Noctilux.95

I bought a 2019 Madone SLR frameset that did not come with a seatpost. I added the overpriced seatpost ($275) but it didn't come with a seat clamp that allowed the use of carbon railed saddles. I added the seat clamp (7x10) but restricts you from using anything but 7x10 Bontrager made saddles. So now I would like to know if anyone has used 7x9 carbon rail saddles on 7x10 clamps? I really would like to use my current 7x9 saddle rather than spending nearly $400 on a stupid Bontrager saddle.

WhyFi

I don't remember - doesn't Trek have 7x9 ears and 7x10 for the clamp? I have a Toupe Pro, which is 7x9, I ordered the new ears (it was outfitted for round rails) and it works dandy.

Noctilux.95

Trek makes 7x9 ears for the Emonda, not the Madone.

WhyFi

Ah, I​​​​​ have a Domane. Different ears, eh? That's dumb.

TiHabanero

"Different ears, eh? That's dumb. "

That is the beauty of it. Nonsensical enough to keep you in locked in to the world of Trek. Who would have ever thought they'd be dumb enough to spec it like that?

bigevil

bumping this as I've now run-into the same problem. I've got a 2020 Checkpoint with the seat mast cap (believe it comes on Domane too) and seems like there are two options, treks 7x7 clamps or their 7x10 clamps. Neither of these will work with Specialized (or other 7x9 carbon rails) so looking for any help/insight. I found this on ebay which the seller claimed will work (I've purchased and will try). Other folks say to give the 7x9 clamp a few wraps of etape and it should secure. Neither of these makes me stoked and I'd love it Trek would just make a 7x9 adapter, I'd gladly pay.

pic attached of the two trek ones I bought (the silver one is 7x9 but I'm not sure its compatible with my current Trek bike and don't want to throw a $400 saddle on it if it won't work)

Sy Reene

I hate hearing ***** like this.

WhyFi

I've used the 7*9 pictured on my Domane with Spec Toupe - it works as it should.

RNAV

I've used the 7x10 ears on a 7x9 saddle without issue. I did line the inside upper lip of the ears with tape to make up the extra 1mm -- I didn't wrap the rails, nor did I put tape in the interior vertical face of the ears that provide the clamping force. As a side note, you may want to measure the rails of the saddle you're using. A lot of companies claim 7x9 when the rails aren't exactly 7x9 . . . sometimes they're 7x9.5, or 7x8.5, etc.

Kimmo 

If you can figure out what to look out for with clamping interfaces (basically any concentration of load, and what's bearing on where in the mechanism), you can assess stuff like this for yourself, and when it looks iffy, with a bit of creativity you can often make it work.

A bit of judicious filing or dremelling a corner here, a radius there, maybe a carefully trimmed bit of a aluminium tape just so, and Bob's yer uncle.

If this is your first rodeo, just stare at it. It'll come to you. But the less experience you have with fettling, the more you need to think about it before you do anything.