Accessories	Bicycles	Parts	Specials	Tools

In West Newton Since 1952 - On The Web Since 1995

Search HarrisCyclery.com Search WWW

Parts for Older American Bicycles

by Sheldon Brown

Bottom Brackets | Chainrings | Cranks | Frame tube diameters | Seatposts | Pedals | Headsets | Stems

We love old American bicycles.
We stock repair parts to help keep yours on the road.
We can help with hard-to-find parts and accessories and good advice.

We ship hard-to-find parts, tools and accessories all over the world

From the WW I era to the 1970s, U.S. made bicycles, often of very high quality, were built to rather different standards than those that prevailed in the rest of the world. These bicycles used different standards for bottom brackets and cranks, frame tube diameters, seatposts, pedals, headsets and handlebar stems.

When the 1970's bike boom brought large numbers of European (and later, Asian) bikes to the U.S., the older American dimensional tolerances went into retreat, and were increasingly relegated to department store bicycles, such as Huffy and Murray. People began to associate the American dimensions with these low-end bikes, and to forget that many high-quality machines had been made to these standards. While the European bikes were undeniably lighter and faster, the better American bikes were made with a greater emphasis on durability and ruggedness.

BMX bikes are still largely made to American dimensions, and the BMX segment is one of the key sources for American sized parts. The early ancestors of the mountain bike were based on older American "cruiser" frames, and many early purpose-built mountain bikes used these standards.

One-Piece "Ashtabula" Cranks and Bottom Brackets

The most distinctive part of this type of bike is the one-piece steel crank. The better ones are a solid forging, incorporating the left arm, axle, and right arm in a single piece of steel. These are the strongest cranks available. This is what makes them popular for BMX and children's bikes that are subject to rough usage. They are also the only type of crankset that can be serviced with ordinary household tools...all you need is a large adjustable wrench and a screwdriver.

Interchangeability

There are two major types of one-piece crank sets, differentiated by their threading. The more common size uses 24 threads per inch, but some bikes, particularly older U.S. made Schwinn and Mongoose models, use 28 threads per inch. No part of the bearing assembly is interchangeable between threadings.

24 tpi cranks (with the exception of Tange brand, which use #64 9-ball)
use #66 retainers, with 10 5/16" balls

28 tpi cranks use #64 retainers, with 9 5/16" balls.

The pressed-in cups are also a different size. It is usually a good idea to buy a whole set (cones, cups, retainers) if there is serious wear to any of the parts. These are not expensive.

Note: any frame that will work with one of these sizes will also work with the other. The compatibility issue is with the actual one-piece crank, not the frame.

Tange 24 tpi thread Bottom Bracket Bearing Kits BB030 $15.95 The 24 tpi thread size fits almost all one-piece cranks except for the original-equipment cranks on older U.S. made Schwinn and Mongoose bikes.
Tange 28 tpi thread Bottom Bracket Bearing Kits BB029 $15.95 This 28 tpi thread size fits original cranks on most older U.S. made Schwinn and Mongoose bikes. (Other brands and replacement cranks generally use the 24 tpi size shown above.)

One Piece Cranks (1/2" Pedal Thread) Part # Brand Thread Length Price CK286 Generic 24 tpi 165 mm (6 1/2"-adult size) $12.95 CK285 Generic 24 tpi 140 mm (5 1/2"-child size) CK286 Generic 24 tpi 165 mm (6 1/2"-adult size) Long pin-for triple chainrings $12.95

New!  One Piece Crank for 9/16" Pedals At last!! Now you can put high quality and clipless 9/16" pedals on your vintage American bike! Sheldon always wished a pedal mfr. would make clipless pedals in 1/2" thread for the old American One Piece Crank bicycles. Here's the next best thing! An OPC crank threaded for 9/16" pedals. This crank is compatable with all standard (24 tpi) OPC bottom brackets. Not recommended for BMX bikes. 6-1/2" steel crank. Black With long pin for triple chainring (Will work with singles and doubles too.) Be the first kid on your block to put clipless pedals onto your Schwinn Varsity!

