• Please take a moment to read the new post TRADING SAFETY. It contains important information for those who use the classified ads for buying and selling.
Most Recent BUY IT NOW Items Listed on eBay
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture
eBay Auction Picture

cbustapeck

Wore out three sets of tires already!
I just purchased this Schwinn Cruiser Seven for the Shimano Nexus 7 speed internal hub wheel set, with the idea of selling off the remainder of the bike to cover the purchase cost.

I'd love to own an Elgin Twin Bar, but they're more money than I care to spend, and I've heard bad things about the flexibility of the frame. A bicycle that I'm worried about breaking because of how expensive it is, combined with it flexing and making me worry? No, thank you.

The idea of a Schwinn Twin Bar came to mind and I started thinking through it.

4C1B97C4-E484-4FA7-B419-18A09E0A100A (1).jpg


Note: I'm writing this because I know absolutely nothing of structural engineering and because I want input on structural engineering. Take any "I think" or "it should" statements with that massive grain of salt.

I see two big issues with getting rid of the seat post:
1. A significant amount of weight is being placed on the frame at a point without structural bracing.
2. You've made this major structural compromise and the aesthetic advantage of it is hidden mostly by your legs!

If we remove the seat from that position, both of these problems are solved, at least somewhat.

The visual of the rack isn't bad. I was thinking about a custom cushion to go on top of it, with the intended sitting position above the rear axle. That way, the majority of the weight is supported by the axle, rather than the frame.

Has anyone tried something like this? What are your thoughts about structural stability? What major issues, other than those of having another bike in the house, am I missing here?
 

Andrew Gorman

Cruisin' on my Bluebird
Break out the hacksaw or angle grinder and test it out! There will be more flex and wiggling, but you can see just how much before you commit to the whole project. You can still sell of the other bits if you want to.
 

Frank and Pam Skid Kings

I live for the CABE
I'm not an engineer, so like you said I won't comment on structure, but...there were a lot of Elgin Twin bars made and a lot still exist. I think the flex on original is somewhat of a myth. They ride great, built like a tank, just don't go jumping with them (or any old bike). That being said if you can live without all Twin extras, the frames are fairly easy to come by and not a lot of money. It's when you start talking "all original" it gets scary (trust me ,I know). Sell off your parts bike and check around for a Elgin twin frame, usually under $400 with wheels, sprocket etc. Less if you get just a frame. Ether way good luck and have fun !
 

cbustapeck

Wore out three sets of tires already!
I'm not an engineer, so like you said I won't comment on structure, but...there were a lot of Elgin Twin bars made and a lot still exist. I think the flex on original is somewhat of a myth. They ride great, built like a tank, just don't go jumping with them (or any old bike). That being said if you can live without all Twin extras, the frames are fairly easy to come by and not a lot of money. It's when you start talking "all original" it gets scary (trust me ,I know). Sell off your parts bike and check around for a Elgin twin frame, usually under $400 with wheels, sprocket etc. Less if you get just a frame. Ether way good luck and have fun !
Seriously? I must be looking in all the wrong places!
 

Frank and Pam Skid Kings

I live for the CABE
Seriously? I must be looking in all the wrong places!
I bought one in January that had been for sale on line for a month for $450. Nice frame, good but incorrect seat, nice wheels and tires, bars, a rider when I picked it up. Missing the head shroud, crank shroud, no chain guard, no rack and oh no fenders or kick stand or original Elgin grips. Still a good looking bike without all that stuff. I did add most of that, gave me something to hunt down during covid and no swap meets. Here's a not bad deal that may or may not still be available, but gives you an idea. https://thecabe.com/forum/threads/elgin-twin-bar-frame-set-and-wheels.169999/
 

Freqman1

Riding a '37 Dayton Super Streamline
There are a lot of bikes more susceptible to breaking than a Elgin Twin--post war Monark's come to mind. I had a Twin and rode the heck out of it and never noticed flex. I would waste my time trying to weld one these Chinese bikes. If you want a Twin save some coin and get a frame like F&P said. V/r Shawn
 

cbustapeck

Wore out three sets of tires already!
I did it!

A0FB42A0-0821-4B0D-BA96-989387F9324A.jpeg


The lines work even better than I had hoped.

