one piece crank mod

I am thinking of taking an old one piece crank set and grinding down
the spindle into a square tapered so I can put a decent low gear on my
junky bikes, will this work?

On Dec 3, 7:41*am, cmcanulty wrote:
I am thinking of taking an old one piece crank set and grinding down
the spindle into a square tapered so I can put a decent low gear on my
junky bikes, will this work?

If you could do the taper with enough precision to get the arm to fit,
how would you bolt the arm on? Drill and tap holes?

And would you trust your weight on it? Even if you weigh 98 lbs?

This falls into the realm of Tremendously Bad Idea.

They make OPC shell fittings that you can thread a regular BB into.
Get one of those.

http://aebike.com/page.cfm?PageID=30...ils&sku=CR0500

cmcanulty wrote:

I am thinking of taking an old one piece crank set and grinding down
the spindle into a square tapered so I can put a decent low gear on my
junky bikes, will this work?

I wouldn't try it. That is an advanced technique.

These are better:
http://www.bikepartsusa.com/bikeparts/item/01-98690
http://www.danscomp.com/455021.php

Chalo

On Dec 3, 9:41*am, cmcanulty wrote:
I am thinking of taking an old one piece crank set and grinding down
the spindle into a square tapered so I can put a decent low gear on my
junky bikes, will this work?

Ya sure, just shove a crank set on there, then mushroom the end of the
taper with a big mallet. It should hold real good and nice.

cmcanulty wrote:

I am thinking of taking an old one piece crank set and grinding down
the spindle into a square tapered so I can put a decent low gear on my
junky bikes, will this work?

There is another option. One of these might suit you, depending on
how junky your tastes run:

http://www.bikepartsusa.com/bikeparts/item/01-97697

At less than $14, that's the undefeated cost-effective champion if you
want multiple front sprockets.

Here are other appealingly (appallingly?) thrifty options as low as
28t:

http://www.bikepartsusa.com/bikeparts/category/1_Piece

If you use the 36T version of one of these http://www.danscomp.com/457051.php
, you can mount a larger chainring to the 110mm bolt pattern intended
to carry a bash guard.

Chalo

Thanks for the great ideas I didn't realize an adapter was sold. I get
a junk bike out of trash to ride in salt and snow but need the lower
gears as it is quite hilly here. I bought a cheapo crank at Nashbar
for $10.

On Dec 4, 5:54*am, cmcanulty wrote:
Thanks for the great ideas I didn't realize an adapter was sold. I get
a junk bike out of trash to ride in salt and snow but need the lower
gears as it is quite hilly here. I bought a cheapo crank at Nashbar
for $10.

I'm going to ask a follow-up question that I'm likely to get ridiculed
for, but I need to ask anyhow.

I just got a 74 Schwinn Sprint (the model with the bent seat tube).
What are your comments on drilling out the pedal threads to accomodate
larger diameter thread size pedals. There appears (to me) to be
enough meat on the steel crank-arm to do it. How dumb of an idea is
this?

I want to retail the original look of this funky old bike but really
don't like to ride without clipless pedals.

Tom

On 12/4/2008 3:03 PM wrote:

I'm going to ask a follow-up question that I'm likely to get ridiculed
for,

Pshaw, par for the course here. Gives a man character.
Being ridiculed on r.b.t is the gift that keeps on giving.

--
Mike "Rocket J Squirrel"
Bend, Oregon

On Dec 4, 3:03*pm, "
wrote:
On Dec 4, 5:54*am, cmcanulty wrote:

Thanks for the great ideas I didn't realize an adapter was sold. I get
a junk bike out of trash to ride in salt and snow but need the lower
gears as it is quite hilly here. I bought a cheapo crank at Nashbar
for $10.

I'm going to ask a follow-up question that I'm likely to get ridiculed
for, but I need to ask anyhow.

I just got a 74 Schwinn Sprint (the model with the bent seat tube).
What are your comments on drilling out the pedal threads to accomodate
larger diameter thread size pedals. *There appears (to me) to be
enough meat on the steel crank-arm to do it. *How dumb of an idea is
this?

I want to retail the original look of this funky old bike but really
don't like to ride without clipless pedals.

I thought the Sprint '74/75 was spec'd with a cheap three piece
cotterless crank. That took standard pedal threads, IIRC. No? If
you really want to keep the crank and the threads are too small, you
could drill and use inserts. See http://tinyurl.com/6oxvtt Seems
like a lot of work for a beater. -- Jay Beattie.

On Dec 4, 4:39*pm, Jay Beattie wrote:
On Dec 4, 3:03*pm, "





wrote:
On Dec 4, 5:54*am, cmcanulty wrote:

Thanks for the great ideas I didn't realize an adapter was sold. I get
a junk bike out of trash to ride in salt and snow but need the lower
gears as it is quite hilly here. I bought a cheapo crank at Nashbar
for $10.

I'm going to ask a follow-up question that I'm likely to get ridiculed
for, but I need to ask anyhow.

I just got a 74 Schwinn Sprint (the model with the bent seat tube).
What are your comments on drilling out the pedal threads to accomodate
larger diameter thread size pedals. *There appears (to me) to be
enough meat on the steel crank-arm to do it. *How dumb of an idea is
this?

I want to retail the original look of this funky old bike but really
don't like to ride without clipless pedals.

I thought the Sprint '74/75 was spec'd with a cheap three piece
cotterless crank. *That took standard pedal threads, IIRC. *No? *If
you really want to keep the crank and the threads are too small, you
could drill and use inserts. *Seehttp://tinyurl.com/6oxvtt*Seems
like a lot of work for a beater. -- Jay Beattie.- Hide quoted text -

Well lo and behold. Here is the culprit. http://www.geocities.com/sldbgallery...74sprn001.html
I love how they call these "lightweights" -- compared to what? An
Edsel? -- Jay Beattie.