Sun Crusher 'fat tire' cruiser

[KCvale]

If you ever venture to a real bike shop it is amazing what you can find when you do a lot of business there and the owner starts stocking things you might want to buy because they understand what you do with them.

Try Me Bicycles around the corner got me today.
They had a Sun Fat Tire bike for months, still do I think, but the old models had a suckey 2-speed kick-back rear hub and no hand brakes.

Today when we went shopping for just a couple little parts and maybe a mountain bike to put the electric kit I have on, we spotted it...

A Sun 'fat tire' bike with front and rear V-brakes, and a simple 7-speed twist rear!

Ya, $584 out the door for the bike, but with the proper engine and drive train it can be one heck of an off road (beach like) or city riding bike, and though I'm sure there are some examples before this Crusher design, this one might be pretty cool once I decade on what power plant and drive to use.

I have every power plant type and drive parts sitting right here.
I'll look, fit, play with math, then I'll decide what system best fits this particularly fun looking thing to motorize.

Don't you just frigg'n love it when you can do stuff like this?
I sure do ;-}

 

[KCvale]

I have to smile at those side pics, it looks like a regular bike with really close fenders.

Here it is parked next to my electric shifting mountain bike with 2" tires.

Tire says 3.5" but I think that is rim size as my caliper says 4" at the widest point of the tire.
They run 8-35 PSI.

I have decided on a tricked out 66cc 2-stroke shifter for it ;-}

SunBicycles web site.
http://www.sunbicycles.com/product_detail.php?short_code=Crusher+7

 

[maniac57]

Man I wish it were not so expensive! I've been DYING to do a fatbike and the Beast and Dolo frames are no good without major surgery or silly mounting setups.
All the suitable design frames are out of reach for me.
That frame looks MADE for a motor!

 

[Davezilla]

I agree.. that's an awesome looking bike and just dying for an engine installed in it... that one's got the goodies too like the V brakes and the 7 speed rear... Looks like a perfect cantidate for a shifter kit

 

[greaser_monkey_87]

KC, you're in a position where you're making money hand-over-fist with these motorbikes. You also have a relationship/rapport with your lbs, due to the volume of business you do. I would go out on a limb and say you probably do a larger volume of business than any other builder associated with this forum. So for the average builder/seller of bikes who doesn't do the volume of business you do, they probably don't have the rapport with their local lbs that you do, and they probably don't make enough money to throw 5 or 6 bills on a bike just because they want to or because it's cool and fun. You share posts like these sometimes as if the average builder can relate to you, but the fact is, sometimes they can't. Sometimes you're sharing helpful info, and other times you're just tooting your own horn.

 

[knightscape]

Oh man, that looks like a pile of fun to just cruise on, let alone motorizing. I'm thinking it needs a handlebar cup holder... 6:00am sunrise cruise with a cup of joe. A shift kit would be pretty sweet on that to help keep slow speed torque turning those giant tires. I'm glad we're finally seeing economies of scale affect some of the weird parts we need for giant tire pedal bikes like the 170mm rear hubs on that and the big fat rims. We're in a fun time to be building bikes. A shift kit would also help avoid messing around with drive chain tension since you've got vertical dropouts on that.

 

[KCvale]

KC, you're in a position where you're making money hand-over-fist with these motorbikes.
...(more speculation)...
Sometimes you're sharing helpful info, and other times you're just tooting your own horn.

I'm not making a living building bikes, my wife is the real bread winner here, I just generate enough business, a bike or 3 a week, so my best friend since high school and I can have some spending money in our pockets, work maybe 20 hours a week, and have a whole lot of fun while staying out of trouble.

I help when I can around here, and you bet your sweet patotie I show off things I build, we all do that here as we are all proud of what we build, I just build a lot cool things and if nothing else my builds certainly inspire at least some builders to spend the extra buck and go the extra mile for their own builds ;-}

Most everything I build is custom ordered for the customers needs and paid for with their money so yes I do get breaks from both local suppliers and my main parts vendors, and yes I can usually squeek via a credit card afford to take advantage of any sales I see and stock up on parts.

However, my Pop's passed late last year and I got some inheritance now.

I looked at all my options to grow that money for our own retirement and my best return on investment is what I'm doing now with MB's (beside putting in 100% of what we can with matching funds from my wife's work in a 401K).

It's not a lot, but it beats the heck out of .05% a year and I get to try even more new things.

But back to this Fat Tire build....

Going with a 66cc Skyhawk 2-stroke with SBP shift kit and expansion chamber exhaust.

It's the only logical choice considering the drive options and why I jumped on this bike despite the big initial cost as it's the first one I seen with potential to motorize.

The interesting part will be how hard it will be to get a dual chainring freewheel system on the thing so the engine can use the 7-speed pedal side drive system.

Again all fun stuff but the bike has what I need:
Dual V-brakes.
7-speed with simple twist shifter.
3-peice threaded bottom bracket.

