Looking for a zero offset Thomson seatpost

93 views
Skip to first unread message

Fryfam

unread,
May 19, 2020, 1:45:35 AM5/19/20
to RBW Owners Bunch
Anyone have a 27.0 Thomson zero offset seatpost they'd be willing to sell and ship to me in Seattle? Need something for my old Centurion tourer - to bring my aging self just a little closer to the handlebars... ;-/
thx

Clayton Scott

unread,
May 19, 2020, 1:52:08 AM5/19/20
to RBW Owners Bunch
I think I do. It would be black though. PM me your contact if of interest.

Clayton Scott
HbG, CA

Fryfam

unread,
May 19, 2020, 2:09:35 AM5/19/20
to RBW Owners Bunch
Just did, let me know if my PM fails to arrive

Bill Lindsay

unread,
May 20, 2020, 1:22:41 PM5/20/20
to RBW Owners Bunch
This is obvious and self-evident to a lot of people, but is counter-intuitive to a lot of people: slamming your saddle forward to fix a reach problem will often make your problem worse rather than better.  If your bars are too far away, and you are 'hunched over' too much, slamming your saddle forward also pushes your weight forward, so now you will have a lot more weight on your hands, making your hands, elbows, shoulders, neck and upper back all worse off.  

Most road bikes from the 1980s have way too steep seat tubes, and require you to slam the seat all the way back, often with an extra laid back seatpost, to get your bum back as far back as it ought to be.  When that weight distribution is right, you should be able to just lay your hands on the handlebars.  If you are bent over too far when your saddle is in the right position, then the right way to fix that is to get the bars up.  Slamming the saddle forward on a 1980s road bike would destroy my shoulders.  It makes my neck tense even thinking about it.  

It's worth experimenting with a zero-offset seatpost if you don't mind the expense of it.  Just know that you may find that you've made things worse rather than better.  

Fryfam

unread,
May 20, 2020, 3:06:29 PM5/20/20
to RBW Owners Bunch
Appreciate hearing about your experience, Bill. If looking for a cheapo post for the sake of experimentation there's always Origin8.

Probably worth noting that not everyone feels the same about zero setback:
http://lovelybike.blogspot.com/2011/12/on-seatpost-setback-and-related-matters.html

Analog’s stance, which seems to follow prevalent attitudes and perhaps fuels 0mm stem interest:
https://www.analogcycles.com/zero-offset-seatposts-make-zero-sense-mostly/

Let’s not forget Steve Hogg (IBFI):
https://www.stevehoggbikefitting.com/bikefit/2011/05/seat-set-back-for-road-bikes/

There are few hard / fast rules regarding bike fit that I follow. A big YES on cockpit experimentation to find one's optimal riding position (ideally established over yrs of micro tuning) on various cycling machines from different eras and with unique geos. Zero setback works perfectly for me *on a few of my bikes*. I’m 155-lbs, pbh ~35.5” and 5’11”… so even with an inline post my weight is distributed quite evenly within my semi-aero-levered “masters” cockpit. Most of my rides these days are 2.5-4 hours in length w/ average speeds of 18mph.

In any case, zero setback in the 27.0 diameter is very difficult to come by as of late, given global shipping restrictions.

Always up for Seattle rides with new friends...

Bill Lindsay

unread,
May 20, 2020, 3:30:25 PM5/20/20
to RBW Owners Bunch
Fryfam pointed out:

"Probably worth noting that not everyone feels the same about zero setback:
http://lovelybike.blogspot.com/2011/12/on-seatpost-setback-and-related-matters.html"

There are several major qualifiers there, and the linked article discusses it appropriately and in context.  That linked article is about moving the saddle forward on a frame with a very very slack seat tube angle and an unusually long top tube.  That first generation 52cm Sam Hillborne has a 71.5 degree seat tube angle and a 57.5cm top tube on a "small".  The author has already put a short stem on to partially correct the reach.  A typical 1980s road bike like a Centurion may have a 73 or maybe even a 74 degree seat tube angle.  That means that the saddle setback on a Hillborne would start out more than an inch further back.  A zero-offset seatpost on a Hillborne and a mega laid back seatpost on a Centurion would likely achieve a similar amount of saddle setback.  On my own Sam Hillborne, with a small setback post (Nitto 65), my saddle is near mid-rail, biased maybe a couple mm forward.  On my vintage 1980s bikes, I slam the saddle back as far back as it will go.  Many of us oldtimers remember the standard saddle setup of hammering one's saddle back with a rubber mallet.  

If your Centurion has a 71.5 degree seat tube angle, and you've already shortened the stem as much as is appropriate, adding a zero offset seatpost is a worthwhile next step, just like the article.  A zero-offset seatpost on a typical 1980s road bike would result in more of a triathlon/time trial/aero bars kind of fit, which may be OK.  

For context, my experience has been as a 'decent' bike fitter in 15 years of working at bike shops in my youth.  Maybe 1000 customers asked me over the years to slide their saddle forward because they were too leaned over.  Maybe 800 of those 1000 agreed to try sliding it back instead.  Maybe 500 of those 800 were surprised to see that it helped a lot.   

I hope it all works out for you and you get the fit you are after.  

Bill Lindsay
El Cerrito, CA

Bill Lindsay

unread,
May 20, 2020, 3:44:15 PM5/20/20
to RBW Owners Bunch
Regarding Steve Hogg's approach:
That approach is essentially identical to how I approached bike fitting.  I was not a KOPS zealot.  The longer and lower your body would allow you to go, the further back the saddle can go.  Sliding the saddle forward is totally appropriate in balance with a higher-height shorter-reach stem.  It's all about the total body position in relationship to the bike.  I really like his illustrations of three riders with identical torso measurements requiring different setups to account for their differences in flexibility.   

Bill Lindsay
El Cerrito, CA

On Wednesday, May 20, 2020 at 12:06:29 PM UTC-7, Fryfam wrote:

John G.

unread,
May 20, 2020, 4:21:53 PM5/20/20
to RBW Owners Bunch
This is all really interesting info. I just recently replaced an old Dura Ace seatpost on my Roadeo with a Thomson Masterpiece zero offset seatpost that I had laying around. My Berthoud saddle is as far back as it could go. The position hasn't bothered me so far, which surprises me a bit. I'm not sure what I was expecting, but my Roadeo is a hair small for me, so I guess I predicted I would feel cramped. The fact that I've felt fine so far (for about 150 miles total) almost has me nervous.
Reply all
Reply to author
Forward
0 new messages