Working 4 stroke but many questions HELP! :)

Montezumasviper · Feb 28, 2011

Hey all,

I've recently completed a build of Dax's xc50S on a cranbrook cruiser (walmart cruiser with baloon tires" The bike runs but I have several concerns. All in all my china girl bike will whip it by a big margin in many ways so something is wrong. Dax didn't have the kit so I created one from a heu* engine mounting plate and a other parts.

Its set up like this. Currently has a Hoot gearbox (has an internal chain reduction in the gearbox) w/ Dax's 56 tooth rear sprocket on a # 41 chain

Issues:

Low torque - even with the 56 tooth is has no power in the low end
Low overall power - just doesn't feel strong
Brakes - I have a set of caliper brake from SBP installed and they are totally unacceptable; What brake and Caliper set do you suggest for a big tire bike like this?

Questions:

Why does the power seem so low?

What gearbox / sprocket combo do you suggest? The hoot one sucks and quite honestly seems dangerous

What kind of RPM's am I running? Where should I be at?

Brakes! What Caliper set do you suggest for a big tire bike like this?

Where can I buy a tachometer?

Do you have any other suggestions?

ANY help is appreciated, can't ride the bike right now because honestly is just feels too dangerous. THANKS!!

-Andrew

Edited: Also some ideas on the bike, the rims are steel and smooth so I thought about roughing them up a bit to get a little bit more traction for the pads. Also, i'm going to take the carb out and try to clean it up and see if that helps at all.

This is the gearbox i'm using http://cgi.ebay.com/bicycle-Motoriz...Cycling_Parts_Accessories&hash=item2c5aaa3a15

zean · Feb 28, 2011

Hi Montezumasviper. The brakes: try those shoes that are almost twice as long as the regular caliper brake shoes except thinner. The bike shop should have a selection to chose from. The tach: staton-inc has one. If your carb work doesn"t work, I'd talk to Duane at dax. RPM's: the engine should run 6800rpm all day no problem. Maybe 7000 to 7500rpm for a couple hours at a time. There's only one gear box I've heard about (for inframe builds), I don't think it fits your engine, it's solid, reliable and built to be repaired with easily accesible parts: Easy Motor Bike. I've got to go get ready for work while my job is still manufacturing in America. I pray that I can remain employed for as long as I'm able to work. Thankyou for your motorized bicycle questions.

Tad Bit Tipsy · Feb 28, 2011

The longer brake pads and roughing up the wheel is the way to go... or stop, lol. As for the gear box, I think that one is a 3.25 to 1 reduction which has no torque what so ever. I'd go with a the G4 belt drive at 4 to 1 or 5 to 1 reduction. You'll feel the difference. The EZM(Easy Motorbike) gear box is not made for the Centrifugal Clutch version of 50cc engine that the Dax's are, so you can rule that out till they make one, still waiting for that myself. Try Bicycle Engines.com for the G4 Belt drive, or Blow By You, they both have it for sale by itself, not in a kit. L8R.

zean · Mar 2, 2011

I think EZM is working on or considering working on a gear box for the robin-subaru 35cc which would make their bicycle kit available to the States that have a 35cc engine size limit on motorized bicycles like Oregon. Maybe that future gear box would also fit the hauseng 142f cc and/or the dax titan? As you said Tad Bit Tipsy, waiting on that. Thankyou.

cannonball2 · Mar 2, 2011

I have a Grubee G4 with the HS engine. It has plenty of torque to even pull away from stop with no assistance. Its overall ratio I believe is 16.6:1 or there abouts. My larger engine bikes run as low as 12+:1 but it takes around 3hp+ to do it well Whats the overall ratio you are running? If its much below 16:1 its probably to high for the engine. A simple rear sprocket change may set you right.

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Working 4 stroke but many questions HELP! :)

Montezumasviper

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zean

Active Member

Tad Bit Tipsy

New Member

zean

Active Member

cannonball2

Well-Known Member