# To C or not to BC



## Obi-Wan Schwinnobi (Jan 8, 2015)

Here is a quick primer on the frame difference between c models and bc or some straight down tube motorbike models. 
First up is a cmod frame. Take notice to the rear stay geometry along with the difference in where the straight bar attached to the down tube and mast tube. Notice on the c mod the bar has more of a gap between the top tube and where it meets the mast tube top tube juncture also the the straight bar attached higher up the straight down tube. The top tube also has a different bend to it.  Sometime in 1940 but probably 41 c mods had ears attached to the frame for a drop stand from what I've researched. Tank aperture is smaller. 



 1939


 1941 with ears




Next up is a BC frame or motorbike depending on year. Notice the rear stay geometry.  Notice where the straight bar tube attached higher up the mast tube being closer to the top bar. The bar also attached further down the down tube like a b model. Tank aperture is bigger then c model. Notice top tubes gentle curve as compared to a c model. 






This is a late Louisville cycle supply motorbike courtesy of Mr zebb




Next up is a double diamond frame notice rear stays are straight forming a diamond






Rule o thumb... if your fist is a super tight fit in between the top bar and lower bar it's a cmod... if you have wiggle room depending on your fist size it's a bc or equivalent. Please feel free to add differences between the years of both models.. ie tank fender lights fenders ect. Sometime in the late 40 I want to say the bc frame started having a curved down tube from what I've seen.


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## Obi-Wan Schwinnobi (Jan 8, 2015)

Here is a 1940 b and bc pictured side by side. 




Notice the bc sits lower and has a curved down tube. I believe the rear stay on the Autocycle is perhaps longer? Notice how the bottom stays curve up a bit going into the drop outs on both of these as opposed to being straight like on c mods and  bc mods.  Maybe someone can shed some light on that. If you see your bike let me know and I'll add photo credits. Also thsnks to everyone who I've been able to gather this info from.


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## Obi-Wan Schwinnobi (Jan 8, 2015)

Like I said feel free to correct me on anything that is wrong via pm as to not cloud up the info and I will change and give credit


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## fordmike65 (Jan 8, 2015)

...........


As you wish.


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## Obi-Wan Schwinnobi (Jan 8, 2015)

Thanks you big lug


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## Robertriley (Jan 8, 2015)

Obi-Wan Schwinnobi said:


> Thanks you big lug




Agree with mike...lol. 

In all seriousness, this is great info and should be a sticky thread.  

Thank you for taking the time to put this information together.


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## tripple3 (Jan 8, 2015)

Thank you Obi-Wan. I look at these and still get confused but I'm learning and wanted to add a couple pics. 



1936  electric C mod above. 



1936 Moto bike above. 



1939 Mead crusader C mod with curved downtube above. 



Same bike a little different angle.


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## Obi-Wan Schwinnobi (Jan 8, 2015)

Nice tall frame c model


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## tripple3 (Jan 8, 2015)

*C-mods*

Trying not to add more confusion...the Crusader is a Tall frame, 20 " center of BB to top of seat mast; black Electric is 19"


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## Obi-Wan Schwinnobi (Jan 8, 2015)

...............


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## El Hefe Grande (Jan 8, 2015)

Thank you Obi - Wan for the explanation and images...I had to pull out my frame to make sense of the descriptions but it has really helped...

I have a few more questions if that is okay...

On the "C' model - The truss rods (that I have seen from images) have a slight angle after the fork eyelets and go straight up to the fork bracket... they do not have any bend to them.  

On other models, the truss rods have a slight bend after the fork eyelets.  this style is more pleasing to the eye in my opinion

Did the truss rods style change over the production of the model "C" or were they all the same?

Maybe I'm confusing these with the "BC" frames?


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## Obi-Wan Schwinnobi (Jan 8, 2015)

El Hefe Grande said:


> Thank you Obi - Wan for the explanation and images...I had to pull out my frame to make sense of the descriptions but it has really helped...
> 
> I have a few more questions if that is okay...
> 
> ...



 The early production c models are the ones that had the bend you speak of, after that all the same I think. So 36 to 37 possibly
C mod was a way to get rid of parts they had laying around.  So that style truss probably is leftover b10 stuff


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## Obi-Wan Schwinnobi (Jan 8, 2015)

El Hefe Grande said:


> Thank you Obi - Wan for the explanation and images...I had to pull out my frame to make sense of the descriptions but it has really helped...
> 
> I have a few more questions if that is okay...
> 
> ...



You mean these yes?


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## decotriumph (Jan 8, 2015)

I think I shall never learn to speak Schwinnese.


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## schwinnking310 (Jan 8, 2015)

Thanks bro for posting this post helps 


Sent from my iPhone using Tapatalk


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## Ozark Flyer (Jan 8, 2015)

Thanks for posting Obi.  Great info.  Never heard of the fist trick.  Just knew the opening was smaller on the C.


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## bobcycles (Jan 8, 2015)

Anyone know whatever happened to *JC*? I think he had a *BC*.....and maybe a *C*...........and tho not *PC* could have swung both *AC / DC..........there, C how EC that was?*


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## Obi-Wan Schwinnobi (Jan 8, 2015)

Ozark Flyer said:


> Thanks for posting Obi.  Great info.  Never heard of the fist trick.  Just knew the opening was smaller on the B.



Smaller on the c


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## El Hefe Grande (Jan 8, 2015)

Yes, these are the truss rods...notice the flat fender braces...


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## Ozark Flyer (Jan 9, 2015)

Obi-Wan Schwinnobi said:


> Smaller on the c




All thumbs, yes, c.


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## ChattyMatty (Jan 9, 2015)

So th correct label for this '38 would be a 16" Model C?