When it's all said and done I figure I'll have no shortage of buyers for a 3+ HP 7-speed shifting Fat Tire cruiser at $1295 out the door.

*toot toot* ;-}

 

[2door]

$1295? Cheap.
I'm so glad you're going the 2 stroke in-frame route with this one. Nothing else would look as cool.
Keep us posted on the build. Should be a winner, for sure.
With the shifter you won't need to off set the engine, so no odd-ball custome mounts as with most wide tire bikes. Good luck.

Tom

 

[maniac57]

Hey KC! Need any help? I'll sleep in a broom closet and work for food till I get the first one you build paid off.
*grins appealingly*
I can weld and run a tape measure....
And I'll supplement my board by hunting squirrels in the local parks so I won't eat much.

 

[maniac57]

I'm thinking all you will need is a longer jackshaft to reach the chainring. The existing chainline is already set correctlyfor the wide tire, so all you have to do is reach the pedal sprocket. You shouldn't even need any engine offset since you won't have to clear the tire with your added parts, just reach a bit farther with the jackshaft to line up.
I LOVE the look of that thing.
Exactly what I plan to do when I find an affordable fatbike to chop up and graft with a curved toptube cruiser style frame. A bit more room between seatpost and tire though...I like the longer look.

 

[greaser_monkey_87]

Come on, bro. How many other independent builder/sellers out there can afford to drop 6 bills on a bike for kicks? How many of them know it will walk out the door for twice that? You're excited and happy about motorizing that bike, and that's cool I mean who wouldn't be. But you present it to us assuming that we can relate to your situation ("Don't you just love it when you can do stuff like this? I sure do"), but I've never heard any independent builder/seller besides you brag about dropping 6 bills on a bike and knowing it will walk out the door for twice that, so who exactly is it that you think can relate to being able to do stuff like this. "I don't make that much money selling motorbikes" but you can drop 6 bills on a bicycle. Does your wife support your business that much? I wouldn't run a business if I needed my wife's money to keep it going.

 

[knightscape]

Greaser, I don't want to start an argument here, but I'm not sure where you're coming from in this conversation. This is an open forum, KC has a fun bike to show, and some of us are having a good time talking about it. If you don't want to see it, just don't read his threads, it's easy as that. I'm sorry not everyone can afford the same bikes but if you're going to get irritated that we can't all have the same things, you're in for a long and frustrating life. Bikes can be expensive (and $600 for a bike ain't even near the upper end...), anything can be expensive. KC has figured out how to make it into a self supporting business, so good for him. IMO, that hardly means he shouldn't show off his bikes. If anything, I would think other small builders might want to pay attention to figure out how he and the other guys/gals around here that build/sell make it work. Again, I'm not interested in getting into an argument, and please don't read any sort of tone into what I'm saying, I'm not trying to be like that. Just step back and look at the scene here, we're all into a weird little hobby (sorry guys, it's true, we're all weirdos), and we've all got something different to share. You're making KC out to be some kind of fat-cat high roller, when he's just another dude building fun bikes in his shop. There's room 'round the campfire here for everyone.

 

[silverbear]

Come on, bro. How many other independent builder/sellers out there can afford to drop 6 bills on a bike for kicks? How many of them know it will walk out the door for twice that? You're excited and happy about motorizing that bike, and that's cool I mean who wouldn't be. But you present it to us assuming that we can relate to your situation ("Don't you just love it when you can do stuff like this? I sure do"), but I've never heard any independent builder/seller besides you brag about dropping 6 bills on a bike and knowing it will walk out the door for twice that, so who exactly is it that you think can relate to being able to do stuff like this. "I don't make that much money selling motorbikes" but you can drop 6 bills on a bicycle. Does your wife support your business that much? I wouldn't run a business if I needed my wife's money to keep it going.

I don't understand the need for all of this negativity. If KC is able to make a modest income from something he loves to do, then more power to him. I can't afford the bikes SportsCarPat produces either, but I admire them, admire his great shop and the advances he has made in performance which has shown up at Bonneville in world records. Way out of my class. But good for him and his brother. I'll cheer them on. And I'm glad when others here have turned their passion into a profitable enterprise. Way to go!

When you plunk down $600.00 all at once it does seem like a lot of money. I can delude myself in what my builds end up costing by the slow process of buying the vintage frame, buying rims and spokes and fatty tires, making the modifications to the frame, stripping the frame to bare metal and painting it, then adding in the seat and fork, handlebars, maybe a multi speed geared hub if the bike is to get a shift kit. I can pretend I'm not spending a whole lot because it is doled out a bit at a time. But it does add up. And that does not account for the amount of time involved in finding, ordering and assembling everything.

