My daily commuter (first proper build)

Hi guys,

After a long and tiresome search ive finally picked a bike to start my first proper commuter build, Its a Fluid Method mountain bike, 21 speed, 26" wheels, disk brakes and front suspension.

Dad picked it up for me yesterday, im getting it from his house tommorow.

The motor will be a Z Box 49cc HT that ive had for a few years now, but with RSE clutch, billet throttle and possibly dual brake lever, and an SBP shift kit

I am also getting a friend of mine to CNC machine a "200w powermax" logo into the clutch cover and put a build plate on the magneto cover similar to what the RSE 200w motors have, ive also printed off and laminated a dyno graph of 198.4w max power so hopefully these should fool most police into thinking it is under the 200w legal limit where i live.

High on the list of priorities when i get the bike are also front and rear lights, some kind of horn, and a nice comfy seat depending how it feels.

Thanks for looking, il get some pics of the actual bike and motor up tommorow if i have time

 

[trydrew]

Very cool! I like seeing go-getters gettin' stuff done.

What kind of things do you plan to haul if you don't mind me asking? The only thing that I'd be concerned about (you probably considered it already ) is the slight moment that that hitch will put on your rack. I'm sure you know that good axle placement will aid in taking extra static force off the bike.

 

[bobo333]

Thanks trydrew,

Im not 100% sure what il be carrying so i made it as big as the materials i have allowed, the width is the same as the ends of the handlebars (630mm) so i know anything i can fit the bike through the trailer will fit too and it is exactly 1m long, it will most likely be used to groceries but could be used on hardware store trips, recycling drop offs or whatever.

The mounts of the rack will need to be beefed up, im not really concerned about vertical weight as it has been fine carrying 10-15kg many times before but horizontal weight could be an issue with the trailer pulling it side to side around bends, i will swap the aluminium angle mounts for steel and triangulate them for extra rigidity

Today i finished the trailer off after collecting the wheels, axle and top yesterday, for the wheels i used some 200mm solid rubber tires with steel rims usually used on sack trolleys or small wheelbarrows, they are rated at 60kg each, the axle is 1/2" threaded rod:


Once i had the wheels i made up axle mounts out of steel angle and welded them onto the frame:


Then i bolted the wheels and axle in place and screwed some aluminium mesh from an old house door onto the top, this allows me to tie down things of any shape or size:



Last but not least i put some general sealant i had on the shelf on the axles to stop the nuts from coming loose:


overall is weighs about 11kg and you can barely tell it is there when its empty, after a couple of empty test runs i decided to load it up and see how it went:


With around 40L of fuel in jerry cans on board and barely tied down so the weight shifted around there was definitely noticeable load under pedal power, no bad handling effects though just much harder to get moving with so much weight on board, once i strengthened the rack mounts i will give it a run on motor power and see how she really goes

 

[bobo333]

Hi guys,

Not sure if anyone is still watching this thread but il keep updating it anyway...

Took the trailer out for its first full motored test run to the shops yesterday... it didnt go well, about half way though 3rd gear it got the speed wobbles something shocking and ended up bouncing side to side almost 90 degrees to the bike, lucky its so light otherwise it may have pulled me off the bike, it does go to show the strength of it though, nothing bent or broken after bouncing along the road at 25-30kmh for a hundred meters or so

But i also think the lightness was the problem, it seemed much more stable once i got a big pile of shopping onto it (i took it slow the rest of the journey though), the other part of the problem i think is still my rear carrier/hitch, i havnt gotten around to strengthening the mounts yet so it has some slight play from side to side

Carrier upgrades are next on the list, il keep you updated

 

[bobo333]

Hi guys,

Had a few troubles over the weekend... went for a long trip into the city and never made it

First the engine started dieing, seemed like it was running out of petrol but the tank was still half full so i thought it might be a blockage in the carby or fuel line, it was too dark to really do much but i took off the air filter and blew it out and took the fuel line off and drained it out to get rid of anything in there... was fine for another minute or so but then started spluttering and dieing again...

