Author Topic: A7 1958 crankshaft regrind info needed.  (Read 437 times)

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
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Re: A7 1958 crankshaft regrind info needed.
« Reply #15 on: 15.11. 2020 18:52 »
Here is some info on grinding etc. https://www.a7a10.net/forum/index.php?topic=5028.0

As per prior posts the regrind job should not be expensive, an hours work for a specialist set up to do the job. The BSA service sheet covers the topic.

Paying someone to build an engine for you WILL be expensive as that is many hours of painstaking work, if you want a good outcome.

Cost is an issue for most of us which is one of the reasons why the forum is so successful, the solution for many is to do as much as work as you can yourself, and don’t try to work to an end date, and to use this forum for advice (and any mates you have with knowledge).

These bikes are relatively simple to work on, with basic tools, if you invest time in learning the necessary knowledge, buying or borrowing any tools you need you will feel much more satisfied with the final result, and saved yourself a bundle of money in the process.

Just my 2 cents worth!
New Zealand

1956 A10 Golden Flash (1st finished project)
1949 B31 rigid “400cc” (2nd finished project)
1968 B44 Victor Special (3rd project,in progress)
2001 GL1800 Goldwing, well, the wife likes it
2007 KTM 950 Adventure, cos it’s 100% nuts

Online Butch (cb)

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Re: A7 1958 crankshaft regrind info needed.
« Reply #16 on: 16.11. 2020 11:50 »
The vibration from those 2 brg cranks was horrendous.

My Nimbus four is a 2 bearing. Keeps the motor short I suppose.
Warning - observations made by this member have a 93% unreliability rating.

Of Bikes; various, including ...
'58 Iron Head Flash Bitza


Online Greybeard

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Re: A7 1958 crankshaft regrind info needed.
« Reply #17 on: 16.11. 2020 16:01 »
The vibration from those 2 brg cranks was horrendous.
I don't recall being aware of bad vibration. Mind you, after breaking a crankshaft soon after I bought the car and replacing it with a Remax replacement I drove more carefully.  *work*

Offline Jules

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  • 1956 A10 s/arm Golden Flash
Re: A7 1958 crankshaft regrind info needed.
« Reply #18 on: 16.11. 2020 23:37 »
 " As an aside,  lubrication is the single most important factor to consider. Damaged journals have multiple causes, but by far the most common cause is poor oil supply. Make a critical examination of everything from " the tank filler cap to the big ends." The timing bush acts as an oil distribution hub, any wear here contributes to poor oil supply to the big ends, compounded by an obstructed crank sludge trap. Don't forget the PRV Valve."
Rich, this comment from Swarfy is well worth due consideration in your cost saving effort, if you do the crank regrind then ensure you do the whole thing, that timing side bush takes a lot of load/wear in particular....