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I decided to do a build incorporating some very unusual parts
First off is a prewar Iver johnson frame I acquired in a trade
Most of these bikes seem to have a schwinn like following for guys who restore bikes
but I have not seen many if really any done up as a full on rat
they posses a lot of proprietary size parts that I think make it difficult to customize these
One problem the have is their different size B.B
too small for standard one piece cranks
too big and not threaded for the euro B.B
Turns out to measure out to 43mm which is the same size as the Roadmaster Jr one piece cranks (as well as newer children's bikes)
The cup on the far left is the stock Iver version
It normally is used with an Iver 2 piece crank so the center whole is a lot smaller
I got lucky and found a one piece crank from a children's bike that is longer than normal (for a child's bike)
This one measures 140
Standard full size crank measuring 165 or 175
standard kids bike crank 115 or 125
There is a possibility of using bmx 3 piece cranks but the mid B.B size uses 41mm bearings
so those are a hair too small
the other is to use the spanish B.B size bearing that are 37mm but I need an adapter fabricated
or find an aftermarket sealed bearing that is 43mm outside with a center hole of 19mm or 22mm
even though the current one piece crank I found is thinner than a typical one piece
I still had trouble putting it in the B.B with both new cups in the frame
so I installed the chainring side cup first
then install the crank
after getting the crank through then I can set the last cup in before putting on the bearing and hardware for that side
First off is a prewar Iver johnson frame I acquired in a trade
Most of these bikes seem to have a schwinn like following for guys who restore bikes
but I have not seen many if really any done up as a full on rat
they posses a lot of proprietary size parts that I think make it difficult to customize these
One problem the have is their different size B.B
too small for standard one piece cranks
too big and not threaded for the euro B.B
Turns out to measure out to 43mm which is the same size as the Roadmaster Jr one piece cranks (as well as newer children's bikes)
The cup on the far left is the stock Iver version
It normally is used with an Iver 2 piece crank so the center whole is a lot smaller
I got lucky and found a one piece crank from a children's bike that is longer than normal (for a child's bike)
This one measures 140
Standard full size crank measuring 165 or 175
standard kids bike crank 115 or 125
There is a possibility of using bmx 3 piece cranks but the mid B.B size uses 41mm bearings
so those are a hair too small
the other is to use the spanish B.B size bearing that are 37mm but I need an adapter fabricated
or find an aftermarket sealed bearing that is 43mm outside with a center hole of 19mm or 22mm
even though the current one piece crank I found is thinner than a typical one piece
I still had trouble putting it in the B.B with both new cups in the frame
so I installed the chainring side cup first
then install the crank
after getting the crank through then I can set the last cup in before putting on the bearing and hardware for that side
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