Using an "8-speed" crankset with a 9-speed cassette

[Tom Anderson]

Hi,

Can i use a crankset described as "Rear Speeds: 8/7", like this:

http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078

With a 9-speed cassette, like this:

http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette

?

I'll be using a 9-speed chain.

I have been told yes by one person, and maybe not by another.

Thanks in advance,
tom

--
only positivistic reason and the forms of philosophy based on it are
universally valid -- Pope Benedict XVI

[John Forrest Tomlinson]

On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <twic@urchin.earth.li>
wrote:

>Hi,
>
>Can i use a crankset described as "Rear Speeds: 8/7", like this:
>
>http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078
>
>With a 9-speed cassette, like this:
>
>http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette
>
>?
>
>I'll be using a 9-speed chain.
>
>I have been told yes by one person, and maybe not by another.

Yes. If you shift to the small ring tentatively, the chain might
occassionally skid along the top of the inner riing, instead of
engaging right away, but it's no big deal and can be avoided by
shifting decisively.

[Art Harris]

Tom Anderson wrote:
> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>
> http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PROD...
>
> With a 9-speed cassette, like this:
>
> http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=...
>
> ?
>
> I'll be using a 9-speed chain.
>

My wife's old Motobecane has a Stronglight triple crankset from the 6-
speed era. It works fine with a 9-speed chain and cassette. She uses
the original DT shifter and Huret derailleur for the front, and an STI
brifter and 9-speed derailleur for the rear.

Art Harris

[Werehatrack]

On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <twic@urchin.earth.li>
may have said:

>Hi,
>
>Can i use a crankset described as "Rear Speeds: 8/7", like this:
>
>http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078
>
>With a 9-speed cassette, like this:
>
>http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette
>
>?
>
>I'll be using a 9-speed chain.
>
>I have been told yes by one person, and maybe not by another.

It will work just fine. The only place where I encountered problems
with chain/sprocket issues on a multispeed was one instance when a
bike owner wanted to try to shoehorn a 10s rear cassette and wheel on
to a bike that had been built for a 5s rear; the old stamped steel
front sprockets on that fossilized near-beater were still thick enough
that the 10s chain wouldn't ride down on it properly. Your 7/8
sprockets will carry a 9s chain with no problem.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

[Tom Anderson]

On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:

> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <twic@urchin.earth.li>
> wrote:
>
>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>>
>> http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078
>>
>> With a 9-speed cassette, like this:
>>
>> http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette
>
> Yes. If you shift to the small ring tentatively, the chain might
> occassionally skid along the top of the inner riing, instead of engaging
> right away, but it's no big deal and can be avoided by shifting
> decisively.

Aha. Can i ask why that might happen?

tom

--
I'd better quit my talking, 'cause I told you all I know. But please
remember, pardner, wherever you may go: the people are building a peaceful
world, and when the job is done, that'll be the biggest thing that man
has ever done.

[John Forrest Tomlinson]

On Thu, 5 Jun 2008 08:38:13 +0100, Tom Anderson <twic@urchin.earth.li>
wrote:

>On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
>
>> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <twic@urchin.earth.li>
>> wrote:
>>
>>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>>>
>>> http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078
>>>
>>> With a 9-speed cassette, like this:
>>>
>>> http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette
>>
>> Yes. If you shift to the small ring tentatively, the chain might
>> occassionally skid along the top of the inner riing, instead of engaging
>> right away, but it's no big deal and can be avoided by shifting
>> decisively.
>
>Aha. Can i ask why that might happen?

I think the distance between chainrings is a little more than the on a
"9-speed" crank and the inner sideplates of the chain end up on top of
the teeth of the inner ring.

I was using a Shimano 8-speed crank on an 8-speed set up and it was
fine, and when I changed the shifters, chain and cogs to 8 I would
have this problem. It was rare -- like one shift every five or ten
hours of riding -- and no big deal.

I would not let that stop you from making the switch.

