In frame Predator fricton drive build

wayne z · Jun 22, 2011

I snuck in a few minites of test drive this AM before leaving town for a few days

Takes off rather quickly, not much slippage at all from the roller.I got it up to about 30 mph,and the motor wasn't revved much at all, Feels like it will top out about 40, so I need to gear it down some. After a few munites, grease I put in the clutch bushing got on the metallic shoes and started slipping under moderate load, so i couldn't get over about 30mph.

Can't wait to see how it performs when I get it tweaked out!

When I get it right, I'm gonna install it on my Chromed Micargi springer cruiser.

Dan · Jun 22, 2011

Awesome Build Wayne.

Great to read your liking the engine. I just picked one up. $93 bucks with coupon. Really like the looks! Loved the 79cc HFs but always hated the paint job. How is the sound? Can't believe they got 20 more cc's in what looks like the same engine. Just uber cool. (aside from the shaft, a Comet tourq-a-verta popped on it like it was made for it!

Forgive the ramble. Was just encouraging to see you are enjoying the Predator. Thanks again for letting me know the dimensions. Was the deciding factor in trying one.

wayne z · Jun 24, 2011

I am SO impressed with this thing!!

Wrung her out today after reducing roller pressure some.

My neighbor clocked me at 37 MPH!

Cruises 30 mph with very little effort

The large roller is very smooth and quiet, and has way less rolling resistance and way more surface area for fricton than the smaller rollers.

The Preditor engine is great! Revs out to about 4500 no probs. Kinda torquey at low rpm too. I can chug up some quite steep hills on my street with just enough throttle to keep the shoes engaged.

This thing performs way past my expectations. I'm gonna refine it a lil and put it on a better suited bike with good brakes wheels ect.

I put about 15 miles on it this eve. Guess you could say that i broke it in hard.Nothing changed, including tire appearance.

Oh, and i will need a "49cc" sticker LOL

cannonball2 · Jun 24, 2011

Great to hear its a winner! Really like the jackshaft clutch. Really we do need some 49cc stickers. Ive looked everywhere. Tried to take a pic of the one on my HS engine, but could never make it look right. Anybody got a line on any?

daRog · Jun 24, 2011

cannonball2 said:
Really we do need some 49cc stickers. Ive looked everywhere. Tried to take a pic of the one on my HS engine, but could never make it look right. Anybody got a line on any?

I'm pretty sure I could come up with something. Let me give it some thought.

wayne z · Jun 25, 2011

OK, I removed the Solex, and adjusted the roller/ clutch for even less pressure. Only 1/8" tire deflection. Full throttle at dead stop it just barely and slowly slips on the tire.Very low rolling resistance with the motor off.

So I took it for another 10 mile run.

This thing rocks! Very quiet and smooth drive train at all speeds. The Predator engine has plenty power. The stock muffler is kinda loud at full power at it's current location.
The valve train is a little noisy too. Might be normal for these? I'll check lash after some more run in time.

Changed the oil after this run. Had the usual mettalic tinge to the oil, and a few tiny aluminum flakes in the bottom of the drainpan. Used a magnet in the sediment and detected no ferrous particles.
I am concerned about the extra stress on the frame tubes where ith roller is attached. I am considering an adjustable strut attached from roller mount to engine. Maybe flat plate, and I'll have something to mount a belt guard on.

wayne z · Jun 25, 2011

daRog said:
I'm pretty sure I could come up with something. Let me give it some thought.

The stickers need to be 2 3/8" in diameter. I'll gladly pay for one. I will post a close up pic of the Predator's sticker later.

daRog · Jun 25, 2011

Excellent work, wayne z!

silverbear · Jun 25, 2011

Well done, Wayne! About how much money do you figure you have in this build? Any problems with pedal clearance? The engine looks smaller than I imagined it might. I like your thinking out of the box.
SB

wayne z · Jun 25, 2011

I bought the engine and the pillow blocks and a pulley and belt for about $150 total.
I already had the clutch and other stuff. The bike and engine mount is from my BGF Huashing build. The crank was already bent to clear the 10" wide HS and it clears this engine too.

Thanks for the compliments.

wayne z · Jun 25, 2011

OK, I took it out this eve and flogged the sheet out of it for 25 more miles. Nothing's changed, you can't hurt it. It will cruise 30mph all day. It pulls all the steep hills around here easily.
I am using a Hall Bros airspeed indicator for speed verification. They are known to be very accurate.

