Upgrading an old road bike

I have a Shogun brand 12 speed bike I bought new in 1980. I love the old bike and everything works
great, but I'd like to change to a triple crank. I thought I might be able to just swap out the
cranks and be done. So I read through Sheldon Brown's info at the Harris Cyclery, and eventually
went into information overload. (Chainline, chainring clearance, crank clearance, tread, etc.)
Here's what I've sorted out...

Double SR "Tourney" alloy cranks (38/52) Six-speed freewheel (13/30) Derailers and shifters are
Shimano "600" series 68 mm bottom bracket with tapered square axles

I expect that the derailers will have to be replaced to handle the greater range of the triple
cranks. What will I also have to replace... the bottom bracket, shifters, or ??? Is there some kind
of standard conversion for all of this?

I don't want to put junky stuff on the bike, but I don't need top-of-the line either. I'm a
recreational rider with a few big hills in the neighborhood. Any pitfalls, comments,
recommendations?

All replies will be greatly appreciated.

Thanks,

Bill Kingson Caribou, Maine

 

In article <[email protected]>, Bill Kingson
<[email protected]> wrote:
>I have a Shogun brand 12 speed bike I bought new in 1980. I love the old bike and everything works
>great, but I'd like to change to a triple crank. I thought I might be able to just swap out the
>cranks and be done. So I read through Sheldon Brown's info at the Harris Cyclery, and eventually
>went into information overload. (Chainline, chainring clearance, crank clearance, tread, etc.)
>Here's what I've sorted out...
>
>Double SR "Tourney" alloy cranks (38/52) Six-speed freewheel (13/30) Derailers and shifters are
>Shimano "600" series 68 mm bottom bracket with tapered square axles
>
>I expect that the derailers will have to be replaced to handle the greater range of the
>triple cranks.

The front derailleur will work better if you replace it.

The rear derailleur might work depending on the cage length and gearing - the old engraved "600"
derailleurs existed in both long and short cage versions. Also, the newer rear derailleurs really do
shift better.

> What will I also have to
> replace... the bottom bracket,

Bottom bracket - probably yes. I suggest getting the BB designed to work with your new crank. It
won't be very expensive.

> shifters,

Assuming they are friction you can keep your shifters, they are compatible with everything.

 

Bill Kingson <[email protected]> wrote:
: I have a Shogun brand 12 speed bike I bought new in 1980. I love the old bike and everything works
: great, but I'd like to change to a triple crank. I thought I might be able to just swap out the
: cranks and be done. So I read through Sheldon Brown's info at the Harris Cyclery, and eventually
: went into information overload. (Chainline, chainring clearance, crank clearance, tread, etc.)
: Here's what I've sorted out...

: Double SR "Tourney" alloy cranks (38/52) Six-speed freewheel (13/30) Derailers and shifters are
: Shimano "600" series 68 mm bottom bracket with tapered square axles

: I expect that the derailers will have to be replaced to handle the greater range of the triple
: cranks. What will I also have to replace... the bottom bracket, shifters, or ??? Is there some
: kind of standard conversion for all of this?

: I don't want to put junky stuff on the bike, but I don't need top-of-the line either. I'm a
: recreational rider with a few big hills in the neighborhood. Any pitfalls, comments,
: recommendations?

: All replies will be greatly appreciated.

: Thanks,

: Bill Kingson Caribou, Maine

For a cheaper solution...

I would suggest getting a mega range rear six speed freewheel with a 34 tooth low gear. You will
also need a longer chain and a long cage deraileur to handle it. This will give you that real low
gear for the tougher hills.

--------------------------------
Bob Masse' [email protected]
--------------------------------

 

wkingson-<< I have a Shogun brand 12 speed bike I bought new in 1980. I love the old bike and
everything works great, but I'd like to change to a triple crank.

<< So I read through Sheldon Brown's info at the Harris Cyclery, and eventually went into
information overload. (Chainline, chainring clearance, crank clearance, tread, etc.)

<< Double SR "Tourney" alloy cranks (38/52) Six-speed freewheel (13/30) Derailers and shifters are
Shimano "600" series 68 mm bottom bracket with tapered square axles

Any shimano or Campagnolo triple crank and associated BB.

Any shimano long cage rear der-road or MTB-

Any shimano or Campagnolo road triple fder

is all ya need....

don't need shifters...

Like 105 or Veloce level stuff....

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[email protected] (Qui si parla Campagnolo) wrote:
>wkingson-<< I have a Shogun brand 12 speed bike I bought new in 1980. I love the old bike and
>everything works great, but I'd like to change to a triple crank.

Why? From your description, you have a pretty wide gear range as is... you must be looking to go
lower, right?

><< So I read through Sheldon Brown's info at the Harris Cyclery, and eventually went into
>information overload. (Chainline, chainring clearance, crank clearance, tread, etc.)

Always a good first step!

><< Double SR "Tourney" alloy cranks (38/52)

A triple front will get you much lower gearing, yes.

>Six-speed freewheel (13/30)

You won't gain much by swapping that out.

>Derailers and shifters are Shimano "600" series

Long cage, I assume (due to the 13-30 rear)... keep it.

>68 mm bottom bracket with tapered square axles

You MIGHT want to swap for a sealed cartridge unit with a longer axle.