I noticed recently that my saddle seems to have a problem. When hopping/jumping up on things, my seat bends right in the middle. You can replicate it by merely pulling up on the grab handle while holding the back of the seat still. This saddle is only a few months old, so I can’t imagine it should be having issues.
I guess I should state that it is a Nimbus Gel.
You might check for a loose front handle or a crack in the seat post but it does sound like something is up with the saddle itself. I don’t think I’ve ever had one bend in the middle.
I say a post or handle also, any video?
Sorry for the watermark.
I think it is a seat post or saddle base. What the seat post look like we’re it attaches to seat
Broke saddle base 
I’m sorry
So, new saddle then? And can you explain?
The base of your saddle is cracked pretty significantly. If you take the post off it should be pretty obvious. Your choices are to continue riding it as is until the seat actually rips in half or replace the seat now.
(edit: Unless that’s just a loose staple)
Did you change the seat bolts at some stage? It looks like you screwed new oversized bolts into your saddle base,causing it to crack.
Looks an awful lot like a staple to me (if you compare with the other ones in the pic). Seems fairly implausible that the OP wouldn’t have noticed a crack as big as that would be, and that it stops suddenly like that. Also a clean straight crack is an unlikely failure mode.
Unfortunately it’s clear from the video that the seat is bending - just not at the point where it looks like a crack in that pic.
I believe it is the base, mine all snap clean like that
It’s neither a crack nor a staple, it’s actually a piece of the seat cover. The flash on my camera made it look like a crack. A picture of it here.
I’ve never changed the bolts. At one point my grab handle’s bolts were loose, so I tightened them, but those are all original bolts.
That’s strange. I can’t see the bolts you put in doing that either (excellent idea BTW, I HATE allen screws). I wonder if it could be the metal stiffener plate under your seat foam.
Wait, what? I said I didn’t change any bolts…
If it is the stiffener plate, how could I see to that?
He’s got the older model that had bolts set in the base of the seat, using nuts on the outside to attach the extra bits to the seat.
While we are on the subject, is there a way to find what year-model my Nimbus II is? I bought it from a third part vendor who bought it themselves from UDC, as such I don’t know how long they had it in their inventory.
Whoops! My bad, I totally skipped over that part. Regardless, I don’t think that’d cause it anyways.
If it truly is that metal stiffener plate, it’s under your seat foam. This would mean removing all the staples, pulling back the cover, pulling back the foam, and pulling off the paper tape, just to see if it’s really cracked. If it is, I think you’re SOL. I’m not sure if UDC sells them, and you’d need a new seat cover anyway. If it isn’t the plate, I have no idea what it could be, and you’d be stuck with a ripped apart seat.
Sorry, I’m not sure what I’d do in the situation. Just trying to think of possible culprits.
Maybe I could ask my brother-in-law to x-ray it, see if the plate’s broken…
If the stiffener plate is broken, as seems most likely, what causes it? I haven’t been too particularly abusive. Did I just happen to get one of the few lemons? Or was it most likely user-caused?
Anyways, thanks for the help, I really appreciate it. I’ll probably be buying another seat soon. I guess that’s gonna be about $50 less for my 29’er fund =P
Actually an intermediate model (I wasn’t aware existed). It appears to be the newer KH base, but with bolts rather than nut inserts. The older Nimbus Gel seat I have uses the Velo base.
Not that that helps the OP - if there’s no visible cracks to the plastic, then I can’t see anything else it could be other than the internal metal plate (though I’m still a bit surprised as the plastic base on its own has more inherent stiffness than the one in the video appears to). If you have fabrication skills and facilities I’m sure it’s far from impossible to make yourself a new one - the one in my Velo base is 2mm sheet steel, and I’m sure I could make myself a replacement using hand tools (I’ve made myself an alu bottom reinforcement plate - write up to come soon). The fact it uses bolts makes things easier here as you just have to cut/file the square holes for the heads to sit in.
Also don’t be put off by those suggesting you’ll destroy your seat by pulling it apart - plenty of us on the flat seat project taking our seats apart and putting them back together again without any problems.
