Build log - 2nd Build, WIP Target Magna Rip Curl

As an incoming college freshman without a car (and having sold my previous build), I found that everything I needed to commute to was in around a 4 mile radius. I guess I could pedal the distance and get a $500 road bike off craigslist, but the area is hilly and I have plenty of spare time so why not build another bike?

I'm still about as experienced and well-equipped as you would expect an 18-year old with no prior mechanical experience to be, but I'm determined to make this build right the first time by reading the forums and such.

So here's a build log I'll be updating for the next week or two as I receive more parts in the mail:


Day 1 - Sept 12, 2012

I bought a Magna Rip Curl and some parts off eBay about a week back and it's finally starting to come together. The motor kit, at first glance, seems fine cosmetically but it seems I can't mount it without a Sick Bike Parts front mount (that I ordered yesterday) because the U-bolt mount that came with the motor had the holes drilled in the wrong places.

Here's the parts list so far:
BGF Z80 motor kit - $150
Schwinn Springer fork - $50
Generic turn signals - $5
Chain breaker - $10
Experimental chain tensioner - $15 (to my knowledge noone has used it)
NGK B5HS spark plug - $3
A length of 41 roller chain - $20
Bike - $110

Oh well, there's still plenty to work on, so I installed the throttle and clutch lever (relatively simple, they seem to have gotten rid of the metal nub on the throttle that used to make it a bit harder to install) and set on attempting to disassemble the hubs for cleaning.




For being Chinese build quality, the amount of grease in the hubs was an acceptable amount, contrary to many complaints on the forums - there was plenty of fresh-smelling grease smeared everywhere on every surface and I could have probably ridden a hundred or two miles without the grease acting up. Hub disassembly was simple too - it pretty much just unscrewed using two wrenches, no specialty tools.

So now that the hubs are clean, I ordered some more things:
Pyramid MX1000 BMX side-pull brakes (for the front or rear, with 96mm reach) - $20
Some generic bullet light that looked cool - $30

Time to buy some high-temp grease and pack the hubs for the next step, then. I'm not sure the MX1000 brakes will work on the front, with the springer front end and all - but they were the longest reach brakes that I could find and if they don't fit on the front they'll probably fit on the rear.

More updates to come as parts come in. Comments and criticism always appreciated.

Bought some grease, some two-stroke oil and some gas can from a shop 4 miles away. Gas cans are not very ergonomic for long walks. Cost $30 or so including gas.

Anyway, some progress now that I've got the grease.



I bought this kind of bearing grease. It's red. It cost around $8 at the hardware store. It smells like the bottom of the latrines in the fourth layer of the underworld - truly nasty stuff. Ew.

The process seems pretty simple. Stuff bearing with grease using fingers. Stuff bearings in. Wipe fingers. Repeat for rear wheel, except the coaster brake requires you to put the brake-thing in and screw on the sprocket. The brake-thing only fits in one way so you don't really have to worry about which way the wheel goes. Wash hands.





Front wheel done.



And... done.

The front wheel spins FOREVER if spun by hand, but also has a very very minute amount of play. The rear has some drag, but I'm sure that's just the chain and pedals dragging on the wheel. Hopefully. I didn't buy a cone wrench so I just tightened the wheel hub using pliers and the smallest wrench I could find. Both hubs seem to be dead quiet.

More to come once I get my SBP front mount! The size I bought was the 1 and 1/2"-1 and 5/8" model, I think, with the 1.9 inch stud width for my specific engine.

...This bike is longer than I expected, and becomes even longer with the springer fork. My mountain bike was like, 2/3 of this bike's length. Also, grease is messy, and I didn't even use like 1/10 of the tin, you really don't need much even if you're like me and stuff the hubs with grease.

So it turns out that the Universal mount by Sick Bike parts comes with a hole for a 6mm bolt instead of an 8mm one for the front mount. Ah, bugger, I'll have to drill it out with a 5/16" bit - which is a bit tricky considering that the holes are slightly off center. I mean, come on!



Anyway, a light. Nifty. Had to grind down the tab a bit so it fit on the springer - probably going to JB it on or something later so it stays on.

Sept. 16, 2012 (By the way, velodrome, I just moved to Kalamazoo to go to WMU)

With some struggling with the drill holes and a 5/16 drill (the holes are now oblong), I managed to drill out the SBP front mount and mount the engine / carb / etc.



Everything fits, somewhat! Had to flip the head around and switch out the bolts so I could mount the CDI and such, but oh well.

Rode it around a bit and here's how the bike is so far:

1. It has insanely low ground clearance. I mean, seriously, I rode off a low curb and the exhaust hit the ground with an unhealthy crunch that made me wince.

2. The extra length of the springer fork... makes it handle like crap, quite honestly. It's like pushing a shopping cart around and I can't even take my hands off the handlebars because it steers on its own. At least it makes the ride pretty smooth, which is nice.

3. Apparently I need to grind the dust cap on the rear hub down to install the rear sprocket. ...Oh, well, at least I have plenty of extra bearing grease.

4. The brakes suck. Need to install front brakes. Will require front fork to be taken off, due to the fact that the brakes need to be offset forward and the only way to do that is a big spacer and a recessed nut that you drill a hole for.

Otherwise, just duck taped the fuel tank and CDI on for now. Will think of a more permanent solution later due to the fact that they seem to have mounting bolts that are a bit too small to use the stock mounts.

First test-ride to come once I get the dust cover ground, but for now it seems I'll be tearing it down again and rebuilding to fit everything!

atombikes said:

Give us a pic looking at the bike from the side (with the bike upright and steering straight ahead); I'm wondering if the trail value was affected by the springer fork.

Click to expand...

Aye, you can pretty much compare the current status of my build to Dave's.



Anyway, got the bike running. A few comments:

1. The fuel cap is broken. Have to kind of unscrew for it to let air in. Will fix fuel tank mounting later when I get access to a machine shop and scrap metal friday.

2. Clutch lever lock broke with an M1 Garand style Ping! while I was test riding it. uh, alright... I'll just get a new one, then.

3. The bike runs like crazy.

4. The bike runs like crazy oh god why is my coaster brake locking up when I brake hard


Looks like I'll be taking a short trip to the hardware store so I can mount my front brake, then getting a rear brake and removing the coaster. Apparently, it likes to randomly lock up and turn into a fixed gear under hard braking for some reason, which scared the bejeesus out of me.