Author Topic: I swear, it's not for me, its for the old lady (Read 6547 times)

eyebrows · « **on:** September 20, 2010, 07:36:22 PM »

So I picked up another mini bike off craigslist a week ago with the intent to fix it up for the old lady to ride. Previous owner didn't take care of it and I gave up on the engine after a couple days of tinkering, went down to harbor freight and picked up a gx200 clone to replace it.

Holy cow batman! This little beast flies now! No way I'm gonna keep up with her on my mini, my sprockets are set up for hill climbing and her's are stock(I also have a gx200 clone).

3 months ago I didn't have any mini's or desire to own one. Then I rode a souped up one... now about $450 and 40+ hrs of work later I realize I fell into the hobby trap again. This is gonna be as bad as firearms... hey! is that a dirt bike for sale over there??!?

mtnbkr · « **Reply #1 on:** September 20, 2010, 07:46:18 PM »

That sounds like a lot of fun. It will take all I can muster to resist... :D

Chris

Tallpine · « **Reply #2 on:** September 20, 2010, 07:56:46 PM »

So you two are the ones running up and down the road and making all then noise

zahc · « **Reply #3 on:** September 20, 2010, 09:12:44 PM »

Some guy at church has a homemade road-legal 3-wheeler with some kind of air-cooled, pancake 4-cylinder engine. VW bug engine maybe? It looked pretty cool anyway.

charby · « **Reply #4 on:** September 20, 2010, 11:40:04 PM »

I have one with a 5 hp briggs on it. This winter it is going to get coat of John Deere Green, 4hp head and new clutch for the 2 speed jack shaft. Should be able to break 30mph with it.

eyebrows · « **Reply #5 on:** September 21, 2010, 06:07:45 AM »

What do you mean by "2 speed jackshaft"? That sounds delightfully interesting.
I've clocked mine at 30 on the street and "faster than you wanna go" on the trails. Hers is going noticable faster on the street.

eyebrows · « **Reply #6 on:** September 21, 2010, 06:16:46 AM »

Tallpine: Just wait until I mod it witha high flow exhaust/intake. You'll hear me comin for sure :)

eyebrows · « **Reply #7 on:** October 02, 2010, 09:53:13 AM »

Well her bike is zeroed in, I adjusted her gov so it kicks in early and limits her top speed. Safer that way until she gets more confident. She dumped it in the woods the other day and know what she did then? Got right back on and took off. I sure love that girl.

Now my problem is I have the 6.5 hp motor that came with her bike and its running now (replaced emulsion tube and jet). I noticed 2 different gocart frames on craigslist for $70 each... must resist. must resist. Just cause I have a running motor with nothing to put it in doesn't mean I need something to put it in.. right?

HeroHog · « **Reply #8 on:** October 02, 2010, 07:02:35 PM »

GO FOR IT! I had literally a hundred mini bikes, mini cycles and motorcycles that I road and raced since I was 9. My dad would NEVER allow me a go-kart and I later fond out that he used to race them using McCullough chainsaw motors at some radical speeds and had a close friend decapitated on one and that ended that. A guy I know made one using a Bultaco Open Class Moto-X engine that was a terror!

bedlamite · « **Reply #9 on:** October 03, 2010, 05:13:00 PM »

Just an FYI: If you end up using an old Kawasaki 650 twin for a motor on a go cart, then don't use turf saver lawn tractor tires. They grow as you go faster, and will come apart somewhere around 60mph.

charby · « **Reply #10 on:** October 03, 2010, 06:41:17 PM »

Quote from: eyebrows on September 21, 2010, 06:07:45 AM

What do you mean by "2 speed jackshaft"? That sounds delightfully interesting.
I've clocked mine at 30 on the street and "faster than you wanna go" on the trails. Hers is going noticable faster on the street.

how it works.

The larger sprocket (let's say it's 20 teeth) on the jackshaft is 1st gear (gear ratio drive 12: driven 20; or 1: 1 2/3). This sprocket is the one being driven until the clutch on the jackshaft engages at so-and-so rpm, and the now small clutch sprocket (let's say it's 12 teeth as well) is the driven sprocket. Now the gear ratio between the jackshaft and engine is 1:1 instead of 1: 1 2/3.

eyebrows · « **Reply #11 on:** October 03, 2010, 11:30:14 PM »

Quote from: charby on October 03, 2010, 06:41:17 PM

how it works.

The larger sprocket (let's say it's 20 teeth) on the jackshaft is 1st gear (gear ratio drive 12: driven 20; or 1: 1 2/3). This sprocket is the one being driven until the clutch on the jackshaft engages at so-and-so rpm, and the now small clutch sprocket (let's say it's 12 teeth as well) is the driven sprocket. Now the gear ratio between the jackshaft and engine is 1:1 instead of 1: 1 2/3.

Hm I'd have to see it I guess. In my head I don't see how that would work.
I have found out about torque converters, specifically the TAV2 comet clones which will bolt right to my motor with only minor modification.
That has a spring loaded driven pully that spreads as the RPM increases thus allowing the belt (belt to jackshaft, chain to rear) to slip down and change the ratio on the fly.
Problem is those puppies cost about $150. Thats $50 more than I paid for the second bike and $50 dollars less than the first. I have beeen watching craigslist hoping to find a junk roller with one installed. Word on the 'net is it still has the low end torque and big gains in top speed.

