CB400/4

[alankelly]

Evening all

Always has a soft spot for the CB400/4

And after a chat with the darling wife I am now a proud owner of a red 1977 bike.









The bike itself is reasonably tidy and is running ok and even came with,when I opened up the seat, the original tool kit and a 43 year old owner’s manual 😳😳



The bike could do wilt a bit of work here and there and first thoughts were to restore it to an original bike, but to be honest I thought the same when I got the original “project bike” for the Yellow RD350LC project but I would rather have something that is still in keeping with the period but also has a few personal unique touches / changes

Took it out for a quick ride today and the front brake is totally carp and is In dire need of either repair of replacement so first change will be to look at the possibility to replace the complete front disc brake with a more modern single piston floating calliper twin disc set up off a bike from the mid 80s just to keep the period look

Once this is done and she has had a good check over (and a mot just to tick the box for insurance proposes as it’s not been for a mot since 2012) then I will use her for the summer in its current state while getting other goodies such as a Yoshi cyclone exhaust, ally rims and stainless spoke kit electronic ignition and a few other bits and bobs in preparation for the end of summer where it will be time for a complete strip and rebuild from the ground up just like the RD

In the meantime will keep you all up to date on how goes including the front disc upgrade

Best wishes Al

[veg]

Looks lovely al, restoration is over played, mich rather see something used and enjoyed

[alankelly]

Thanks veg

Yes I think restored originals are a bit too much for me

I think when they were new like the rd everybody put their “signature” on their bike

A mate at work had a yellow one with the cibe headlight conversion sports exhaust Boyer ignition and a dolphin fairing with rear sets and clip ons

It looked the biz to me as a Tomas moped riding 16 year old 😍😍

Best wishes Al

[donkeychomp]

Love it! Fishy brakes I have mentioned earlier lol. Get those ghastly red anodised bolts out first! And is the zorst the original one? If so I'd keep it or at least hang onto it if you ever sell the bike. They are unobtanium these days. Good luck with it!

Alex

[alankelly]

Evening Alex

Thanks for the comments

Yes she needs a bit of work and the exhaust is a motard that will be swapped out for the Yoshi pipe during the rebuild

As for the red bolts yes they need to come out ASAP but let’s sort the front brake first😀

Best wishes Al

[donkeychomp]

Thing is I've ridden one of these ages ago. The brakes seemed fine to me. I reckon you either need to ride another 400/4 to see...or strip the lot down and do a rebuild.

Alex

[Deleted]

I too have a soft spot for them . Had a ride on one when I was 15 after a year or so on a cb100.
One thing that really stands out for me is the standard pipes.
I think I read somewhere that silverspoons purchased all the tooling awhile back for the original pipe.
Hopefully it's not a figment of my imagination. Great bike. Wish it was mine.

[alankelly]

Hi all

Well decided to take the plunge and convert the CB 400/4 to a twin disc front end😎

I know it’s not original but really like the symmetry of a twin disc front end and bike was alway going to be slightly different from original anyway





There’s a bit of way to go yet as to get the correct fork length the fork assemblies are 400/4 stanchions / damper assemblies with CB400N lower sliders that will need the lower section of the stanchions modifying to incorporate the later Honda design that has a spilt bush on the bottom of the stanchion that runs in the slider bore rather than the complete stanchion leg

Also hub and discs will need some changes as original disc is a four bolt mounting and the donor discs are five

(And the plain discs will be drilled at some point too)

Lastly due to the extra disc the speedo drive willl need a tweaking to get the drive past the extra disc,

But none of the above are impossible to solve and I have alway enjoyed the challenge of solving problems )Also having access to a full tool room helps😀 😀) Plus the bike it will stop much better than the original pivot design👍

Catch up with you all soon

Best wishes Al

[lolly]

i am with you on twin disc ; single disc just doesn't look right 

[Tobyjugs]

Happy Birthday Alan.

[alankelly]

Thanks mate

52 and still going 😀😀

Best wishes Al

[cb250g5]

Knew I had a photo of ours somewhere

www.dropbox.com/s/28d54093u938z86/DSC00142.JPG?dl=0

[markhoopy]

Jan 23, 2020 10:19:47 GMT 1 lolly said:

i am with you on twin disc ; single disc just doesn't look right 

Doesn't look right on the 400/4 .. or 500/4 .. 550/4 .. or the CB750 either.
Were Honda just scrimping to keep list prices down or did they think gentle braking would suffice?

[alankelly]

Hi all

Just a quick update

Managed to dry fit the twin disc set up on the bike and all looks good so far



As for the fork stanchions as I mentioned they needed a modification so that they match the original CB400N forks so they will work with the CB400N lower sliders, so spent some time in the workshop today modifying the ends to match the original CB400N forks stanchions



Plan now as the stanchions are finished are the get them off to Brooks for rechroming and while they are away sort out the rest of the modifications like modifying the front hub from a 4 bolt disc mount to a five to match the new discs and refurb the rest so when the parts are back from Brooks I am in a position to fully rebuild the complete fork and brake assembly

Think thats all for now

Best wishes Al

[alankelly]

Hi all.

