Source
r/MTB•
tanmedium

Which dropper?

Hello, I just realized today that I could find a good mtb reddit, and should. Cool to see there is a healthy group here. My question is, I have a Motobecane fantom 29er f/s and I just got a dnm cheapie dropper post. 380mm. I really don't know much about droppers, and just figured I could hit the button and set the height with what is comfy in that moment, and release the trigger to set height.

Apparently that is not true, the bros at the bike shop right away said that it's too high, and riding with it not fully engaged is a no no. Is that true? Will this thing start to "suspension" out on me if I start riding on it. I'm 5ft 9 btw. This bike is a size medium, but really, it is a bit to much for me. A motobecane medium is rather large. Plus this 29er... I need a seat that gets low in the clutch.

I figure I need a seatpost with max length of 310mm. I took that measurement from the bottom to the top of the POST, on my current seatpost set up. Where the post meats the piece that holds the seat wires. Should I be measuring to the seat wires? I thought I read somewhere that is how the max engagement mm is measured. But I thought just the post...

The area to put the dropper post is shallow. Sucks I can't just put it in deeper but what can I do? Will I find a dropper that will only raise like... 55mm? I guess I found my own answer. It's a 31.6 by the way.

Posted Aug 5, 2018, 6:01 AM UTC

07
miasmicAotearoa•

and riding with it not fully engaged is a no no. Is that true?

It depends, what do the specifications for the dropper post say? Linking to the post you're talking about would be helpful here. Why did they say it's bad?

Will I find a dropper that will only raise like... 55mm?

If your saddle only has room to go down 2" and you're having this issue the bike is too big for you and a dropper post is a waste of time/money. Either that or your regular riding position is with the saddle too low, this is common with beginners who want to be able to put their feet easily on the ground while sitting in the saddle.

3
tanmediumOP•

It's just a DNM 31.6mmx380 external airshock style deal. The article that i read said something about these things getting some give on you if used incorrectly (suspensioning), thinking back on it, it may have only been if you had been picking it up by the seat, when engaged only half way, was bad for it. BUT, the guys at the bike shop are SMUGGG as always and assured me something bad is about to happen to me whenever I go in for maintenence. The type of shop to take the work from me (installing the shock) then when I go to pick it up, telling me why its all wrong for me lol. Gee thanks guys. Prob because I didn't buy my bike there, and etc etc. Always frowns and smug looks when I go in for service. It's in an exteremly expensive part of town. Anyways, I'm riding this dropper now and it's awesome.

1
Raymond-Finkle•

If this is your frame , it looks like you should be able to fully insert the dropper post down to the collar. At least in the picture it doesn’t look like there is a curve or narrowing of the seat tube.

What is preventing you inserting the dropper post down further?

1
tanmediumOP•

Wow! In the photo you are right it looks hella straight!! wtf, in real life there is a little bend there I'm pretty sure, and it changes diameter to some extent, me and two different bike shops all concur, she's as deep as we can get her.

Anyways, instead of fretting about it, I decided after talking to my buddy who is both a mechanical engineer, and a semi pro mtb dude, to just go ahead and ride it. Run it at whatever height is comfortable when I'm climbing/etc, and drop it like usual as needed. I loved it. At the end of the day, he said it was really about my own convenience because if you can just hit the button and it automatically goes to your optimum height, that is quicker and better. But I have to do a small amount of guess work for a moment to dial in my height before I release the trigger. Its less then optimum. After one ride, the learning curve was very brief. I'm able to find the sweet spot for max cranking really quick. If within a stroke or two I realize I could be a hair lower I just give it a touch. Having a dynamic seat post position opened up whole new worlds for me yesterday for the initial ride. If the thing is going to "suspension" on me, or if riding it like this while engaged halfway most the time is really bad for it time will tell. So far it was just fine and didn't creep on me. It's just an airspring, I don't see why it would really crap out on me. I only weigh 165 as well... If it lasts even one year I'll be stoked and will get the correct dropper next time around. This thing was a game changer though. I'm speechless by how easy it made mountain biking.

1
Raymond-Finkle•

I’ve had the issue where my bike came with a dropper that was a little to tall. Did what you plan on doing for a bit, but eventually bought a dropper with less travel and shorter post.

1
tanmediumOP•

Cool, did you ever notice the stock unit starting to fail from riding it like you were?

1
Raymond-Finkle•

No, but I only did maybe a dozen rides with it before getting a new one.

1