I had been cycling to work for a couple of years and then cycling to get food but now I’m under lockdown and the local shops are too close for cycling so there’s nothing to force me to get on the bike.
I tried cycling purely for exercise but got a little bored and started thinking it would be nice to have a stereo on the bike to make the exercise time pass more enjoyably.
Weight isn’t a huge concern since I’m not racing and not really using the bike much for anything else at the moment.
I had some yellow sports cones left over from my previous speakers build and I thought I’d try 13cm drivers in them this time. After the success of my previous build I decided to go for some higher quality drivers and I chose a set of Focal Flax Evo PS 130 FE which is a 2-way component kit.
The original thinking behind this was that the woofers would go on the front forks but they wouldn’t have much separation so I wanted to put tweeters at the ends of the handlebars to get a better stereo image.
My original plan was to use another one of my car stereos to bi-amp them but none of the stereos I have left over from the scrapyard purchases have the required crossover. Alpine sold one with Bluetooth, DAB and a 3-way crossover which would work but it’s expensive and I was struggling to work out how I would attach it to the bike so I could use it easily on the go. Flat over the centre of the handlebars looks like the best bet but challenging to make it waterproof.
Another problem I’d had on my previous trip was that my phone battery went flat before I got home which left me with no navigation. I wanted to solve that too.
I bought a 4S 6000 mAh lipo and charger and a motorcycle 12V USB charger (and cigarette lighter socket) so I could get the battery voltage display on the handlebars and the usb sockets for charging my phone and front light.
Then I remembered I had a small fosi audio class D amplifier with Bluetooth and aux input surplus from before I started using old car stereos. I tested that running from the lipo and driving my home speakers and it sounded OK. It also fit into my bike’s top tube bag along with the lipo and my phone which all seemed a bit miraculous.
With only one stereo channel I was forced to use the passive crossovers that came in the speaker kit and they wouldn’t fit in the bag so I pop-riveted them to the outside. They are supposed to be ventilated anyway and they are vertical so won’t get too wet unless the rain is really heavy.
I stuck the tweeters onto my wing mirrors with 3m mounting tape.
The woofers are mounted in the yellow sports cones with 3m mounting tape to seal the gap between the plastic rings and the cone. They are each held onto the bike with a bike bottle bracket. I’ve used some washers inside to spread the load on the plastic a bit so hopefully they won’t rip off when I hit a bump.
The wiring is done using the original Focal wires for the tweeters but the woofer wires were too short so I’ve used some ultra flexible silicone wire. There is slack in the wiring to allow the steering to turn to the full extent. It’s a bit of a mess of wires but I think it’s safe. There’s a 25A fuse on the hot wire from the lipo.
The complete build took about two days. I need to get black cable ties to replace the other colored ones to tidy it up a bit. And I need some waterproof shower caps to put over the woofers when it rains. I haven’t tried riding it outside yet. I wanted to get some photos just in case it doesn’t survive its first trip.
Sound is going to be OK I think. Obviously it’s spectacular for a bicycle. I haven’t been able to turn up the volume yet because I only just got it working and it’s too late at night.
My panniers are also yellow and black so the woofers match nicely.
I tried cycling purely for exercise but got a little bored and started thinking it would be nice to have a stereo on the bike to make the exercise time pass more enjoyably.
Weight isn’t a huge concern since I’m not racing and not really using the bike much for anything else at the moment.
I had some yellow sports cones left over from my previous speakers build and I thought I’d try 13cm drivers in them this time. After the success of my previous build I decided to go for some higher quality drivers and I chose a set of Focal Flax Evo PS 130 FE which is a 2-way component kit.
The original thinking behind this was that the woofers would go on the front forks but they wouldn’t have much separation so I wanted to put tweeters at the ends of the handlebars to get a better stereo image.
My original plan was to use another one of my car stereos to bi-amp them but none of the stereos I have left over from the scrapyard purchases have the required crossover. Alpine sold one with Bluetooth, DAB and a 3-way crossover which would work but it’s expensive and I was struggling to work out how I would attach it to the bike so I could use it easily on the go. Flat over the centre of the handlebars looks like the best bet but challenging to make it waterproof.
Another problem I’d had on my previous trip was that my phone battery went flat before I got home which left me with no navigation. I wanted to solve that too.
