Every Modifications for the BSA A10

[AnthonyA]

Hi guys,
A little more disruptive today: I intend to regroup on this topic all the modifications (or at least the most of it) you can do to improve a BSA A10. I'm more interested in swing-arm models, since that's what I have, but let's make this for everyone !

I want to regroup here the most and less useful, famous, basic modification. The "Must-Do" and even the "No-go" to warn off people. Everything really, to make sort of an encyclopedia. I will edit this first post along the way to include every mod.

I've heard about Vandervell bush conversions, Newby Belt drive conversions, Roller bush conversions, SRM,... but I know nothing about it ! Enlighten us with your personal knowledge, with text, pictures, schematics, website links,...

Thanks for doing your part !

[Klaus]

Hi Anthony,
I do racing with A10 also Tim  with an combination at the other side of the world, Muscrat seems to be a vey fast man with  good experiance.
Some modifications you ca do with a good sorted workshop, others are expensive and only done by handfull companys spread ofer the the world. It depends on the bikes use, if you do only a few hundred miles a year, you dont need a roller confersion.

A simpel way to reduce wear is to modificate the valve gear. A few years ago I wrote about.

https://www.a7a10.net/forum/index.php?topic=9604.msg69737#msg69737

cheers Klaus

[AnthonyA]

Thanks a lot Klaus !
I'm very interested in the roller conversion.
I love to travel across Europe, usually 2000km trips, but that's on my Honda so far. I really want to be able to do that on my BSA too.
I'll check that.

[Rocket Racer]

Anthony, thats a big ask and potentially a broad definition "improvements" , ignoring the wide variations between the 500 and 650 models even the swing arm models had a wide variety of brakes. Likewise some of the engines are more naturally capable of accepting tuning having stronger cranks and barrels.

If I was asked the number 1 thing required to make all the engines last, I would say start with  a clean sludge trap and keep the oil clean.

From a performance perspective the emphasis is slightly different and based on actual use. My race engine has regularly pulled 7500 before I fitted a lovely 6 speed TT industries box (a good modification if the pockets are deep), so now can keep it to 6500.
On my race engine I likewise run a BNR (bob newby racing) belt drive clutch. tough as old boots and a sound investment. He does road clutches including semi unit engines.

I do run timing side bearing conversions on several of my engines (not my 54); having oil flung out to the mains by centrifugal force, rather than pushing against centrifugal force to get past the bush to the mains.

On my race engine I also run shorter rods and a shortened barrel, (a65/a70) the rods are alloy with steel caps so maintain pressure well and short rods reduce the dwell at tdc (albeit increase piston speed) so have been popular for racing a10's since the fifties.

I own two early road rockets, as std these have the lovely single sided QD wheels and also the twin port heads.

On most engines (ignoring race) my preference is mild compression, unless you can readily source good quality high octane (98-100).

Cake Street Classics recommend a mod to groove the length of the cam followers to improve oiling as they are typically a high wear item.

Likewise they recommend a mod to slightly extend the timed breather timing

well that's a start, I'm always happy to offer my opinion via a PM

Tim
 

[duTch]

 

.....rather than pushing against centrifugal force to get past the bush to the mains. .......

 RR-  I'm  wondering if you mean '' past the bush to the big ends ' ?
 

[Rocket Racer]

 

.....rather than pushing against centrifugal force to get past the bush to the mains. .......

 RR-  I'm  wondering if you mean '' past the bush to the big ends ' ?

On a stock motor the oil pump feed gets to the crank by coming in from the outside of the timing side bearing/bush and then has to work its way against centrifugal force to the centre of the crank, this works when the bearing is good (I even ran a race engine like this for a season or two) but can result in catastrophic failure once wear in the bush allows the pressure to the big ends is reduced, whereas a triumph or norton will still get good oil flow even on a bushed timing side motor.

[duTch]

 

....but can result in catastrophic failure once wear in the bush allows the pressure to the big ends is reduced,....

 Yes- which is what I was getting at....that I figured you had in mind

[scotty]

Steering head taper roller bearings mod

S

[Black Sheep]

A well put together bog standard A7 or A10 does a pretty good job. How many 'improvements' are actually necessary or justified? None at all in my limited experience (47 yrs A10, 43 yrs A7). And no, they are not ornaments, they are everyday transport.

