with shed loads of Ariel Square Four parts.

[StevieWonder]

Thanks for your kind offer Jamesh, I have today appealed to DS for a new set of bolts FOC, if not forthcoming perhaps we can make a swop.

Thanks AshimotoK0, I'll study the subtle differences of a K0 wheel so I know next time I buy one ......nothing Dear. I've been working hard to get the bike really correct and this is quite a set back. £405 plus postage for a new K0 hub, plus lace up/rebuild is hard to find and justify when '...who would ever know anyway....". Don't know if I'll ever be lucky enough to find a cheap scrap one, especially as it would need to be like new to match the rest of the bike.

I'll most likely go with changing the bolts. Trouble is, I'll know and it will irritate me.

[JamesH]

No problem - happy to help if I can. So did DSS supply the machine?

[Nurse Julie]

Thanks for your kind offer Jamesh, I have today appealed to DS for a new set of bolts FOC, if not forthcoming perhaps we can make a swop.

I'll most likely go with changing the bolts. Trouble is, I'll know and it will irritate me.

You won't notice it when you're riding it, or any other issues it has...i take it you are going to ride it and not just bow down and worship it 😊😊😊

[AshimotoK0]

Thanks for your kind offer Jamesh, I have today appealed to DS for a new set of bolts FOC, if not forthcoming perhaps we can make a swop.

I'll most likely go with changing the bolts. Trouble is, I'll know and it will irritate me.

You won't notice it when you're riding it, or any other issues it has...i take it you are going to ride it and not just bow down and worship it 😊😊😊

Or become a "Collector of Shiny Parts" like yours truly 

[Nurse Julie]

Thanks for your kind offer Jamesh, I have today appealed to DS for a new set of bolts FOC, if not forthcoming perhaps we can make a swop.

I'll most likely go with changing the bolts. Trouble is, I'll know and it will irritate me.

You won't notice it when you're riding it, or any other issues it has...i take it you are going to ride it and not just bow down and worship it 😊😊😊

Or become a "Collector of Shiny Parts" like yours truly 

🤣🤣🤣🤣🤣 Indeed Ash.

[StevieWonder]

Yes bought it from DS back in 2016.

Been ridding it for 3-years , with a loose disc brake according to Honda's bulletin, but not noticed a problem.

What's wrong with kissing your bike good night anway 

[Nurse Julie]

Yes bought it from DS back in 2016.

Been ridding it for 3-years , with a loose disc brake according to Honda's bulletin, but not noticed a problem.

What's wrong with kissing your bike good night anway 

I wouldn't kiss any of mine goodnight.....they are always so filthy dirty I may contract Anthrax or Botulism or something similar 🙄🙄🙄