difference IWC 5102-03 and IW5102-05, althrough the same caliber?

Hello, I need your help.

I recently acquired two watches.

IWC 5102-03

IWC 5102-05

Both have the same caliber (59215).

With the 5102-03, you don't feel any end resistance when winding it, as you normally would with a

manual-winding watch.

As with my Monopusher 5153-01 (also manual winding, 8-day power reserve), the effect is like that of an automatic watch.

This watch was even sent to IWC, who said that this was normal,

that the watch had a drag spring ?, if I remember correctly. My watchmaker didn't know the

details either, and there is no indication in the manual that the watch cannot be overwound.

The 5102-03 is identical to the monopusher, no overwinding possible, no end resistance.

As already mentioned, my 5102-05 has the same caliber etc. as the 5102-03,

but there is a massive end resistance.

Both watches are running correctly.

Perhaps someone knows more about this?

I can't find anything on the web; the information about the monopusher came after I sent the watch to IWC.

I would like to avoid sending watches to IWC on a whim, as they are working perfectly.

I just want to know if everything is as it should be.

I would be very grateful to you all for your information.

thank you very much!

ulrike

Thank you very much for the explanation, now I'm reassured -:)

The IW5102-03 and IW5102-05 use the same in-house caliber, so mechanically they are identical in movement, power reserve, and reliability; the differences lie mainly in external details such as dial finish, hand and font colors, and strap/buckle combinations as well as production context, with one reference sometimes made for a specific market or catalog period. Essentially, they are the same watch internally, with minor aesthetic and configuration differences justifying separate reference numbers.

A bot is still a bot, but at least briefcasejoe443 was able to provide a correct answer. The bots are getting better, but the embedded external link is still quite obvious. 

Yes, same caliber, no mechanical differences between the two ref 5102 watches. 

What you’re feeling is consistent with two different mainspring implementations within the same base calibre. Some IWC 592xx movements use a slipping (bridled) mainspring, similar to an automatic, which eliminates hard end-stop resistance, while others are configured with a fixed bridle that gives a firm stop at full wind. Both behaviors are normal if factory-configured that way, and neither indicates a fault as long as power reserve and rate are correct.

IWC does not utilize different mainspring "implementations" within the same base caliber. Especially not a contemporary caliber. 

I am 99% certain that Hadi446 is a BOT. 

Hi Ben,
You shared great thing throughout the forum and have strong grips on different products, but am totally human bro you can share the captcha as well (:.

Thank you for the follow-up, Hadi446; the BOTs are getting better but sometimes things just don't add up.  My suspicions were raised as your contributions, although carefully worded, are slightly off. Almost as if composed using AI, yeilding slightly imperfect results.  A curiosity for sure.  

May I ask what brings you to the forum, are you an IWC collector, or a watch collector in general? Are you involved in restorations or repairs? It seems you have more than casual knowledge of IWC movements, both new and old.