When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Prewar ballooner forks vs forged blade forks

#eBayPartner    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

Mack the fork

Look Ma, No Hands!
I have lusted for some time, for an earlier fork for my ‘40 DX bomber.
I don’t know what it is, but I just love the appearance of the earlier trust forks with the forward facing stanchions that brace the truss rods.

I’ve never actually fondled one of these forks in real life, therefore I actually don’t know how they’re made, or if they’re actually very strong compared to the forged
Ashtabula blade-type trussed forks.

From photos, it appears that the earlier prewar truss forks ( with the truss rod braces )were solid near the top , but became tubular nearer the axle end. As if welding a forged fork crown onto tubular fork legs , then smoothing the welds to appear all one piece.

Is that a correct observation/ description?

whereas the later, forged blade Ashtabula forks were forged flat as a single piecefrom top to bottom.

question #1 :
How were earlier Schwinn truss forks made
( such as on a 1936 “Double Diamond ) ?

question #2 :
What year was the forged Ashtabula flat blade fork introduced into the DX line ?

question #3 :
Is the later, forged, one piece,Ashtabula blade-type truss fork considered to be stronger than the earlier prewar truss forks ?
 
A properly constructed tubular fork will generally be stronger than a flat blade, ashtabula-type fork. Both types are relatively strong in terms of normal up/down shock stress. Both forks will bend, usually up at the steerer tube (but sometimes just below the shoulders) when hit with a strong blow from the front, which is not a "normal" riding stress, but the sort of stress from being run into something. My experience is tubular forks are little stronger in this regard, but it's possible to bend any of these old forks if you run into something.

Where the tubular fork is significantly more rigid is in resisting side-to-side stress, such as you would encounter banking steeply into a hard turn. The flat blade forks have a good deal of softness/give when you do that, whereas the tubular forks are more rigid side-to-side. In fact, some of the later flat forks used on the early BMX bikes actually have a reinforcing bar welded on below the crown to add rigidity.

So if one had to say which is "stronger", I would say the tubular type fork. But either type should be sufficiently strong unless you are really beating the hell out of the bike, or running into things, etc. Both forks will hold up to normal use. I prefer the extra rigidity of a tubular fork, but I wouldn't pass up a nice bike with a flat fork at the right price. The main virtue of the flat fork was the production cost and time for manufacturer/supplier.
 
A properly constructed tubular fork will generally be stronger than a flat blade, ashtabula-type fork. Both types are relatively strong in terms of normal up/down shock stress. Both forks will bend, usually up at the steerer tube (but sometimes just below the shoulders) when hit with a strong blow from the front, which is not a "normal" riding stress, but the sort of stress from being run into something. My experience is tubular forks are little stronger in this regard, but it's possible to bend any of these old forks if you run into something.

Where the tubular fork is significantly more rigid is in resisting side-to-side stress, such as you would encounter banking steeply into a hard turn. The flat blade forks have a good deal of softness/give when you do that, whereas the tubular forks are more rigid side-to-side. In fact, some of the later flat forks used on the early BMX bikes actually have a reinforcing bar welded on below the crown to add rigidity.

So if one had to say which is "stronger", I would say the tubular type fork. But either type should be sufficiently strong unless you are really beating the hell out of the bike, or running into things, etc. Both forks will hold up to normal use. I prefer the extra rigidity of a tubular fork, but I wouldn't pass up a nice bike with a flat fork at the right price. The main virtue of the flat fork was the production cost and time for manufacturer/supplier.
Thank you SirMike , that’s what I was looking for !
 
if I were going to do Evil Knievil jumps on a bike I'd pick the blade fork over the truss rod, and definitely over the lightweight tubular fork.
 
if I were going to do Evil Knievil jumps on a bike I'd pick the blade fork over the truss rod, and definitely over the lightweight tubular fork.
Hmmmm…. Evil Knievel jumps you say ..,
if I were going to do Evil Knievil jumps on a bike I'd pick the blade fork over the truss rod, and definitely over the lightweight tubular fork.
Hmmmmm… Evil Knievel jumps you say …

1631243309710.png
 
Back
Top