Aluminum frame fatbike? Do I dare?

Urban Fatbiker

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Nashville TN
I measured tubes this afternoon to do something like that. Funny, I meant to correct that post, I’m not buying isolators, but isolating frame from mounts.
I saw isolators looking for mounts later. Nothing like that.

I do have a welder, and was looking at cutting tubes like clamshells to spread load, using PVC braid tube cut to fit ID. So, take it a step further and weld the lower half to the ID of the U-clamps?
Downtube is 1.75” ordered the universal large up to 2” clamp.

Seat tube 1.25”, haven’t yet checked how I’ll change the SBP mount clamping.
 

Don_Parsons

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All of our 80cc fat tire bikes are aluminum...
20211015_121338.jpg



Of course there geared down for all season riding off road and farm operations
20220224_140227.jpg


Just getting some custom long shafts machined
Screenshot_20220223-212512_Photos.jpg

19mm longer for the 4" tires...
22mm for the 5" boots...
That way the power plant stays centered in the frame and we don't have too work with a jack shaft kit...

We're direct drive folks since We'd rather ride them less tinkering all the time...

Most of the time we run 68 tooth sprokets,,, we have some on the 54,,, 62 that we change out in in the summer months...

PS: We get these srokets built with step out depending on the style of hub...

20210101_121443.jpg


A 54 tooth puts us in the 17 too 22 mpr range with 30 mpr bursts...

62 tooth is in the 11 too 17 mpr with 25 mpr hits

68 tooth is a 7 too 12 mpr with 22 hits...

We like slow since its safer and it allows us too do hot shots coming out of the creek banks...

No Pedaling required on any hill we encounter...

Leanest jet,,, needle in lowest setting with 42:1 mix for optimum crisp snap coming out of the hole,,, fat tire bikes need zap because theres alot of rubber tire too spin...

Factory Zeda engines ,,, and yes,,, they last a long long time so long as we flip the throttle alot

Kill switch on with partly open throttle on the long mountain decents too prevent a lean melt down...
Some of the mountains we drop off of are 15 too 20 minutes down...

Jt
 

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Don_Parsons

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We fit the engine's into the frame,, grind out aluminum engine frame mounting spots so they fit the bike frame tube diameter...

We use thick rubber mud flap peaces cut too size too spread out engine vibration and off road shock which helps spead out the engine weight over a larger area up and down the front & rear bike tubes...

Cut too fit mud flap rubber on both sides of frame tubes which gets sandwiched when we cinch the engine's tight,,, these engine's ain't going no where,,, a re- tork after a few rides...

All of our rides are off road,,, and these units get hammered hard for farm operations...

Yes,,, find some stiff solid rubber to spead out the engine weight above and bellow the frame tubes is a good idea...

Heavy duty truck mud flap rubber seems too work for us since its what we have in stock

Jt
 

Street Ryderz

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Ft Erie Ont
I'm taking notes. You guys are like the old guy at the flying field who watched me crash my 1st RC plane on its 1st takeoff.

He scolded me for being a fool.
Then, helped me learn how to fly my 2nd plane.
And...rebuild my 1st plane too.

Its kinda like that here.
I've seen that happen a few times LOL, worse is when I went back to a flying club after some years they wanted me to do a flight test with their instructor and I had brought a plane (Piper Cherokee)that he couldn't fly, I had to recover it from him when he tip stalled it in a slow turn.
I couldn't believe that their instructor had never flown a low winged aircraft or even said anything before making his first attempt with my plane!
 

Don_Parsons

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Yes,,, We still class Wrench as our Old Guy... lol

Anyways,,, I'm the king of rat bikes,,, put them together with ductape and hay wire,,, never wash them and drive the crap out of them...

The dirty'er it is the happier I am...
20220309_213510.jpg


This engine got mounted with bicycle tire tube and mud flap rubber...

Front
20220309_213251.jpg

20220309_213224.jpg


Rear
20220309_213153.jpg


20220309_213044.jpg


I need too change out the rear rubber too the thicker stuff now that the engine has settled in...

