Comments on S&S Couplers

[Ryan Cousineau]

In article <[email protected]>,
[email protected] wrote:

> Matt O'Toole writes:

> > I wonder about the Ritchey setup though, which has nothing
> > bolstering against this twisting of the downtube. Maybe it doesn't
> > matter if it moves a little, as long as the coupler is re-tightened
> > occasionally.
>
> I am not familiar with that connector.
>
> Jobst Brandt
> [email protected]

http://www.ritcheylogic.com/bab_home.htm

This is the same system Dahon uses for their Allegro transportable. Like
the S&S system, it makes the bike come apart, not fold. There's a video
on that site showing Tom Ritchey demonstrate the somewhat fussy assembly
process. The basic idea is that the downtube, headtube, and top tube are
one unit. the top tube and seat tube both have seatpost clamps at their
ends, and both clamp to the seatpost (which thus forms the upper joint
between the subframes). The downtube goes into a sleeve on the bottom
bracket, and is clamped with something much like an external seatpost
clamp or a derailleur hinge clamp.

I'm thinking carbon fibre seatposts aren't recommended,
--
Ryan Cousineau, [email protected] http://www.wiredcola.com
Verus de parvis; verus de magnis.

 

[TBGibb]

In article <[email protected]>, "Matt O'Toole" <[email protected]>
writes:

>I don't see how the S&S coupler could loosen unless it was loose to begin
>with.
>There are tapered teeth on each piece that mesh together when the coupling
>ring
>is tightened. If the ring is tight enough the teeth should prevent any
>twisting
>motion that could loosen the ring.

I don't either, but they will.

Tom Gibb <[email protected]>

 

[Mike Murray]

I have one of the Ritchey Breakaways that I put a fair amount of mileage on
this year without disassembly. I have not noted any loosening of the
downtube clamp. I have had problems with the seat clamps coming loose but I
have wondered whether this is due to failure to adequately tighten both of
them since one is so used to only tightening one clamp when adjusting seat
height.

--
Mike Murray

"Matt O'Toole" <[email protected]> wrote::

"I wonder about the Ritchey setup though, which has nothing bolstering
against this twisting of the downtube. Maybe it doesnt matter if it moves a
little, as long as the coupler is retightened occasionally.

 

[(Pete Cresswell)]

RE/
>Ritchey Breakaways that I put a fair amount of mileage on
>this year without disassembly.

Have you checked the tubes at the butt joint under the clamp?
If so, how's the rust situation?
--
PeteCresswell

 

[Andrew Martin]

"Mike Murray" <[email protected]> wrote in message news:<LAsqd.410154$wV.296623@attbi_s54>...
> I have one of the Ritchey Breakaways that I put a fair amount of mileage on
> this year without disassembly. I have not noted any loosening of the
> downtube clamp. I have had problems with the seat clamps coming loose but I
> have wondered whether this is due to failure to adequately tighten both of
> them since one is so used to only tightening one clamp when adjusting seat
> height.

Mike-

How has the Breakaway been for you? I'm looking at picking one up soon.

-a

 

[(Pete Cresswell)]

RE/
>How has the Breakaway been for you? I'm looking at picking one up soon.

This isn't Andrew, but I've got one.

Significant rust forming around the flange joint, lots of rust on the little 4mm
cap screw that holds it all together. I recently set the 4mm screw in blue
LocTite and have started shooting the whole assembly with chain lube every so
often.

Maybe it's different on a road bike, but mine is on an MTB and I get worried
looking at what little there is down there between me and a catastrophic frame
separation. S&S looks much, much more robust.
--
PeteCresswell

 

[Mike Murray]

So far so good, but it has not been ridden in wet conditions. I do think
that water intrusion at that point could be a big problem. I plan to avoid
it by not riding the bike in the wet.

--
Mike Murray

"(Pete Cresswell)" <[email protected]> asked:
"Have you checked the tubes at the butt joint under the clamp? If so, how's
the rust situation?"

 

[Mike Murray]

I have liked it. riding it is just like any other bike. Packing it is very
similar to an S&S coupled bike which is a bit more difficult than packing a
regular bike in a full size case but the convenience of carrying the smaller
case and avoiding airline fees more than offsets the packing issues.

I have always thought that putting a bike in a case or box, a regular bike
or even more so a separating bike, is too much like assembling a puzzle. Too
often a piece will be out of place and cause problems. I have considered
molding a foam insert for the inside of the case that will have a spot for
each part to make packing a bit easier.

