Hybrid Bicycles - suspension seat post

I have often heard that one should avoid suspensions because they detract from pedaling efficiency. Which contributes more to the inefficiency: the suspension in the seat post or the one in the fork?

The Jamis Coda series all have suspension seat posts (45mm travel). The Trek FX series, on the other hand, has no suspension anywhere. I test rode the Jamis Coda Sport yesterday and it was as comfortable as the 7.6fx.

How much of a concern is the suspension seat post?

Thanks.

Go with the bike that feels best. You can always swap out the seat post. Given your budget (which I infer by the 7.6FX in your consideration set), a different seatpost is not material added cost. The stock seat post on the 7.6 FX lists for $69 but in reality can be had for much, much less (~$20 on ebay, people are always trying to unload the stock hardware when they upgrade). Cheers, Matt.

I suspect that most of the energy is lost thru the front suspension fork. But I'll let the experts chip in!

Mikey

On a hybrid there is very little efficiency lost to a seatpost with suspension. Decent suspension seatposts have a bolt on the bottom you can tighten to reduce the travel. I keep mine pretty tight. I don't think too much is lost in the suspension fork either. It is not like you are bouncing up and down on the fork to pedal a bike

Go with the bike that feels best. You can always swap out the seat post. Given your budget (which I infer by the 7.6FX in your consideration set), a different seatpost is not material added cost. The stock seat post on the 7.6 FX lists for $69 but in reality can be had for much, much less (~$20 on ebay, people are always trying to unload the stock hardware when they upgrade). Cheers, Matt.

Matt,

Thank you for your response. My budget is currently limited to Coda Comp/7.5fx. I test rode the 7.6fx just to check out the difference the Isozone Monostay made.

Although not a strict apples-to-apples comparison (since the pavement was different), the 7.5fx seemed more jarring than the Coda Sport.

I don't quite understand Jamis' description of the suspension seat post:
``Coda Comp’s telescoping suspension seat post offers 45mm of bump-eatng (sic) suspension travel, with an MDU elastomer damping mechanism [that?] is lighter and smoother than coilspring types.'' http://jamisbikes.com/usa/thebikes/pdfs/10_codacomp.pdf

The Coda Sport brochure also mentions the MDU elastomer.

Doesn't 45mm of travel seem like a lot? Is there a difference in pedaling inefficiency between a coil spring seat post suspension and an elastomer seat post suspension?

I am not a big fan of suspension seatposts. They get loose, they rattle or squeek, they move around, they rob energy......

However, it's no big deal - if you like it - fine - if not, replace it later.

Suspended front ends - make sure you get one that is capable of being locked out. That, makes a big difference when you are pushing hard, or going up a hill.

I got an '09 Coda Sport about a month ago and I can't feel the suspension seat post doing anything . I ride with the saddle angled down slightly and I can pop the seat loose on big bumps if don't torque it down extremely tight. If the suspension was actually absorbing bumps I would think that wouldn't happen.

Now, I immediately dump the suspension seat post, I finally got tired of trying to mount an over extended seat post to compensate for the suspension seat post's squish. The next thing to go was the quick release seat post clamp for a hex wrench style. I never could get the quick release tight enough to keep the seat post from "creeping" downward, plus the hex style is better for saddle theft prevention.

I have one on my off-road bike and it's going on my hybrid. Came with three springs for different rider weights, and a screw in the base to adjust preload. I don't notice it robbing power, the theory was that badly damped front shocks or seat-posts on road bikes absorbed energy. The trade off was a bike you could actually ride around London or New York without getting haemorrhoids or crushed vertebrae. On road, I can't tell if mine is working or not, which is probably a good sign. It was a better option for me than hefty tires or front suspension. If there's too much squish I imagine it would become boring. If you're more comfortable you're going to ride further, I find. So that means get one you can adjust.

Once you've loaded up your hybrid with water, cameras, jacket, sandwiches, iPad, backpack, laptop and satellite dish, the last of your worries is going to be whether your suspension is robbing you of power. Be comfortable. Ride further. Get the bike you want. The geometry of hybrids is very different to road bikes, and any 'power sapping' is likely to be with the rider's fitness, rather than the bike.

Once you've loaded up your hybrid with water, cameras, jacket, sandwiches, iPad, backpack, laptop and satellite dish, the last of your worries is going to be whether your suspension is robbing you of power. Be comfortable. Ride further. Get the bike you want. The geometry of hybrids is very different to road bikes, and any 'power sapping' is likely to be with the rider's fitness, rather than the bike.

There's another item I dumped in favor of panniers, talk about a spine crusher when fully loaded, suspension seat post or not, along with blocking brightly colored outerwear on those busy urban commutes.

agreed: get it off your back. Even a bottle of water in my jacket pocket is a pain. :-)