Author Topic: Julian's Scrambler build "Post 1"  (Read 20145 times)

Offline JulianM

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Julian's Scrambler build "Post 1"
« on: 20.08. 2012 10:57 »
Hi, thought I would now start the build I mentioned before. Been compiling a few pics etc and hope I can keep it interesting for you all.

Firstly a little project background.
I bought a nice "looking" BSA Super Rocket that had been visually very nicely converted to a Spitfire Scrambler, and it had been built with all the right bits etc and photo documented. Should have been one to just take home and enjoy!  Guy was short of money so got it cheap enough without ripping him off. (I should be so lucky)

Here it is,


First thing to do was to fit some proper tyres fitting for such a machine.


And so I had a play with it in my yard, (which is quite big)
The performance was VERY disappointing and I kicked myself for only hearing it and not test riding it but as I collected it at 10pm it was not the easiest thing to test with no lights etc.
So I fiddled with it and eventually found the float level on the TT carb massively low. This was adjusted and performance improved tenfold!
However!!!!!!
After about 5 runs up the yard and back there was a loud nock under load, just like big end bearings! Subsiding when retarded.  *sad2*  *sad2*   So, put it away and decided to do a full rebuild on the complete bike.  I didn't love it any more  :!

Problem with me is that when I pull something apart I start to imagine and fantasize and get quite imaginative!  That's my job after all.
But sometimes I get a little carried away.  That's what happened here!
I had a set of old Marzocchi 38mm forks from an old 60s scrambler in my collection of bits in the "parts room" and thought I maybe should fit them, on offering them up they were 70mm longer than standard and would lift the front just nicely I thought. So one evening I fitted them in a mockup.
I also had some nice period looking "Redwing" racing rear shocks which happened to be about 1" over stock, so fitted these too.  Bike looked really good but the tank was steel and oil tank heavy etc etc.
I then managed to find a twin carb head on ebay while no one else was looking and got it pretty cheap in really excellent condition. Tested it as standard on my flow bench against my big valve single carb head and got some pretty impressive results for an un touched head that everyone says "won't flow"  ;)  
Mocked that up and mounted a pair of new 32mm Amal Concentrics from a Commando with a quick pair of manifolds I made.



Then it was off to my friend "Frank the Tank"  http://streugmetalshop.be/  for some finer modifications.

Here she is with Frank,

The new tank is ally and about 1 1/2" longer than std at the front end, and narrower at the sadle end. Subtle but very pleasing.


When it came back, I made some extensions to raise the rear an inch and a half more in order to get the look I wanted and then made the front and rear mudguards myself.  The rear mudguard is completely sealing off the rear "inner frame area" so as not to get mud in my air filters etc.



Initially I was going to run with no front guard but in some classes you have to have one so I made this one to look period and I think it works quite well.



I also made a pair of long bent trumpets to go from the carbs to the air filter area under the saddle, this is bent ally tube with a nice big bell mouth formed on the end. Foam air filters will then fit offer the trumpets.  You can also just see the new oil tank I made to fit under the seat.



Also cut and modified the front "roundel" to fit and mount directly round the new headlight and made the stainless headlight holder and mesh cover for the lens




And then finished the inlet manifolds properly,


So this is how it ended up looking with me quite happy with the general look.



Stripdown time!
And time to do some mods to the frame.








Basically these consist of the following.
Rear mudguard loop.
Reinforcing swingarm mounting,
Front down tube bracing,
Modified head stock, extended and modified to fit the Marzocchi fork yolks and taper rollers.
Side stand and side stand bracket made to tuck the long stand up and out of the way when not in use.
Head stock bracing,
Steering stop tubes.
Numerous small tacking and bracing jobs.

Then off for frame painting.
I was going to do the frame and some of the tank etc Black, but could not sell it to myself in the end so chose a nice dark grey metallic.
Hope you like it when finished.





On return it was time for assembly to start.

Re-bushed the swingarm with newly made bronze bushes, and modified to take grease nipples, new spindle bought and fitted but drilled with a 3mm hole in the centre so the grease can get to the brake spindle also. Notice the much thicker frame support for the swing arm spindle.



Next job was to tidy and polish the yolks,
These were just tidied with the die grinder and a little weld here and there to plug unsightly holes etc. and then finished off with the rasp file and then a needle file where needed.







Followed by polishing on the mop and fitting up to the frame.






More to follow as and when!
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline iansoady

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Re: Julian's Scrambler build "Post 1"
« Reply #1 on: 20.08. 2012 12:35 »
That's a lovely job - congratulations.
Ian.
1962 Golden Flash (arrived)
1955 Velo Viper/Venom (departed)
2004 Triumph Tiger 955i (staying)

Offline spiralz

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Re: Julian's Scrambler build "Post 1"
« Reply #2 on: 20.08. 2012 16:18 »
wow what a job, thanks for sharing i think it looks amazing.

 wink2

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #3 on: 20.08. 2012 17:20 »
Thanks guys, glad you like it!

Julian.


Dear Mr Admin,
On my "Hi" post I did ask where to post the build thread and this was the answer.

"Start a new topic in the engine board call it monster mash or something to suit.
Cheers"
 
However I don't mind where it is as long as people like to read it and enjoy.
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Online bsa-bill

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Re: Julian's Scrambler build "Post 1"
« Reply #4 on: 20.08. 2012 18:13 »
Wow, that's something else as Eddie once said

a beautiful non standard bike, not easy to do, you need a mind that can see the finished article from way off.

congratulations JulianM , hope you enter the next photo competition
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline muskrat

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Re: Julian's Scrambler build "Post 1"
« Reply #5 on: 20.08. 2012 20:27 »
 Clever little vegemite, I can see you don't do things in 1/2's. Really well done mate.
Might have to send the cafe over for a refurb. Any chance of knocking up another set of those inlet manifolds?
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline a10gf

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Re: Julian's Scrambler build "Post 1"
« Reply #6 on: 20.08. 2012 22:07 »
Wow, nice story, pictures, workmanship and bike. Thanks for posting.

