Any suggestions for a behind the seat bottle on a mountain bike. I have a dropper post and only one other cage on the frame. Doing 5+ hour events with aid stations/support crew but want to be able to hold two bottles without a camelbak. Is the risk of bottle ejection too high for a mountain bike event?
Thanks!
If there’s room, sounds like a cage zip tied to the saddle is your best bet. I always use a hair tie or (elastic strap) and loop one end around the bottle cage and loop the other end over the valve on the bottle to prevent any ejections. (Otherwise, no matter the bottle or cage combo, that shit will eject on me!)
Good luck!
I don’t like camelbaks either but they sure do make a lot more sense than a BTS on a dropper post.
I saw the cannondale guys do it at cape epic last year. I’ll have a look if i can figure out what cages they were using at the time 
Would you consider something like a soft flask or 2 in your jersey pocket? Nicer alternative to a backpack if you want to carry extra water.
Zip tie a cage under your downtube and/or your stem.
Zip tie a cage under your downtube
If you ride trails/areas that are shared with horses and other animals, this is a bad idea.
That’s what plastic bags and elastic bands are for…
ETA - it’s not really going to get more contaminated under the DT than behind the seat…
On a long ride I’d use a Camelbak or zip-tie an extra bottle mount to my top tube before messing around with a bottle in the vicinity of my saddle/dropper post. I also like the idea of simply sticking a bottle or two in my jersey pockets.
Are you planning to carry spare tubes, trail tools, gels, etc? How and where?
Let us know what you end up doing.
Good luck.
David K
I have a Intense Tracer 275C with dropper post and use a single water bottle behind the saddle since I don’t have room for a bottle on the frame because of the rear shock location. I’m using a Arundel water bottle cage and it doesn’t fly out over rough terrain. I believe I’m using a old profile design mount that I had laying around. I’ll have to double check that since it’s been a while since I installed it. It’s a mount attaching to the saddle rails.
Have you looked into a small running backpack? Lighter and doesn’t bounce around as much as a camel back.
What do you do if you need to go down a sharp descent and get behind your saddle when it’s dropped?
Are you planning to carry spare tubes, trail tools, gels, etc? How and where?
Let us know what you end up doing.
Good luck.
David K
Good question - historically one spare tube in my jersey pocket with 2 co2’s and a tool. Otherwise, i ride with a camelbak and put spares there. I just find i sweat so much more with the camelbak. For race day i’m trying to avoid the camelbak.
What do you do if you need to go down a sharp descent and get behind your saddle when it’s dropped?
Honestly didn’t consider that yet! One of the races i’d like to avoid using a backpack in is Leadville and i probably will have minimal use of the dropper post there. I’ll play around with zipties on the frame and see if that’s feasible. I’ll probably do another qualifier race to try and get a better starting position than my current corral so could be a good test of whatever i choose (outside normal training). Any other events i can get away with one bottle.
A lot of the guys I ride with have gone to Lumbar packs like the CamelBack Flash. That is another idea to consider, if you are close to an REI - they usually have a great setup with about 20 hydration packs in various flavors set up for trying. ( Of course they may have it full of ski gear now… )
I’d recommend a small 2 liter running or riding hydration pack. You can fit your flat kit in it as well as the water, and it is much easier to drink from than reaching all over your frame to grab a bottle. Finally, you won’t be in trouble from a hydration standpoint, because it is very unlikely that your pack will fall off.
Even if it is a 5 hour event with multiple aid stations, I highly recommend not risking the launching of your bottle.
I raced Cape Epic this year and a hydration pack was definitely the way to go. I also did a 4 hour race this past weekend with zero aid stations, all self supported, and I had 2 bottles of nutrition on my frame and 2 liters of water in my pack, along with a multi tool, zip ties, and a flat kit. I was also able to fit a few bars in the pockets on the straps for easy reach.
For a longer mtb ride, I personally want to take out the risk factors that I can control.
jake
Lezyne Flow cages. The only cage I’ve found that’s reliable enough for MTB behind-the-seat use. With the right bottle (Spesh ones, like the Gu-branded, seem to work best) your chances of ejecting a bottle are slim. I’ve ridden MTB marathons, multi-stage desert epics and singetrack on both hardtails and full-sussers with this cage. Certain bottles (I’m looking at you, Camelbak!) would get launched, but designs with a good “lip” never launched. Never.
I used clamps made by a local CNC shop to attach the cage to the seatpost.
Here is my setup. I don’t have any problems getting behind the saddle on steep descents since it doesn’t stick out much. I think a single is fine, but going dual would probably be too wide. I don’t know the make of this mount, I’d need to take the cage off and see if there’s a name behind it.
Looks like a great cage for MTB and appears it would hold a bottle very well.
I have a Minoura like that. Currently it’s residing between my aero bars.