Brodie's BSAki

[Brodie]

Thought I would start a new thread as the old one in introductions was unintentional into a build thread.

I bought a BSA A10 frame and swing arm a few years ago, the original plan was to build a TriBSA out of it but I do not have the funds to buy a Triumph engine and BSA gearbox to suit. I could save like hell and buy them but I thought there had to be a better option.

A few years and engine ideas go past and I decided on a parallel twin with at least 50hp and a 6 speed gearbox.
After searching for some time I came across a written off Kawasaki Er5 which fitted the bill.

So the plan is to resto/mod the BSA to look like it should have come from the factory with that engine.

Instead of a TriBSA I will have a BSAki (bizarreki).
So far I have had a custom triple tree built so that I could fit GS550 forks that have ZX6 calipers and CBR1000 rotors. I am using a set of Boranni rims with stainless spokes on GS750 hubs. I have bought an original tank, toolbox and oil tank. I have test fitted the Er5 engine and everything look like it will be good to go. I will be able to adjust chain alignment with a custom sprocket carrier.

[Brodie]

Today I relocated the front seat mount to its original location as someone had moved it backwards at some stage. I am not the best welder but I beat on it with a hammer and it did not move.
As the saying goes "A grinder makes a welder what he ain't"

[Rocket Racer]

look forward to seeing this journey unfold, suspect a v twin might be able to be hung a bit lower and fill the frame better. are you hoping to modify the sump so you can hang it lower?
Pipes and footrests will mask that height though. 

[Sluggo]

Bravo!    Not sure how the purists will respond but I enjoy a wide range of vehicles and while restorations have their rewards and the moral and socially responsible thing to do in certain applications,,.
(I rescued my 59 Bonnie, and 66 T120C from a life as choppers)
Not everything has to be grey porridge.
I ran a shop for a while doing vintage cars and bikes and while there was a steady stream of restorations, What paid the bills by 2/3rds were the custom stuff.  I tried to be ethical about what got the custom treatment and what did not, But to many locals I am STILL that F##k'n chopper guy. 
(You date a sheep just once as a favor to a friend, and forever after you are known as that SheepF******)

I have what might or might not be a Triumph quadrant basket case, story behind that.

I also have a number of friends over the years who have built fun hybrids like what you are doing. 
SirEddy had Horton- Hotrodded CB750Sohc4 in a 750 Commando rolling chassis
Doc Harms built ALL kinds of crazy stuff, many with BSA origins my favorite was the Suzuki Savage mtr in a BSA M20 chassis
Mark married a BSA A65 with a Yammie XS650 which is not much a  stretch, And there is a fellow in Alaska with a MuchLess that is a Japanese bike with some Matchless bits.  A few others but you get the point.

I have never heard of this motor, but it caught my eye as I kind of like some Kwakker bikes and had a few, currently have 2 KZ750Bs which is an Aircooled 750 twin and while not very fast, and a bit UJM, its enough metrified BSA twin I like them.  They only made them 2 years and the UK mag "Classic Bike" says they are a
"Future classic collectible" so that helps my self esteem.

But this motor seems very interesting with a 500 twin w/ alleged 50 hp? 
See: https://en.wikipedia.org/wiki/Kawasaki_ER-5
Being liquid cooled will be interesting how you address that.
Also fun to see what you do for wiring, electrics and adapting and mixing & matching bits as you already are doing with the forks & wheels.

My only advice/opinion is that you will benefit from ditching those carbs and getting something NON CV like a VM Mikuni is a popular choice with the XS650 crowd, or the JRC/PKW flat slide Keihen types.
 (or just for fun some Amal Monoblocs?)
Thumbs up! 

[muskrat]

Down here we had the Kwaka LTD440 and 750, probably the same motor as the KZ.
I like the CV carbs if their set up right, they need the restriction of a good aircleaner to work properly. The beauty of them is that they work on atmospheric pressure so self adjust to altitude so riding from sea level up to the hinterland there is no mixture problem.
Cheers

[Sluggo]

Here in the US I had a couple LTD 750 4s and in US Specs they were more "Cruiser" spec, and suspension and styling to match.  I like the KZ750B as here in the US a bigger twin like that is not common, only the Yamahas XS series seemed to cover that market.
But many people seem to prefer the V twins and it appears what drove the market at least for US offerings is my take on it.

The CV is a technically interesting carb when new, But on aging bikes or ones that have been neglected they are a mechanics nightmare especially when it comes to multiple carbs.  The diaphragms are expensive to replace (You can generally source a replacement non CV carb for the cost of the CV carb rebuild kit) and while many report pinholes or leaking diaphragms that was not that common in my experience.  The challenge for me was getting all the carbs to work, and then sync them.   I picked up a 2nd KZ750B cheap as a spare and possible parts bike as they are rare, But the reason I parked mine was issues with the CV carbs was causing massive headaches.  4 cyl models with CVs from the 1970s on are especially challenging.

Many of the Asian V twins use a impossibly complicated carb arrangement that has most people scrapping the bikes rather than repair or service them, But have seen a few enterprising types create a 2>1 manifold and run a single Non CV carb off to the side.  I am playing with some conversions on some NON BSA applications and replacing EFI to a Mikuni HSR currently and expect to have then on the road this summer.