Quote
On my "Hi" post I did ask where to post the build thread
No problem, and I think will be widely read with great interest, don't worry. btw usually we are trying to avoid big pictures in posts (only thumbnails, to avoid 3 meters deep posts... or 2 meters wide if anyone links to some massive picture) but this post was nicely made with great content, and I suppose links to screen-size pictures should be allowed in the bikes & pictures board. Please do not edit or change picture hosting settings, or else all pictures will disappear from here, to avoid this it's good to use the forum attachments service (but ftm one cannot put pictures inside the post, they all end up at the end of the post). End of offtopic :O)

A10 GF '53 My A10 website
"Success only gets you a ticket to a much more difficult task"

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #7 on: 21.08. 2012 07:06 »
Thanks for the kind words everyone, it helps to inspire very much!

Will do the photo comp if it's finished in time and if I can take a good photograph!  Two big "ifs"   *smile*

Muskrat,
Yes, I can do some manifolds but need a bit of time first.  (very short on that at the moment)
Drop me a line and we should get together and natter about what you need sometime.
I only do things for free or for "swapsies" though as I try to stop it crossing over with work and stopping it being so much fun  ;o)

Regards,
Julian

PS.
A10gf,  Will try to make sure it's as forum friendly as poss.  Thanks for the pointers.
Julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline chaterlea25

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Re: Julian's Scrambler build "Post 1"
« Reply #8 on: 31.08. 2012 22:24 »
Hi Julian,
I was away last week and somehow missed your postings
The way the build is going there wont be much BSA left and mostly replaced by "Julian parts"  LOL *smile*
Looking forward to the engine build pictures, and those alloy barrels *ex* *ex*

Regards
John
1961 Super Rocket
1963 RGS (ongoing)

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #9 on: 03.09. 2012 13:39 »
*smile* *smile*
I know what you mean and partly true.
My "ethos" behind it all was to build a BSA based scrambler using all parts from the A10 Super Rocket (what my bike started it's life as) and ending up with what someone could have built in the late 50's early 60's  hense the 190mm front brake and steel wheels etc that ideally should be replaced to save weight etc, for a tidily japanese one from a 70's MX bike or a twin leader from something more trick.  Even the forks are Marzocchis from an ex-works 63 Husky apparently, (leftovers from a mate of mine that was lucky enough to have once owned one)  so it should be as much BSA as any real competition bike would have been in period "if you understand my meaning"  which is why I am going to the effort to make the engine fast and reliable instead of sticking in a Triumph motor.

A bit of a test to see what could be done to an open class BSA A10 with what was available at the time.

Regards,
julian

PS.
The new crank is almost finished   *smile*
Did I not mention the new crank? 
Well I "need" it to get as big and bad as poss.  so now it will be 780cc which is ok by me!
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #10 on: 18.09. 2012 07:37 »
Small update,
Had a little chat with the CNC man last week as I was sorting out to start machining and we decided to get the bores ceramic coated and run the pistons direct with no liners, similar to Nikasil bores etc. This means with a little addaption to head bolt possitioning I can get a 75mm bore and my initially aimed for 800cc with safety! 
Crank should be finished this week.

Will keep you informed.

julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline muskrat

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Re: Julian's Scrambler build "Post 1"
« Reply #11 on: 18.09. 2012 20:28 »
 Ceramic bores, thats trick. Didn't Honda do that with their oval piston GP bike in the '80's?
Shame your putting knobbies on it. Would love to try it on a black track.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #12 on: 19.09. 2012 09:40 »
Morning,

Yep, ceramic and coated ally bores are used quite a lot these days including F1.  Makes sense really and the company I am using have a special 4 day turnround for racers, and 24 hour if desperate!  and only 40% extra cost!  

I do kind of wish it could be tested on track also, maybe I will stick a couple of road tyres on for fun one day.
I am building another bike wich will use 19" Maxxis Flat Track tyres so maybe pop these on for a giggle!
I will need to fit a road tyre to the back when I rolling road it anyway so maybe that will be the oportunity.

Regards,
Julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #13 on: 26.09. 2012 13:04 »
Little bit of work I did last night,
New Wheel/Sprocket carrier in 6061-T6





Should be fun!
Julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,

Offline JulianM

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Re: Julian's Scrambler build "Post 1"
« Reply #14 on: 03.10. 2012 09:29 »
Small update from Saturday,

Made a new air compensator pipe for the fork pressure valve.


Sorted out and machined the front engine mounts


Fitted the rear sprocket etc

To check clearance at min chain adjustment


Rebuilt the forks and fitted the nice new gaiters

Then fitted to the bike.


Julian
55 Ariel HS mk1,
58 BSA Super Rocket Scrambler special,
60 BSA Gold Star, Jim hunter desert racer,
64 Norton N15CS,
65 Triumph TR6 SS,
66 Triumph Bonneville,
71 AJS Stormer,
71 BSA Rocket 3,
71 Laverda 750SF,
71 Laverda/Egli 750SF, Race bike,
73 Norton Commando 850,
74 Moto Morini 3-1/2 Sport,
74 Bultaco Sherpa 350,
76 Beta Cross 50,
77 Moto Guzzi Le Mans Mk1,
80 Ducati 900 MHR,