Seatpost rear light project?

2tired2ride

Ok.... for college in Graphics (D.T) I'm thinking about designing a seatpost with an intergrated rear light for my project, this means people can't steal your rear light if they are quick release. It also makes for a tiedier, cleaner looking bike. Also it would be good if you forget your rear light or went for a ride and it got dark.

What do you think?

Has it been done before?

I made a really really quick picture just to give an idea of my thought, I make a much better one if people think it's a good idea.



Incase you can't tell from the picture it would have 3 or 4 LED's with a battery in the seatpost and maybe a switch under the saddle so you don't have to reach around the back of the bike to turn it on.

Just a thought?

It would be good if you could help, thanks.

Any imput would be great.

redvee

I'm sure it has been considered before but the variation in seatpost diameters might have been the major reason for this idea not taking off. Thinking about it the seatpost will need to be a large diameter to accomodate the battery pack, AAs?, and wiring inside the post. A press switch and LEDS can be mounted in dilled holes at the top of the post front & rear.

2tired2ride

Thanks for the feedback Redvee

If I do this this idea I may just say about shims?

I liked the idea of not having to try to feel around behind me to turn on my rear light when riding my bike.

Another very quick picture to show the switch.



Thanks

redvee

When I was in the trade many moons ago we sold a suspension post that came in 2 sizes, 25.4 & 27.2mm, and then was shimmed up to suit. Looking at the pic it looks like the switch is loose with a wire connecting it to the circuit, think it might be better if it was fixed to the post.

downfader

Another idea might be to have a more secure lighting set up where it is bolted in place and needs a key to switch it on - keeping the key with your lock keys would obviously be the idea. Then that way you could have the optics rather than just a few leds that scatter light

Just an option

landrew

It has already been done

http://www.edinburghbicycle.com/ebwPNLqrymode.a4p?f%5FProductID=9810&f%5FSupersetQRY=C417&f%5FSortOrderID=1&f%5Fbct=c012372c012369

redvee

Rode a hybrid with that post fitted a few weeks after C+ did a test on it, in fact it was the test bike but for the life of me I can't remember the make.

ansbaradigeidfran

redvee wrote:

I'm sure it has been considered before but the variation in seatpost diameters might have been the major reason for this idea not taking off. Thinking about it the seatpost will need to be a large diameter to accomodate the battery pack, AAs?, and wiring inside the post. A press switch and LEDS can be mounted in dilled holes at the top of the post front & rear.

My seat post (1", or 25.4mm) has plenty of room for an AA battery to fit in and rattle about. Most cheap rear flashers run on AAAs, so that's anecdotal evidence that they're up to the job, if you're got a realy skinny post.

My first rear light's holder snapped some weeks back, and I bought a cheap replacement. I salvaged half of the original light's holder, and it's now mounted to the underside of my saddle using some bits of stripped earthing wire. I'll get a photo of it tomorrow and post it: it may be of use to you as an example for your project.

2tired2ride

Thanks all.

The project is that I have to "improve" a product so having a button to turn the light on placed in a way so you don't have to struggle was a way to improve it. I will think of places to mount the on/off switch.

Thanks.

JGS

Why not take the opportunity to have a larger array of lights on the post not only vertically, but maybe on the sides to increase side visibility? LEDs don't really weigh much, so it's not like it'd be any heavier than having a normal light strapped on.

ansbaradigeidfran

2tired2ride wrote:

Thanks all.

The project is that I have to "improve" a product so having a button to turn the light on placed in a way so you don't have to struggle was a way to improve it. I will think of places to mount the on/off switch.

Thanks.

Could I also recommend that you consider using a longer line of LEDs going some distance down the seatpost? I've got a small saddlebag under my saddle, which would obscure your 3 LED design. Too long a line would result in LEDs being obscured in the seatpost clamp (or stopping the seatpost going far enough down, unless they're flush). I'm sure you could think of/design a compromise.

redvee

downfader wrote:

Another idea might be to have a more secure lighting set up where it is bolted in place and needs a key to switch it on - keeping the key with your lock keys would obviously be the idea. Then that way you could have the optics rather than just a few leds that scatter light

Just an option

Duracell original MK1 lights were lockable and bulky as hell, ran on D cells. The key acted as the switch. Pretty sure others have tried similar too.

Nick6891

i thought about this before, but i figured it would be too hard to do, too fiddly with batteries etc

Wrath Rob

JGS wrote:

Why not take the opportunity to have a larger array of lights on the post not only vertically, but maybe on the sides to increase side visibility? LEDs don't really weigh much, so it's not like it'd be any heavier than having a normal light strapped on.

Erm, because those big flappy things flailing up and down either side of the seat post, propelling you along might get in the way of the lights?

2tired2ride

Thanks again this is realy helpful.

I like the idea of side visability and longer line of LED's, I'll work out how long the LEDs need to go down the post and maybe do a proper drawing like in 3D if I have time later.

ermmm... and about having a saddle bag on, the LEDs will need to be too low so it probally won't work so well but I'll think about it.

And the LEDs will most likely be flush.

Thanks

singlespeedexplosif

if you don't mind me saying so, it really does seem like trying to find a solution to a problem which doesn't exist...:)

beverick

It's OK for a mountain bike but there's only about 1 1/2" of post showing on my road bike - just enough to fasten a rear lamp and toolbag onto it in fact. If I raised the seat to give sufficient space to see the LEDs and fit a battery in the post I wouldn't be able to reach the floor.

