Seiko Club Singapore Museum

Thoughts on the Grand Seiko 5646

lamhewtot
Thoughts on the Grand Seiko 5646
I've just been offered a vintage Grand Seiko 5646-7010 at a reasonable price. I'd like to know your thoughts on this particular model. I was not able to find much about its movement other that it is from the Hi-Beat range, but being from the 70's if i'm not mistaken, only beats at 28,800 bps. Is this correct? I would like to know more about this particular model and any insights or opinions you may have.



Thanks
Andoy
Re: Thoughts on the Grand Seiko 5646

"lamhewtot"

I've just been offered a vintage Grand Seiko 5646-7010 at a reasonable price. I'd like to know your thoughts on this particular model. I was not able to find much about its movement other that it is from the Hi-Beat range, but being from the 70's if i'm not mistaken, only beats at 28,800 bps. Is this correct? I would like to know more about this particular model and any insights or opinions you may have.



Thanks


Good morning Bro. I cannot offer you more information but I do have an opinion.



So, after I searched and had a quick look at it, IMHO, it's a nice, simple, beautiful watch. ;)



That's all I've got.



Good day Bro and let us know how it worked out. Have a nice weekend. :mrgreen:



Oh, and welcome on board! :lol:



Cheers!
Astro2212
Re: Thoughts on the Grand Seiko 5646
Seiko good
big-e-294
Thoughts on the Grand Seiko 5646

"lamhewtot"

I've just been offered a vintage Grand Seiko 5646-7010 at a reasonable price. I'd like to know your thoughts on this particular model. I was not able to find much about its movement other that it is from the Hi-Beat range, but being from the 70's if i'm not mistaken, only beats at 28,800 bps. Is this correct? I would like to know more about this particular model and any insights or opinions you may have.



Thanks


Just to share what I can remember and have read about this GS calibre.



56GS was produced in the 1970-78 or there about iirc.

It is the first mass produced GS using robots, but some manual production was still in place. It's not to say that it's is in anyway inferior in quality and accuracy.



The 56GS came in the following calibre:

5641 A: GS standard official approval. 28,800bph. 25j DATE

5645 A: GS standard official approval. 28,800bph. 25j DAY/DATE

5646 A: GS standard official approval. 28,800bph. 25j DAY/DATE



The advantage of this calibre is that parts are more readily available.

Perhaps due to mass production, there is more in the market or that it could be sharing similar parts to the 56KS?



Nevertheless, the 56GS was the last production GS before then quartz revolution, which almost destroyed the mechanical watch.



I own a 56KS and it's a fantastic watch in all accounts: styling, reliability, quality, really a classic Seiko dress watch.



(All information is taken from the web from various sources I've come across in the past. Mostly from forums, so there may be some errors here and there).









Sent from The Force
lamhewtot
Re: Thoughts on the Grand Seiko 5646
Thanks for all the replies guys, I'm seriously considering it but I have only two concerns that I am still contemplating. Firstly is its size, I'm more comfortable with a slightly larger diameter as my watches then to be at least 42mm. I'm concerned that at 36mm, it'll wear a little small. Secondly is the slight misleading of the hi-beat. I think I would be a lot more intrigued with it if it was a true hi-beat at 36,000bph as opposed to 28,800bph. However, I'm still considering it though.
Andoy
Re: Thoughts on the Grand Seiko 5646

"lamhewtot"

Thanks for all the replies guys, I'm seriously considering it but I have only two concerns that I am still contemplating. Firstly is its size, I'm more comfortable with a slightly larger diameter as my watches then to be at least 42mm. I'm concerned that at 36mm, it'll wear a little small. Secondly is the slight misleading of the hi-beat. I think I would be a lot more intrigued with it if it was a true hi-beat at 36,000bph as opposed to 28,800bph. However, I'm still considering it though.


Your standards are much higher. Me is at least 40mm dia enough already! :lol: :mrgreen:



Listen to your heart! Good luck.



Cheers!
Maxbliss888
Re: Thoughts on the Grand Seiko 5646

"lamhewtot"

Thanks for all the replies guys, I'm seriously considering it but I have only two concerns that I am still contemplating. Firstly is its size, I'm more comfortable with a slightly larger diameter as my watches then to be at least 42mm. I'm concerned that at 36mm, it'll wear a little small. Secondly is the slight misleading of the hi-beat. I think I would be a lot more intrigued with it if it was a true hi-beat at 36,000bph as opposed to 28,800bph. However, I'm still considering it though.


