Tandem Cycling - Saddle position on Macchiato

The long search for a comfortable saddle distracted me from the realization of
how much Macchiato departed from 'standard' geometry with 72-74D seat tube
angles. I have found that the Terry Butterfly variants are much more comfortable
than the Fly versions, I now have a surfeit of Terry saddles (10 I believe). All of
these saddles work well enough on singletons out to 100mi where it is easy to
shift pressure points around at will but only the Butterfly can do a century on
Sat and another on Sunday on the Macchiato without any more discomfort than a
30 mile ride on a singleton. (I have also divided my shorts into tandem and
non-tandem rated categories after a particularly bad choice on one century.)

After finding a good saddle, a 15month search, it became apparent that any vigorous
pedaling resulted in sliding forward onto the nose of the saddle and I was constantly
repositioning. I swapped the Alpha Q post for a set forward Thompson and this
helped some, as did raising the nose of the saddle. I am now about 2" forward of
where the Alpha Q placed the saddle. The pix below indicate the position of the
BB relative to the saddle nose: http://picasaweb.google.com/lh/viewPhoto?uname=sch1943&aid=5104250388360581633&iid=5208913188531742242

And for a comparison I put my old Titan in front of the Macchiato with the BB spindles
approximately collinear with the same T square:
http://picasaweb.google.com/lh/viewPhoto?uname=sch1943&aid=5104250388360581633&iid=5208913192132111282

Notice the difference in seat tube angles and how much further forward the seat is relative
to the BB on the singleton compared to the M seat nose. I believe this is the reason for the slide
forward under power. Having the nose up that much felt a bit strange for about 20mi but it
was easy to get used to and practically stopped the slide forward. It took 2400mi on the M
and 1700 on the Burley to sort all this out. The real test comes on 6/21 when we tackle Cherohala.

Wow, all I can say is you must have really short femurs.

I for one think saddle position is saddle position is saddle position. What I mean by that is that once properly fitted your saddle position with regard to the bottom bracket should be the same from bike to bike of like type (road single vs. road tandem).

If the Macchiato has a 72° stoker seat tube angle I can see where you might have a problem compared to the Teledyne Titan at 74.5°. That said, it appears to me that you are making a very big compromise with regard to comfort just to avoid sliding forward on an difficult to fit frame geometry, either that or I would have suggested that your Titan wasn't fitted properly. JMHO

sch, I looked at all the pictures in the Picasa album and read all the captions too. I hate to say this, but it looks to me like this was not the bike for you. This is especially considering the fit issues you are having not only with the saddle position but also with heel rub on the chainstays. The other issues you mention are simply adjustment issues and easily resolved.

I am simply not sure how your LBS let the both of you walk out of his shop with a bike that fits as poorly as pictured. JMHO.

Well the whole point of the post was that as set up, it is now pretty
comfortable to ride, at least out to 100mi/ two days in a row with
tandem rated shorts. The other point is that the Macchiato has
significant geometry variants from standard bikes such that the seat
position is 2-3" behind where it would be on an equivalent half bike.
Not sure I disagree with your supposition as to bike fit otherwise.
I spend about 50% of my ride time on the tandem, last yr about 5900
miles total, and feel that this year is going to be a lot better with
the fit problem neutralized. First approximation for the M is that
the seat tube angle for the stoker is ~71D. Pilot seat post is 72+
with the pilot seat also behind where it would be on his singleton.
Looking at other Co-Mo tandems the seat tube angles are 72-73
typically with the saddle in a more typical relationship to the BB
that singletons have. This appears to be a Macchiato peculiarity
and may be adjustable for future buyers. Ours was early in the
manufacturing cycle and may represent a learning experience for
Co-Mo as much as it has for us.

Couple of points . 1) where is the bony putubrence on the bottom of your knee in relation to the pedal spindle?

2) the position on your Teledyne is very foward, to the point it would not be legal in a UCI event. ( UCI regs require the tip of the saddle to be 5cm behind the BB)

3) I'm assuming the Macchiato was built for you. Given that they all are custom, I'm very surprised that you would would end up with a fit requiring a negative setback seatpost. Have you talked to Co-Motion and your dealer about this?

4) It's a sin to put a luggage rack on a Macchiato.:eek:

5) Excellent color choice on the bike.;)

Merlin: 1) Checking approximately, all three bikes the knee position with the crank horizontal forward the bony knob is 1-2cm behind the spindle on the M, about on with the 54cm Vortex
and 1-2cm forward on the 55-56cm Titan.
The Titan was bought in '75 when sizing criteria differed, I was 15# lighter and 100watts stronger
than I am today. My current preferred size were I to get a new singleton would be 52 cm.
Top tube on the Titan is 1" longer than the Vortex. Titan is 'way' too big, but after 33 yrs one adapts.

2)See above. My preferred singleton ride is a Rotator Pursuit bent. You may notice a set forward
seat post on the Titan, not as much as the M though. FWIW tri bikes are more extreme than this
but they are not UCI legal either.
3) Retrospectoscope works best. Once built and checks written 9mo after acceptance is a little
late to cavil. Co Mo appears to have revised its opinion of who the M is most suitable for, an
opinion not apparent last summer. I have been able to adjust and am pleased with the result.

4) Ten Hail Co-Mos and ten Hail Santanas and ten Hail Davincis after each ride. We have been doing century out on Sat, motel overnite and century back on Sunday, hence the rack. Took a bit
of adapter machining to get it mounted. Still think paint is too soft.
5) The pix in the '07 catalog probably sold a lot of that paint scheme.
Steve