DIY Bicycle Trail Light

I’ve recently dipped my toe into mountain bike racing.  I realized there aren’t any mountains in North Texas, but there are lots of trails.  It’s also hot as blazes out so the endurance races I’ve been doing go from 6-11 PM and a light is a requirement.  Riding a trail at night requires a fairly bright light.  The first race I tried to use a hiking head lamp and I thought I was going to crash about a thousand times.  Most decent bike lights start at 100-200 lumens and around $100.  They go up to 1000 lumens and cost a couple hundred.  There are $30 bike lights available but those are in the 20-50 lumen range and they glow more than they shine.

At this point $100 is too much of an investment for me so I thought it’d be more fun to build my own bike light.  The LED technology in the flashlights advances really fast so the best lumen for your buck comes from general use flashlights instead of biking specific ones.  Costco had 220 lumen flashlights in a 3 pack for $15.  The only downside is that their 3 AAA batteries only last 1 hour.  I wired in 3 D batteries in an external battery holder and I should have 10 times the capacity (12000 mAh vs 1200 mAh source).

Here is my step by step instructions.  Total cost at the bottom:

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Used drill press to drill hole in side. You can see the battery holder inside, but that wasn’t in there for the drilling.
Battery holder removed
Power chord soldered into the battery holder
Flash light reassembled
Battery holder on other end of power chord
Drilled a hole in an old water bottle and routed the power chord through there before attaching to battery holder
Assembled and working on external power




$5 Flashlight ($15 / 3pack at Costco)
$1 Power Chord (18/2 wire at Home Depot $.42/foot)
$3 Battery Holder ($2.03 + shipping from McMaster-Carr)
$13 Flashlight handle bar mount(not pictured, Amazon)
$3 D Batteries (Not sure on price, these came from my battery drawer, not sure what I paid for them)
$0 water bottle (free from doing a triathlon)

$25 total

I also bought a $5 handle bar mount but it doesn’t hold the light still through the bumps on the trail so the $13 is necessary.  I made a second one of these and put the batteries in my Camelbak and velcro+zip tied it to my helmet and it worked awesome as well ($12 total since no fancy flashlight mount required).

At the last race there were certainly brighter lights out on the trail, but there were also worse lights.  It was a totally workable solution and I feel like I saved at least $100 over buying two cycling specific lights.

Not all of my ideas are winners

I have this set of Russian Kettle bells I love to work out with.  I also gave one to my mom for Christmas.  When you are buying them there are the regular ones and the fancy rubber-dipped ones.  The heavy ones only come in the regular type because I guess people buying big heavy blobs of iron just want the cheapest one.

The pink one is not mine. Promise.

I store these in the laundry room with tile floor. I always worry that I’m going to set the 40 pounder down too hard and do some damage.  I’ve been looking to do a similar dip job that the others came with, but I can’t find anyone that sells a “bucket of rubber” – it’s possible I don’t know what I’m looking for.

Good Kettle Bell covering?

I came across this product Plasti Dip and they show a wrench with a rubber grip so I thought I found a solution.  I couldn’t find the canned version at Home Depot or Lowes, and it appears to only come in small 7 and 14 ounce cans and I reckon I’d need about a gallon to dip the kettle bell. They did have the spray on version which I guessed was equivalent.  I masked off the kettle bell with some duct tape and grocery bags and sprayed on 6 layers over the course of a few days.  Here it is in progress:


Classy masking job done with duct tape.

My results suggest that this is not the ideal application for Plasti Dip.  It doesn’t  take to masking since the layers form a plastic film.  I can’t blame them for that, it’s exactly what the product promises.

Masking removed, 6 layers of dip sprayed on. Notice wrinkled edges from attempted mask job.

It also did not adhere to the smooth enamel paint on the kettle bell.  I’m sure the rubber on the smaller bells only stays on because it goes all the way around the body, but it would have taken a couple of cans of plasti dip to cover this up but there was another reason it wasn’t suitable for me.

Plasti Dip peeled right off the polished kettle bell.

It’s also not called “Rubber Dip” for a very important reason.  The resulting surface was almost as hard as the metal it was covering.  It’s not as rubbery as I expected, maybe the canned version is different.  I’m not reviewing Plasti Dip here, it’s good for a lot of stuff, but it’s not the rubber coat I needed for the kettle bell.