[andresmuro@aol.com]

On Jun 5, 3:52 am, John Forrest Tomlinson <usenetrem...@jt10000.com>
wrote:
> On Thu, 5 Jun 2008 08:38:13 +0100, Tom Anderson <t...@urchin.earth.li>
> wrote:
>
>
>
> >On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
>
> >> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <t...@urchin.earth.li>
> >> wrote:
>
> >>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>
> >>>http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PROD...
>
> >>> With a 9-speed cassette, like this:
>
> >>>http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=...
>
> >> Yes. If you shift to the small ring tentatively, the chain might
> >> occassionally skid along the top of the inner riing, instead of engaging
> >> right away, but it's no big deal and can be avoided by shifting
> >> decisively.
>
> >Aha. Can i ask why that might happen?
>
> I think the distance between chainrings is a little more than the on a
> "9-speed" crank and the inner sideplates of the chain end up on top of
> the teeth of the inner ring.
>
> I was using a Shimano 8-speed crank on an 8-speed set up and it was
> fine, and when I changed the shifters, chain and cogs to 8 I would
> have this problem. It was rare -- like one shift every five or ten
> hours of riding -- and no big deal.
>
> I would not let that stop you from making the switch.

Just to corroborate what JT is telling you, yes, you can use pretty
much any crankset and it will work. The difference for both rear
cassettes and front cranksets is not in the teeth, but in the
separation between sprockets. With more gears in the back, you make
the distance between sprockets smaller or narrower to the point that a
wider chain will not fit, so you need to get a narrower chain.
However, in the front it doesn't matter if you have a little more
distance between chain rings. The level of precision to move the chain
from sprocket to sprocket in the back is very high. too little and it
won't shift. Too much and it will over shift. In the front, you don't
need that level of precision. Hope that his helps,

Andres

[Tom Anderson]

On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:

> On Thu, 5 Jun 2008 08:38:13 +0100, Tom Anderson <twic@urchin.earth.li>
> wrote:
>
>> On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
>>
>>> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <twic@urchin.earth.li>
>>> wrote:
>>>
>>>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>>>>
>>>> http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441771278&FOLDER%3C%3Efolder_id=2534374302049828&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1212620610078
>>>>
>>>> With a 9-speed cassette, like this:
>>>>
>>>> http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=SRAM%20PG970%209%20Speed%20Cassette
>>>
>>> Yes. If you shift to the small ring tentatively, the chain might
>>> occassionally skid along the top of the inner riing, instead of engaging
>>> right away, but it's no big deal and can be avoided by shifting
>>> decisively.
>>
>> Aha. Can i ask why that might happen?
>
> I think the distance between chainrings is a little more than the on a
> "9-speed" crank and the inner sideplates of the chain end up on top of
> the teeth of the inner ring.

Ah, so because the chain is narrower, it has slightly harder time making
the jump from the middle ring to the small. A bit like if i was jumping
from one boulder to another and had tiny legs.

I take it that in a 9-speed chain, the gap between the plates, the holes
in the chain as it were, is smaller than in an 9-speed? But still wider
than the width of the teeth on any of the sprockets?

> I was using a Shimano 8-speed crank on an 8-speed set up and it was
> fine, and when I changed the shifters, chain and cogs to 8 I would have
> this problem.

To 9, you mean?

> It was rare -- like one shift every five or ten hours of riding -- and
> no big deal.

Okay, that sounds fine.

> I would not let that stop you from making the switch.

Thank you so much for your advice, sir!

tom

--
Can you make fun of everything? Well, my opinion is: if it's been funny,
you were right to do it. -- Coluche

[Tom Anderson]

On Thu, 5 Jun 2008, andresmuro@aol.com wrote:

> On Jun 5, 3:52 am, John Forrest Tomlinson <usenetrem...@jt10000.com>
> wrote:
>> On Thu, 5 Jun 2008 08:38:13 +0100, Tom Anderson <t...@urchin.earth.li>
>> wrote:
>>
>>> On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
>>
>>>> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <t...@urchin.earth.li>
>>>> wrote:
>>
>>>>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>>
>>>>> http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PROD...
>>
>>>>> With a 9-speed cassette, like this:
>>
>>>>> http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=...
>>
>>>> Yes.
>
> Just to corroborate what JT is telling you, yes, you can use pretty much
> any crankset and it will work. The difference for both rear cassettes
> and front cranksets is not in the teeth, but in the separation between
> sprockets. With more gears in the back, you make the distance between
> sprockets smaller or narrower to the point that a wider chain will not
> fit, so you need to get a narrower chain.

