Sun Crusher 'fat tire' cruiser

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KCvale

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Feb 28, 2010
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Phoenix,AZ
I'm excited to see this "Fat Bike" come together, I think it will be a sick ride when it's done.

Map
dnut
She's coming together pretty good so far, got the 66cc Skyhawk with SBP jackckshaft shift kit in.
Didn't even need to change out the BB cartridge!

As mentiond earlier I figured I could just put the engine drive sprocket on the inside which pretty much used every bit of the actual jack shafts length but it fits and rolls sweet ;-}



Plenty of work to do which is on-going as I post but ya, it is possible to mount a 2-stroke with a shift kit properly and make the drive train work ;-}
 
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mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
Looks excellent KC, that thing is gonna be a nice ride when you get it finished, those FAT Tires are gonna make that thing ride like a Cadillac I'll bet.

Glad its working out good so far for you.

Map
 

KCvale

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Feb 28, 2010
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Looks excellent KC, that thing is gonna be a nice ride when you get it finished, those FAT Tires are gonna make that thing ride like a Cadillac I'll bet.

Glad its working out good so far for you.

Map
Cole has it out for the initial test ride as I type just to make sure the drive train works, 'stretch' the chains with some oil on them, most of you know the drill, don't button it up until you know it runs well.

Lots more work to do but we got the SBP X-chamber plumed in and mounted as well now.
I amaze myself and my helper Cole sometimes, 'I want this here, lets make it work' and we do.

It's late on a Friday afternoon (for me) and my wife worked from home today and already in her 'queens recliner' in front of the TV with food so stick a fork in me for the day.

Enjoy life, it is short in cosmic terms and can end with a simple mistake, like not having good brakes so protect yourself guys.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
Cole has it out for the initial test ride as I type just to make sure the drive train works, 'stretch' the chains with some oil on them, most of you know the drill, don't button it up until you know it runs well.

Lots more work to do but we got the SBP X-chamber plumed in and mounted as well now.
I amaze myself and my helper Cole sometimes, 'I want this here, lets make it work' and we do.

It's late on a Friday afternoon (for me) and my wife worked from home today and already in her 'queens recliner' in front of the TV with food so stick a fork in me for the day.

Enjoy life, it is short in cosmic terms and can end with a simple mistake, like not having good brakes so protect yourself guys.
Thats great KC, looking forward to hearing about how the (Maiden) voyage went.

Thinking about what you said about this life being short makes me think of an excellent song with and excellent message.

Link to some anti- Rap Crap that actually has talent and a real message that matters.

http://youtu.be/cOVzXYEU3Bk

Peace, Map
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
Thats great KC, looking forward to hearing about how the (Maiden) voyage went.
Well, this bike even with the big a$$ wheels and backwards sprocket configuration just frigg'n fly's.

I was concerned about the chains crossing but ya know, 3rd is the lowest gear you need with that 66cc 2-stroke and SPB X-chamber and ya, even new on rich gas she fly's.

That X-chamber was no easy task though, we had to to custom 'plumb' it in but it's where I wanted it.

Plenty of 'buttoning up' to do but yep, this particular model of SunBicycles Crusher can and will function with the engine mounted in the proper way, and for $9 in chrome paint you can make everything mount related blend in.

Not sure what I'll do next with it but the darn thing runs like a banshee.



Got to love it when something you thought couldn't be done can be with a little ingenuity ;-}
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
Well, this bike even with the big a$$ wheels and backwards sprocket configuration just frigg'n fly's.

I was concerned about the chains crossing but ya know, 3rd is the lowest gear you need with that 66cc 2-stroke and SPB X-chamber and ya, even new on rich gas she fly's.

That X-chamber was no easy task though, we had to to custom 'plumb' it in but it's where I wanted it.

Plenty of 'buttoning up' to do but yep, this particular model of SunBicycles Crusher can and will function with the engine mounted in the proper way, and for $9 in chrome paint you can make everything mount related blend in.

Not sure what I'll do next with it but the darn thing runs like a banshee.



Got to love it when something you thought couldn't be done can be with a little ingenuity ;-}
That is an awesome looking bike KC,

Paint that frame Blue and with those Bright Green rims I bet some Seattle Seahawk fan would jump all over that thing....LOL

I can see in the pics how you get it all mounted up, actually a very simple set up once you got it all figured out looks like and it looks clean and good.

if I were you I might have to add that one to my personal fleet and just let other drool over it and wish it were theirs...!dance1

if I ever run across one of those fat tire bikes I'll jump on it and build me one like that in the future possibly, the bike I'm working on now is gonna be my fifth personal bike and I know at some point I'm gonna have to sell something, I just dont have the room for all the bikes, 5 motorized bikes, my Harley, My old Yamaha and a 150cc China made Scooter, not counting a few old peddle bikes and a pile of parts and pieces.. my wife calls it my toys and my junk and she's right but it keeps me busy and I enjoy the hobby.

Keep the pics and results coming KC, you have done a nice job on that one.

Map
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
Update time.

This is turning out rather well I think...





I am not to the cable and wiring yet, obviously, but the custom expansion chamber exhaust pipe went in sweet in my eyes.

All steel parts hard welded and then coated with 4 coats of silver high temp engine paint and left outside to bake in the AZ sun and cool down overnight.

I had to sacrifice some high end power reducing the length of the pipe, but it is where it simply has to be to function AND look good on this bike.