OPC Single Chainrings These work with either 3/32" or 1/8" chain, fit any standard one-piece crank.
44 teeth	CRA501 $8.95
46 teeth	CRA502 $8.95
48 teeth	CRA503 $8.95
52 teeth	CRA504 $8.95

OPC Chainrings for Derailer Applications:
Single 44 teeth	CRA509 $11.95	With double plastic guards
Triple 28-38-48 teeth	CRA535 $19.95	Riveted construction with steel guard disc
Power Disc Aluminum 110 or 130 BCD	$19.95	Use any 110 mm BCD or 130 mm BCD chainring(s) with your existing one piece crank. Single or double. Chainring bolts not included.

One-Piece Compatible Parts from the Quality Special Order Catalogue
Conversion Kits	Bottom Brackets	One-Piece Cranks	Chainwheels	Crank Spiders

 

Conversion Kits

If you wish to upgrade a bike built for one-piece cranks to use modern 3-piece "cotterless" cranks, you need a "conversion kit." This consists of a special bottom bracket axle and associated bearing parts that can be pressed into a one-piece-crank type frame.

TruVativ American-to-Euro Conversion kit Out Of Stock These beautifully machined aluminum bushings fit into the shell of a one-piece-crank bottom bracket, and are threaded to accept a standard threaded bottom bracket, normal 68 mm width. 3 long CrMo bolts connect the two bushings to one another for a secure mounting. This saves weight, improves shifting, and allows the use of modern clipless pedals. Be the first kid on your block to put a Dura-Ace crankset into your Schwinn Varsity!

The TruVativ Conversion kits will be out of stock for the foreseeable future. The Bulletproof version is very similar to the TruVativ.

New! Bulletproof American-to-Euro Conversion kit $21.95 4 long CrMo bolts connect the two bushings to one another for a secure mounting. This saves weight, improves shifting, and allows the use of modern clipless pedals.

Frame dimensions

American-style bikes generally are built with thinner tubing than foreign ones. The compensate for the thinner diameter by using tubing with thicker walls. The frames tend to be plenty sturdy, but a bit on the heavy side. The thick-walled tubing lended itself to welded construction, which was not possible with thin-wall tubing before the development of TIG welding and similar processes.

Seatposts

Since American style frames use smaller tubing diameters, they also need to use skinnier seatposts. The most common sizes are 7/8" (22.2 mm) and 13/16" (20.6 mm)

Wald 13/16" (21.15 m) Seatpost, 15 inches $9.95

Many older U.S. made bikes take this thin size. Unfortunately, there's very little choice in this diameter. This Wald galvanized steel seatpost is plenty long, but if fully extended, a heavier rider may well cause it to bend.

The top end is enlarged to 7/8" to fit standard saddle clamps.

7/8" (22.2 mm) Seatposts

See the Quality Bicycle Products Catalogue

We carry seatposts in these sizes, but haven't yet had time to list them on the Web site.

Pedals

Since one-piece cranks have to be able to fit through the bearing cones for assembly, the cranks cannot be as thick as three-piece cranks. As a result, they have to use a smaller diameter pedal thread, 1/2" instead of 9/16".

New! Wellgo Toe-Clippable Quill Pedals PD1036 $24.95/pair

These are really nice 1/2" pedals! Aluminum cage and body. Serviceable/adjustable ball bearings. You can attach any standard toe clip, and the pedals have slots for toe straps.

Pyramid Toe-Clippable Pedals PD104 $19.95/pair

These are much nicer than the usual run of 1/2" pedals. Cast aluminum bodies won't fall apart, serviceable/adjustable ball bearings. Snap out the reflector and you can attach any standard toe clip, and the pedals have slots for toe straps.

More 1/2" Pedals from the Quality Bicycle Products Catalogue

New! 9/16" to 1/2" Pedal Thread Adaptors $44.95 These adaptor bushings have a male 1/2"-20 thread to fit into your one-piece crank, and a standard 9/16"-20 female thread that will let you install standard 9/16" pedals, even modern clipless pedals. These install with a standard 6 mm Allen wrench.

Headsets

American-style bikes use the same headset threading and diameter as ISO standard (British) headsets, also the same 26.4 mm fork crown race size, but the frames have larger diameter head tubes.