What KC did in his purchase was buy the bike he wanted with everything done other than turning it into a motored bike. Since what he does is ultimately for his customers (and they are the ones paying the bill) time is money. If I were paying myself minimum wage for my builds (which are labor intensive and often involve scrounging and making parts) the cost of the build would be through the roof. All things considered I think his initial purchase is reasonable and the intended sale price is a real bargain.
SB

 

[greaser_monkey_87]

So far, no one understands the actual point of what I'm saying, it has naught to do with the price of the bike or me wanting something I can't have. I'm mostly fine with my current setup, I'll be making some changes soon to better suit my wants and needs, but it won't be much different than it is now, and I have no desire whatsoever to go out and spend $600 on a bike before motorizing it, even if I could. There are also other bikes I think are nice that I can't afford, but I'm not salty about that either. I'm fairly sure that no one will understand my actual point, and that's ok. I'm not going to say anything more on the subject. Enjoy talking about the bike, everyone.

 

[KCvale]

$1295? Cheap.
I'm so glad you're going the 2 stroke in-frame route with this one. Nothing else would look as cool.
Keep us posted on the build. Should be a winner, for sure.
With the shifter you won't need to off set the engine, so no odd-ball custom mounts as with most wide tire bikes. Good luck.

Tom

Ya Tom, just a nice solid center mount with shift kit.
This is the first 'fat tire' I've seen with all the right stuff on it to motorize and why I simply couldn't resist buying it.

The trick will be the dual sprocket bottom bracket freewheel.
It has to take the engine power and it looks like an odd duck but 3-peice cranks, I just haven't got into it yet.

Typically the outer sprocket gets the engines jackshaft chain so the inner sprocket drives the back wheel, may have to go the other way on this one with the shift kit, the engine drive sprocket on the inside might be ideal.
No biggie as it's just about how you install the sprockets on the freewheel.

Heck I might even be able to keep the chain guard too.
It's really fun when I can pull that off.

All fun stuff for me but it's kind of sad to see some people slam me because I can do things they can't but ya know, that's not my problem, I have no problems ;-}

 

[knightscape]

The trick will be the dual sprocket bottom bracket freewheel.
It has to take the engine power and it looks like an odd duck but 3-peice cranks, I just haven't got into it yet.

I'm curious how you're going to handle that part too, the bottom bracket shells on a lot of the big tire bikes are 100mm rather than the more usual 68 or 73mm sizes. I know there are wider set spindles out there in the chopper scene for that size shell. I'd love to see some detailed pics of whatever solution you figure out.

 

[KCvale]

I'm curious how you're going to handle that part too, the bottom bracket shells on a lot of the big tire bikes are 100mm rather than the more usual 68 or 73mm sizes. I know there are wider set spindles out there in the chopper scene for that size shell. I'd love to see some detailed pics of whatever solution you figure out.

I don't foresee any issue with the standard size SBP wider sealed bearing BB cartridge pedal axle with the shift kit, I think it will come down to how I build the freewheel pedal sprocket set.

I usually take lots of pics of all kinds of new things I'm doing, this build will have plenty of pics so you can build your own too, and what it takes to do it.

 

[knightscape]

The trick with the cartridge BB in the kit (or any of the 3 piece conversions) is that the cartridge is designed for a 68mm BB shell and I think your BB shell is 100mm. If you thread in a standard BB, the left side cup will actually thread inside the BB shell and you'll end up having the pedals biased towards the pedal side of the bike. It's not the width of the spindle I'm talking about (though those are wider on fatbikes too), it's the spacing of the bearings. On the fat bikes they space the bearings out wider to get a shiftable chainline on the pedal side. That make any sense?

I found an example of what I'm talking about at Choppers US.
http://www.choppersus.com/store/product/792/Extra-Wide-Bottom-Bracket-Axle/
See how far apart the shoulders are on the spindle?

 

[mapbike]

Greaser, I don't want to start an argument here, but I'm not sure where you're coming from in this conversation. This is an open forum, KC has a fun bike to show, and some of us are having a good time talking about it. If you don't want to see it, just don't read his threads, it's easy as that. I'm sorry not everyone can afford the same bikes but if you're going to get irritated that we can't all have the same things, you're in for a long and frustrating life. Bikes can be expensive (and $600 for a bike ain't even near the upper end...), anything can be expensive. KC has figured out how to make it into a self supporting business, so good for him. IMO, that hardly means he shouldn't show off his bikes. If anything, I would think other small builders might want to pay attention to figure out how he and the other guys/gals around here that build/sell make it work. Again, I'm not interested in getting into an argument, and please don't read any sort of tone into what I'm saying, I'm not trying to be like that. Just step back and look at the scene here, we're all into a weird little hobby (sorry guys, it's true, we're all weirdos), and we've all got something different to share. You're making KC out to be some kind of fat-cat high roller, when he's just another dude building fun bikes in his shop. There's room 'round the campfire here for everyone.

Only thing that strike me odd about everything you said here is calling our Hobby " a weird little hobby " in reality there is absolutely nothing weird about this hobby since the modern motorcycle derived from motorized bicycles, we are only taking a step back in time to when things with engines and two wheels were a lot simpler NOT weird...LOL!

I call our hobby a (Unique Hobby) but it is far far from being a "weird hobby"

Just my $0.02 on that subject.....

Peace, map

 

[mapbike]

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

Map