Author Topic: 77 CB750 F1 Cafe Racer  (Read 5118 times)

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Offline martin_uk

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77 CB750 F1 Cafe Racer
« on: March 05, 2015, 10:02:47 AM »
In addition to my stock F1 and K8 in progress I also have 2 more F1's I bought in in bits  ::)

Decided to do one as a mild cafe racer, without modifying frame, so it could be changed back at a future date if wanted.

Liked the idea of doing a single seat conversion on a standard seat base so I could retain hinge fitting and below seat storage box.

Thought about options and decided to try a modified seat foam and custom cover.

Standard foam and cowl

2015_0116frame0001 by nitram2010, on Flickr

Very rough mock up on top of standard seat

2015_0116frame0002 by nitram2010, on Flickr

Standard seat cover

2015_0225eng0013 by nitram2010, on Flickr

Modified seat foam on my stock F1

2015_0227seat0001 by nitram2010, on Flickr

Tried seat on my stock bike and hopefully trimmer will have new cover fitted tomorrow :D

CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #1 on: March 05, 2015, 10:15:16 AM »
Decided to have painted in Toyota Orange Twist, which is a 3 stage pearl finish

2015_0214frame0044 by nitram2010, on Flickr

2015_0210frame0030 by nitram2010, on Flickr

2014_1205fparts0013 by nitram2010, on Flickr

2014_1205fparts0015 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #2 on: March 05, 2015, 10:19:10 AM »
Black powder coated rims and new spokes

2015_0128frame0002 by nitram2010, on Flickr

2015_0128frame0012 by nitram2010, on Flickr

2015_0126frame0091 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline SOHC4 Cafe Racer Fan

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Re: 77 CB750 F1 Cafe Racer
« Reply #3 on: March 05, 2015, 12:04:08 PM »
Nice looking wheels.
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)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.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 and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #4 on: March 06, 2015, 01:37:56 AM »
Just picked up seat and really pleased  ;D

2015_0306seat0005 by nitram2010, on Flickr

2015_0306seat0006 by nitram2010, on Flickr

2015_0306seat0007 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #5 on: March 06, 2015, 01:39:51 AM »
Nice looking wheels.

Thanks, it difficult to know what will look good, as I considered black hub and spokes, but decided on this combination and pleased with look
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline Restoration Fan

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Re: 77 CB750 F1 Cafe Racer
« Reply #6 on: March 06, 2015, 03:06:34 AM »
Oh man, I dig that seat!
Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #7 on: March 06, 2015, 09:41:43 AM »
Here is a shot of standard and modified seats together

2015_0306seat0010 by nitram2010, on Flickr

2015_0306seat0008 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #8 on: March 19, 2015, 12:41:04 PM »
The engine that came with my first F1 was in a terrible state, so used another engine in rebuild.

Major problem with the engine was a broken right front top enging mounting on crank case.

2014_0502cb750B40094 by nitram2010, on Flickr

Decided to see if it could be welded and very please with outcome although needs some tidying.
2015_0319eng0004 by nitram2010, on Flickr


2015_0319eng0011 by nitram2010, on Flickr

2015_0319eng0010 by nitram2010, on Flickr

2015_0319eng0001 by nitram2010, on Flickr
« Last Edit: March 20, 2015, 02:34:05 AM by martin_uk »
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #9 on: April 26, 2015, 03:10:57 AM »
While I wait for registration on K8 to come through, thought I would start on frame.

I have two to choose from and started looking at the one that had been powder coated but scratched a bit.

Closer inspection revealed the centre stand mounting had been repaired.

2015_0424beforel0024 by nitram2010, on Flickr

I am not planning on fitting stand but its nice to keep brackets so this could be used to temporarily fit whilst working on bike (without spring)

Thought I had better check and tidy up.

2015_0424beforel0030 by nitram2010, on Flickr

Unfortunately found a crack so will have to get repaired,

Decided to mod the right front lower engine lug, as helps fitting engine so does not catch.

2015_0424beforel0028 by nitram2010, on Flickr

2015_0424beforel0029 by nitram2010, on Flickr

Will tidy with a file.

Pleasant surprise to find swinging arm bushes replaced with bronze versions.

2015_0424beforel0022 by nitram2010, on Flickr

Steering lock (UK fit) painted in so will need to remove.

2015_0424beforel0002 by nitram2010, on Flickr

I do like the look of Cafe racer style fairing and already  have a spare BMW R90S style one, wondering if I should weld some brackets to frame head stock at this stage so that a neater fairing mount can be used?

Any suggestions?   
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #10 on: May 04, 2015, 02:15:22 AM »
Initial fit up of clip ons revealed they hit tank.

Decided to modify steering stops.

To save having to remove lower yoke, it can be done in situ.

Needed extra long drill to drill from front (need longer drill to allow chuck to clear yoke) and then drill M4 tapping size 3.3mm from rear.

Used M4 Allen screws and seems to do the trick :)

2015_0503after0033 by nitram2010, on Flickr

2015_0503after0036 by nitram2010, on Flickr

2015_0503after0037 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline Restoration Fan

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Re: 77 CB750 F1 Cafe Racer
« Reply #11 on: May 07, 2015, 05:51:52 AM »
Boy do I love the detailed photos you take.  Also, bonus points for using "in situ" properly in a sentence there.  ;)

Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html

Offline eddiebpool

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Re: 77 CB750 F1 Cafe Racer
« Reply #12 on: May 07, 2015, 07:54:34 AM »
Hi Martin - delighted to see another UK-based F1 project.  I love the seat idea.  I have no intention of ever carrying a passenger so very tempted to try something like that.  Great work.

