July 14, 2014

Contents:   1. Rear sprockets with large center hole
Contents:   2.
Rear sprockets with small center hole
Contents:   3.
Front sprockets
Contents:   4. Sprocket Info


1. Rear sprockets with large center hole

These sprockets are on the same side as the drum brake. So the brake is in the center of the sprocket.



2. Rear sprockets with small center hole

These rear sprockets are on the opposite side as the drum brake.


Italian 1-chain sprockets

1-chain sprocket holes, Italian sizes

Sprockets (single chain 4 bolt, A,B,C are 1/2″ x 3/16″ chain #415)
 (single chain type, 4 bolt, (D is 1/2″ x 1/4″ chain #420)
x part xxxxxxxxx   center bolt xxx xxxx xxx SB = sealed bearing
xx number xxxxxxxxx  hole holes teeth price   applications

X 209261 xx sprocket Ø17.0 Ø60 22T  $35  early Tomos wire wheel
H123/22W sprocket Ø39.5 Ø62 22T  $40  for Ø32 cup (Tomos)
 sprocket Ø39.5 Ø62 30T  N/A  for Ø32 cup (Morini)
H123/32W sprocket Ø39.5 Ø62 32T  $40  for Ø32 cup (Garelli 30)
H123/36W sprocket Ø39.5 Ø62 36T  N/A  for Ø32 cup (Garelli 25)
H123/38W sprocket Ø39.5 Ø62 38T  $20  for Ø32 cup (Minarelli)

H123/42W sprocket Ø39.5 Ø62 42T  $40  for Ø32 cup (Minarelli)
A H123/44W sprocket Ø39.5 Ø62 44T  $40  for Ø32 cup (Minarelli)
633084 xx sprocket Ø42.5 Ø60 20T  $10  must grind to clear chain
222586 xx sprocket Ø42.5 Ø60 22T  $20  for Ø32 SB Tomos ’89-on
227361 xx sprocket Ø42.5 Ø60 24T   N/A  for Ø32 SB Tomos ’89-on
223119 xx sprocket Ø42.5 Ø60 28T  $10  for Ø32 SB Tomos ’89-on
227863 xx sprocket Ø42.5 Ø60 31T  $15  for Ø32 SB Tomos ’89-on

H123/30M sprocket Ø42.5 Ø66 30T   N/A  for Ø35 cup (Morini)
H123/32M sprocket Ø42.5 Ø66 32T   N/A  for Ø35 cup (Garelli)
H123/42M sprocket Ø42.5 Ø66 42T   N/A  for Ø35 cup (Minarelli)
C H123/44M sprocket Ø42.5 Ø66 42T   $30  for Ø35 cup (Minarelli)
D 713-0244 sprocket Ø45.5 Ø66 42T   N/A  for Ø35 SB (Columbia)
D 713-0245 sprocket Ø45.5 Ø66 48T  $30  for Ø35 SB (Columbia)

Sprocket parts
H122 x
   locking plate Ø39.5 4-bolt Ø62  $4.00  for Ø32 cup
H122M   locking plate Ø42.5 4
-bolt Ø66 $12.00  for Ø35 cup
222583   locking plate Ø42.5 4-bolt Ø60  $8.00  for Ø32 SB Tomos
H124 x   sprocket bolt (4) M7 x 18 or 20 $1.00  for 1-chain steel Ø90 hub
H124T    sprocket bolt (4) M7 x 22 or 25 $1.00  for 1-chain alloy Ø90 hub
H124Mx  sprocket bolt (4) M7 x 30 xxxx  $1.00  for 1-chain alloy Ø90 mag
026304   sprocket bolt (4) M7 x 25 xxxx  $1.00  for 1-chain alloy Ø105 hub & mag
026305   sprocket bolt (4) M7 x 35 xxxx  $1.00  for Revival, Streetmate hub
H124A x
  sprocket nut (4) M7 xxxxxxxxx  $0.50  for 1-chain sprockets
H61 xxx  sprocket bolt (4) M6 x 20 xxxx  $0.50  for 2-chain sprockets


3. Front sprockets




4. Sprocket Info

Coming up: How to tell the chain pitch by measuring the sprocket. Hint: the diameter at the tooth tops is not important.

Chain Pitch equals Pitch Diameter times Pi divided by the number of teeth.

Measuring the Pitch Diameter is difficult, especially with odd numbered and low numbered tooth counts.

Locating two pin centers, 180 degrees apart, and measuring the distance between, is the problem.

You have to know the roller diameter to locate the pin center. Something like a chopstick is needed…

Under construction …