Dont mean to siderail this guys excellent build, and he is free to run intake design he likes, Just illustrating that there is options.  Here is 2 pictures illustrating how some address this problem.  (DOHC4 Hondas really suffer from this issue and expensive to rectify otherwise)

[edboy]

sorry to *** on your parade. but the standard a10 motor , well set up, is a much better engine than that kawasaki short stroke thing. more acceleration? try a 19 or20 tooth engine sprocket on the bsa. the carbs are good on those engines and conversion onto the a10 engine might have been interesting. but a water radiator? no thanks.

[Brodie]

The plan is to remove the centre tube from the lower half of the frame after I went in a new section further forward. This frame has had a lot cut off and welded on before it came into my possession.
I don't expect the Er5 engine to be any better than the A10 but when empty engine cases cost the same as the engine and wiring harness some can see why I went this route.
I will try and hide the CDI and other electrical stuff the best I can. I am going to try and avoid just shoving them into the tool box like many people might.
I had thought about a v-twin but ultimately I want to try and make this look like it could have been an option originally. That will be hard with the radiator. I am unsure what radiator I will use but this will be the biggest eye catcher I think.
This bike will not be built for speed but more for rideablity as some of my favourite roads to ride around my area are quite steep.

I understand this bike will not be to everyone's liking but it is for me to ride and enjoy.

As for the build. I am still not 100% on the Suzi rear hub. It is quite wide and fitting a rear brake may be difficult. I do need to use a cush drive hub due to the engine so I will see what I need to do to make it work once the engine is mounted.
As the engine is running and I have rebuilt and inspected the carbs I will keep them until I work out all the kinks.
I have replace the worn out CV carbs on my XV1100 with TM36 Mikunis and they were a great improvement, but for this bike and the areas I want to take it I feel properly set up CVs with a proper intake would be the best choice.
I plan to use a remote front master cylinder and minimal bar switches to try and keep a fairly original (obviously not that achievable) look.
My plan is to use high rise clip ons and route the wiring internally.

But first things first I need mud guards!

[muskrat]

"But first things first I need mud guards!"
There would have to be a bike wreckers up there near you. As it's not a nut and bolt resto you could make something fit. A modern plastic front would work with the Spuzi front end.
Cheers

[Brodie]

There are a couple of wreckers around my area but I am attempting to use original body work where I can. I like the early A10 guards and if I can find a set that are a bit shabby at the swap meet this weekend I can fix them up. I am not a big fan of flashy chrome so hopefully I will find a set to paint. If not I still need the rear guard for the seat mounting as far as I am aware.

[Brodie]

Didn't manage to find anything at the swap meet. Met a bloke who should be able to help me out though, just need to find time to contact him and get up to have a look at what he has. Working 6 days a week sure does get in the way of my bike time.

I did a quick mock up of the engine with a few parts on. Looks like I will need to move the oil sensor to get the the engine to sit level. Custom plates will need to be made to have it sit level. Very little clearance in there

[Sluggo]

Swap meets (Jumbles apparently in the UK) are tremendously variable.  There was 2 yesterday in 2 different states about 300 miles apart, The one North of me has ranged from cancelled due to lack of interest to sold out whole venue in the last 10 years, Nobody really knows why it ebbs & flows.  The other one south of me, is GREAT for buyers generally and I have been attending since 1990 but prices are always low because most of the members of our vintage club are cheap B#####d's, So many sellers dont return. 
Going to a event with an expectation of filling your shopping list rarely works out IMHO, but the nice thing about having a large and varied collection of treasures (Junk) is that no matter what you can usually come home with SOMETHING of interest. (I always do)
But more specifically, I dont know what or where you are having issues on your frame/motor as I am not familiar with that motor, but is it the sump giving you trouble???    All I can offer is that USUALLY on most bikes you want the motor as far fwd as possible for weighting the front wheel and suspension, A light front end can be twitchy and unstable.
I do have some design and engineering materials for perf cars and there is a wealth of info on weights-balance and design that is very clear cut (For example some vehicles offset the engine/trans from the rear diff, and HOW you align the driveshaft is critical.)
I am sure there is technical materials for motorcycles on how to do weights and balance on a bike,  (IE: 60% front, 40% back.  And how to set up suspension for loading and unloading events)  But clearly the lower the CG the better.

For example Eric Buell popularized the oil bag/tank in the rear swing arm, Fuel inside the frame structure and perimeter brakes all to lower CG, Overall weight and most importantly Unsprung weight.  However he was not the first to do so.  Both the Germans and the English started doing such out of the box ideas in the 1930s

[KiwiGF]

Didn't manage to find anything at the swap meet. Met a bloke who should be able to help me out though, just need to find time to contact him and get up to have a look at what he has. Working 6 days a week sure does get in the way of my bike time.

I did a quick mock up of the engine with a few parts on. Looks like I will need to move the oil sensor to get the the engine to sit level. Custom plates will need to be made to have it sit level. Very little clearance in there

It looks like the sump needs to fit inside the bottom frame tubes, and the engine be further forward. Is the sump too wide for the frame tubes? If so that could be tricky to change....... 

[duTch]

 seems like it needs to tilt forwards a bit to be level, but hard to tell how much room there is under the tank

[Brodie]

Yep the engine needs to go forward and tilt forward as well. There is no way to fit the sump inbetween the rails unless I have it that far back.
There is a bit of room between the head and frame so I should be able to get the coolant lines on. I have been thinking about placing the radiator inside the frame so where the engine is will not look so far out of place with that in.
I do want to get the engine further forward for handling. So I think that will win out over the sump being inside the frame rails.


I did pick this up at the swap from the aforementioned bloke.