set back seat post ?

For discussions about bikes and equipment.
scottg
Posts: 665
Joined: 10 Jan 2008, 8:44pm
Location: Highland Heights Kentucky,, USA

Re: set back seat post ?

Postby scottg » 9 Oct 2019, 1:36pm

+++++++++++++++++++++++++++++++++++++
Why not the best, buy Cyclo-Benelux.

slowster
Posts: 984
Joined: 7 Jul 2017, 10:37am

Re: set back seat post ?

Postby slowster » 9 Oct 2019, 1:37pm

WoodBurner81 wrote:already have a fairly long stem and flat bar setup - mainly for ride position but also wasn’t overly confident using drops when clipping 20kg of 4yr old on rear for school run !

That does not sound like a good set up to me. I've never ridden a bike with a child on the back, but I would not want to have my bodyweight further forward (and lower) than necessary with such a large weight positioned well behind me above the rear wheel.

As a general rule I would expect a bike to handle better and more safely with the rider in a relatively upright position and thus closer to the child, such that the centres of mass of the rider and child are close together and closer to the combined centre of gravity.

A more upright position with a shorter stem may eliminate or reduce the need for more saddle set back (at least for now while the child seat is being used.

rjb
Posts: 3466
Joined: 11 Jan 2007, 10:25am
Location: Somerset (originally 60/70's Plymouth)

Re: set back seat post ?

Postby rjb » 9 Oct 2019, 3:28pm

Anybody tried one of these suspension adapters.? Could give you more layback and you could damp the suspension with a suitable placed rubber ball.looks like 10cm layback available
https://www.ebay.co.uk/itm/Aluminum-All ... SwHwddJd4Y
51lUambH9jL._SY355_.jpg
51lUambH9jL._SY355_.jpg (10.9 KiB) Viewed 153 times
Last edited by rjb on 9 Oct 2019, 4:45pm, edited 1 time in total.
At the last count:- Focus Variado, Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin, Raleigh 20, Falcon K2 MTB dropped bar tourer, Longstaff trike conversion on a Falcon corsa. :D

NetworkMan
Posts: 714
Joined: 25 Aug 2014, 11:13am
Location: South Devon

Re: set back seat post ?

Postby NetworkMan » 9 Oct 2019, 3:58pm

WoodBurner81 wrote:
amediasatex wrote:I am also short of leg and long of torso and run a lot of setback, to counterbalance the cantilever of my upper body. Also tend to run longer stems or long reach bars as my short legs require 52-54cm frames but I prefer a 54-56cm top tube.


sounds familiar

already have a fairly long stem and flat bar setup - mainly for ride position but also wasn’t overly confident using drops when clipping 20kg of 4yr old on rear for school run !


I'm a trendy consumer. Just look at my stupid phone.

Not wanting to add even more confusion here but did you switch from drops to flats on this bike? I only ask because drops provide extra reach in themselves so that switching to flats would decrease the reach unless you changed the stem for a longer one. Did you use the same stem? Did you notice the reduced reach? If so, did that feel better or worse or the same?
.... Or have I misunderstood completely! :?

MikeF
Posts: 3770
Joined: 11 Nov 2012, 9:24am
Location: On the borders of the four South East Counties

Re: set back seat post ?

Postby MikeF » 9 Oct 2019, 4:21pm

horizon wrote:
MikeF wrote:
horizon wrote:
Are you sure? That says to me you need your saddle nearer with maybe a longer stem.

No it definitely doesn't. This is a major flaw in thinking and followed by many bike manufacturers.


MikeF: can you say a bit more about this as, AIUI, the OP's short legs and long torso shouldn't be giving him any problems on this bike so I am wondering what else is going on. I've had my own battle with seat set-back so I'm interested in what is happening here (but cannot provide expert advice).
I would say adjust the saddle position first eg height set back etc.. Then adjust other things stem length, handlebar height etc., but do not alter the saddle position to fit around other dimensions. If you aren't seated properly nothing will ever be right.

The problem is the majority of bikes are set (designed?) for someone of average male height/dimensions. If you are shorter or more of average female height, seat tube angles will most likely be increased to make the cycle "fit". There isn't any logic at all in this and the cycle doesn't of course "fit" in reality, because the rider is perched almost above the bottom bracket so as to reach the handlebars. Note how many small sized cycles have an absurd 75 degree seat tube.

People have problems with seat set back because seat tube angles are too steep. Nobody ever seems to problem that they can't set the seat far enough forward.
"It takes a genius to spot the obvious" - my old physics master

Rod Goodfellow
Posts: 22
Joined: 22 Aug 2017, 12:02pm

Re: set back seat post ?

Postby Rod Goodfellow » 9 Oct 2019, 5:50pm

I have an adjustable layback 27.0 diam seatpost similar in design to the one shown above available.PM me if interested.

User avatar
CyberKnight
Posts: 572
Joined: 18 Dec 2009, 4:44pm
Location: Derbyshire

Re: set back seat post ?

Postby CyberKnight » 9 Oct 2019, 5:50pm

Im following this with interest as im of similar proportions and i just oredered a new seat post for my commuter as the current post has a large clamp area and running the seatback i like it was actually rubbing the upper leg and causing premature bobbling
Image
John Wayne: "I won't be wronged, I won't be insulted, and I won't be laid a hand on... I don't do these things to other people, and I require the same from them."

WoodBurner81
Posts: 19
Joined: 8 Oct 2019, 4:42pm

Re: set back seat post ?

Postby WoodBurner81 » 13 Oct 2019, 2:39pm

thanks for all the replies folks, will post an update when had chance to play with new arrivals


I'm a trendy consumer. Just look at my stupid phone.