Optimus Pro Falls Apart 45 Days

I own both the Optimus Pro and Prime. While I’m very happy with the Prime, be aware of my experience with the Optimus Pro falling apart after just under 6 weeks of usage. It appears to be a hardware material failure as I woke up one morning, the band was detached, and the corner of the body (lug) was laying in my bed. I want to be clear that my watch has not been under any physical duress, in fact I am extremely careful about protecting it.
I sent an email to Customer Service and they indicated that I should reach out to Bangood. Obviously a major flaw by the manufacturer, not Bangood.


I would like to concur with ‘eswiderski’ The exact thing happened to my new Optimus pro only two months old. The plastic casing cracked and broke near the strap housing the same as the above photo. Fortunately I managed to buy a secondhand Optimus pro for spares. Only yesterday I managed to swap the casing over. (Aprox repair/swap about a half an hour.) It was much easier to do than I thought it would be but that’s not the point. It’s a real shame that many are and will be, left in this position. I am sure a few people were shocked like myself after purchasing this, to find the material of the casing is of brittle plastic and certainly not suitable or strong enough for holding watch straps in my opinion. My next watch phone will be with a metal casing.
Just a note, I will also attempt to glue and reinforce the broken plastic casing and keep it as a spare because I have very little confidence that my new watch casing will last very long either. If I feel that I have succeeded to do a reasonable job, I will post the results on here to explain how I did it and with what materials I used. Perhaps it may help others that may otherwise end up throwing the damaged watch/case, in the bin like I was tempted to do myself.
I would also like to add that I tried contacting Kosfet by email a week ago and still waiting to get a reply.
Thanks to all, Jake.

1 Like

iv’e had my optimus pro since aug 2019 and it’s showing no signs of damage
i put a metal bracelet on the watch a couple of weeks after purchase which has been fine

iv’e seen a couple with broken cases where the strap connects and i can’t think of a reason why they are doing that
maybe they are too tight on the wrist ?
dunno but mine has been fine

Hi cosmicma I am glad that your watch has been okay and no problems. It may be the case that some of us wear the watch with tighter straps but I would have expected the materials used to be able to handle this. We will see how long my new replaced watch casing lasts. However I love the device and have had great fun with it but am very disappointed with the material quality of the casing.

The screws used are very low quality and highly susceptible to rust from the salt in our sweat. In conjunction with the weak plastic body, the result is as above.

Causes of Plastic Oxidation

Chemicals in plastic react with oxygen in the air. The oxidation of plastics leads to degradation. Plastics become physically abraded or are subject to sunlight, air pollution, moisture, high temperature and biological exposure. Ultraviolet B radiation (UVB) breaks down plastics via photo-oxidation. Eventually this leads to brittle, cracking plastic.


Thanks ‘Mark2’ for the detailed info regarding plastics.
Like I said in my previous posts I did manage to replace the casing myself if took about a half an hour to complete. I found a seller on Ebay that was selling an Optimus pro for spares which was my donor parts. The screen and bezel looks firmly attached to the actual casing so to replace the casing means that the complete display module with the bezel and the casing is required for the replacement/repair.
The part can be found here. https://s.click.aliexpress.com/e/M9zveBYM Thanks to Jaroslav_Polak for posting this info.


Suggested way to repair fractured or broken watch case.

My suggestions on a way to repair damaged casing. In my case and a few other peoples cases the lug broke on the case which holds the strap on.
It’s my guess that holes were drilled and then a screw sleeve plug is inserted during manufacture and when inserted slightly compromises/fractures the body on the inside, the area where the straps are held on gets slightly fractured causing this to be a week point. Which may explain why some people as yet are not having this problem. (note) There were no signs of corrosion or reaction noted from the screws as been suggested in other posts)
This repair idea assumes that you still have the two pieces of the broken object.
Because there is very little meat at this point of where the fracture is. It seems that they always break in the same place and this is the weakest part because there is a brass screw plug inserted at this point. I decided to glue the two pieces together using JB Weld product (Original ) a two pack epoxy resin based adhesive which has metal fibre reinforcement. (it would have been great to have reinforced the joint with something like pins but would have been very difficult because there is a screw sleeve right in the way where it broke))The first stage was to prepare the two parts for glueing using a procedure similar to what a dentist would do if filling a hole in your tooth or inserting a cap. I used a dremel tool to try to make a sort cavity in the two pieces to try to create a decent fix for the adhesive to bond to and also roughing up the joint faces with the dremel tool. Then I cleaned the area very carefully using isopropyl alcohol with a fine paint brush. When using this you must be very careful not to get any or even a drop on the front face of the plastic because this will eat in and leave a mark. Possibly a good idea to mask the face area first. I find that this is good to use as a prep because is slightly softens and cleans the face of the ABS and creates good surface for when applying the adhesive. The epoxy adhesive that I used was a very slow setting type and takes at least 4-5 hours to set and at least 15 hours to cure depending on the temperature of the room. The two parts are mixed together at a 1to1 ratio. Although more difficult to use than quick setting epoxy resin, this is the strongest that you can get when cured. The glueing and holding in to position was quite straight forward and by all accounts should hopefully do the job.