I bought a 4S 6000 mAh lipo and charger and a motorcycle 12V USB charger (and cigarette lighter socket) so I could get the battery voltage display on the handlebars and the usb sockets for charging my phone and front light.
Then I remembered I had a small fosi audio class D amplifier with Bluetooth and aux input surplus from before I started using old car stereos. I tested that running from the lipo and driving my home speakers and it sounded OK. It also fit into my bike’s top tube bag along with the lipo and my phone which all seemed a bit miraculous.
With only one stereo channel I was forced to use the passive crossovers that came in the speaker kit and they wouldn’t fit in the bag so I pop-riveted them to the outside. They are supposed to be ventilated anyway and they are vertical so won’t get too wet unless the rain is really heavy.
I stuck the tweeters onto my wing mirrors with 3m mounting tape.
The woofers are mounted in the yellow sports cones with 3m mounting tape to seal the gap between the plastic rings and the cone. They are each held onto the bike with a bike bottle bracket. I’ve used some washers inside to spread the load on the plastic a bit so hopefully they won’t rip off when I hit a bump.
The wiring is done using the original Focal wires for the tweeters but the woofer wires were too short so I’ve used some ultra flexible silicone wire. There is slack in the wiring to allow the steering to turn to the full extent. It’s a bit of a mess of wires but I think it’s safe. There’s a 25A fuse on the hot wire from the lipo.
The complete build took about two days. I need to get black cable ties to replace the other colored ones to tidy it up a bit. And I need some waterproof shower caps to put over the woofers when it rains. I haven’t tried riding it outside yet. I wanted to get some photos just in case it doesn’t survive its first trip.
Sound is going to be OK I think. Obviously it’s spectacular for a bicycle. I haven’t been able to turn up the volume yet because I only just got it working and it’s too late at night.
My panniers are also yellow and black so the woofers match nicely.
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Nice kit. I live near a bike path and see so many boom boxes just bungee corded to the handle bars. Your application is much more sophisticated. Hope it survives.
Heard "Back in the saddle again" during the summer from a passing "cyclist" and i could not stop laughing all the way home.
Heard "Back in the saddle again" during the summer from a passing "cyclist" and i could not stop laughing all the way home.
I have added some tape to reduce the wobbling. I think the plastic was going to fail pretty quickly without it. It’s much better with the tape but maybe still not good enough. The Focal drivers are quite heavy. Maybe better to have gone for cheaper and lighter ones.
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Sure, because smaller magnets will just give you extra bass.
I also know you don't want too much weight on the steering. I've put speakers on the handlebars. The benefit is to get them closer so you don't need as much speaker for the same output.
Instead maybe consider the way a motorcycle fairing is attached to the frame. In your case maybe putting the mass onto the headtube, and steadying it on the down/toptubes.
I also know you don't want too much weight on the steering. I've put speakers on the handlebars. The benefit is to get them closer so you don't need as much speaker for the same output.
Instead maybe consider the way a motorcycle fairing is attached to the frame. In your case maybe putting the mass onto the headtube, and steadying it on the down/toptubes.
Wow, like Stryper, the Yellow and Black Attack!
I remember my oldest brother bought a Viking bike over 50 years ago, only the saddle looks the similar to yours..
Moving the woofers up on the forks would reduce vibration considerably, and also increase their sound level at your ears. May still need a secondary mount, lots of flex and flop with just one, and the tape won't stop that bending moment.
Ride On!
Yeah, I wouldn’t recommend the Viking bike. I was living in China and had a bike there. When I came back to UK during lockdown there was a bit of a bike shortage and I ended up with the Viking. I had to take an angle grinder to the front fork to get clearance to fit the fat tires I wanted to put on it. It’s quite a heavy steel frame with no suspension. The ride is better with the 42mm tires and I actually like it best when it’s weighted down with shopping in the panniers. In China I had an aluminum MTB with front suspension which I put even fatter slicks on and I remember that being a nicer ride but the roads I was on there were also a lot smoother.
The forks get wider towards the top and the bottle mount brackets won’t fit any higher. They don’t fit well where they are anyway because the forks are teardrop in cross section and the brackets are round. I would like the woofers to be higher to get the distance closer to the tweeter distance. The car stereo I was considering originally has timing correction to fix this in software but the fosi audio amp obviously doesn’t.
I need to come up with a better mounting solution. Maybe built on a proper front fork pannier rack. As it is, there seems to be a slight risk of getting a woofer in the front wheel and going flying over the handlebars.
