Hi All, I read something recently that contradicted what I thought was the usual practice and need some clarification.
I recently moved my saddle fore-aft more forward on the rails which I always thought that meant it drops the saddle height by a couple of mm. But I read somewhere its the reverse where if you set it back further it drops the saddle height. So what is it really?
I'm having a few lower hamstring (where it meets the knee) issues. I think the saddle is too high but I need to play with the fore/aft as well.
Edit: From Neil's Bike fit:
"Remember that as the seat setback is adjusted, so too does the seat height. Move the seat 10mm back and you will likely need to drop the saddle around 3mm to account for this effect. After any major setback change, saddle height should be re-assessed and fine-tuned"
This is what is confusing me as I always thought it was the other way around...
Saddle forward = saddle up or down?
Forum rules
The information / discussion in the Cycling Health Forum is not qualified medical advice. Please consult your doctor.
The information / discussion in the Cycling Health Forum is not qualified medical advice. Please consult your doctor.
- rodneycc
- Posts: 2879
- Joined: Mon Oct 14, 2013 1:50 pm
- Location: Melbourne Eastern Suburbs, Victoria
Saddle forward = saddle up or down?
Postby rodneycc » Thu Aug 20, 2015 12:27 pm
2013 BMC TM SLR01;2013/14 Bianchi Inf CV
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
- Derny Driver
- Posts: 3039
- Joined: Wed Nov 21, 2012 12:18 pm
- Location: Wollongong
Re: Saddle forward = saddle up or down?
Postby Derny Driver » Thu Aug 20, 2015 12:31 pm
If you slide your saddle forward, you need to raise the seatpost height slightly.
If you slide the saddle back, you need to lower it.
Usually 3-5mm.
If you slide the saddle back, you need to lower it.
Usually 3-5mm.
- rodneycc
- Posts: 2879
- Joined: Mon Oct 14, 2013 1:50 pm
- Location: Melbourne Eastern Suburbs, Victoria
Re: Saddle forward = saddle up or down?
Postby rodneycc » Thu Aug 20, 2015 1:25 pm
Thanks Derny, I had to re-read that a couple of times before it got through my thick head. So both of those statements and my understanding were right. I was just reading it wrong. So moving the saddle forward gets you closer to the spindle so it reduces the saddle height (which is what I was trying to achieve). Good.
There are other factors here with my setup like the ISP has two offset pivot positions that I have been playing with and with the Selle Smp has those angled rails but its more about the theory that I was after so thanks again. Time to have a bit more of a play I think. Got a feeling I need to cut that ISP a bit more too, darn it.
There are other factors here with my setup like the ISP has two offset pivot positions that I have been playing with and with the Selle Smp has those angled rails but its more about the theory that I was after so thanks again. Time to have a bit more of a play I think. Got a feeling I need to cut that ISP a bit more too, darn it.
2013 BMC TM SLR01;2013/14 Bianchi Inf CV
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
- Duck!
- Expert
- Posts: 9876
- Joined: Tue May 21, 2013 8:21 pm
- Location: On The Tools
Re: Saddle forward = saddle up or down?
Postby Duck! » Thu Aug 20, 2015 4:58 pm
Saddle design can play a part in whether or not you need to tweak the height; if the rails are a considerable angle off horizontal (lower at the back) then sliding the saddle one way or the other will alter the height automatically, but may still need a fine tweak.
To illustrate how it works, try some rudimentary geometry. You will need a bit of paper, a ruler & maybe a protractor & compass:
On your sheet of paper, scribe a straight line vertically. Length isn't critical, but longer helps. From the bottom end of your first line, scribe another of identical length, but at an angle (17 degrees represents a typical seat tube angle from vertical ). You could use a compass to scribe an arc between the other ends of the lines to show your constant distance. Now mark a line at a right angle to your original one, at a height that intersects with the end of your angled line, and extends past it. See where this is going? Moving along this horizontal plane toward the vertical axis reduces the distance from the base point, ergo lower seat height. Sliding back increases the distance.
To illustrate how it works, try some rudimentary geometry. You will need a bit of paper, a ruler & maybe a protractor & compass:
On your sheet of paper, scribe a straight line vertically. Length isn't critical, but longer helps. From the bottom end of your first line, scribe another of identical length, but at an angle (17 degrees represents a typical seat tube angle from vertical ). You could use a compass to scribe an arc between the other ends of the lines to show your constant distance. Now mark a line at a right angle to your original one, at a height that intersects with the end of your angled line, and extends past it. See where this is going? Moving along this horizontal plane toward the vertical axis reduces the distance from the base point, ergo lower seat height. Sliding back increases the distance.
