(MBBO#05 Class 2) GET SMART!

[LukeTheJoker]

Looking forward to seeing it with a 20" on the back, will it change the angles and ride height much?

Luke.

 

[The Renaissance Man]

That's a good question. Maybe @kingfish254 can help answer it. He has the original wheel and tire (measure from the ground to the axle Brian). I'm guessing that it will only drop the rear between 1/2 to 3/4 inch.

 

[GuitarlCarl]

24 down to 20 should drop you half of the difference, or approximately 2 inches... on paper.

Carl.

 

[LukeTheJoker]

24 down to 20 should drop you half of the difference, or approximately 2 inches... on paper.

Carl.

Actually as you are only dropping one end, and the bb is approximately halfway down the length of the frame, it is probably half of the single tire difference, so not 2", but 1"...

Luke.

 

[The Renaissance Man]

24 down to 20 should drop you half of the difference, or approximately 2 inches... on paper.

Actually as you are only dropping one end, and the bb is approximately halfway down the length of the frame, it is probably half of the single tire difference, so not 2", but 1"...

The reasoning sounds right, but the missing variable is the tires. That's why I'd be interested in the original wheel/tire hight if Brian still has it.

(Read with the voice of Maxwell Smart)... Well Chief, I measured a 24" Mt. bike that I have on hand and came up with 11 1/2" from ground to center of the axel. The 20" wheel and (fat) tire that I've got is 10 3/4". That works out to be 3/4" shorter at the drop out. Using Luke's formula it would only be 3/8" at the bottom bracket. Now, take that and factor in the angle of the slot in the drop out and it's conceivably possible for there to be no difference depending on the location of the axel in the drop out for each size wheel/tire combination!

...So to answer Luke's original question, the frame height and angle should be virtually the same for all practical purposes.

 

[kingfish254]

I tossed the tires when I parted out the bike. I'll have to wait until I'm at my office to measure the wheels for you.
The tires that were on it would probably be pretty close in height to your MTB 24" wheels.

 

[The Renaissance Man]

I tossed the tires when I parted out the bike. I'll have to wait until I'm at my office to measure the wheels for you.
The tires that were on it would probably be pretty close in height to your MTB 24" wheels.

No need, I was just curious about the height with the tires. Thanks anyway! Like you said, it's probably close to the same.

 

[GuitarlCarl]

Using stock crank and pedals? I'll bet it changes more than you think... but it won't be unmanageable. An inch or so change in ride height at the crank shouldn't scrape too bad except deep into the cornering.

Carl.

 

[The Renaissance Man]

Carl, you may be right. I wish I had the original specs to know for sure.

I mounted the wheels and rolled it out to compare it to my 20" Schwinn Scrambler. I found that the BB on both bikes are almost exactly the same. However, the crank arms are shorter on the Schwinn. It (the Schwinn) measured 4 1/2" from the pedal to the ground and the Smartbike is 3 1/2". Who knows what the Smartbike measured originally.

I lined up the two front axels for a side by side comparison. They are very close in size but the Smartbike has far more leg room! You can also get an idea of just how much taller the rear tire is. I didn't think to point the cranks down. The seat on the Schwinn is raised about as high as possible and is in a good riding position for me.

 

[Chad T]

Wow that looks cool with the 20 on the back. 20 x 1 3/8 would look sweet on the front IMO but I'm sure you have a plan already...

Totally want one of those frames now. Love the way it lines up with the Stingray. The later long frame Stingrays are fairly roomy and you've got a lot more with that bike.

Plenty of ground clearance. The later Schwinn frames are pretty high at the bb. Fastbacks and short stingray frames are pedal draggers from the factory.

 

[LukeTheJoker]

The reasoning sounds right, but the missing variable is the tires. That's why I'd be interested in the original wheel/tire hight if Brian still has it.

(Read with the voice of Maxwell Smart)... Well Chief, I measured a 24" Mt. bike that I have on hand and came up with 11 1/2" from ground to center of the axel. The 20" wheel and (fat) tire that I've got is 10 3/4". That works out to be 3/4" shorter at the drop out. Using Luke's formula it would only be 3/8" at the bottom bracket. Now, take that and factor in the angle of the slot in the drop out and it's conceivably possible for there to be no difference depending on the location of the axel in the drop out for each size wheel/tire combination!

...So to answer Luke's original question, the frame height and angle should be virtually the same for all practical purposes.

Gold!

Carl, you may be right. I wish I had the original specs to know for sure.

I mounted the wheels and rolled it out to compare it to my 20" Schwinn Scrambler. I found that the BB on both bikes are almost exactly the same. However, the crank arms are shorter on the Schwinn. It (the Schwinn) measured 4 1/2" from the pedal to the ground and the Smartbike is 3 1/2". Who knows what the Smartbike measured originally.

I lined up the two front axels for a side by side comparison. They are very close in size but the Smartbike has far more leg room! You can also get an idea of just how much taller the rear tire is. I didn't think to point the cranks down. The seat on the Schwinn is raised about as high as possible and is in a good riding position for me.
View attachment 33137

That looks awesome!
Any chance you could get me some measurements on a diagram of the frame?
I am thinking about gearing up to build 5 or so production frames, and this looks like a great candidate for inspiration!

Luke.

 

[OddJob]

 

[OddJob]

Jim, this Get Smart theme is pun-ishing....love it!

 

[The Renaissance Man]

Here's a look at the profile by itself. I'm liking this more and more!

I'm on the hunt for the skinniest 20" front tire possible. Very minimal tread also, any suggestions?

 

[Dr. Tankenstein]

Found these skinny minis
https://www.ebay.com/itm/262370637208
https://www.ebay.com/itm/311652072273
https://www.ebay.com/itm/122038588962
https://www.ebay.com/itm/291420300728
I really like this one
https://www.ebay.com/itm/182128695227
Loving this so far!


Sent from my iPhone using Tapatalk

 

[Psycho Sammi]

Kids bicycle trailers and joggers usually have very narrow tires and don't have much in the way of tread. The ones I just took off my trailer were 20x1.75 kendas

 

[furyus]

Carl, you may be right. I wish I had the original specs to know for sure.

I mounted the wheels and rolled it out to compare it to my 20" Schwinn Scrambler. I found that the BB on both bikes are almost exactly the same. However, the crank arms are shorter on the Schwinn. It (the Schwinn) measured 4 1/2" from the pedal to the ground and the Smartbike is 3 1/2". Who knows what the Smartbike measured originally.

I lined up the two front axels for a side by side comparison. They are very close in size but the Smartbike has far more leg room! You can also get an idea of just how much taller the rear tire is. I didn't think to point the cranks down. The seat on the Schwinn is raised about as high as possible and is in a good riding position for me.
View attachment 33137

I'm sold on this concept. Love the dimensions. Really cool.
furyus

 

[GuitarlCarl]

20 x 1.5 Vee Rubber Baldy on eBay
20 x 1.5 Schwalbe Tryker on eBay
20 x 1.35 Schwalbe Kojak on eBay

Carl.

 

[kingfish254]

I knew there was a cool muscle bike hidden in that frame when I first saw it on craigslist. I'm liking the stance so far. As far as skinny 20" slicks, there are a few that people run on Dahon and Bike Friday bikes.

 

[OddJob]

Carl is on to something (or on something) ^ with his suggestions. I am running this tire on Four-gone. The English wheels always run a bit skinnier too.....
http://www.ebay.com/itm/Vee-Tire-Co...ffb84d1&pid=100623&rk=4&rkt=6&sd=291594926539