Right - that's exactly what i was hoping.

> However, in the front it doesn't matter if you have a little more
> distance between chain rings. The level of precision to move the chain
> from sprocket to sprocket in the back is very high. too little and it
> won't shift. Too much and it will over shift. In the front, you don't
> need that level of precision. Hope that his helps,

It does, thanks.

tom

--
Can you make fun of everything? Well, my opinion is: if it's been funny,
you were right to do it. -- Coluche

[andresmuro@aol.com]

On Jun 5, 7:22 am, Tom Anderson <t...@urchin.earth.li> wrote:
> On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
> > On Thu, 5 Jun 2008 08:38:13 +0100, Tom Anderson <t...@urchin.earth.li>
> > wrote:
>
> >> On Thu, 5 Jun 2008, John Forrest Tomlinson wrote:
>
> >>> On Thu, 5 Jun 2008 00:07:11 +0100, Tom Anderson <t...@urchin.earth.li>
> >>> wrote:
>
> >>>> Can i use a crankset described as "Rear Speeds: 8/7", like this:
>
> >>>>http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PROD...
>
> >>>> With a 9-speed cassette, like this:
>
> >>>>http://wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300001391&n=...
>
> >>> Yes. If you shift to the small ring tentatively, the chain might
> >>> occassionally skid along the top of the inner riing, instead of engaging
> >>> right away, but it's no big deal and can be avoided by shifting
> >>> decisively.
>
> >> Aha. Can i ask why that might happen?
>
> > I think the distance between chainrings is a little more than the on a
> > "9-speed" crank and the inner sideplates of the chain end up on top of
> > the teeth of the inner ring.
>
> Ah, so because the chain is narrower, it has slightly harder time making
> the jump from the middle ring to the small. A bit like if i was jumping
> from one boulder to another and had tiny legs.
>
> I take it that in a 9-speed chain, the gap between the plates, the holes
> in the chain as it were, is smaller than in an 9-speed? But still wider
> than the width of the teeth on any of the sprockets?
>
> > I was using a Shimano 8-speed crank on an 8-speed set up and it was
> > fine, and when I changed the shifters, chain and cogs to 8 I would have
> > this problem.
>
> To 9, you mean?
>
> > It was rare -- like one shift every five or ten hours of riding -- and
> > no big deal.
>
> Okay, that sounds fine.
>
> > I would not let that stop you from making the switch.
>
> Thank you so much for your advice, sir!

Didn't know that JT had been knighted
>
> tom
>
> --
> Can you make fun of everything? Well, my opinion is: if it's been funny,
> you were right to do it. -- Coluche

[John Forrest Tomlinson]

On Thu, 5 Jun 2008 14:22:46 +0100, Tom Anderson <twic@urchin.earth.li>
wrote:

>I take it that in a 9-speed chain, the gap between the plates, the holes
>in the chain as it were, is smaller than in an 9-speed? But still wider
>than the width of the teeth on any of the sprockets?

Yes, the 9-speed chain wil fit over the teeth in front and in back
from and 8-speed system.

My bike now is 10-speed, but I'm using an "7 or 8-speed" chainring (on
a 10-speed crank) and there is no problem with that even narrower
10-speed chain fitting over the teeth of that older ring.

[Colin MacDonald]

On 5 Jun, 14:22, Tom Anderson <t...@urchin.earth.li> wrote:
> I take it that in a 9-speed chain, the gap between the plates, the holes
> in the chain as it were, is smaller than in an 9-speed? But still wider
> than the width of the teeth on any of the sprockets?

According to Sheldon, "Chains for derailer applications also come in
various external widths. Newer clusters which have more sprockets use
chain with thinner side plates and flush rivets."

So the holes are the same, but the sides are thinner.

Colin