The tape actually works quite well as the forks are quite wide. It’s kind of borderline good enough but I’d prefer it to be something I didn’t need to worry about.
I was looking at jubilee clips and pannier racks earlier. Pannier racks deal with the bending by putting a loop over the top of the front wheel. I haven’t thought of a good way to do that without buying one.
There’s no need to increase the sound level at the ears. In fact, there’s already a risk of hearing damage if you slip with the volume control 😀 It’s necessary to set the control on the amp relatively low and then use the phone volume control for fine tuning.
It has a nice sound. Bass isn’t as good as the buckets of my home system but the midrange and treble sound natural and clear. I’m hoping for a dry day with a bit of sun to go test how it sounds when actually riding it. I’ll take the gorilla tape and cable ties with me when I go.
The forks get wider towards the top and the bottle mount brackets won’t fit any higher. They don’t fit well where they are anyway because the forks are teardrop in cross section and the brackets are round. I would like the woofers to be higher to get the distance closer to the tweeter distance. The car stereo I was considering originally has timing correction to fix this in software but the fosi audio amp obviously doesn’t.
I need to come up with a better mounting solution. Maybe built on a proper front fork pannier rack. As it is, there seems to be a slight risk of getting a woofer in the front wheel and going flying over the handlebars.
The tape actually works quite well as the forks are quite wide. It’s kind of borderline good enough but I’d prefer it to be something I didn’t need to worry about.
I was looking at jubilee clips and pannier racks earlier. Pannier racks deal with the bending by putting a loop over the top of the front wheel. I haven’t thought of a good way to do that without buying one.
There’s no need to increase the sound level at the ears. In fact, there’s already a risk of hearing damage if you slip with the volume control 😀 It’s necessary to set the control on the amp relatively low and then use the phone volume control for fine tuning.
It has a nice sound. Bass isn’t as good as the buckets of my home system but the midrange and treble sound natural and clear. I’m hoping for a dry day with a bit of sun to go test how it sounds when actually riding it. I’ll take the gorilla tape and cable ties with me when I go.
My forks don’t have any mounting points. I don’t think that rack will fit. I think I’d need one with jubilee clips. I don’t like my front fork though so another option would be to replace it with one that had mounting points.
There are adapters for everything. It is a big rack (fits a case of beer) and I was being funny, but a front rack would give you more mounting options.
First trip out
I put on a couple of extra loops of tape before setting out on the first test run today. It was a dry and sunny day so great weather for it.
Very pleased with how it went.
Sound is good. The sound stage seems to be basketball sized and centered around the headset. Volume was sufficient. I set it before leaving home then had to stop and turn it up quite a bit to hear properly over traffic but still nowhere near maximum volume.
The mounting isn’t perfect but it survived 50km with no apparent degradation so it’s good enough for the time being.
When the wing mirrors are set to see the road properly the tweeters appear as the continuation of the reflection of my arms so don’t really detract from the functionality of the mirrors. I didn’t quite manage to get the tweeters angled to point at my head; they are pointing a bit low.
Situational awareness is still good. I could hear the traffic approaching behind and still see it in the wing mirrors.
The added weight was noticeable when going uphill but I’m used to carting a couple of panniers of shopping and the panniers were almost empty on this trip so the weight wasn’t a problem. It’s supposed to be exercise anyway so there’s not much point making it as efficient as possible. Neither the weight nor the wires caused any problems with the steering.
There’s a screenshot of the before and after comparison. In the first ride I got cold hands and was bored so stopped early. In the second ride I had gloves and had the stereo playing podcasts so I went on a lot longer. The average speed was the same but that’s deceptive because I was quite a bit faster the second time (21+) until about 40km when I got cramp in one leg and then slowed more after 45km when I got cramp in the other one as well.
I used 1152mAh from my 6000mAh cell at an average voltage of 16.4V which is about 0.019 kWh and that works out as 7.3W average over the 2h36m journey. I had my iPhone plugged in to the usb socket which was on the whole time. The iPhone started and finished the journey fully charged.
The battery life ought to be about 12 hours.
It really helps to focus on the content of the podcasts rather than the distance remaining or the leg pain. This trip was really much more enjoyable than the last one.
Another benefit is that, compared to the last journey, when I had pedestrians stepping out in front of me without looking, the pedestrians now turn and look around when I’m about 10m away which is early enough for any evasive action to be very controlled.