Just before dark, dead calm winds, I opened it up on a stretch of fresh , level asphalted highway near here.

I let off when I hit 38 mph, It wanted to keep winding up but the lil motor was already screaming. Now that's a break-in run LOL.

I never imagined that a fricton drive would perform this well.

Who needs those troublesome and messy chains and sprockets:~)

I have 3 " pulleys everywhere, drive roller too, and 26" wheels. Can someone tell me what the engine rpm is at 38 mph?

Thanks, Wayne

wayne z · Jun 25, 2011

This engine is very smooth at all speeds. No vibes at all like the chinagirls. From this and the cylindrical profiled spot on top the engine block, I would assume that this engine has a counterbalance shaft.

daRog · Jun 25, 2011

wayne z said:
I have 3 " pulleys everywhere, drive roller too, and 26" wheels. Can someone tell me what the engine rpm is at 38 mph?

4270. Just a guess, though.

cannonball2 · Jun 26, 2011

daRog said:
4270. Just a guess, though.

daRog is exactly right. My calc shows 38.1@4272. The engine will turn more Im sure, but its topped out on power there or you are going faster than indicated. With my lower geared FDs the 79cc HF turns in the vacinity if 4800, The Lifans are about the same. Might want to GPS it. Still the top speed in not the ultimate, it the useable criuse speed and a relaxed(engine speed) 30mph is happening! Sounds like the ultimate FD.

cannonball2 · Jun 26, 2011

Forgot about my old Western Flyer. I had shoved it in the corner after I robbed the Grubee G4 for my DIY shifter bike build. Had one NIB Lifan left. Whattaya know, fits right in! All I need to complete an inframe is 2 pillow bearings, have the rest. Just hafta decide if I want to do an inframe FD. Was going for another direct drive on an aluminum frame Schwinn MTB. Descisions, descisions.

wayne z · Jun 26, 2011

WoW,that Lifan looks good in there! Go ahead and do an in-frame, you won't be dissapointed. The balance and cg weight is way better than a rack mount, and it just looks right.

The large roller definitly drasticly increases the efficency of a fricton drive.

You can buy the clamp on engine mount from bGF on e-bay for about $25 but it does add about 1" to the overall engine height.

Next time i will use a 4" long piece of 6" aluminum channel , bored on each side to recieve bearings with snap rings on them, and use shaft collare to keep things together. Then clamp and bolt the channel to the frame. This would be a lot simpler and lighter than all that scrap iron that I used on this one.
I use aluminum strip shims under the front of the mount to adjust roller pressure, and an adjustable pulley on the jackshaft for belt adjustment .

cannonball2 · Jun 26, 2011

The mount is already welded in place, thats the plate from the G4 mount, all I have to do is drill the mounting holes. Stole the wide pedal set up for the shifter bike so will have to come up with something, Have plenty of sets to butcher. Looking at the feasibility of mounting the bearings above the kick stand to keep the belt low and close. Can use the kickstand bolt and another bolt and clamp bar to hold them on. Can then just slide the bearing plate to adjust the roller tension.

cannonball2 · Jun 26, 2011

BTW have the 3" plastic wheel I Posted pics of earlier to use for the roller. When I calc the overall ratio it comes out to something like 8.75:1, pretty steep for hill climbing in my area. Can still use it but probably at a ratio of less than 1:1

wayne z · Jun 26, 2011

Great idea about using the kickstand area for the jackshaft mount. The frame is a lot stronger down there. May have some issues with pedal clearance down there to deal with.

Can't wait to see what you come up with.

cannonball2 · Jun 26, 2011

Youre right about the pedal interference. Not used to the drive being on ther right on an inframe. Will have to go higher up. Found a 5.5" pedal crank to replace the stock 6.5", the crank now clears the engine with enough pedal exposed to easily pedal the bike. So now its just down to fabbing the roller/jackshaft assembly. Im with you on the snap ring bearings. Its off to Ace in the morning for an 1 3/8 hole saw and the lawnmower shop for the bearings, My clutch is too big to use as a roller(4.25"), Im out of rubber mat, think I might give oak a shot.

In frame Predator fricton drive build

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