Looks like I need too spray some gear oil on the bolts and plates,,, dam salt and calcium chloride on our roads in the winter months...

Eastern Canada uses magnesium chloride on there roads,,,

Calcium chloride eats Steel...
Magnesium chloride eat Steele rubber and plastic...

Its nasty stuff...

Jt

PS: A person can get away with aluminum frame power bikes,,, but its a good plan too keep a eye on things... inspect as needed...

Helmit ,,, leather gloves and thick jacket ,,, just incase something lets go,,, this is another reason We like Slow...

A 7 mpr crash on a power bike could be a major thing,,, faster then that in a tumble is definitely not good...

Slow is your friend...
 

Karl Snarl

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Chunky Monkey Mole Hole
Yes,,, We still class Wrench as our Old Guy... lol

Anyways,,, I'm the king of rat bikes,,, put them together with ductape and hay wire,,, never wash them and drive the crap out of them...

The dirty'er it is the happier I am...
View attachment 168995

This engine got mounted with bicycle tire tube and mud flap rubber...

Front
View attachment 168996
View attachment 168997

Rear
View attachment 168998

View attachment 168999

I need too change out the rear rubber too the thicker stuff now that the engine has settled in...

Looks like I need too spray some gear oil on the bolts and plates,,, dam salt and calcium chloride on our roads in the winter months...

Eastern Canada uses magnesium chloride on there roads,,,

Calcium chloride eats Steel...
Magnesium chloride eat Steele rubber and plastic...

Its nasty stuff...

Jt

PS: A person can get away with aluminum frame power bikes,,, but its a good plan too keep a eye on things... inspect as needed...

Helmit ,,, leather gloves and thick jacket ,,, just incase something lets go,,, this is another reason We like Slow...

A 7 mpr crash on a power bike could be a major thing,,, faster then that in a tumble is definitely not good...

Slow is your friend...
Nothing wrong with ratrods or ratbike. Make'n due with what ya got is way better then burying yourself in a hole for something you don't need.
 

Wrench

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Nov 14, 2018
Messages
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so cal
All of our 80cc fat tire bikes are aluminum...
View attachment 168985


Of course there geared down for all season riding off road and farm operations
View attachment 168986

Just getting some custom long shafts machined
View attachment 168988
19mm longer for the 4" tires...
22mm for the 5" boots...
That way the power plant stays centered in the frame and we don't have too work with a jack shaft kit...

We're direct drive folks since We'd rather ride them less tinkering all the time...

Most of the time we run 68 tooth sprokets,,, we have some on the 54,,, 62 that we change out in in the summer months...

PS: We get these srokets built with step out depending on the style of hub...

View attachment 168989

A 54 tooth puts us in the 17 too 22 mpr range with 30 mpr bursts...

62 tooth is in the 11 too 17 mpr with 25 mpr hits

68 tooth is a 7 too 12 mpr with 22 hits...

We like slow since its safer and it allows us too do hot shots coming out of the creek banks...

No Pedaling required on any hill we encounter...

Leanest jet,,, needle in lowest setting with 42:1 mix for optimum crisp snap coming out of the hole,,, fat tire bikes need zap because theres alot of rubber tire too spin...

Factory Zeda engines ,,, and yes,,, they last a long long time so long as we flip the throttle alot

Kill switch on with partly open throttle on the long mountain decents too prevent a lean melt down...
Some of the mountains we drop off of are 15 too 20 minutes down...

Jt

Hey Don where did you get these huge rear sprockets guys wanna know ?
 

Don_Parsons

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Joined
May 6, 2020
Messages
188
Princess Auto Western Canada...
I'll have too look up the chain size in our stock room...
I """think""" its #40 but not 100% sure until I look...

The factory chain with the engine kits wont work on these sprokets due too the width of the replacement rear sproket...

The replacement chain that fits the chinese Princess Auto sprokets will work on the Zeda engine drive sproket...

The Princes Auto Sprokets are just a bit wider then the thin sproket that comes in the kit,,, I could get my Machinist too mill the sprokets down so the engine kit chain would fit...

I'll post a photo of the step out rear sproket and let you know what pitch of chain We're using...
 
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