And can you believe I found the perfect chain guard for it my bike box of them?
The original was way too small but that one from an Electra I think with just a couple of 'snip snips' for the drive chain went right on!

Still need to fashion a cover for the JS sprocket but we have done that before, it's just rare that I can keep pedal side guard that actually fits right.

The delema now after a bunch of riding miles is how to either lock out any gear below 3rd on the derailleur, or just put a new sprocket set on that sticks out far enough.

As with anything like this on my own dime it takes back seat to a buying customers build so it may be a couple of days before I 'button it up', but then again I am unpredictable when it comes to things like this ;-}
 

KCvale

Well-Known Member
Feb 28, 2010
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Phoenix,AZ
That is an awesome looking bike KC,

Paint that frame Blue and with those Bright Green rims I bet some Seattle Seahawk fan would jump all over that thing....LOL
Hehehe, bet your right but I have already had a couple of calls on it, and it's not even done yet.
Cole just rode out to my local bike shop to have Leon take a look and see if we can fit something on that back wheel with a little better gear range given the chain cross issue.

I can see in the pics how you get it all mounted up, actually a very simple set up once you got it all figured out looks like and it looks clean and good.
It's close to my standards now, just need to work out the shifting drive issue and then I can button it up.

One this test ride with he's going to swing by the local hobby shop and see if he can score a little bottle of that lime green rim paint so we can add so accents, we decided to just mask off the air cleaner and paint the blue parts

if I were you I might have to add that one to my personal fleet and just let other drool over it and wish it were theirs...!dance1
I have no 'personal fleet' these days, I barely have enough room for the things I am working on for customers, but that also means I have an ever changing 'personal fleet' around and I kind of like that better ;-}

Keep the pics and results coming KC, you have done a nice job on that one.

Map
Thanks Map, we are plugging alone, builds like this take time and patience.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
You've done well, KC. I've been watching silently but now that it's near completion I'll toss out my congrats. Nice job on a unique bike. Thanks for sharing.

Tom
 

KCvale

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Feb 28, 2010
3,966
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Phoenix,AZ
Thanks Tom,

Picked up a 5 sprocket cluster for the rear and upon inspection 1st on the 5-speed is no bigger than 3rd on the 7-speed so we just kept the 7 and locked out 1st and 2nd on the derailleur.
Chain cross issue resolved and she still gets up and goes great, she just won't be climbing any telephone poles.

Cole and I pretty much just dinked off yesterday and watched the world cup and painted, the ugly blue on the nice high flow air cleaner is now chrome and all the parts for another build done.

Just a shot of it leaning against the build bay stand because it won't fit in it.
This is a shot from my office chair where I spend most of the working day doing that pesky business part of things but still keep an eye on things.



Doubtful we will get much work done today either.
That's part of the beauty of us both having well paid working wives and mine gets off at noon today and the couch is already calling ;-}
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
Looks good KC and glad you got the chain cross issue worked out best you could.

I also have a well paid working wife, thing is though she expects me to be a well paid working husband..... dang the luck..LOL!

Map
 

KCvale

Well-Known Member
Feb 28, 2010
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Phoenix,AZ
Stick a fork in the beast, he's done.​







5 cables and the kill button wire from the handlebars but he buttoned up nice I think.





This is like a Monster Truck motorized bicycle for adults only.
It is big and heavy but with all the 66cc Skyhawk engine mods and SBP shift kit it has all the power it needs and a frigg'n joy to ride with just 18# of air in those big fat tires.

I'd like to keep it because it's so cool and fun to ride but I have much more expense 'box of parts' to build to ride next.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
My big (6' 220#) mechanic / best friend absolutely loves this bike.

He took it out for over 2 hours test riding it yesterday and snapped a few pictures of where he rode it which was up a pretty steep local trail with dirt/gravel/shale under him...







And then he hit the park...





Note that those fat tires didn't even leave a mark on the grass.
You could ride this thing on a golf course and not do any damage, but it's not very practical as a golf cart ;-}

I don't have easy access to sand but I'd bet he floats right over that as well.
All in all a really fun bike if you put enough power in it.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,237
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Looking good. Those fat tire rims are on one of mine. Well I got Large Marge Surly's I like them a lot! I still had to adjust. Those tires will never come off those rims. Trust me they stay on! If they are like mine. I got a few tricks for them now.
 
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Goat Herder

Gutter Rider
Apr 28, 2008
6,237
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N.M.
The trick will be if you can get the tire off gracefully? On my Larg Marge rims, I tried many things lubricants etc. The tire bead becomes one with the rim. What does this mean? Well with no air what so ever in the tire the bead is still one with the rim. 8 inch long metal pry bars specifically for the task will not break the bead loose. You have to actually pry to remove all tire beads.

However when absoluty no tool will ever even get under the bead at all to start with. Short of running it over with a semi. I adapted pick tools to gently pry up the steel belts. One at a time I cut them with a angle grinder. ''Carefully''

Last I still need scrape tools to work the rest of the tire's bead off. Yes the bead sticks that good!


Now to put one of these tires on? Is very easy. Take advantage of the V shaped valley in the rim. When you set the tire's bead deeper in that valley so to speak. The tire goes right on!

Now the good news. Since I use slime good tires and leather thick tubes I never will be doing a road side repair. laff


Check these tubes out...Metzeler ME-E 19 M/C They are a perfect match for these rims. Why? Good question.

Becuase no matter how heavy duty the tube. If it has to balloon and streach to fit. That is truly a paper thin tube now.laff