[Klaus]

If you whant to go around the world and do a high milage

Belt drive conversion
http://bobnewbyracing.co.uk/

12 Volt conversion
https://www.alton-france.com/generators/#gen2

elctronic ignition
https://www.bt-h.biz/

SRM have many of goodies are recommented, like needle roller conversion, Oilpump, stearing head taper, Oilsumpplate. Only the pushrods keep your hands off.
http://www.shop.srmclassicbikes.com/

You can dig a lot of money in an old bike, and sometimes it will drive you creasy......its like a woman ..... but you can have a lot of fun with. But dont forget to go to the pub

cheers Klaus

[Greybeard]

I did a few minor tweaks to my A10:
A high capacity steel oil pump. SRM make a super-dooper ally billet pump that is rather expensive and too pretty to hide inside the engine.
SRM pressure relief valve. Updated design.
LED rear light assembly. I'm still on 6v electrics.
DVR2 electronic voltage regulator. Highly recommended!
Oil filter in return pipe.
Taper roller steering head bearings.
Stainless rims and spokes.
Good quality drive chain. Expensive!
Custom shop single seat. Comfortable.

[RoyC]

SRM pressure relief valve. Updated design.
LED rear light assembly. I'm still on 6v electrics.
DVR2 electronic voltage regulator. Highly recommended!
Oil filter in return pipe.
Taper roller steering head bearings.
Stainless rims and spokes.
Good quality drive chain. Expensive!
Custom shop single seat. Comfortable.

All the above +

12v electrics
dynamo belt drive
Twin leading shoe front brake
Electronic ignition
SRM clutch
All LED, including headlight
Indicators
Rod operated rear brake
Front & rear crash bars
Front brake stop light
SRM Oil sump plate

[BSA_54A10]

The list of what you CAN do is endless
The list of what you SHOULD do is a lot shorter
And a lot of it will depend more upon YOU than the bike.

We have just come home from the Aust BSA National Rally.
Once again Steve rode his flash from Coffs Harbour to the event ( Hahndorf )
1800 km there and 2400 km back via the coast.
Earlier this year he rode to the All British Rally at Newstead 1400 km each way.
The bike is bog standard apart from the following
1) fully enclosed chain guard
2) 12V dynamo conversion ( so ,he can run the sat nav & heated grips )
3) heated grips
3) spin on oil filter
4) windscreen
5) modified oil seal holder in primary chain case so it no longer leaks oil ( just a little )
6) higher power headlamp globe cause he tries to avoid skippys while riding.
7) DVR II voltage regulator because to mechanical ones have points that oxadize if not used for extended periods.

He used to run a belt drive but after having one fail on the way to the BSA International Rally at Halls Gap ( yes he rode it to that too ) and the replacement fail on the way home he went back to a primary chain cause he can pick up a chain anywhere but down here it can take 2 weeks to get a belt.

The secret to a reliable bike is MAINTENANCE.
So for instance he paid to get the magneto cam ground so that it is exactly the same both sides and actually 180 degrees apart ( most are not )
The bike is timed with a disc not a pencil down the plug hole.
The AA unit has been bushed so it has no slop in it
The bushes in the gearbox have all been replaced and carefully honed.
The change forks have all been replaced so there is no sloppy gear changes.

When he got to the rally, he adjusted the primary chain and of course the rear chain, then lubed the rear chain and somewhere on the way back he will change the oil.
In the panniers he carries a spare 12V Cyclon battery just in case the genny fails so he will have power for the sat nav.

The rest is down to YOU
Steve rarely rides faster than 110 kph and usually sits on 100 where the bike runs comfortably, unless he is riding with me when the speed drops to 90 kph which is the fastest that the M20 will run comfortably.
He does servicing WHEN IT IS REQUIRED not when it is convienant to do so as mentioned he adjusts the chains regularly and will do an oil change on the side of the road when the interval comes up, where as I would wait till I got back home.
Every day at the end of the ride while the chain is hot it get a little squirt with spray grease after that it is beer time after which no spannar is touched.

The A7/10's are very reliable bikes when set up properly.
The big problem is clowns shove an electronic ignition on an engine that is worn way past service limits then think they can mix it with to Porches or try to out run modern bikes with 5 times their horsepower.

So my list of modifications would be a :-
DVR II regulator ,
LED tail light
external oil filter
fully enclosed chain guard
BEESA Bills roller gearbox detent ( google it )

However this is AFTER a full strip down and thorough inspection replacing all parts that are worn to more than 50% of their wear limits.

[Greybeard]

I forgot that I have belt drive for the dynamo.

[Black Sheep]

Ah yes, electronic voltage regulator and LED rear light. The A10 has a TLS front brake, the A7 a 12 volt dynamo (for heated grips in winter). The A7 (plunger Star Twin) has a 4 gallon Flash tank to give a better fuel range.

One of the great Land Rover expedition gurus when asked about modifications for expeditions said Leave it alone - if it breaks, you can get standard parts. Anything modified that breaks can leave you stranded for weeks.

Riding a long way from civilisation and phone coverage whenever I get the chance, as well as the normal bike toolkit I have a cheap Lidl magnetic tank bag that goes on any bike which has all the things I hope never to need. Food, water, 1st aid kit, spare tube, CO2 inflator, cable spares, mag and dynamo brushes, Leatherman tool, space blanket, hand warmers, tow rope, hat. Still leaves room for a toothbrush!