For a real hi beat, you should go for the 36000bph either in manual winding or automatic.



For example, manual wind







Or Grand Seiko automatic 6146



KKFA
Re: Thoughts on the Grand Seiko 5646
Nice hi beats.
big-e-294
Re: Thoughts on the Grand Seiko 5646
28800 is considered hibeat for Seiko and also keep in context that it's a 70s watch.



Even now Seiko regular calibres are only 21800bph.



Ofcourse it'll be great to get a 36000bph.

But don't get to caught up with all these beat rates.



Get it coz it's a piece of Seiko history and a vintage.

But most importantly, u like it!

It's your watch.





Sent from The Force
Maxbliss888
Re: Thoughts on the Grand Seiko 5646

"big-e-294"

28800 is considered hibeat for Seiko and also keep in context that it's a 70s watch.



Even now Seiko regular calibres are only 21800bph.



Ofcourse it'll be great to get a 36000bph.

But don't get to caught up with all these beat rates.



Get it coz it's a piece of Seiko history and a vintage.

But most importantly, u like it!

It's your watch.





Sent from The Force


The 36000 bph hi beat is really different as you can see that the second hand move so smooth that it looks like an electric watch. Even though it's a 1970s watch, the technology was way ahead of its time. Even the modern Longines watches and many brands now are 28800 bph only..
big-e-294
Re: Thoughts on the Grand Seiko 5646

"Maxbliss888"

[quote="big-e-294"]28800 is considered hibeat for Seiko and also keep in context that it's a 70s watch.



Even now Seiko regular calibres are only 21800bph.



Ofcourse it'll be great to get a 36000bph.

But don't get to caught up with all these beat rates.



Get it coz it's a piece of Seiko history and a vintage.

But most importantly, u like it!

It's your watch.





Sent from The Force


The 36000 bph hi beat is really different as you can see that the second hand move so smooth that it looks like an electric watch. Even though it's a 1970s watch, the technology was way ahead of its time. Even the modern Longines watches and many brands now are 28800 bph only..[/quote]

Totally agree.

36000 hibeat is fantastic.



I'm still hunting for a good cond 6145-8000.





Sent from The Force
Maxbliss888
Re: Thoughts on the Grand Seiko 5646






There is one nice Grand Seiko in HK if you are keen..
big-e-294
Thoughts on the Grand Seiko 5646

"Maxbliss888"







There is one nice Grand Seiko in HK if you are keen..


Thx. But I prefer the 6145 - date only.



I'll keep hunting. Just like my 56KS. Was worth the wait.









Sent from The Force
Maxbliss888
Re: Thoughts on the Grand Seiko 5646
Why the fixation on higher-beat movement?



Is faster really better, given that mechanical gears tend to degrade more rapidly as beat frequency increases? Despite the pros and cons, why are some manufacturers like Seiko and Zenith insisting on having higher-beat movements while others are not? The answer lies in the escapement itself, or the regulating organ, that comprises of the balance wheel, hairspring, escapement wheel and pallet fork. These parts combined oscillate at a certain natural frequency. For a 5 bps movement, the natural frequency would be 2.5 Hz.



A properly designed escapement would settle into a stable oscillatory mode and maintain a constant swing. The design would not be a problem if no mechanical disturbances were delivered to it. However, the natural motion of our hands subject the system to mechanical disturbances that can affect and cause timing errors. Studies have shown that the movement of our wrists are rated at frequencies below 3 Hz (6 bps). As our hands approach the natural frequencies of the escapement, the higher the likelihood for timing errors. So in essence, the higher the beat rate of the movement, the lower would be its sensitivity towards mechanical disturbances. .





Please see:



http://monochrome-watches.com/seikos-affinity-to-hi-beat-movement-part-one/" false;
KKFA
Re: Thoughts on the Grand Seiko 5646
Interesting read. Thanks for sharing.



Yes the smooth runing of the wecond hand in a 36000 hi beat is truely a wonder to see. :D
big-e-294
Re: Thoughts on the Grand Seiko 5646
Thanks for sharing.

I love reading articles like this.





Sent from The Force
Maxbliss888
Re: Thoughts on the Grand Seiko 5646
Grand Seiko 6145