Offline SOHC4 Cafe Racer Fan

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Re: 77 CB750 F1 Cafe Racer
« Reply #13 on: May 07, 2015, 11:51:48 AM »
Boy do I love the detailed photos you take.  Also, bonus points for using "in situ" properly in a sentence there.  ;)

Now let's see the correct use of a fortiori.  ;)
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)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.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 and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #14 on: May 08, 2015, 01:09:55 AM »
Hi Martin - delighted to see another UK-based F1 project.  I love the seat idea.  I have no intention of ever carrying a passenger so very tempted to try something like that.  Great work.
Thanks Eddie
I used the original seat cover on my first F1, with powder coated base, as it seemed a shame to replace the original.

Only trouble is, it is a bit shiny and can feel myself sliding with the massive acceleration  ;)

Have just tried the single seat on my new project frame and feels better, with raised section to prevent this.

Just need to decide on foot rest position to go with clip ons.
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #15 on: May 08, 2015, 08:39:35 AM »
Checking main bearing clearance with Plastigauge.

Thought I would do as a precaution.

Crank shaft fitted to upper case which is on a  Workmate bench opened to accomodate studs .

Plastigauge applied to all main bearings and held in place with grease.

2015_0508after0015 by nitram2010, on Flickr

Fitted lower case and torqued main bearing bolts.

Remove bolts and case.

Looks to be about 2 thou on all, which is within tolerance.

2015_0508after0023 by nitram2010, on Flickr



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Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #16 on: May 08, 2015, 08:42:01 AM »
Trial fit of seat.

2015_0508after0012 by nitram2010, on Flickr
CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #17 on: June 21, 2015, 11:45:13 AM »
Getting ready for MOT tomorrow.

Decided to use a SS Motad 4 into 1 I already had and cone/pod air filters with 836cc conversion.

2015_0621after0011 by nitram2010, on Flickr

Standard cam, electronic ignition 64A carbs, 110 main and needle clip at bottom, mixture screw 1 turn out.

No changes to head apart from clean and recut valve seats.

2015_0621after0012 by nitram2010, on Flickr

When DSS reduced price of generator covers due to a flaw on underside I couldnt resist ;D

I have 4 broken covers from the projects I bought. !

Runs OK statically, will see what its like on way to MOT :-\

In the UK you can only use legally to drive for MOT test until you get a pass certificate.

Looked at lots of rear set options.

I already had a spare set of CBR600FK rear sets so decided to see if I could make them fit.

Also bought some aftermarket foot pegs.

Need to make a device to hold foot rest up for kick start use.

2015_0621after0020 by nitram2010, on Flickr

2015_0621after0016 by nitram2010, on Flickr

2015_0621after0022 by nitram2010, on Flickr

From the outset I had decided not to modify the frame and to adapt whatever was fitted.

The rear sets came out OK, not pretty as I use angled ally and various spacers.

2015_0621after0023 by nitram2010, on Flickr

2015_0621after0024 by nitram2010, on Flickr

Seem quite solid, though  was approximate and then try out before final decision on position.

Rear brake hose was a bit of a compromise as had MOT booked for Monday and had to use what I had and standard too short.

Thought I would paint the worst bits as cam cover was deeply pitted.

2015_0621after0027 by nitram2010, on Flickr

Cable routing

2015_0621after0029 by nitram2010, on Flickr

Standard front brake master cylinder would not fit so used an after market one.

2015_0621after0030 by nitram2010, on Flickr

Engine mounting repair looks OK.

2015_0621after0033 by nitram2010, on Flickr

Used F2 tank badges painted satin black, yet to decide whether to pin stripe tank and side panels.

2015_0621after0034 by nitram2010, on Flickr

Replica side panel badges satin black.

2015_0621after0035 by nitram2010, on Flickr

2015_0621after0037 by nitram2010, on Flickr

The images dont show colour that well as looks better than some of pics.

Generally quite pleased to have recovered the badly seized and broken  engine I started with :D





CB750F1, CB750K8,  Triumph Street Triple R, AJS 350, Triumph 3TA

Offline koendd

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Re: 77 CB750 F1 Cafe Racer
« Reply #18 on: June 21, 2015, 12:50:40 PM »
looking real good!!
good luck with the mot,
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Offline seanbarney41

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Re: 77 CB750 F1 Cafe Racer
« Reply #19 on: June 21, 2015, 05:09:48 PM »
great bike!   love the seat and exhaust
If it works good, it looks good...

Offline martin_uk

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Re: 77 CB750 F1 Cafe Racer
« Reply #20 on: June 22, 2015, 02:13:13 AM »
Thanks Guys for positive comments.

Rear set position doesnt seem too bad, mind you only done 4 miles  :)

Passed MOT  ;D
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Offline Restoration Fan

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Re: 77 CB750 F1 Cafe Racer
« Reply #21 on: June 22, 2015, 04:45:04 AM »
Martin,
That turned out really nicely.  You do great work!

Ron
Ron

Stella - Logan's Senior Project    78 750K http://forums.sohc4.net/index.php?topic=141761.0

Logan's Reward - CB500 and CB550 Cafes    http://forums.sohc4.net/index.php/topic,147787.0.html