There was not a lot of reaction from pedestrians. I had been a bit worried that it would cause offense but people seemed to be fairly unsurprised and accepting. I got a few smiles but that is normal on a bike.
It was also a lot easier to hear the navigation directions from the speakers compared to the previous journey when they were coming from the iPhone inside the top tube bag.
I’m not really very proficient at using the iPhone touchscreen with gloves on through the plastic top of the top tube bag whilst riding along. I’d like to try to get a volume control onto the handlebars and maybe some kind of speed sensing volume control app for the iPhone if they exist. A mute button might be useful too for those times when you are stopped at a level crossing with families on bikes and the podcast gives you a heads-up with a trigger warning.
I also want to wire in a charging socket so I can bundle it up neatly and leave it all installed permanently.
Another improvement might be some kind of splash guard for the woofers. It was a dry day but there were a couple of big puddles and I was worried the passing traffic would splash them.
For a little while, I was worried the whole project was a mistake, but it’s not. It’s really a great improvement to the bike (for exercise purposes at least).
I put on a couple of extra loops of tape before setting out on the first test run today. It was a dry and sunny day so great weather for it.
Very pleased with how it went.
Sound is good. The sound stage seems to be basketball sized and centered around the headset. Volume was sufficient. I set it before leaving home then had to stop and turn it up quite a bit to hear properly over traffic but still nowhere near maximum volume.
The mounting isn’t perfect but it survived 50km with no apparent degradation so it’s good enough for the time being.
When the wing mirrors are set to see the road properly the tweeters appear as the continuation of the reflection of my arms so don’t really detract from the functionality of the mirrors. I didn’t quite manage to get the tweeters angled to point at my head; they are pointing a bit low.
Situational awareness is still good. I could hear the traffic approaching behind and still see it in the wing mirrors.
The added weight was noticeable when going uphill but I’m used to carting a couple of panniers of shopping and the panniers were almost empty on this trip so the weight wasn’t a problem. It’s supposed to be exercise anyway so there’s not much point making it as efficient as possible. Neither the weight nor the wires caused any problems with the steering.
There’s a screenshot of the before and after comparison. In the first ride I got cold hands and was bored so stopped early. In the second ride I had gloves and had the stereo playing podcasts so I went on a lot longer. The average speed was the same but that’s deceptive because I was quite a bit faster the second time (21+) until about 40km when I got cramp in one leg and then slowed more after 45km when I got cramp in the other one as well.
I used 1152mAh from my 6000mAh cell at an average voltage of 16.4V which is about 0.019 kWh and that works out as 7.3W average over the 2h36m journey. I had my iPhone plugged in to the usb socket which was on the whole time. The iPhone started and finished the journey fully charged.
The battery life ought to be about 12 hours.
It really helps to focus on the content of the podcasts rather than the distance remaining or the leg pain. This trip was really much more enjoyable than the last one.
Another benefit is that, compared to the last journey, when I had pedestrians stepping out in front of me without looking, the pedestrians now turn and look around when I’m about 10m away which is early enough for any evasive action to be very controlled.
There was not a lot of reaction from pedestrians. I had been a bit worried that it would cause offense but people seemed to be fairly unsurprised and accepting. I got a few smiles but that is normal on a bike.
It was also a lot easier to hear the navigation directions from the speakers compared to the previous journey when they were coming from the iPhone inside the top tube bag.
I’m not really very proficient at using the iPhone touchscreen with gloves on through the plastic top of the top tube bag whilst riding along. I’d like to try to get a volume control onto the handlebars and maybe some kind of speed sensing volume control app for the iPhone if they exist. A mute button might be useful too for those times when you are stopped at a level crossing with families on bikes and the podcast gives you a heads-up with a trigger warning.
I also want to wire in a charging socket so I can bundle it up neatly and leave it all installed permanently.
Another improvement might be some kind of splash guard for the woofers. It was a dry day but there were a couple of big puddles and I was worried the passing traffic would splash them.
For a little while, I was worried the whole project was a mistake, but it’s not. It’s really a great improvement to the bike (for exercise purposes at least).
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Bluetooth media remotes exist so that will solve the volume control and mute buttons easily. Also I found an app which adjusts volume according to speed with a manual configuration option so I can configure it for the bike and not a car.