HeroHog · « **Reply #12 on:** October 04, 2010, 01:42:31 AM »

They do and they are tunable too! Change the springs and weights (in some models) and you can make them perform to match your motor. I used to race Husky Enduro bikes and had an Automatic. REAL cool setup! It was a series of 4 sequential centrifugal clutches, each with a different gear ratio then the previous. They were on one-way sprags so that the cross shaft simply passed passively through the next clutch until the clutch spun fast enough to engage making it spin faster than the shaft and the sprags then locked them together. In the previous clutch(es) the shaft was now spinning FASTER than their clutches so they freewheeled. Made for a VERY tunable and smooth setup that was ALWAYS in the right gear with no input from the rider! Think of your torque converter on steroids!

charby · « **Reply #13 on:** October 04, 2010, 08:32:16 AM »

Quote from: eyebrows on October 03, 2010, 11:30:14 PM

Hm I'd have to see it I guess. In my head I don't see how that would work.
I have found out about torque converters, specifically the TAV2 comet clones which will bolt right to my motor with only minor modification.
That has a spring loaded driven pully that spreads as the RPM increases thus allowing the belt (belt to jackshaft, chain to rear) to slip down and change the ratio on the fly.
Problem is those puppies cost about $150. Thats $50 more than I paid for the second bike and $50 dollars less than the first. I have beeen watching craigslist hoping to find a junk roller with one installed. Word on the 'net is it still has the low end torque and big gains in top speed.

Dual sprocket on the engine clutch, jack shack has a clutch on it too. Two speed jack shafts cost as much or more than a Comet clone.

eyebrows · « **Reply #14 on:** October 05, 2010, 05:48:04 PM »

Did a little reading today about 2sp jackshafts. Seems the key to how it works is the low gear on the js is typically a one way gear that lets the js overrun the low gear when high kicks in. Makes sense to me now.

Charby:
Let me ask you this - Do you get a squishy spot in your power when the 2nd engages?
From what I've read that seems a common thing, maybe can be avoided if it's tuned just right. I ride fairly hard and climb a lot of hills so don't think I would like anything less than peak power. Also seems like a 2sp js is more prone to breakage/wear than a torque converter.

If I see 2sp js setup for cheap I'll buy it just to play with it but I'm thinking right now that a tc would be a better option for the places I ride. Quite satisfied with the bikes right now but always willing to do something to get moar speed with little to no low end torque loss.

charby · « **Reply #15 on:** October 05, 2010, 06:01:12 PM »

Quote from: eyebrows on October 05, 2010, 05:48:04 PM

Did a little reading today about 2sp jackshafts. Seems the key to how it works is the low gear on the js is typically a one way gear that lets the js overrun the low gear when high kicks in. Makes sense to me now.

Charby:
Let me ask you this - Do you get a squishy spot in your power when the 2nd engages?

A little because its just a 5hp engine. Plus the clutch on my jack shaft is shot so 2nd gear isn't working right now. A little google fu found me a new jack shaft set up for under $50. http://www.masterlowrider.com/catalog/item/1293023/996201.htm

I think I'm going to just buy a new shaft instead of a new clutch

eyebrows · « **Reply #16 on:** January 16, 2011, 12:53:07 PM »

I ended up finding a pretty good deal on a new Tav2 comet clone. Just installed it the other day.

Couple other things I'm gonna do before spring, and riding time, comes back around. But I gotta wait for the parts to get here.
-replacing stock muffler box with a highflow 2 stage header
-replacing stock air filter box assy with a highflow K&N open element(gonna put a sock on when its dusty out)
-a bigger jet and better emulsion tube for the carb

All these mods are on my bike. All I've done and will do to SO's bike is replaced the jackshaft bearings. Gonna keep her stock for awhile longer, bike is plenty to handle as it is.

bedlamite · « **Reply #17 on:** January 16, 2011, 05:53:00 PM »

As long as we're showing off new toys, I recently picked up a KLR 650:

JonnyB · « **Reply #18 on:** January 17, 2011, 09:56:28 AM »

Cool! Another "Pig" owner. I bought an '04 last spring. It's a hell of a lot more fun then the Road King. I shed about 30 years of age when I fire that thing up.

(Then, of course, I gain 40 when I have to *pick* it up...)

The KLR is the Rodney Dangerfield of dual-sport bikes.

jb

eyebrows · « **Reply #19 on:** January 17, 2011, 10:44:03 AM »

Nice bike. Never rode a dual sport or even seen one up close. Are they like a dirtbike(made for banging crap out of) or is it more like a trail bike(take it easy riding)?

bedlamite · « **Reply #20 on:** January 17, 2011, 03:25:43 PM »

It's bigger and heavier than a motocross bike, but it is capable of just about everything off road. It's also big enough it can handle the highway. The M1030 is the same bike with a Diesel conversion.

gunsmith · « **Reply #21 on:** January 17, 2011, 03:47:42 PM »

KLR's are great on gravel/dirt roads & fine on the H'way as log as you don't need to maintain 65mph for long distance ... the brakes are not that hot though but I used it for bay area mc messenger work so it would work anywhere.

bedlamite · « **Reply #22 on:** January 17, 2011, 04:01:28 PM »

Quote from: gunsmith on January 17, 2011, 03:47:42 PM

KLR's are great on gravel/dirt roads & fine on the H'way as log as you don't need to maintain 65mph for long distance ... the brakes are not that hot though but I used it for bay area mc messenger work so it would work anywhere.

The plan right now is for Galfer green compound pads. There are kits available to use 320mm rotors and better calipers if that isn't enough.

News:

Author Topic: I swear, it's not for me, its for the old lady (Read 6547 times)