after restarting it every 30 seconds my RHS motor chain snapped so i gave up trying to fire the motor and continued on pedal power, i was still about 15km from the end of my 40km journey when the LHS crank fell off, i must not have loctited the bolt and it had come loose somewhere along the journey so i called it quits and got a mate to pick me up in his car

After getting home I used the bolts from my old crank, and fixed the RHS chain. I then pulled apart the carby to thoroughly clean it out but still couldnt find any evidence of a blockage, the next step was to pull the spark plug out where i found the middle electrode was no longer fixed and was just flopping around inside the plug, i have no idea how it ran at all :O

So now i need to get a new spark plug, might as well get a decent lead (and maybe a jag CDI) while im at it, what model is good for a relatively stock HT motor?

Thanks for looking

 

[bobo333]

Oh yeah while i had it apart i also modified the rear carrier slightly, the front 2 mounts werent strong enough so after time worked their way loose and let the tray sway side to side a bit, so i pulled them off and made a much bigger stronger triangular brace that mounts to the 2 threaded inserts in the frame just behind the seat post...

Before:


After:

 

[bobo333]

My daily commuter (custom trailer, lighting, shift kit etc.)

Hi guys,

The bike has been pretty reliable for the passed couple of months since my last update, of course due to the horrible winter weather i havnt been riding as much but apart from routine chain tensioning and refueling i havnt had to touch it

I did however modify the trailer and mounting system, the high mounted hitch on the back of the rear carrier allowed lots of trailer sway even at low speeds so i moved the hitch down to the axle with a piece of right angle steel:


I then cut the hitch arm of the trailer and remounted it to suit, its also now bolted instead of welded so it can be folded for storage if i need to:


i went on a shopping trip today and had to keep looking back because i couldnt tell if it was still there or not! even loaded up with groceries the only way i could tell it was there was from the sluggish acceleration caused by the extra weight, no handling abnormalities at all!

Today i also swapped the LED Torch i got to use as a headlight, it obviously wasnt built to take the vibration from the bike and after sending it back for a new one twice i gave up and swapped for these tiny LED spotlamps:


They put out unbelievable amounts of light for their size and being made for 4x4 use they can be wired into my existing 12v system so i dont have 2 different types of battery any more, they also conveniently fitted perfectly on the bracket i made to suit the torch:


Im yet to go for a ride with them, will probably go out tommorow and give them a thorough testing

Thanks for looking

 

[bobo333]

Hey guys,

its been pouring with rain the last couple of days so i havnt had the chance to give the new lights a good test, but i did do some rewiring

First i made a new switch panel and added 2 more switches, then i rewired the lights so that the taillights (and soon a white LED strip on the front) turn on via the middle switch, and the left switch is a 3 way that when pushed down turns on the low beam (one of the headlights is tilted down) and when pushed up turns on the high beam (both headlights):


This way when im around the brightly lit suburban streets i will only have the front and rear markers on to save battery, when i go onto the bike track i can turn the low beam on and when i go further off the beaten track and in dark twisty sections of the bike track i can turn the high beam on

I also relocated the lights under the handlebars, looks much better imo:


thanks for looking

 

[bobo333]

Hi guys,

Did my biggest shopping run ever the other day and the trailer passed the test with flying colours:


The new headlights are also going great and its much more convenient to control now that i have separate switches for everything, ive been going on rides for no reason more lately too because the weather is getting better

Loving it

 

[joshua97]

bobo she looks absolutely amazing mate!! i love the trailer too. i was thinking as u have the battery and wires etc up the front why not be safer and have the tank at the rear rack? i have done this and its much nicer, enjoy, josh

 

[bobo333]

Thanks Joshua97

If i have the tank on the rear rack then i wont be able to use it for small shopping trips or holding my tool kit which defeats the purpose of making it in the first place

The wiring is all soldered solidly and heat shrunk so there is no chance of shorts, the spark plug lead coming loose is a much more real danger, but i cant really move that!