Well the saga of fitting twin disc to my project CB400F continues



To be honest its not an easy change and requires lots of slight changes and modifications. And due to the twin disc set up the original speedo drive does not fit as the second disc gets in the way of the cable run[emoji34]

But after a bit of thought problem solved[emoji106]

So decided to fit a drive from a CB400N also (as it’s the same ratio as a original CB400F unit) but it’s not a straight fit due to me wanting to keep the original CB400F front hub[emoji34]

Needed to do a few modification to the drive itself as the original width was 32mm but it needed to machine it down to 28mm to suit the CB400F hub width, so have now modified the drive to this new width that including modification to the housing and drive gear





Also due the the original hub design I lost the original drive dogs so designed and 3D printed at home a new drive dog part in an engineering nylon and then attached the to the original hub with two tapped M3 screws



And then the speedo drive simple mounts on this new driver dog plate



Really please with the final result and now have a fully sorted speedo drive[emoji106]



Next step is to finish the dry build of the front end and then once happy get the sliders powercoated and finish the rebuild of the front end

Think that is all for now

Catch up with you all soon

Best wishes Al


Sent from my iPhone using Tapatalk

[donkeychomp]

Wow. Top work matey but why not just slap on an entire Wet Dream front end? But credit to you, I know your engineering skills first hand. Always perfect. What's the next job to do?

Alex

[alankelly]

Hi Alex

Thanks for the reply

No did not want to fit a complete wet dream front end as wanted to keep spoked wheels and not fit those horrible comstar wheels that would look so out of place on a 1970’s bike so needed to get the CB400N speedo drive to work with the original CB400F front hub

As for the next job got new alloy rims and stainless spokes on order to replace the corroded originals and decided to build them myself so off to make a wheel jig and going to learn how to lace up a new wheel 👍

Should be fun😁😁😁

Catch up soon

Best wishes Al

[rich]

Very nice job, love reading stuff like this

[donkeychomp]

Any more news on this?

Alex

[alankelly]

Hi Alex

Progress bit slow at the moment as have been doing other stuff but got the rechromed stanchions back from Brooks this week so can start to finish of the front end






But while waiting for the stanchions I have been doing some other small jobs like made up a splitter for the twin disc/ calipers set up the other day that uses the original brake light switch so I can keep the original brake master look and planning to model up a cover to fit over this assembly



The original front headlight was not great, but as I wanted a different look from a original bike going to move away from original and playing around with possibly fitting something like this with more better looking indicators





Also on the go I am currently rebuilding the original clocks





And lastly got the new alloy rims the other day from CWS





So like I said progress is a bit slow at the moment but lots of jobs progressing well

And think it won’t be long before I am home full time so will have plenty to do when in self isolation in the garage

That’s about all for now

But to everyone keep safe and wish you all good health to you your family and friends

Best wishes always Al

[donkeychomp]

Those clocks look amazing! Did you cut out the redline and make a new one?

Alex

[alankelly]

Hi Alex

Yes very please with how the clocks came out as I love the look of the original Honda clocks and central pilot light assembly

The actual faceplates were replaced with a new set supplied by a company in the Netherlands called CB750faces.com and
they have also supplied me two new glass bezels too, as the originals were badly scratched and lastly they also stock the replacement rubber boot for the speed trip reset knob,so once finished they should look like new

Catch up again soon

Best wishes Al

[alankelly]

Speedo and tachometer finally finished and fitted




Just the brake callipers to rebuild and a few other bits to sort or tidy so the bike looks presentable and then she’s ready for a mot and summertime

Best wishes Al

[donkeychomp]

Sweet!

Alex

[guiri]

Nice work mate.. but its just screaming out for original down pipes which are the identity of these bikes..its what sets them apart..

[alankelly]

Hi

Yes those pipes were unique and sexy

But as it’s going to be a bit of a hybrid like the front disc change and the plan to fit alloy rims planning to fit these as the next phase of changes as alway nice to have something a bit different from the norm



Best wish Al

[midlifecrisisrd]

Mar 21, 2020 16:08:25 GMT 1 alankelly said:

Speedo and tachometer finally finished and fitted




Just the brake callipers to rebuild and a few other bits to sort or tidy so the bike looks presentable and then she’s ready for a mot and summertime

Best wishes Al

Clocks look brilliant

I've just checked and that place does GT750 clock parts too so happy days 😀

How did you find opening and crimping the rings? Did you buy new ones

Steve

[alankelly]

Hi Steve

No in the end I decided to reused the old rings and also found opening and recrimping was not a problem after looking at this as this tutorial on YouTube



But I did make a special tool on the lathe at work out of a piece of nylon and get a large pipe clip like I saw in the videos to allow you to both remove the ring without damaging it, and also you can use the white ring tool to fully support the fully assemble clock like in the video to prevent damage to the new painted clock surrounds while you push over / recrimp the ring 👌






Also providing you take your time the recrimped ring is hidden by the new damper rings so it does not need to be perfectly flat



Now that the clocks are finished and I don’t think I will need these tools again so if you want I can post the bits to you so you can use them as I think my shed is already full of bits and bobs I no longer need 😳

Best wishes always Al

[tony2stroke]

A good job well done, kudos

[midlifecrisisrd]

Mar 22, 2020 22:49:18 GMT 1 alankelly said:

But I did make a special tool on the lathe at work out of a piece of nylon and get a large pipe clip

Now that the clocks are finished and I don’t think I will need these tools again so if you want I can post the bits to you so you can use them as I think my shed is already full of bits and bobs I no longer need 😳

Best wishes always Al

That would be brilliant Al

I've got 3 sets of GT clocks to do now

There was a set on the bike that the glass was broken and needle missing so I bought another Speedo

Then I bought a complete set of clocks but the inside of the glass needs cleaned

Then I bought a "mint" set with only 3k miles on them. Pity en route from America they have been upside down and all the dust from inside made it's way onto the glass of the tacho 🙄

With those bits I can make 3 good sets with a few parts from the cb750 site

I'll send you a pm

Steve