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Myles Raymond
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Originally Posted by BSA_WM20
So how many ride John'O'Grotes to Lands end, all 603 miles of it in winter ?
Where as we do ride MElbourne to Brisbane , 854 miles in winter

How many months do you ride a year ?
comparred to sunny climates like California / Texas or OZ where most ride all year round
And how many ride all over Europe comparred to the number who just rode to & from work which was not likely to be more than 20 miles each way.

Boy you lot get touchy.
I did notice at the National at Halls Gap a lot of people complaining the Saturday ride was way too long where most locals considered it too short.
For 2 years I rode 75 mies each way to & from work every single day and there were people who rode / drove further than me.
Back in the 60's 30,000 miles was considered the AVERAGE distaance ridden yearly in NSW and was a consistant complaint because most vehicles only came with a 12/12 warranty ( 12 months or 12,000 miles ) which regularly ended up being less than 6 months till the Japanese imports went 12/12 what ever came last .
Add to that the larger numbers of A10's in the UK comparred to OZ there is a much better chance of finding a good crank there, or Canada or US border states than here .

So yes some do big miles but there would be a lot more who do very little where as down here it is the other way round and the only chance of getting a good crank is a bike some one pulled down to restore 30 years ago then never got around to finishing it .

Which year? The present year or back when I was at home a lot more to ride the bike? At around 30,000 driving miles a year it doesn’t give me much time to spend it with family.
I used to ride a bantam for about 1000 miles over a British winter period, and I used to ride all year, mostly because it was cheaper than putting fuel in the car (back when I was poorer) Each weekend doing 150-200, easily 200 miles a week if I was riding to work as well.
I’m more a fair weather biker these days and I’d much prefer to ride the European motorways than the British ones.
I was not one of those that complained about the distance of the halls gap rides, might of complained about the heat, we pommies complain when it gets above 28°c in the uk as we’re not used to it, so for us it was hot but we would rather ride as the riding kept us cool. There were also some fantastic riding to be had on those routes and the bike Shane kindly loaned me was perfect for the task. It was also a fantastic rally!!

Not being touchy though. It was meant as a joke. You might get a better crank in the UK, but they still dont come up for sale often and many have been left to rot in damp sheds.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (now rebuilt)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

BSA on eBay
bones_bir #854417 07/22/21 11:32 pm
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Peeing matches aside, areas with shorter distances and shorter riding seasons should give a better chance of a big journal A10 crankshaft which isn't cracked.
There was also a tendency in quite a bit of the US to buy a new bike after a couple of years and stick the old one in the shed or basement. One of those would have an even better chance of having a good crankshaft, but is also likely to still be in such good shape that you wouldn't want to cannibalise it.
I've bought a few low mileage US bikes over the years which fall into this category.

The bottom line is that decent A10 crankshafts are becoming as rare as hens teeth.

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bones_bir #854418 07/22/21 11:51 pm
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The mob i mentioned that make cranks in the 'states are not e+v.

They made the crank for Kevins bike (a triumph) and he actually posted that
they have a few 84mm a65 cranks on the shelf they would like to move.
Can't remember their damned name now........... At the time, i had a look and
they were a nice job, they've been at it for years.

Nourish used to be the goto place in the uk but they are gone now. They made loads of
85mm and 90mm offset and standard ones for srm etc.


At the time a10's were being sold in the uk, blokes that bought them would be riding them
to and from work and most would be thrashing the daylights out of them in the evening
and at weekends, certainly most of the ones i knew anyway. Me included. The a10 crank i've
just stuck in an a65 race engine is at -10 and i had my reservations about using that.
A redline of 6850 is set on a rev-limiter and a large red led indicates slightly before that,.
I can check how many times it's got there and kick the rider in the bum if i think it's too often.

NickL #854420 07/23/21 12:47 am
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Originally Posted by NickL
The mob i mentioned that make cranks in the 'states are not e+v.

They made the crank for Kevins bike (a triumph) and he actually posted that
they have a few 84mm a65 cranks on the shelf they would like to move.
Can't remember their damned name now........... At the time, i had a look and
they were a nice job, they've been at it for years.
I'd be quite interested if you remember the details as well.

bones_bir #854421 07/23/21 12:56 am
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Tony, Hillbilly Bike, you know Kevin, who made his crank?

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Matt said he was revving the 650 to what he thought was 6,600 is that really all? You definitely have that little motor going well. Shift lights are great just shift when it blinks.

It's the750 going on the dyno is it? The factory ran one past 7,000 where it was peaking, it would be interesting to compare them. They used an engine dyno but we can convert it fairly accurately. And if you have the curve you can see where it's going without revving more than you want. The Norton F750 was tested on both; 67rwhp and 76hp at the engine.

