Saddle set way back...safe?

[jackchoo]

hi i was doing some own bike fitting and finally settled on a position whereby I felt quite comfortable. I'm right at the seat post limit line (hidden by the steel lug)...about 70cm into the frame. Adjusting the fore-aft saddle position the saddle is 'way' back.

Am I going to damage my frame? its 54cm vintage 80's italian steel frame (lugged). I ask because since the saddle is way back, my seating position seems that it will bend the post more compared to if i have the saddle clamped right at the centre of the rails...

 

[Phill P]

Impossible to tell, but if you have max low, and max rearwards, you are either a freak of nature or you haven't done a good job of the bike fit.

Safety wise you should be fine. Might put extra load on the seat post clamp. I had a well rearwards seat seat up, and the seat post saddle clamp bolt fatigued and broke (but I weight just under 100kg).

My advice is get somebody check you set up as the load of knees may be more dangerous.

 

[oldbobcat]

Am I going to damage my frame? its 54cm vintage 80's italian steel frame (lugged). I ask because since the saddle is way back, my seating position seems that it will bend the post more compared to if i have the saddle clamped right at the centre of the rails...

Probably depends on how high the seat is, too. The more seatpost you're showing above the clamp, the more leverage you're applying to that section of the frame.

One Masi I tried, I knew was too small because I could see and feel the frame flexing at the seat lug under my weight.

It might also be a good idea to not use a super lightweight saddle-seatpost setup.

 

[daveryanwyoming]

Probably depends on how high the seat is, too. The more seatpost you're showing above the clamp, the more leverage you're applying to that section of the frame....It might also be a good idea to not use a super lightweight saddle-seatpost setup.

In addition to the points above, you might want to buy a setback seatpost like this: http://www.treefortbikes.com/81_333222337944__Elite-Setback-Seatpost-410mm.html

If you really do need to be so high and far back then you can kill two birds with one stone by getting a seatpost that moves your seat back and one that's longer than your current seatpost so you have enough post in the frame for safety. Just make sure you get the correct diameter for your vintage frame which is most likely a 27.2mm seatpost diameter.

Good luck,
-Dave

 

[alfeng]

In addition to the points above, you might want to buy a setback seatpost like this: http://www.treefortbikes.com/81_333222337944__Elite-Setback-Seatpost-410mm.html

While most current, ROAD seatposts are longer than those available back in the 80s-and-earlier, you/(jackchoo) essentially want to ditch the apparently-vintage ROAD seatpost you currently have & buy-and-use what is generally/generically classified as a MTB seatpost, now ...

An Easton EA30 (the alloy version of their carbon seatposts) will cost less than the Thomson seatpost (the EA30 should cost less than $40US) ... the Easton posts have more setback than most of the other, "regularly" available seaposts have. Easton's alloy seatposts are available in either "silver" or black.

 

[Phill P]

My appologises....I read the OP's first post as maz rearwards and max inserted, not max extention.

This maynot be a bad setup is you have long legs/short torso and have a sloping top tube frame.

The long extension will put the max load on the seat post tube, and the frame due to high bending loads (force x distance). However the post is marked as being ok. The tube should be butted to take the bending load and the frame clamp/supporting load.

I had an EA70 seat post, and after 12,000 ish km the single bolt that holds the saddle cradle fatigued through (left me sitting on fresh air as the saddle decided to suddenly be left behind...no damage dwon to saddle or rider). Result of an extreme set back (I have long legs dimensions) and may large **** (ie too much load). The simple fact is parts are made to last a given length of time under a given load. If you push the load case to the extreme, expect durability to suffer.

The best solution may not match your budget right now, and that is get a new frame that suits your leg geometry better. I have noticed the past few years there are more frames out there with slacker seat angles in the larger frames, and some of these frames are in the "affordable range" not just the euro brands. Cannondale giant and trek come to mind. Also get something with a longer seat tube to better support the seat post. I don't know about the front end fit of your frame, but take what you have learnt from this bike, and apply it when window shopping for something new.

Correct fit is THE MOST IMPORTANT aspect of picking a frame. Get it right and both rider and frame will last longer.

 

[jackchoo]

I'm about 180cm, weigh 90kg and the frame size is '54cm'.

Really appreciate all the help you guys gave but to make it easier, I attached a photo of the current setup....

 

[alienator]

I'm about 180cm, weigh 90kg and the frame size is '54cm'.

Really appreciate all the help you guys gave but to make it easier, I attached a photo of the current setup....

I think your body wants a larger frame.

 

[Phill P]

ooooo doing bike fits over the internet!!!!

Horz top tube frame......lots of seat tube exposed..... lots of set back..... large handle bar drop......

Its a lovely looking frame, but you may enjoy your cycling more on a larger frame. I'm betting not only is you saddle setup a little unusual but I'm betting your front end fit might be out as well.

Go to a GOOD bike shop and have them sort you out. Even if you spend a little bit of money on a bike fit it is often very valueable advice.

BIKE FIT IS THE MOST IMPORTANT ASPECT OF PICKING A FRAME.

Chances are if you are riding for less than an hour you'll be fine. But on long rides your body may start to complain.

 

[oldbobcat]

I attached a photo of the current setup....

Ooh, nice bike. And, yeah, there's a chance you're stressing the seat cluster with all that leverage. In fact, it looks like your seat tube has already taken a bit of a bow. You might want to test for straightness with a straight edge.

 

[jackchoo]

Ooh, nice bike. And, yeah, there's a chance you're stressing the seat cluster with all that leverage. In fact, it looks like your seat tube has already taken a bit of a bow. You might want to test for straightness with a straight edge.

Its still straight.....guess the pic has a little distortion in it due to my wide angle camera phone....

previous owner cycled this one (this setup) for 15 years.....before I got it from him...ok, he was about my height but was much slimmer than me (tri-athlete maybe)...attached photo with none/little distortion (50mm lens maybe...)

 

[Phill P]

did he only ever ride that bike up hill because that saddle is baaaaaad.

Doesn't matter how somebody else had the bike fitted, they aren't you. For the same height you could have longer/shorter everything, and that effects the fit for you.