I had a thought, but it got run over as it crossed my mind.
- rodneycc
- Posts: 2879
- Joined: Mon Oct 14, 2013 1:50 pm
- Location: Melbourne Eastern Suburbs, Victoria
Re: Saddle forward = saddle up or down?
Postby rodneycc » Fri Aug 21, 2015 2:36 pm
Thanks Duck, I didn't go as far as the compass and protractor but I got a piece of cardboard out and a ruler and tape measure and kind of got the idea with measurements from saddle to stem and BB to top of saddle and did the same comparison on my other bike as well (with the same selle smp saddle). I don't know how much the compact geometry plays a part but I kind of just imagine a straight line on the top tube and get an idea where abouts in the ballpark it needs to be. Verdict is I need more seatpost cut.
2013 BMC TM SLR01;2013/14 Bianchi Inf CV
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
- Tim
- Posts: 2948
- Joined: Wed Jul 07, 2010 5:02 pm
- Location: Gippsland Lakes
Re: Saddle forward = saddle up or down?
Postby Tim » Fri Aug 21, 2015 3:03 pm
Rodney, I can lend you a clamp-on cutting guide for the TCR aero seatpost if you don't already have one. It'll make the cut nice and properly square and I think helps avoid a frayed edge.rodneycc wrote:Got a feeling I need to cut that ISP a bit more too, darn it.
- rodneycc
- Posts: 2879
- Joined: Mon Oct 14, 2013 1:50 pm
- Location: Melbourne Eastern Suburbs, Victoria
Re: Saddle forward = saddle up or down?
Postby rodneycc » Fri Aug 21, 2015 7:39 pm
Thanks Tim but I have already paid my lbs to cut it once so should be no probs to take it back there and get a little more taken off. Just painful I didn't get it right the first time. Thanks for the offer though and will look you up if I have any dramas with them.Tim wrote:Rodney, I can lend you a clamp-on cutting guide for the TCR aero seatpost if you don't already have one. It'll make the cut nice and properly square and I think helps avoid a frayed edge.rodneycc wrote:Got a feeling I need to cut that ISP a bit more too, darn it.
2013 BMC TM SLR01;2013/14 Bianchi Inf CV
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
2013 Lynskey Helix;2013 XACD Ti Di2
2013 Giant TCR Adv SL1;2014 Giant Defy Adv SL
Jump to
- General Australian Cycling Topics
- Info / announcements
- Buying a bike / parts
- General Cycling Discussion
- The Bike Shed
- Cycling Health
- Cycling Safety and Advocacy
- Women's Cycling
- Bike & Gear Reviews
- Cycling Trade
- Stolen Bikes
- Bicycle FAQs
- The Market Place
- Member to Member Bike and Gear Sales
- Want to Buy, Group Buy, Swap
- My Bikes or Gear Elsewhere
- Serious Biking
- Audax / Randonneuring
- Retro biking
- Commuting
- MTB
- Recumbents
- Fixed Gear/ Single Speed
- Track
- Electric Bicycles
- Cyclocross and Gravel Grinding
- Dragsters / Lowriders / Cruisers
- Children's Bikes
- Cargo Bikes and Utility Cycling
- Road Racing
- Road Biking
- Training
- Time Trial
- Triathlon
- International and National Tours and Events
- Cycle Touring
- Touring Australia
- Touring Overseas
- Touring Bikes and Equipment
- Australia
- Western Australia
- New South Wales
- Queensland
- South Australia
- Victoria
- ACT
- Tasmania
- Northern Territory
- Country & Regional
Who is online
Users browsing this forum: No registered users
- All times are UTC+10:00
- Top
- Delete cookies
About the Australian Cycling Forums
The Australian Cycling Forums is a welcoming community where you can ask questions and talk about the type of bikes and cycling topics you like.
Bicycles Network Australia
Forum Information
Connect with BNA
Brought to you by Bicycles Network Australia | © 1999 - 2024 | Powered by phpBB ®
This website uses affiliate links to retail platforms including ebay, amazon, proviz and ribble.
This website uses affiliate links to retail platforms including ebay, amazon, proviz and ribble.