--
Mike Murray

"Andrew Martin" <[email protected]> asked:
"How has the Breakaway been for you? I'm looking at picking one up soon."

 

[jasong]

I´ve only had issues with my top tube coupler coming loose (steel and Ti frames). Upon first riding the Ti frames couplers, its self-detorquing was quite frequent. Now it´s toned that down completely, presumably with whatever small scale changes have taken place after a few thousand miles.

So here´s a vote for top tube problems. A knocking noise when getting out of the saddle and the other minor shifting nuances were also indicators for me. I think following their advice and torquing these down pretty much eliminates the possibility. I´ve also just gotten into a habit of carrying the small wrench on rides when the 60g weight wasn´t a consideration (most always!).

Those concerned - you´ve seen their lightweight carry with you wrench (39g)?´

http://www.sandsmachine.com/ac_wrenc.htm

Matt O'Toole writes:

As I said, these are metals and metals are elastic. Therefore, there
are fretting motions, similar to those that make pedals loosen with
right hand threads on left cranks, or Italian BB cups to unscrew.

 

[David Reuteler]

jasong <[email protected]> wrote:
> Those concerned - you´ve seen their lightweight carry with you wrench
> (39g)?´
>
> http://www.sandsmachine.com/ac_wrenc.htm

thanks, good tip. that must be pretty new.
--
david reuteler
[email protected]

 

[Matt O'Toole]

jasong wrote:

> I´ve only had issues with my top tube coupler coming loose (steel and
> Ti frames). Upon first riding the Ti frames couplers, its
> self-detorquing was quite frequent. Now it´s toned that down
> completely, presumably with whatever small scale changes have taken
> place after a few thousand miles.
>
> So here´s a vote for top tube problems. A knocking noise when getting
> out of the saddle and the other minor shifting nuances were also
> indicators for me. I think following their advice and torquing these
> down pretty much eliminates the possibility. I´ve also just gotten
> into a habit of carrying the small wrench on rides when the 60g
> weight wasn´t a consideration (most always!).
>
> Those concerned - you´ve seen their lightweight carry with you wrench
> (39g)?

> http://www.sandsmachine.com/ac_wrenc.htm

A bike mechanic friend said he thought the S&S wrench was too short, leading to
insufficient torque.

Matt O.´

 

[jasong]

That's a bit general statement isn't it? Depends quite a bit on what the torque specs of the coupler are and the force someone can apply at that lever arm distance. Additionally, the designer may have kept the wrench length there for that very reason - to avoid overtorquing.

jasong wrote:
A bike mechanic friend said he thought the S&S wrench was too short, leading to
insufficient torque.

 

[Baird Webel]

In article <[email protected]>,
jasong <[email protected]> wrote:

> Matt O'Toole Wrote:
> > jasong wrote:
> > A bike mechanic friend said he thought the S&S wrench was too short,
> > leading to
> > insufficient torque.
>
> That's a bit general statement isn't it? Depends quite a bit on what the
> torque specs of the coupler are and the force someone can apply at that
> lever arm distance. Additionally, the designer may have kept the wrench
> length there for that very reason - to avoid overtorquing.


The listed torque is at least 35 ft/lbs, the standard wrench is 6
inches. I would expect that most people are not putting 70 lbs into
that wrench, and thus are undertightening them somewhat. There is a 12
inch wrench offered specifically for people with low arm strength, but
one is warned not to overtighten.

It does seem a little contradictory, the instructions at
http://www.sandsmachine.com/guide_c.htm#Tighten talk a lot about making
sure that you have the coupler tight, but at the same time, the wrench
isn't really long enough to do so.

This said, I've loved the coupled single and tandem that I have had and
never had problems.

Baird

 

[jasong]

You're definitely right about not getting 70lbs into the small wrench. That'd be almost hard to get without the spanner slipping out of its grooves.

In article The listed torque is at least 35 ft/lbs, the standard wrench is 6
inches. I would expect that most people are not putting 70 lbs into
that wrench, and thus are undertightening them somewhat. There is a 12

 

[Matt O'Toole]

jasong wrote:

> You're definitely right about not getting 70lbs into the small wrench.
> That'd be almost hard to get without the spanner slipping out of its
> grooves.
>
> Baird Webel Wrote:
>> In article The listed torque is at least 35 ft/lbs, the standard
>> wrench is 6
>> inches. I would expect that most people are not putting 70 lbs into
>> that wrench, and thus are undertightening them somewhat. There is a
>> 12

To answer your original point, the wrench is short to make it easy to pack and
to carry, not to limit torque.

Matt O.