Does any one know where I can get a giant quantity of rubber? What type of rubber I need?  Would be interested to hear it in the comments.


Steven Gangstead


be prepared to run away

Recently I posted about how to plan a long run for your marathon training.  With some planning you will have an awesome run that you will anticipate instead of discourage you.  Now that you’ve decided to go out and run all morning the next hurdle is the logistics of how to prepare and what to carry.  20 miles brings a lot of challenges that don’t exist at 5 miles and here’s what I do to make it.

I don't know what happened. The runner just ... disappeared.

The Soft Stuff


I realized pretty early on in my running that you need to wear a polyester aka “Tech” shirt when running.  With a regular cotton shirt you come back carrying every drop of sweat from the run in a hot mess around your chest.  Very uncomfortable.


I like the kind with lining and pockets.  The lining isn’t necessary if you are going to wear Under Armour, but for short runs I just wear the shorts so I have ones with lining.  I’ve never tried those short-shorts with the super high cut on the sides that you see serious running dudes wear.  I just can’t bring myself to do it.


I’ve got a pair of under armor  and a couple of Nike Sport.  Any brand will do.  Not necessary for all people, but if you have thighs that are … generous … you’ll like the reduced friction of these.  I don’t bother with these for runs up to 5-8 miles.  You can try to just apply a shit-ton of Body Glide to your butt (almost literally) but it can be too much and the stuff wears away anyways.


Here is one place that I brand name-drop because I think it makes a difference.  You gotta go with Thorlos. They are smartly made with thin fabric on top, thick cushion fabric on toe and heal.  It took a while for me to decide to shell out for a $12 sock, but I’m glad I made the switch. I was having a lot of problems with blisters when I used my “athletic” socks that came in the hundred-pack from Costco.  I’d get little linear blisters along my big toes.  No problems since using the Thorlos.  I’ve tried other non-cotton running socks, like Feetures but they didn’t work nearly as well.  The Thorlos are kind of expensive, but I only have 3 pairs and rotate through them – they’ve been holding up well for more than a year of >300 sweaty miles.


There’s a lot of hype about shoes.  I used to run with cheap $40 shoes from Sports Authority.  They were fine, but as I ran more frequently I noticed general foot pains.  I usually take my worn out shoe to the running store and let the shoe guru do their incantations and bring out a new shoe.  Make sure to run around in it a little bit and if it’s the slightest bit uncomfortable at 20 feet you will be cursing the shoe gods after 10 miles and planning arson after 20  I’ve been on a different brand almost every time, but if you like a shoe get it again if it’s still available.  Then you can compare old to new.  There’s a noticeable step up in quality from cheapo shoes to the $80-100 shoes.  My guess is that anything past that is hype.  Don’t listen to 90% of what the shoe guy says and don’t try to marathon in your vibrams.  Your Achilles tendon thanks you in advance.

Not pictured: the duffle bag I run with to hold all this junk.

Load up the pockets


My latest strategy is 1 gel per 4 miles, so 6 for a marathon.  I used to do it by time: every 45 minutes or every 30 minutes but sometimes I royally screw up my pace and if I’m out for an hour longer than I planned I’m out of energy at the end, but I don’t run farther than I planned.  The dosage and the brand have taken a lot of experimentation.  Expect it to take a lot of trial and error for yourself.  I used to love-love-love Stingers and thought it tasted the best.  Now I’ve decided it’s too viscous late in the run when I get dehyrdated and I’m also blinded by the marketing about protein so I bought a case of Accel Gel which I’m digging.  I normally go caffeine free until the last gel.

Sweat Proof Bag

Maybe you don’t sweat.  But I learned the hard way that salt water doesn’t do your mp3 player any favors in your pocket so now I keep my phone, drivers license and a bill ($20/10/5) in a ziploc in my pocket.  If I’m running to a bar I throw a credit card in there.  I only carry the phone if I’m going a long way, like > 10 miles and there’s possibility I’ll get lost or quit and call in a pickup.  It’s a lot of extra weight.  I don’t carry it during a race because there’s race support the entire time.  Also helps to put a paper towel in there if you have a forehead like mine that channels sweat directly onto sun glass lenses.