Yes, there is some flex, but less than my girl’s 1935 Silver King - not that that is saying much. I feel comfortable using it as a rider, but definitely not with my weight sitting over where the seat post was.

For what it’s worth, I weigh a good bit more than the average rider that these bikes were designed for - at least in 1935.
 

Superman1984

I live for the CABE
I did it!

View attachment 1307221

The lines work even better than I had hoped.

Yes, there is some flex, but less than my girl’s 1935 Silver King - not that that is saying much. I feel comfortable using it as a rider, but definitely not with my weight sitting over where the seat post was.

For what it’s worth, I weigh a good bit more than the average rider that these bikes were designed for - at least in 1935.
It definitely improves the looks of the cantilever frames. You know you could weld flat bar under the top tubes; either in sections or 1 solid piece to stiffen it. Mind if I ask what you paid for the bike? I have the exact girl's model I bought for an ex for $75 minus a rack (If it came with 1?). I need to replace the push button shifter though. Debating the Nexus 7 swap to my Nirve Switchblade until it's motored.
 

cbustapeck

Wore out three sets of tires already!
It definitely improves the looks of the cantilever frames. You know you could weld flat bar under the top tubes; either in sections or 1 solid piece to stiffen it. Mind if I ask what you paid for the bike? I have the exact girl's model I bought for an ex for $75 minus a rack (If it came with 1?). I need to replace the push button shifter though. Debating the Nexus 7 swap to my Nirve Switchblade until it's motored.
.
I paid $90, delivered. It’s a solid bike, but not as nice as it looks. It spent a good bit of time outside.

I think the prospect of a wheel set that you can just swap into any number of bikes and have a range of gears alone is worth a good bit.
 

Superman1984

I live for the CABE
.
I paid $90, delivered. It’s a solid bike, but not as nice as it looks. It spent a good bit of time outside.

I think the prospect of a wheel set that you can just swap into any number of bikes and have a range of gears alone is worth a good bit.
Not bad at all. Mine has some dings & scuffs but not complaining vs what I seen the Nexus 7 going for online alone & useable parts. Guy said he was selling his gf's bike since she didn't ride it & had he known it was like $350+ he said he wished he listed it higher. I was thinking of using an aluminum La Jolla bicycle frame tube to convert it into a boys top bar bike; notch the top tube to the seat post & around the goose neck bolted on since can't weld aluminum. Jus' haven't ground the aluminum welds down & actually decided it's worth the hassle. Currently debating using the fenders & parts for a '53 Monark Rocket or an early post war CWC Roadmaster which I want to convert into a straight bar since it's original but has break at the seat tube & crank. It'll be all steel & welded proper.
 

cbustapeck

Wore out three sets of tires already!
70FAFC20-34EB-4D1D-87B3-E578CF816369.jpeg


9117A36C-C1C3-4E4E-87A0-C157BDB94AFA.jpeg



42F40469-BCEE-4C9A-9C9F-2313E8EABEF8.jpeg


05C03DD1-22B1-4D47-871D-F83AC5B4C8D0.jpeg


I definitely like where this is going.

I am working on figuring out the seating arrangement. Resting on the rear axle makes the most sense, both for structure and the shape of my body, but I am not sure how I am getting there yet.
 

cbustapeck

Wore out three sets of tires already!
Do it!

One big thought:
I would strongly strongly consider keeping the seat clamp in place until you are 100% sure of how the seat is to be held in place. I am thinking about a banana seat, which would still need a clamp, even if the vast majority of the weight would be over the rear axle.

More likely, though, I am going to trade it off to the guy at my bike shop, less the wheels, in trade for wheelbuilding for my Luxury Liner. (It's not that I don't like it, it's that I initially bought it for the wheels, and I would rather have the Luxury Liner on the road than this bike.)

It's also worth noting that it got the fun accessories that it did because I already had them on hand and had not been able to use them. The build was partially an excuse to use said accessories.

All that said:
DO IT!
 

Bike from the Dead

Finally riding a big boys bike
Do it!

One big thought:
I would strongly strongly consider keeping the seat clamp in place until you are 100% sure of how the seat is to be held in place. I am thinking about a banana seat, which would still need a clamp, even if the vast majority of the weight would be over the rear axle.