Threaded Headsets (Yellow background indicates interchange problem)
Size Steerer O.D.	Stem diameter Steerer I.D.	Crown race Inside diameter	Frame Cup Outside Diameter	Threads Per inch	Notes
BMX/ O.P.C. bikes	.833" (21.15 mm)	26.4 mm	32.7 mm	24	Older American Bikes
1" ISO Standard (25.4 mm)	.875" (22.2 mm)	26.4 mm	30.2 mm	24	Modern standard size
1" J.I.S.(25.4 mm)	.875" (22.2 mm)	27.0 mm	30.0 mm	24	Older or lower-quality bicycles from Asia

Handlebar Stems

American-style bikes have thicker steerer tubes than Euro bikes, so they take thinner stems. The usual diameter is 21.15 mm vs the British 22.2 mm size. The stems listed below are this size. Sorry we don't have more to choose from, but these are getting scarce.

The handlebar clamp diameter of American stems is usually the ISO standard size, 1"/25.4 mm, or, in BMX applications, 7/8"/22.2 mm, so matching bars to stems is not commonly a problem, as long as the stem fits the steerer.

Alloy/Steel Stem SM242 $24.95

These were unavailable for a long time, but we found a new stash!

Ideal upgrade for your Schwinn Varsity or other older bike that needs the 21.15 quill size.

Aluminum upper section to keep the weight down, with strong steel quill.

Forward Exension (reach) 3" (80 mm) 8" (200 mm) tall. (bottom to center of bar clamp.) 440 grams Clamp fits ISO standard 1" (25.4 mm) handlebar center.

"Swan"-Type High-Rise Stem SM245 $19.95

These are all-steel with a short 65 mm extension. These are heavy, but if you want your handlebars really high, this is what you need.

Forward Exension (reach) 2 1/2" (65 mm) Quill is 10" (254 mm ) tall. 500 grams Clamp fits ISO standard 1" (25.4 mm) handlebar center.

21.15 mm Stem Raisers SM247 $19.95

A stem raiser fits into the steering column in place of your present stem, and secures with a wedge bolt in the normal manner. The upper part of the stem raiser sticks out above the steerer, and is bulged out so that you can insert your original stem. The bottom of the original stem winds up a bit above the top of the headset, so you gain several inches of height.

Note: Steerers are butted at the bottom, so the hole in the steerer is constant-diameter until near the bottom, then the walls taper inward in the butted section. It is vitally important that the stem extender (or stem) is not inserted so far that the wedge is installed where the steerer is narrowing, or it could come loose unpredictably. This is sometimes a problem on smaller frames if you try to insert the stem or a stem riser too far down into the steerer.

We can supply most of the special parts to keep your old bike running...

Things That We Have (or can get.)

If you are looking for parts for a museum-quality restoration project,
I'm afraid that you will need some of the

Things That We DON'T Have (and cannot get.)

 

Things That We Have (or can get.)

Note; supplies on these items may be sporadic, and prices may vary.
We'll make every effort to keep this page up-to-date as pricing changes, but cannot guarantee the prices posted here.

See also our Specials Page

 

Things We DON'T Have (and cannot get.)

Please don't even bother asking us for:

Any old-stock authentic parts at all

Sorry, we have no sources for such things...wish we did. We are not a source for parts for museum type restorations.

We specialize in fixed-gear conversion of road and mountain bikes...

Check our page of Fixed Gear Goodies!

Ordering Feedback? Questions?

Accessories	Bicycles	Parts	Specials	Tools

Articles by Sheldon Brown and others
Harris Home	Beginners	Brakes	Commuting Lights	Cycle- Computers	Do-It- Yourself	Essays
Family Cycling	Fixed Gear Singlespeed	Frames	Gears & Drivetrain	Bicycle Humor	Bicycle Glossary	Bicycle Links
Old Bikes	Repair Tips	Tandems	Touring	What's New	Wheels	Sheldon Brown

Back to the Harris Cyclery Home Page

Web site by Sheldon Brown

Sheldon Brown's Hotlists

If you would like to make a link or bookmark to this page, the URL is:
http://harriscyclery.com/opc