A big Garmin watch is the new calculator watch

The Garmin 4runner was the best gift I never knew I needed.  The GPS completely changed running for me.  As an engineer I always want data and this gives it to you.  If you are getting one the heart rate monitor is a must as well.  The feed back between the two is great during the run and for analyzing it afterwards.  This is the only real piece of gear I use for biking or running.  Everything else is low tech.  It really deserves its own post.

Asthma medicine (not optional for me)

I don’t want my biennial asthma attack to strike me down on the side of the road.  People would totally think I’m a wuss.  If I’m running a distance that I could hobble back to my house I won’t carry it, but greater than 10 miles and it’s in my pocket.


Nothing's cooler than Body Glide, look he's wearing sunglasses indoors.

I have dainty eyes so I always have to have them if it’s at all bright out.  I get a lot of sweat on them so I sometimes throw a paper towel in the plastic bag to clean them off since after 2 hours there is no dry fabric on my body.

Body Glide

I apply this before hand, I don’t run with this.  This is less optional.  The option is how you want to chafe proof yourself.  The more you sweat the sooner you’ll need it, but by marathon distance everyone needs a lot.  The longer the run the more places you have to put this stuff.  In ascending order of length of run here’s how I apply Body Glide:

0 miles -> Nothing -> 8 miles -> just under armour -> 10 miles -> crotch (upper-upper thighs) -> 13 miles -> crack, nipples -> 15miles ->under arms at sleeve opening-> 20 miles plus -> EVERY WHERE

These are cumulative so at 14 miles I have under armour, body glide on my nether region and nips.  Recently I’ve been doing bandaids on the nipples for 20 miles and beyond and that works better.  The body glide wears away after a few hours and if it’s cold out go straight to band aids.

Don’t know where to put it?  Skip it for a long run and you will know exactly where.  You aren’t going to get scars, it’s just uncomfortable for a day.

5 Hour Energy

Super optional.  I took one of these in the last marathon and felt nothing because I was completely out of gas, but in my 23 and 21 mile runs leading up to it I chugged one of those things with 3-4 miles left and I felt like battery acid was pumping through my veins and I mean that in the greatest way.  It’s like squeezing a balloon.  Air comes out faster, but not if it’s empty.  Take it too early and you might crash.  I have a weird relationship with caffeine because I don’t drink sodas normally and only use it extra long training runs or bike rides so it gives me the jitters.

Triathlon Bib holder thing
Can alternately use this to hold a couple bells so other runners can hear you and get out of your way (like a cat)

Super mega optional for race day.  I don’t like pinning the bib to my shirt.  It’s not that my shirts are that precious.  When you pin the bib to the shirt that rectangle of shirt can’t stretch like the rest and I always seem to get it a little uneven and the slight tug bugs me over the course of the marathon.  With one of these belts it’s nice that you can move your bib up higher or twist it or adjust it any way you want while running.  If you already have one for a triathlon then it’s nice to get one more use out of it, but probably not worth buying just for one marathon.


Isn’t that a lot of junk to be carrying?

Kind of,  the load of gels gets lighter along the way.  The under armor shorts help out a lot in this regard.  They allow the bulky phone to slide along your thigh with less friction and keep pokey edges of gel wrappers from poking as much.  I’ve never had a problem with the stuff swinging around violently once you get to a steady pace.  Plus, I only carry all this stuff for the longest of runs.  The morning 5-miler is “The 4 Sh’s”: shirt, shorts, shoes and shocks. Plus Garmin.

What about one of those running belts?

NERD!  Don’t kid yourself.  It’s a fanny pack.  I’d like to be one of those guys who doesn’t care about what they look like and doesn’t judge people.  I almost am, except when it comes to running fanny packs.  I can’t bring myself to try one, because I’m sure I’d end up liking it.  They seem like they are mostly for carrying water (or recovery drink) and as I said before, a $5 bill weighs less than 5 bottles of water, so run with the bill.  One thing that I think would be nice on race day is the belt that has little loops to hold your gels, but it still looks kind of dorky.


I hope this list isn’t so long as to intimidate someone from going out to run right now.  These are all things you figure out you need along the way. Happy Trails.

-Steven Gangstead