More likely, though, I am going to trade it off to the guy at my bike shop, less the wheels, in trade for wheelbuilding for my Luxury Liner. (It's not that I don't like it, it's that I initially bought it for the wheels, and I would rather have the Luxury Liner on the road than this bike.)

It's also worth noting that it got the fun accessories that it did because I already had them on hand and had not been able to use them. The build was partially an excuse to use said accessories.

All that said:
DO IT!
You aren't planning on trading this bike project before you finish it, are you? I really want to see what this would look and ride like in a finished state.
 

cbustapeck

Wore out three sets of tires already!
You aren't planning on trading this bike project before you finish it, are you? I really want to see what this would look and ride like in a finished state.
I am.

The lines of this bike are as close to perfect as I can make them, except for maybe some minor details.

I’ve thought long and hard about seating options, and everything that I have come up with detracts from the aesthetics or costs far more than I care to spend, and might even not look right once done.

I may have brought this bicycle as far as I can. It may be time for someone else to use their creativity to bring it to completion.

It is also a matter of financial choices: I’d rather have the wheels built for my Luxury Liner and finish that project than keep this one around while I think about it.
 

Bike from the Dead

Finally riding a big boys bike
I am.

The lines of this bike are as close to perfect as I can make them, except for maybe some minor details.

I’ve thought long and hard about seating options, and everything that I have come up with detracts from the aesthetics or costs far more than I care to spend, and might even not look right once done.

I may have brought this bicycle as far as I can. It may be time for someone else to use their creativity to bring it to completion.

It is also a matter of financial choices: I’d rather have the wheels built for my Luxury Liner and finish that project than keep this one around while I think about it.
I understand. Still, it would be an interesting experiment to play around with. I might be testing it out on this trike I'm building right now, but I might see about getting a cheap Huffy or something to do some more thorough experimentation on this idea.
 

Superman1984

I live for the CABE
I understand. Still, it would be an interesting experiment to play around with. I might be testing it out on this trike I'm building right now, but I might see about getting a cheap Huffy or something to do some more thorough experimentation on this idea.
What do you want to know? Save yourself some hassles. I can tell you pretty much from experience on cantilever style frames. There's reasons I don't care for them both aesthetically & build wise
 

Bike from the Dead

Finally riding a big boys bike
What do you want to know? Save yourself some hassles. I can tell you pretty much from experience on cantilever style frames. There's reasons I don't care for them both aesthetically & build wise
Well, I'm mostly hoping to figure this out for my Poison Apple muscle trike build. I don't know if you saw the latest update to it, but I'm thinking of removing the seat tube and original top tube, and converting the frame into a boy's cantilever style frame, sans seat tube, but with the headset angled back and the tank portion all welded to the frame. Like this bike, I plan to put the seat over the rear axle, except mine's a trike, and the rear axle is behind the bike frame. I want to know if my idea would still be strong and rigid enough to work, especially with a 250lb guy riding it.
 

rustjunkie

Moderator
Staff member
I’ve thought long and hard about seating options, and everything that I have come up with detracts from the aesthetics or costs far more than I care to spend, and might even not look right once done.


i’m seeing a bobber seat in the space between frame and fender, with a mount up front and springs attached to mounts welded to the seat stays

1A96F7F0-CE93-4CC9-9C39-61FF2B724ED5.jpeg
 

Superman1984

I live for the CABE
Well, I'm mostly hoping to figure this out for my Poison Apple muscle trike build. I don't know if you saw the latest update to it, but I'm thinking of removing the seat tube and original top tube, and converting the frame into a boy's cantilever style frame, sans seat tube, but with the headset angled back and the tank portion all welded to the frame. Like this bike, I plan to put the seat over the rear axle, except mine's a trike, and the rear axle is behind the bike frame. I want to know if my idea would still be strong and rigid enough to work, especially with a 250lb guy riding it.
I don't know about 250 lbs on most standard bikes but as long as all the weight isn't on where the seat tube is removed it should be fine. On twin tube stuff like cantilevers the seat tube helps distribute the weight to keep it from collapsing/cracking the frames. They're engineered almost like a car's leaf spring but not meant to flex via seat tube. I say too much weight over the rear tire or tires in your case of a trike conversion & it will wheelie or pop up. I would still try to go in front of the axle and after the original seat post as my main weight point
 
Top