new chainwheels: what needs replacement?

[[email protected]]

I need new chainwheels and want to know how much stuff on the bike
needs replacement to accomplish that.

I just put on a new chain. Because the chainwheel is worn it skips
consistently under load going up a hill. The old chain did some of
that, the new one seems worse. The bike shop that sold me the chain
predicted the possibility. They took one look at the chainwheels and
said they were "wasted," but suggested I take a stab at a new chain
since "maybe you'll get away with it." They were right, I didn't. I'm
definitely going to have to replace the chainwheels.

For some reason the bike shop guy said if it came to that, it would be
easier/better (for the bike? for him?) to replace (help me with the
vocabulary here) the whole crankset, maybe bottom bracket if I
understood right. Well, the skipping problem is all about the teeth,
so strictly the only thing that needs to change is the chainwheel. But
the bike is old and maybe the guy was thinking identical chainwheels
to mine are out of manufacture and unavailable or something. Otherwise
I can't think of why he wants to replace other stuff. There are photos
of the bike with chainwheel close-ups at
http://homepage.smc.edu/morgan_david/bike/.

Would you concur that the bike shop guy's correct, that I should
replace everything on the bike down there "below the waist," instead
of chainwheels only?? Thanks for any wisdom.

-----------------

Info about the bike:

the chainwheels read "Sakae" and have 52 and 40 teeth
the cranks read "SR Apex"
the right crank, at the end of the axle, has a metal cap that reads
"Univega cotterless"
the bike is a decent quality Univega (Japanese) purchased in 1979 for
$450
the chainwheels are (and the just-replaced chain was) original

August 2002 I had a different bike shop work on the bike. I asked them
to decide what to do in their professional judgement to "make it good"
after 20 years of use. Among other things they opened up the bottom
bracket to repack the bearings with grease. They didn't mention any
problem with it.They didn't recommend replacement of the chain or
mention the chainwheels. They did replace the freewheel. Although I
have ridden with the old chain and new freewheel for a year, it's not
enough riding for the chain to have spoiled the freewheel and I don't
think I need another one (nor does the local bike shop).

[Jeff Starr]

wrote in message >...
> I need new chainwheels and want to know how much stuff on the bike
> needs replacement to accomplish that.
Hi, your dealer may have recommended going with a new crankset because
of cost. It looks like two chainrings would cost you somewhere between
$40-60. You can get a new Shimano Sora crankset for about $55 list.
May as well replace the bottom bracket, at appr $25, then everything
is new and should be problem free. Cambria has a Shimano 105 5500
crankset on sale for $55, see link, scroll down main page:
http://cambriabike.com/road/
I wish I had known about this sale, before I went with the Sora
crankset. Although I am quite happy with the Sora. It replaced an old
cottered crankset, it said - A Duprat Universal on the crank arm. So,
unless having the appearance of the original is important to you, a
new crankset may be the better way to go.
Life is Good!
Jeff

>
> I just put on a new chain. Because the chainwheel is worn it skips
> consistently under load going up a hill. The old chain did some of
> that, the new one seems worse. The bike shop that sold me the chain
> predicted the possibility. They took one look at the chainwheels and
> said they were "wasted," but suggested I take a stab at a new chain
> since "maybe you'll get away with it." They were right, I didn't. I'm
> definitely going to have to replace the chainwheels.
>
> For some reason the bike shop guy said if it came to that, it would be
> easier/better (for the bike? for him?) to replace (help me with the
> vocabulary here) the whole crankset, maybe bottom bracket if I
> understood right. Well, the skipping problem is all about the teeth,
> so strictly the only thing that needs to change is the chainwheel. But
> the bike is old and maybe the guy was thinking identical chainwheels
> to mine are out of manufacture and unavailable or something. Otherwise
> I can't think of why he wants to replace other stuff. There are photos
> of the bike with chainwheel close-ups at
> http://homepage.smc.edu/morgan_david/bike/.
>
> Would you concur that the bike shop guy's correct, that I should
> replace everything on the bike down there "below the waist," instead
> of chainwheels only?? Thanks for any wisdom.
>
> -----------------
>
> Info about the bike:
>
> the chainwheels read "Sakae" and have 52 and 40 teeth
> the cranks read "SR Apex"
> the right crank, at the end of the axle, has a metal cap that reads
> "Univega cotterless"
> the bike is a decent quality Univega (Japanese) purchased in 1979 for
> $450
> the chainwheels are (and the just-replaced chain was) original
>
> August 2002 I had a different bike shop work on the bike. I asked them
> to decide what to do in their professional judgement to "make it good"
> after 20 years of use. Among other things they opened up the bottom
> bracket to repack the bearings with grease. They didn't mention any
> problem with it.They didn't recommend replacement of the chain or
> mention the chainwheels. They did replace the freewheel. Although I
> have ridden with the old chain and new freewheel for a year, it's not
> enough riding for the chain to have spoiled the freewheel and I don't
> think I need another one (nor does the local bike shop).