Aldana seems to be using rpm on his A70.



Put head phones on and go to 14.31.


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The 650 was being used to 7200. (different ignition unit)
I didn't tell Matt............
The 750 is the one going on the dyno.
Looking like the aussie titles will be cancelled again this year, bollocks!

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For LSR a new strong 84mm crank would be the thing.

Just finished the seats on a head this morning, calibrating using a head with big 44.5 valve and 38mm port that I know flows 158cfm against the 34mm that flows more. And stuck the speed probe in both in the middle of the port the 38mm is 26" the 34mm around 40". They are different depending where you put the hose but it gives an idea. 26" is fast enough but on a small motor esp with big bore headers it will get reversion and there would be more time spent waiting to get revs up when the other one would be long gone.

I've seen LSR bikes doing this, trying to get on the cam and pull the tall gears, finally get going and change gears and try to pull out of the hole again.

It would be interesting to see what hp the 650 has as well if the dyno shop was sponsoring and not charging. The factory got 66hp from one, which would be 58.18 @ the wheel.

Tom might tell us his best? I think it's more.


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This chap makes various cranks up.
He's not the one i mentioned earlier though.

https://offsetcrank.com/history/

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One of our club members has one of his offset A10 crankshafts.

He modifies existing crankshafts rather than making them from scratch, and apparently is finding usable big journal A10 crankshafts difficult to source as well.

From what we've seen, they either crack radially around the drive shaft, or crack through a big end journal at a web. It may be possible for a much better welder than me to repair a radial drive side crack, but as far as I know a crack though a big end journal turns them into expensive paperweights.

It may be feasible to turn up a crankshaft from billet using a suitable grade of steel, but that is similarly beyond my current abilities.

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Hi

Offsetcranks are made by Geoff Collins in Canada. The 84mm 90 degree crank he made me is fine, dynamically balanced, heat treated after welding to stress relieve it. Its 7.25kg while a standard A65 74mm stroke is 10.6kg, going 90 degrees allows you to loose a lot of weight off the crank.

John

Last edited by JER.Hill; 07/23/21 6:19 am. Reason: correction
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Originally Posted by Mark Parker
Aldana seems to be using rpm on his A70.


Put head phones on and go to 14.31.
That might have still been an A65 at the 14:31 section, because it was June 1971. I'm not sure that the BSA team had the A70s that early, and they probably hadn't been homologated. The last batch of the 201 was built in August.

That was an interesting film, for an "On Any Sunday" wannabe. The interview with Dave and Bart at the end was cool, and it was nice that they both rated Dick Mann so highly.

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They made 101 A70s in June '71. But cranks were in the states long before complete bikes. They started using A10 cranks I believe, but that one has the A65 size bush. The maximum capacity allowed was 750, It's hard to imagine them not being on it. Imagine if they had rubber mounted these engines and built them to be totally bullet proof. They knew how.

Maybe Peter's next book will tell us all about the flat trackers.

Meanwhile finishing some heads. They all seem about the same. This has good low lift flow with the seats cut. Cannot really do that till the guides are done and the valve aims where it will. I possibly should have narrower seats because they will work harden a bit. I bought some stones and stuff off ebay which are the best I've used. No point lapping valves.

It really stuffs you up when people use modern seat cutters on them and sink them back with a ridge around them. The one I'm half way through the valves are sunk a bit. Flows ok but it lowers compression a little.

[Linked Image from i.postimg.cc]

Last edited by Mark Parker; 07/23/21 10:13 am.

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Back "in the day" many A10s in UK were used to power road sidecar outfits.
Many of them big "family" outfits.
The engines saw lots of lugging and not many oil changes.
I remember growing up in a working class neighborhood in the industrial West Midlands.
In a typical street of say 20 houses only 2 or 3 would have cars.
There would be maybe half a dozen with solo bikes and 10 with outfits. The remainder used bicycles.
Those outfit engines had a hard life.
Crankshaft fatigue life is not measured in miles but a combination of force and the number of cycles.
Typically the guy would be latre for work--so no gently warming up the oil but start the bike, into gear, maximum throttle when cold to get to work qick so as not to be late and be docked his wages. Short ride of just a few miles--oil never got hot then repeat at the end of the day.
Then once a year load up the outfit with luggage, wife and two kids and ride the fully laden bike for 120 miles to get to the seaside for a one week family holiday.
Not an easy life for a crankshaft!
No wonder so many had fatigue failure!
Back in the day I had an A7 Shooting Star and that threw a rod through the primary side crankcase.
When stripped the crank had fatigued across the primary side big end journal.
If I was going to use an A10 crank for serious racing then I would dig deep in my rear pocket and get a new one made.
Just my two cents worth of course.

