Review of Lexin B4FM bluetooth intercom

[glaschu]

For anyone thinking of buying a bluetooth intercom set here's my experience of the Lexin B4FM that I've been using for the past couple of months.

I bought a pair from Amazon UK based primarily on the large number of positive user reviews. The pair cost £150, so they lie somewhere between the cheap unknown brand sets and the more expensive Cardo and Senna sets. The Lexin's come with both boom and loose wire mics., so no extra cost here if you need either option.

Fitting one to my AGV-K3 was fairly straight forward using the supplied screw-together clamp that grips the helmet shell. As supplied, the clamp did not feel super secure, so I cut a piece of foam rubber to match the contour of the helmet and act as a spacer inside the clamp. This mod made the fitment rock solid.

Same approach was used for my wife's modular MTS helmet, although in this case the boom mic was used. One problem with the MTS is that the tinted visor controls sit at the bottom left side of the helmet, so I had to mount the intercom on the right side instead. I had some concerns that this might cause a problem with water getting into the electronics as the USB-C connector used for the mic and headset now faces forwards, but so far it has been used through some serious rain with no issues.

Battery life is good - running them for a couple of long-ride days doesn't even register a battery drop. Audio quality is good, with wind noise all but removed when talking to a listener on a phone call or on a connected intercom. Headset volume also goes very high - painfully high if not using earplugs, but this is needed if I'm using the silicone wax earplugs that block a lot of sound. I can't really report on range as I don't use the intercoms for communication in a group of riders, only for rider to pillion, phone calls and GPS directions.

 

[knyte]

Nice write up and pics!

I've got a set as well, and also have an AGV helmet, and my g/f also has a modular helmet (boom mic) - although hers is mounted on the left side, like yours and mine.  Because of the contour of my helmet I opted for the 3M sticky mount.

You should have no problems with hers mounted backwards - that 3mm plug is such a tight fit there are blog posts about folks with no audio at all simply needing to push it in HARDER.  Very firm fit and should be more than adequate in the rain.

We find we have to re-pair (not REPAIR, but re - pair lol) them often - they seem to 'forget' that they're paired with other helmets, but it's not a big deal to pair them up again - we've got it down pat now.  Never had a problem with Bluetooth pairing at all.  Pairing up 3 helmets for a ride with Dad one day was a bit fiddly, and it's a minor PITA that each rider MUST stay in formation 1 2 3, but...they're inexpensive, so whaddya want.

Range is good enough for this price bracket.  In the city we've seen it fade out fast just going around the block with houses in the way, but on the open road ~1 km or so apart is usually no issue.

What's really impressive is the noise cancelling - most ppl I've chatted with on a phone call don't know I'm on a bike whatsoever, let alone at speed...to be fair, the volume isn't great at highway speeds, but certainly good enough to say to the caller, hey I'm just going to pull off the highway can I call you right back.

The biggest annoyance of all might be, well with mine, anyway - it's mounted almost TOO strongly.  When I want to remove it from the helmet I always forget (until Jiffy-marker-ing an UP arrow) which way to push it off the helmet mount.  Several times it has sort of 'snapped' out after a lot of effort and I've drawn blood many times - the mount has some sharp-ish edges.  Minor gripe, but that's real life.

I've never really got the hang of the FM radio, but glad it's there if / when I might want it.

[glaschu]

Yeah, the noice cancelling is black magic. Last intercoms I had were old dumb and cheap wired ones which were useless above 30mph, so the Lexin's are a revelation to me.

I did consider using the sticky mount, but wasn't sure how much confidence I would have it  holding on long term through all weathers...

Edited September 29, 2021 by glaschu