As an addition, this may be a bit over the top, but I also decided to reinforce the repaired lug with a peace of metal plate. Probably not needed but I did it either way. I carefully filed the shape of a this thin aluminium plate and pre painted one side with black paint. I roughed up the surface on the plastic surface and glued it in place using the epoxy resin. This way I am not totally relying on the repaired joint to hold. See photos. Of course the idea is to make the repair as unobtrusive as possible. Never going to be perfect but makes the watch still usable until one can source a replacement casing or a replacement device at a later date if need be. When wearing the watch the repair is not really noticeable in my opinion.

I hope that this may help someone in the event that they want or need to try to permanently or temporarily fix their broken casing on their watch phone to at least make it possible to wear again.


Thanks for that highly detailed description of your watch repair mate! :+1: While I haven’t had this problem with my watch myself, I’ll certainty bookmark this post just in case it does happen. Cheers, Doons

1 Like

no problem selvis
i was just emphasizing the prevention angle

great detailed repair tutorial

1 Like

Hi ‘Mark2’ Thanks. No I agree, Plastics do degrade and can become structurally compromised under certain conditions as you rightly pointed out. Though ABS is widely used in many industries successfully.
To be honest if the lcd and bezel weren’t firmly fixed to the casing, I was seriously considering casting my own casing in aluminium. Possibly it could give an even better reception?
Interestingly, I noticed that the plastic casing has a metal layer around the top area under the paint finish, probably for the reception.


well it seems like i spoke a little too soon :frowning:

mine decided to snap a lug off but the good news is iv’e managed to fix it :slight_smile:

i used loctite 3090 which is not the cheapest glue on the market at £20 a tube but it’s the best i have come across for gluing plastic and so far it seems like a strong bond
if it holds it works out as a cheap fix

1 Like

Hi ‘Cosmicma’, just curious, did yours break in the same place as mine and the others on here?

it’s snapped in more or less the same position but a different lug
on the pictures posted in this thread it seems the same lug has snapped on all the watches ( top right above the button ) the lug that has snapped on mine is the top left but i wear my watch on my right wrist which effectively makes the lug the top outer facing lug the same as if i was wearing the watch on my left wrist if you follow what i mean by that

Yes I understand. It’s a real shame, there is a fundamental floor with this construction in my opinion. Please let us know how your repair lasts and will you still be wearing your repaired device for everyday use? My repair seems to be holding up but of course I have not been wearing it constantly, I may just start doing that.
I now/ today, have noticed signs of stress on the lugs of my newly replaced watch casing after only 13 days of careful use. I never sleep with the watch either. It is only a matter of time when it will just break and fall apart.
It is noted that with this, I have deliberately only used the original silicone band and no other. I have purposely put this band on loosely and I have made a conscious effort to not over tighten the band after my first problems and experiences with this model.

My conclusion is that these plastic cased, constructed watches are not suitable for everyday constant wear but are probably great for a dress watch to wear occasionally. These are advertised as being durable but from my experience the Kospet Optimus Pro is not.
Having said that, me being a tech geek, I love and thoroughly enjoyed playing with these watches, I am of course very sad but not really surprised.

My initial reaction when my two month old new watch broke was never to buy a watch with this plastic construction again, now with a different mindset, I am thinking of getting a few of these different watch models mainly to collect and use for casual use only. Perhaps I am mad?

1 Like

i use mine as an every day watch and take it off at night while i sleep
iv’e just started wearing the watch again today after the repair so too early to tell just yet but it’s looking promising the repair seems to be holding

it’s a bit of a catch 22
i want a watch with separate straps but the ones that do have that feature all seem to be plastic cased and the ones with metal casing seem to have dedicated straps with the antennas built into the straps
ideally an android watch with metal casing and removable straps would fit the bill but i don’t think there is one yet

Basically that’s what I do. I had durability issues also (with other watches), and at first I was quite upset. Then I decided these watches are cheap enough that I could afford to buy the latest and greatest model when they come out every few months and have a collection of watches to spread the wear over. In my current rotation I have a Prime for general daytime use, an Optimus Pro for sleeping, a Lem T for phone/cycling/video streaming, a Lem X for backup, and a Thor 3 for emergency backup :slight_smile: When the Genesis arrives I’ll use it for general outdoor use.


I agree, I would like a metal casing with removable straps. Also battery life that lasts a day with constant use that doesn’t need tweaking and optimising to last. A slimmer watch would also be on my wish list but that would only happen when battery and software technology changes.

Hi ‘Bozley’ Today I have ordered a few watches to play with. Allcall W1, Kospet Prime and Pre Ordered Lemfo Lem12. I am also thinking of the Samsung Galaxy older model with the rotating bezel.
I also like the fact that I can now make and receive bluetooth calls from all my watches paired to my smart phone and headset as well as standalone calling.

I everybody.
This is my turn on my kospet Prime.
Two corners are broken

One fall and an other have stress sign.
I’ve this watch since a year and Wear it everyday at work and sports activities.
I take care of it but it was made to be weared a not just for the pleasur of the eyes.
I will try to repear it.

1 Like

Interesting, seems basically the same failure point (at the brass fittings) like we have seen on the Optimus Pro.