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## bikewhorder (Jan 10, 2015)

I rarely get excited about Schwinns but I love the BC's. This is one that Paul had at Copake last year that is the bike I most regret not buying from that show. 





Edit* maybe this is a c mod? I could have sworn these were always called Bc's.  Couldn't someone post some catalogue pages to back this up?


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## Aerocycle36 (Jan 11, 2015)

DX, B model, C model (tall),  and Motorbike.  Then there is the Aerocycle and a Camelback. (The Aerocycle is a fake).


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## scrubbinrims (Jan 11, 2015)

bikewhorder said:


> I rarely get excited about Schwinns but I love the BC's. This is one that Paul had at Copake last year that is the bike I most regret not buying from that show.
> 
> View attachment 190191




and how that bike looks today...
Chris


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## Obi-Wan Schwinnobi (Jan 11, 2015)

Thanks for adding the frames! The early B model shown would become the platform for the BC frame later on among others. Later B models would start having the curved dt and lower stays with a slight upward bend.


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## Aerocycle36 (Jan 11, 2015)

I'm Fairly certain that this fork isn't original to this C frame, I would like to find a tall Cantilever frame to put it on.


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## Obi-Wan Schwinnobi (Jan 11, 2015)

Leave it! You could get a c mod with one. Saw it for xtra cost in the lit. C mod with a double duty would be sweet


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## Aerocycle36 (Jan 11, 2015)

It's a tall frame and I'm sure the fork is the same height as a Girls fork, guess I need to start collecting parts...


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## El Hefe Grande (Jan 12, 2015)

Aerocycle36 said:


> DX, B model, C model (tall),  and Motorbike.  Then there is the Aerocycle and a Camelback. (The Aerocycle is a fake).  View attachment 190343View attachment 190344





If possible, can you clarify the year for each frame?

The third frame that you have identified as a "Model C" is different than the earlier images labeled Model C from Obi-Wan. 

Your frames Straight Bar ( Middle Bar) intersect with Both the Bottom Straight Bar and the Fork (or Steer) Tube. There is another frame shown on page 2 of this thread...a 1939 Mead with the curved down tube that has the same intersection point at the Fork tube so maybe your frame is another type of Model C?

Just trying to understand what the differences are...


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## Aerocycle36 (Jan 12, 2015)

It is a tall C model frame. Due to the taller head tube, the geometry on tall frames is a little different from a regular frame.


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## El Hefe Grande (Jan 12, 2015)

Thanks!


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## tripple3 (Jan 14, 2015)

*C-mod for Mead....*

The Mead is also a tall frame, and the only "C" I have seen with a curved dt. 


Aerocycle36 said:


> It is a tall C model frame. Due to the taller head tube, the geometry on tall frames is a little different from a regular frame.


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## tripple3 (Jan 27, 2015)

*B, BC, C mods*

Old Hotrod put this up. I see BC characteristics... so the B tank would fit this Right??



B and BC take the bigger tank?? 
I dig this BC Dave; thanks for posting.


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## tripple3 (Feb 25, 2015)

*C model*

Bump for more discussion....and to show a Tall Frame C-mod with hanging tank for sale.


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## Ozark Flyer (Feb 25, 2015)

Could someone help explain this?  Note extra tall seat tube, 19" top of seat clamp to center of crank, but the lower top tube attaches to the down tube at a location like the 18" models. It looks like the seat tube came from a tall model but the frame is a standard. Tall or standard frame?


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## tripple3 (Feb 25, 2015)

*Medium size...?*



Ozark Flyer said:


> Could someone help explain this?  Note extra tall seat tube, 19" top of seat clamp to center of crank, but the lower top tube attaches to the down tube at a location like the 18" models.  Tall or standard frame?




My black 36 is identical. 19"


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## ZOOK (Feb 25, 2015)

very interesting thread here. i had to go pull out some bikes and compare the frames to see if i could figure them out. thank all of you for the post/postings


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## OC_Rolling_Art (Sep 8, 2019)

scrubbinrims said:


> and how that bike looks today...
> Chris
> View attachment 190345View attachment 190346



Liking the work you put into this one... the paint came back really nicely.


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## mr.cycleplane (Sep 9, 2019)




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## mr.cycleplane (Sep 9, 2019)

The 'b' and 'bc' are the same frame with different paint schemes. This applies to both the 'diamond' frame and the 'curved lower bar' frame on both 'b' and ''bc'. The 'b' model in general has 'points' pattern(*) and the 'bc' has an 'arrowhead/darts' pattern on the head tube area. (The 'c' model has been found with both 'points' and 'arrowhead/darts' pattern). Depending how they are equipped with or without tanks changes the model within the 'b' or 'bc' range offerings. To answer one of the questions above-the tank from the 'bc' will fit the regular motorbike 'b' frame-and vice verse! (Actually the 'bc' tank pressings are the same as the 'b' motorbike but without a door and have a push button buzzer on the left side in place of the door found on the motorbike tank.).

(*)The paint pattern will vary on 'b.f. goodrich' built models.


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## schwinnja (Oct 3, 2019)

Bump.


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## tripple3 (Oct 5, 2019)

Bump it with a pic!
1936 Electric, C-model, 19" frame


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## BatWaves (Oct 13, 2019)

Though I’m slightly confused again...Haha. Tell me what you think this 18”  ‘36 is. I had thought it was a B model based on the width between the top tubes vs the model C


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## mr.cycleplane (Oct 13, 2019)

Hands down-this is a 'b' frame(1936)-will fit the motorbike tank/bc tank also-but paint scheme says its a 'b'. nice patina!


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