[Peter Cole]

> wrote in message
...
>
> I need new chainwheels and want to know how much stuff on the bike
> needs replacement to accomplish that.
>
> Would you concur that the bike shop guy's correct, that I should
> replace everything on the bike down there "below the waist," instead
> of chainwheels only?? Thanks for any wisdom.
>
> the chainwheels read "Sakae" and have 52 and 40 teeth
> the cranks read "SR Apex"
> the right crank, at the end of the axle, has a metal cap that reads
> "Univega cotterless"
> the bike is a decent quality Univega (Japanese) purchased in 1979 for
> $450
> the chainwheels are (and the just-replaced chain was) original

Often, replacement chainrings are as expensive as a new crank (with
chainrings). The real question is whether you want to spend $50+ on a bike
that's probably worth about that. Unfortunately, replacing worn out stuff on
old, mid-range, bikes is often a losing proposition.

[Peter Portin]

wrote:
>
.. Well, the skipping problem is all about the teeth,
> so strictly the only thing that needs to change is the chainwheel. But
> the bike is old and maybe the guy was thinking identical chainwheels
> to mine are out of manufacture and unavailable or something. Otherwise
> I can't think of why he wants to replace other stuff. There are photos
> of the bike with chainwheel close-ups at
> http://homepage.smc.edu/morgan_david/bike/.

You could try to flip the chainwheel that skips or both chainwheels. With
friction shifting this should be possible.

I recently flipped the middle chainwheel on my 1985 tourer and it works very
well.

Peter P

..

[[email protected]]

OK I've learned a lot here since yesterday. I'm about ready to buy
replacement chanrings unless there's other ideas.

I've learned:

1) Chainring "Plan A" is feasible
My Sakae SR 118mm BCD chainrings, though out of manufacture, can be
obtained. And I found the replacement process is quite doable (I
experimentally took the rings off an put them back on.)

2) There's also a whole-new-crankset-as-long-as-you're-at-it "Plan B"

3) The parts costs are about the same, though Plan B costs some labor
(because I wouldn't try to replace the crankset myself).

So, if I have zero dissatisfaction with the cranks or bottom bracket,
the rational option is Plan A. Plan B gets me some things that are
additional, but that I'm not seeking or (I think) needing. So, why??

Can you can tell me any "unperceived needs" of mine a new whole
crankset would fulfill? If something didn't happen in the last 20
years to make modern cranksets qualitatively beyond my limited
experience and imagination, there's no reason for me to get cranks to
fix teeth. Did anything like that happen? I'm poised to buy the
chainrings unless I identify something else I'd get from Plan B
besides non-skip teeth.

By the way this newsgroup is rich with knowledge and good suggestions!
Thanks.

[David L. Johnson]

On Sun, 13 Jul 2003 00:36:23 +0000, dmorgan wrote:

> Can you can tell me any "unperceived needs" of mine a new whole crankset
> would fulfill? If something didn't happen in the last 20 years to make
> modern cranksets qualitatively beyond my limited experience and
> imagination, there's no reason for me to get cranks to fix teeth. Did
> anything like that happen? I'm poised to buy the chainrings unless I
> identify something else I'd get from Plan B besides non-skip teeth.

Well, on the one hand, certainly the next time you want to replace those
chainrings, you are going to find it harder to get them.

On the other hand, there is a certain esthetic in keeping the bike all
original.

On the third hand, if you did get a new crankset you could have more
options in terms of gearing, if that would interest you.

--

David L. Johnson

__o | It is a scientifically proven fact that a mid life crisis can
_`\(,_ | only be cured by something racy and Italian. Bianchis and
(_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
Glenn Davies