"Shimano tandem"



On 8 Aug, 13:25, "Clive George" <[email protected]> wrote:

> > So why does he need two chain whips to remove it?

>
> Coz he hasn't checked for a freewheel?
>
> Two chain whips will often take the sprockets off a freewheel as well...


The confusion is my fault - I've never dealt with non-cassette gears,
I was going on some half-remembered stuff and making some assumptions.
So far all I've done is taken the back wheel off and seen that there
are no splines for my cassette lockring tool.

The half remembered bit is that for something or other (can't remember
the correct term, so I won't try) instead of a lock ring, something is
held by the smallest sprocket, to get it off you need two chain whips,
one unscrewing the smallest sprocket, and the second holding one of
the other sprockets while you do this (which may, er, be quite
difficult...). As I now understand it, you do this to remove
individual sprockets, which isn't strictly necessary, I can just take
the whole freewheel off, which needs one chain whip + a brand specific
freewheel removal tool, which I don't have. And the freewheel is also
likely to be difficult to get off.

As the wheel isn't that great to start with (only 126mm hub), and I
can't really get the range I need/want with 6 speeds it doesn't seem
worth the effort. (The frame will certainly take 7 speed, but I'm not
sure if the axle will.) So, replacing the wheel is the medium term
plan. Any reason why I shouldn't go to 8 speed - I think the chain is
narrower, does this matter on a tandem?

Rob
 
<[email protected]> wrote in message
news:[email protected]...

> The half remembered bit is that for something or other (can't remember
> the correct term, so I won't try) instead of a lock ring, something is
> held by the smallest sprocket, to get it off you need two chain whips,
> one unscrewing the smallest sprocket, and the second holding one of
> the other sprockets while you do this (which may, er, be quite
> difficult...). As I now understand it, you do this to remove
> individual sprockets, which isn't strictly necessary, I can just take
> the whole freewheel off, which needs one chain whip + a brand specific
> freewheel removal tool, which I don't have. And the freewheel is also
> likely to be difficult to get off.


Taking freewheels off doesn't need a chainwhip at all, just the relevant
tool (sheldon or park tools probably tells you about it). But yes, it's
likely to be hard.

> As the wheel isn't that great to start with (only 126mm hub), and I
> can't really get the range I need/want with 6 speeds it doesn't seem
> worth the effort. (The frame will certainly take 7 speed, but I'm not
> sure if the axle will.) So, replacing the wheel is the medium term
> plan. Any reason why I shouldn't go to 8 speed - I think the chain is
> narrower, does this matter on a tandem?


Going cassette is sensible, since the hubs are stronger. If it's a steel
frame (I'm guessing it is), worth spacing it to 135mm and using an MTB
hub/wheel. 26" wheels with 36 spokes are plenty strong enough.

9 speed is when chains get narrower. It also gives you a nice 11/34 option
:) Personally if upgrading shifters, hub, mech, I'd do that rather than 8
speed (in fact I did, twice), but some prefer the potential strength of 8
speed. (the hubs are the same btw).

However: Once you've started doing any of this, costs start to mount up.
Suddenly that cheap s/h bike starts to become more expensive than a new
equivalent (or even a decent s/h machine). One of the reasons I'm so down on
s/h tandem prices (I reckon they're often too high) is that I've seen so
many people spend a fair amount of money on upgrades, turning it into poor
value. When starting from a decent frame, it may be worth it - but often
people aren't.

cheers,
clive
 
Quoth [email protected]

> Steel frame and I forgot to mention the rear spacing is already 135mm
> clamping down on to (I think) a 125mm hub.

That's a Bad Idea. A 135 mm setup would give you a VERY much stronger
wheel, other things being equal.

> (Actually, checking withSheldonBrown he doesn't mention any 6 speed MTB hubs, does this mean
> it's really a road wheel?)


The terms "road" and "mountain" or "MTB" are primarily _marketing_
terms.

When speaking of hubs, current usage calls 130 mm hubs "road" and 135
mm hubs "mountain/MTB."

Back in the days of 126 mm, this distinction didn't exist.

Sheldon "Numbers, Not Adjectives" Brown
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Sheldon Brown wrote:
>
> Sheldon "Numbers, Not Adjectives" Brown


Bug "welcoming Sheldon back to the forum" Bear