Other failings I see is that when the unit fails (which given the number of lights I've had to buy over the years I'm sure it would after a couple of winters) you'd end up buying a standard unit anyway. Either that or you'd have to buy a complete new post.

The light from single LEDs tends to be very directional ie you have to be looking straight at the diode to get the brightest light - this is certainly true if the LEDs are inlaid into the post. Now, given that seatposts are fitted at different angles (albeit by a few degrees), only a percentage of your customers would be able to fit the post to get maximum benefit.

Fitting a battery housing and switch into a seatpost is going to weaken it so you'd have to design in safeguards against the constant flexing of the post. Get it wrong and either the lighting components or the post would break. Even getting the design right would mean that you'd probably end up with a post weighing more than the bike.

How much is it going to cost? A quick look at Wiggle suggests that posts fall into one of three price points. Up to £20, £45-£60 and £100+. Adding LEDs would put the sub-£20 post closer to the mid-range (and the cost of the assembly would have to be inexpensive to maintain margins so quality would inevitably have to be compromised). Adding them to the mid-range units (I'd argue where the product is most likely to appeal) would put the retail price out of the expected price-point (so the unit becomes expensive) and I'd argue hat someone paying £100+ for a post wouldn't want it compromised by LEDs.

Finally, in my opinion, lights are seen almost as consumable items. You see a 'better' or 'brighter' one than you had last winter and buy that. You're out of that market with this product.

Bob

JGS

Wrath Rob wrote:

Erm, because those big flappy things flailing up and down either side of the seat post, propelling you along might get in the way of the lights?

I don't know what style of riding you use, but I don't think my thighs would obscure my seat post 100% of the time. Therefore it would be a nice easy way of increasing side on visibility without adding a lot of weight.

simon_ramsey

I like the idea that these are backup lights for the times you go out and head back later than expected and haven't got your normal lights with you. Having a front LED or LED's built either into the stem or handlebars would be quite cool. Although you are only doing this for a project for it to be commercially successful it would have to be produced as cheaply as possible and aimed at the cheaper Halfords end of the market. I can't really see people with £1000+ bikes buying them. Kids would love them if the LEDS could be made to flash in different patterns and were bright enough for daytime use.

Feltup

There is a bike downstairs in the office which has a sprung seat post in place of suspension. How about using the energy from the sprung seat post to power a small dynamo which then powers the LED's? Not sure if enough power would be generated from the bobbing up and down but just a thought! Also you would not need an on/off switch because as soon as you sat down it would power it up. Lights on all the time for extra safety.

ansbaradigeidfran

Feltup wrote:

There is a bike downstairs in the office which has a sprung seat post in place of suspension. How about using the energy from the sprung seat post to power a small dynamo which then powers the LED's? Not sure if enough power would be generated from the bobbing up and down but just a thought! Also you would not need an on/off switch because as soon as you sat down it would power it up. Lights on all the time for extra safety.

I think you'd want to look up piezo-electronics if you were to follow this bouncing dynamo idea up.

2tired2ride

simon_ramsey wrote:

Although you are only doing this for a project for it to be commercially successful it would have to be produced as cheaply as possible and aimed at the cheaper Halfords end of the market. I can't really see people with £1000+ bikes buying them. Kids would love them if the LEDS could be made to flash in different patterns and were bright enough for daytime use.

I like the kids bike idea, sounds fun, but I want to something that would actual be good in the bike industory.

Has anyone got any other ideas I could do for a project? I have to improve a product? And/or combinen two product to make it better.

There is so many good products that ready exsit!

I started to 3D model the basic seatpost without lights.



Thanks.

2tired2ride

The two basic ideas so far, individual LEDs and a red strip.

LEDs



Strip

attica

I'd suggest putting the switch in another recess/hole in the seatpost.
Also, I'm assuming that battery changes would be carried out by removing the seatpost - batteries mounted at the bottom? If so you might like to include a cheap seatpost memory clamp. (just a plastic loop clamped to the seatpost so you can reset to the same height quickly)

Hope this helps

2tired2ride

Thanks Attica.

I like idea of the memory clamp.

And yes I was goind to have the batteries mounted at the bottom.

When you said having the on/off button in a hole, did you mean round the front or back? Just I'd like to be able to turn the light on whilst riding safely.

thanks

Wrath Rob

JGS wrote:

Wrath Rob wrote:

Erm, because those big flappy things flailing up and down either side of the seat post, propelling you along might get in the way of the lights?

I don't know what style of riding you use, but I don't think my thighs would obscure my seat post 100% of the time. Therefore it would be a nice easy way of increasing side on visibility without adding a lot of weight.

True, but I don't want anything obscuring my lights at any time. Also if you coast at any point (yeah, yeah, I knwo, we should be max attack all of the time ) you may obscure the side light on one side while you're doing that. If you need side lights then I'd suggest having them somewhere more proper.

Belv

I like the line of individual LED's. My concern with the idea would be how much the strength of the post is compromised. Definitely needs the memory clamp thing for me. I think a switch could just clip onto the front of the saddle rails fed by wires coming out of the top of the post. Will waterproofing be a problem?

2tired2ride

Thanks.

It just an idea at this stage I haven't started prototyping yet, I'll have a look if my leg get in the way of side visiblity at any time.

Thanks.

2tired2ride

Does anyone use an I-Beam system? I may make my design I-Beam so it will be lighter and stronger and mainly because it will be simpler to make.

I know it will limit me to only a few saddles that will be compatible.