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I bought A10 engine parts for my recent bike build from a hoarder friend...He had four crankcase sets, all had welded repairs on the left side....I found a really nice set on Ebay for reasonable money
Had a half dozen connecting rods, all were junk..Bought a set of R&R alloy rods...The are made from Triumph 650 rod blanks so the are .040 longer than stock A10 rods. This presented no problems other than checking valve to piston clearance. Using flat top pistons it raised the compression from 7.25 to about 7.8 or so...No biggie..
The valve work including replacing recessed exhaust seats was done on a Newan single axis machine. Does really nice valve work and minimal valve runout allows tight stem to guide clearances without possible galling..
The engines runs nicely...with the 357 cam it idle fairly smooth, has good power over 3500 rpm.
The engine is balanced to 64%....the vibration subdued and doesn't not get worse at higher rpm..


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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At this point I am more interesting in doing a straight A10 crank conversion than going with an offset crank.

As I said, I have two engines to rebuild. More likely one will be for LSR salt duty (Stroker) and the other for road racing (higher RPM).

but these tech tips are great and a pleasure to read, so thank you for that.

NickL #854485 07/23/21 7:05 pm
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Originally Posted by NickL
Tony, Hillbilly Bike, you know Kevin, who made his crank?
I texted Kevin, waiting for his reply


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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I found Kevin's crank maker.... Ro-Dy in Plymouth Michigan...


79 T140D, 89 Honda 650NT ,61 A10 .On a bike you can out run the demons
"I don't know what the world may need
But a V8 engine is a good start for me
Think I'll drive to find a place, to be surly"
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Originally Posted by bones_bir
At this point I am more interesting in doing a straight A10 crank conversion than going with an offset crank.

As I said, I have two engines to rebuild. More likely one will be for LSR salt duty (Stroker) and the other for road racing (higher RPM).

but these tech tips are great and a pleasure to read, so thank you for that.


I contacted Ed V on the back of this conversation. He does have some A70 end fed cranks that he has had made.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (now rebuilt)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

Allan G #854503 07/23/21 9:22 pm
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Originally Posted by Allan G
Originally Posted by bones_bir
At this point I am more interesting in doing a straight A10 crank conversion than going with an offset crank.

As I said, I have two engines to rebuild. More likely one will be for LSR salt duty (Stroker) and the other for road racing (higher RPM).

but these tech tips are great and a pleasure to read, so thank you for that.


I contacted Ed V on the back of this conversation. He does have some A70 end fed cranks that he has had made.
La la la la la; I can't hear you.


A new crankshaft would be the a more practical approach. The only problem is that the 85mm stroke takes the capacity to 751cc with the standard 75mm A65 bore. BSA managed to use a loophole in the rules to get away with that, but the LSR bike might need to be sleeved slightly undersize.

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That was anticipated and is planned for. Re-sleeve to accommodate triumph pistons that are slightly smaller.

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I got some -20 (undersize) JE pistons made from Ed a few years ago (A70) with a crazy high compression. The idea at the time was to use them on a long rod A65 650 motor. If I remember right I have some Total Seal rings with them too.

It’s been a while since I looked at the rules for Bonneville but I do recall allowing one oversize. So you could easily do 751 or even a standard A65 I believe.

I’m interested in one of these myself, though at the moment I’ve been advised to hold back on bike spends by SWMBO as I’ve just done quite an expensive OIF build.


Now let’s all have a beer beerchug

68’ A65 Lightning “clubman”
71’ A65 823 Thunderbolt (now rebuilt)
67’ D10 sportsman (undergoing restoration)
68’ D14 trials (undergoing transformation)

bones_bir #854513 07/23/21 10:13 pm
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I previously ran in M-CG, which is a production engine class. yes you can overbore by one size, but because the baseline capacity is 654cc, it is already out of the 650 class. A production A70 is also the same, being the baseline is out of class, rendering to overbore rule moot.

Next outing I will likely be running in an altered class anyway. For me it is not about winning races or making records, rather it is about building and running old bike and hanging out on the paddock with friends.

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Originally Posted by Hillbilly bike
I found Kevin's crank maker.... Ro-Dy in Plymouth Michigan...


Ahhh, thanks Tony i got the name correct just the spelling wrong!!

bones_bir #854526 07/23/21 11:55 pm
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According to Peter's book A70 cranks should be in two sizes 85 and 84.5mm stroke. Though I'm sure an 80x74 is a better base. It's all dependent on how they are tuned. And the bigger bore means better breathing area.


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