Using a 'middle' chainring on a double chainset

[Richard Bates]

Can I use a chainring marketed as "MIDDLE" as the smaller of a double?
Number of bolts and PCD are the same.

I've inherited a bike with a 105 double (52/42) and would like to reduce
the 42 to 39

 

[Dave Larrington]

In news:[email protected],
Richard Bates <[email protected]> tweaked the
Babbage-Engine to tell us:
> Can I use a chainring marketed as "MIDDLE" as the smaller of a double?
> Number of bolts and PCD are the same.
>
> I've inherited a bike with a 105 double (52/42) and would like to
> reduce the 42 to 39

AFAIK the only difference is that "middle" rings tend to have ramps, pins,
rope ladders or other bits of bobbins to assist the chain in its ascent from
the inner to the middle. Since you're not going to be doing this, the
answer is "yes".

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
A *National* Socialist Government did you say, Mr. Chaplin?

 

[Paul - xxx]

Richard Bates <[email protected]> farted out
> Can I use a chainring marketed as "MIDDLE" as the smaller of a double?
> Number of bolts and PCD are the same.
>
> I've inherited a bike with a 105 double (52/42) and would like to
> reduce the 42 to 39

As DL says, there isn't much to stop you other than possible ramps and pins.
However, as you won't be using them it's worth at least trying the ring, see
if they hamper gear-changing and if so then maybe the application of a
grinder might be tried.

--
Paul - *** (mobile)

 

[Pete Biggs]

Paul - *** wrote:
> Richard Bates <[email protected]> farted out
>> Can I use a chainring marketed as "MIDDLE" as the smaller of a
>> double? Number of bolts and PCD are the same.
>>
>> I've inherited a bike with a 105 double (52/42) and would like to
>> reduce the 42 to 39
>
> As DL says, there isn't much to stop you other than possible ramps
> and pins. However, as you won't be using them it's worth at least
> trying the ring, see if they hamper gear-changing and if so then
> maybe the application of a grinder might be tried.

The ramps and pins won't affect Richard's gear-changing at all. They are on
the inner face and only come into affect when shifting up from a smaller
ring, but there will be no smaller ring in this case.

The only thing "wrong" will be the waste of money if it's a new one and more
expensive than a plain "double" ring. In fact 39t middle rings are quite
sought-after so even a used one will be worth a few quid.

~PB

 

[Dave Larrington]

In news:[email protected],
Pete Biggs <[email protected]> tweaked the
Babbage-Engine to tell us:

> The only thing "wrong" will be the waste of money if it's a new one
> and more expensive than a plain "double" ring. In fact 39t middle
> rings are quite sought-after so even a used one will be worth a few
> quid.

They may be readily obtained from the likes of Settle Cycles, as long as one
doesn't insist on $himano...

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
Here, take these cheese-shaped stilts. You'll know when to use
them.

 

[Pete Biggs]

Dave Larrington wrote:
> In news:[email protected],
> Pete Biggs <[email protected]>
> tweaked the Babbage-Engine to tell us:
>
>> The only thing "wrong" will be the waste of money if it's a new one
>> and more expensive than a plain "double" ring. In fact 39t middle
>> rings are quite sought-after so even a used one will be worth a few
>> quid.
>
> They may be readily obtained from the likes of Settle Cycles, as long
> as one doesn't insist on $himano...

Couldn't find any middle-specific rings on Settle's site last time I looked,
though I expect they could be ordered.

Dotbike have TA middle rings for Campag, if any triple Campag fans are
reading this. They really do work better than plain rings in the middle
position - but cost more readies.

~PB

 

[[email protected]]

On 2 May, 16:02, "Pete Biggs"
<[email protected]> wrote:
> Dave Larrington wrote:
> > Innews:[email protected],
> > Pete Biggs <[email protected]>
> > tweaked the Babbage-Engine to tell us:
>
> >> The only thing "wrong" will be the waste of money if it's a new one
> >> and more expensive than a plain "double" ring. In fact 39t middle
> >> rings are quite sought-after so even a used one will be worth a few
> >> quid.
>
> > They may be readily obtained from the likes of Settle Cycles, as long
> > as one doesn't insist on $himano...
>
> Couldn't find any middle-specific rings on Settle's site last time I looked,
> though I expect they could be ordered.

<Fx> whoosh.... </Fx>

The OP's requirement was for rings that wern't middle-specific. Mr
Larrington was helpfully pointing out that such items may be purchased
from Settle...

Cheers,
W.

 

[Pete Biggs]

[email protected] wrote:

> Mr
> Larrington was helpfully pointing out that such items may be purchased
> from Settle...

