Author Topic: New project CB400/4  (Read 252 times)

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Offline allankelly1

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New project CB400/4
« on: January 24, 2020, 02:34:14 am »
Hi 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 my  “project bike” a RD350LC which is now all done



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


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« Last Edit: January 24, 2020, 02:39:37 am by allankelly1 »

Offline allankelly1

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New project CB400/4
« Reply #1 on: January 24, 2020, 02:36:28 am »
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


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« Last Edit: January 24, 2020, 02:40:55 am by allankelly1 »

Offline SOHC4 Cafe Racer Fan

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Re: New project CB400/4
« Reply #2 on: January 24, 2020, 09:21:03 am »
Al,

I'm not sure but it looks like you went with a CB750F or GL1000 front brake set up.

Nice looking 400F and RD350.  What's the other project next to the RD?
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2014 MV Agusta Brutale Dragster 800
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold

Offline allankelly1

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New project CB400/4
« Reply #3 on: January 24, 2020, 10:11:21 am »
Hi

Thanks for the kind comments

No it’s a 1981 CB400N super dream front end

Went this route as the fork stanchion diameters on a CB400N are the same as the CB400/4 at 33mm so a reasonable straight swap other than the speedo drive and mudguard mounting

Also because of the fork change looking to fit a chrome mudguard from the same bike so it matches the fork mounts and this mudguard does not need the two steady bars which suit the new sliders as they do not have the lower steady mounts on the lower forks

I know it will not look totally original but I was alway going to go “my way” and hopefully the final bike will look similar to this



I know the CB400N front wheel is a 19” unit but that means we will only have in theory an extra 12mm gap

As for the other bike you spied it’s another project in progress

The bike is being built round a one off Tigcraft Super Mono race frame and fitted for suspension is a Honda MC21 swingarm with an Olins shock and the front is from a Cagiva Mito. Wheels are KTM and brakes are Brembo. Lastly engine is a Yamaha 350 YPVS unit

Like I said it’s a slow burn project in progress that has its own unique challenges unlike the normal restore / tweak 

Here are some more pictures of it



And think when its done it will look pretty awesome

Catch up soon and have a good weekend

Best wishes Al



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« Last Edit: January 26, 2020, 12:29:32 am by allankelly1 »

Offline SOHC4 Cafe Racer Fan

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Re: New project CB400/4
« Reply #4 on: January 25, 2020, 03:44:18 pm »
JeeeeZ! That super mono project looks spectacular -- great track bike.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2014 MV Agusta Brutale Dragster 800
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold

Offline Stev-o

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Re: New project CB400/4
« Reply #5 on: January 26, 2020, 02:56:30 pm »
Hey Al....love the RD and the mono project.  I too have an RD, it's a '73 stocker.

Subscribed to follow what you do on the 400, looking good so far...
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......CB500 Fiddy Dolla Special too!!............plus plus plus.........

Offline allankelly1

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Re: New project CB400/4
« Reply #6 on: January 29, 2020, 11:22:49 am »
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


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Offline allankelly1

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New project CB400/4
« Reply #7 on: February 12, 2020, 11:51:40 am »
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

But after a bit of thought problem solved

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

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



 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


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« Last Edit: February 12, 2020, 01:02:51 pm by allankelly1 »

 

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