How do you know what Mr Larrington is thinking? ;-)

~PB

 

[Paul - xxx]

Pete Biggs <[email protected]> farted
out
> Paul - *** wrote:
>> Richard Bates <[email protected]> farted out
>>> Can I use a chainring marketed as "MIDDLE" as the smaller of a
>>> double? Number of bolts and PCD are the same.
>>>
>>> I've inherited a bike with a 105 double (52/42) and would like to
>>> reduce the 42 to 39
>>
>> As DL says, there isn't much to stop you other than possible ramps
>> and pins. However, as you won't be using them it's worth at least
>> trying the ring, see if they hamper gear-changing and if so then
>> maybe the application of a grinder might be tried.
>
> The ramps and pins won't affect Richard's gear-changing at all. They
> are on the inner face and only come into affect when shifting up from
> a smaller ring, but there will be no smaller ring in this case.

I was thinking more of [1] chainstay / bottom bracket clearances etc.

> The only thing "wrong" will be the waste of money if it's a new one
> and more expensive than a plain "double" ring. In fact 39t middle
> rings are quite sought-after so even a used one will be worth a few
> quid.

Sounded to me like he might have already bought a middle ring and is
questioning it's suitability for use as the 'small' ring of a double
chainset ...

[1] despite me mentioning gear changing ..

--
Paul - *** (mobile)

 

[Richard Bates]

Paul - *** wrote:
> Sounded to me like he might have already bought a middle ring and is
> questioning it's suitability for use as the 'small' ring of a double
> chainset ...


Not quite, but I could only find 105 middles. Of course, I've realised
that it doesn't *need* to be a genuine Shimano ring.

Thanks for the reassurance tho...

 

[Pete Biggs]

Paul - *** wrote:

>> The ramps and pins won't affect Richard's gear-changing at all. They
>> are on the inner face and only come into affect when shifting up from
>> a smaller ring, but there will be no smaller ring in this case.
>
> I was thinking more of [1] chainstay / bottom bracket clearances etc.
>
> [1] despite me mentioning gear changing ..

I don't think that would be an issue. The pins I've seen don't make the
chainring thicker altogether.

~PB

 

[Dave Larrington]

In news:[email protected],
Pete Biggs <[email protected]> tweaked the
Babbage-Engine to tell us:
> Dave Larrington wrote:
>> In news:[email protected],
>> Pete Biggs <[email protected]>
>> tweaked the Babbage-Engine to tell us:
>>
>>> The only thing "wrong" will be the waste of money if it's a new one
>>> and more expensive than a plain "double" ring. In fact 39t middle
>>> rings are quite sought-after so even a used one will be worth a few
>>> quid.
>>
>> They may be readily obtained from the likes of Settle Cycles, as long
>> as one doesn't insist on $himano...
>
> Couldn't find any middle-specific rings on Settle's site last time I
> looked, though I expect they could be ordered.


I think the difference between a TA "middle" and "double inner" is this: 0,
but an outer has a little hole for the chain catcher pin. I am, alas,
unable to confirm this as my luvverly shiny new TA chainset was shipped sans
middle ring and bottom bracket, and with completely the wrong set of
chainring bolts, so I shall have but a 13" bottom gear for pootling up Yat
Rock on Saturday chiz.

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
Flies are the work of Stan, and should be killed by all means
available.

 

[Paul - xxx]

Pete Biggs <[email protected]> typed:
> Paul - *** wrote:
>
>>> The ramps and pins won't affect Richard's gear-changing at all. They
>>> are on the inner face and only come into affect when shifting up from
>>> a smaller ring, but there will be no smaller ring in this case.
>>
>> I was thinking more of [1] chainstay / bottom bracket clearances etc.
>>
>> [1] despite me mentioning gear changing ..
>
> I don't think that would be an issue. The pins I've seen don't make the
> chainring thicker altogether.

Actually, just been to 'the shed' for a looksee ... I have an old, broken
and a few minutes ago discarded, Shimano Bio-Pace chainring that also has
ramps and pins on it, and they're chuffin' massive [1] compared to newer
kit. Which is probably why I answered how I did.

[1] Technical term, from Yorkshire, for larger than usual.

--
Paul - ***

 

[Dave Larrington]

In news:[email protected],
Paul - *** <[email protected]> tweaked the Babbage-Engine to tell
us:

> Actually, just been to 'the shed' for a looksee ... I have an old,
> broken and a few minutes ago discarded, Shimano Bio-Pace chainring
> that also has ramps and pins on it, and they're chuffin' massive compared
> to newer kit. Which is probably why I answered how I did.

I was looking at a not-very-old 105 chainring last night, and the ramps and
pins on that are /also/ chuffin' massive, at least in comparison with those
on Campag and TA rings, which are barely visible to the naked eye.

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
I thought I saw his name on a jar of marmalade the other day,
but when I looked more closely, I saw it read 'thick cut'.

 

[Pete Biggs]

Dave Larrington wrote:

> I think the difference between a TA "middle" and "double inner" is
> this: 0, but an outer has a little hole for the chain catcher pin.

There is a difference with the 135mm TA middle ring I got from Dotbike. It
has pins and extra ramps - which really do help pick up the chain, meaning I
don't have to over-shift my Campag Ergo so much.

Previously I bought TA double inners from Settle Cycles.

TA keep on varying their designs. With inners, middles and outers, you're
quite likely to get a slightly different chainring when it comes to
replacing one or getting another for another bike.

~PB