Looking for advice on dropper post for 20 year old MTB

Historically, 5% of my riding has been on my MTB, a 20 year old Trek Fuel 90 with 26in tires. Over the years I have upgraded the shocks, wheels, pedals, tires and seat. I am an intermediate level MTBer, at best, but plan to do more MTB’ng. While I have considered purchasing a new[er] MTB, I love my current bike, particularly its comfort (due to the upgrades) and controllability/handling (due to wheel size). For the kind of riding I do, I see little value to disc brakes, so the only major upgrade I am considering is adding a dropper post.

The frame is aluminum and as it is 20 years old, it has no pre-holes for internal routing. I am looking for advice/suggestions, such as:

  • Do you drill holes to route cabling internally? Or, external routing suggestions?
  • What brands/models of dropper posts for such a bike?
  • Suggested videos to watch, such as for its installation?


Your first consideration is the seatpost diameter.
That will change your choices. There are external routing options. Particularly useful if you ditch the front derailleur.

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For starters:

I would look at the handful of external options vs drilling, especially on an older frame.

Ones that offer external routing options, in that list:

  • Brand-X Ascend II
  • Fox Transfer Factory 2020

See the ones with the External tag, and the cable port showing in the middle of the post:

Sales options with filter:


The seat post is 31.60mm (1.25in).

Converting to a 1x implies [for me] necessity change the wheel/hub to support a dinner plate type configuration. The time and cost to do all of that would likely lead me down the path of a new MTB or gravel bike.

1x swap is not necessary. There are “over the bar” dropper levers that are more “around the bar” than the “shifter style” paddle that can work fine with a front shifter.


31.6 gives you lots of options. Based on the bike and it’s capabilities, you won’t need much drop.

I don’t know what gearing you have, but it’d be a bit of a faff converting. It starts very quickly to not make sense on a bike like that.

What do you want a dropper for? I assume the riding isn’t overly technical if you’re only riding it 5% of the time (apologies for the wild assumption if wrong)

Not necessary, but I had mentioned it in terms of using the cable bosses on the frame for routing an external cable.

My mate did actually drill a hole in an old XTC to run an internal cable which exited about the normal spot on the downtube. Not for me, but definitely doable.

FWIW: The set up is a 3x9. Crank: 22/32/44. Cassette: 11-34.

Dropper use: Modestly steep, but open descents (generally 8-16%).

I’m a decent climber from my road biking (albeit still learning on the technical turns). But the descents aren’t as much fun as they could because of the additional caution I need to take due to sitting high.
ps. I take no offense at any question.

Here’s an example of an easy-to-get-to local ride I like if that is of value:

Sounds good. There are certainly ways of adapting a dropper to your bike.

I would say one thing, you will always have a very old and steep bike and that won’t inspire as much confidence as a modern bike.

I’ve been talking to a friend the last couple of days who wants to upgrade his bike. It quickly becomes a false economy and you can spend a lot of money and still end up with a very limited bike on terms of capabilities.

If it’s at all an option, I’d also look at some bikes like the Kona Kahuna, Trek X-Calber, Spesh (the one Sarah Sturm rode at Leadville). You may, or may not get a dropper depending on the spec, but you’d get modern geo, bigger wheels, larger volume tyres, modern clutched derailleur and 1x gearing.

I guess it just comes down to, will you only so a dropper. Try make the call now whether you’re commited to the bike I guess. I had an old 26" wheel HardTail I spent far too much time and money upgrading only to find it was still unrideable where I wanted to take it.


All good thoughts. Thank you.

The SF Bay area has phenomenal road cycling that I have enjoyed for 20+ years. However, it is becoming increasingly dangerous due to cars and I am finding that I am enjoying dirt. Unless adding a dropper post goes much over $500, I’d like to do that upgrade and see how my MTBng progresses. Pending situational circumstance, including my soon-to-be son-in-law getting into MTB, and my my son (former collegiate road racer, now into gravel bikes) moving back to the Bay Area, I can see myself getting a new MTB in a couple of years.


The good thing is if you get a 31.6 internal routed dropper, and drill a hole in the frame for the cable, you’d find it easy to reuse on a future bike as many are 31.6mm and internal ready.

I can’t comment on how to do the drilling of your frame or how it affects the safety, but I’ve seen a few bikes with it done (one in person, a couple online)


Brand x ascend 11 is a great value post. I use it on my xc bike so that I can swap it out with a rigid post when required. Just cable tie the cable to the top tube.

Alternatively, you could just put a quick release seat clamp on. Its what we all used to do. If you put a scratch mark at the required height, then it’s really easy.

If you hold off a bit you could get one of these.

Not sure these would help but I had a similar situation with an old mtb. I was lucky that I had unused cable guides on my top tube and could use these adaptors to mount the external hydraulic hose from a rockshox dropper.

@mcneese.chad @liam_mail Do you have any advice on drop lever given the set up I have (see pic)?

I have watched several YTs on PNW loam and Wolf Tooth levers but have concerns as to positioning given the presence of left side (and right side) shifters in addition to the brakes. Would you place them to the right of the left-side shifter?

Alternatively, here are a couple of over-the-top levers. Any opinion on using one of these instead of the horizontal level types above?


You’ve got the added issue of super narrow bars. There’s not much space before it starts to increase in diameter. Hard to see where the clamp could fit.

I don’t know what to offer as advice sorry.

Order now, and you’ll have it by then :laughing:

Based on the trail pics you posted, I actually think a modern 29er bike geo (even with seat fully up) would give you the confidence you are looking for.

So I think I’m with @liam_mail on this

So main takeaway —> You need a new bike :rofl:


In the near term, my plan remains as described. However, as my club’s mailing list is over 2,000, I have seen plenty of great deals on used MTBs that have made me drool (usually offered prior to Craigs List posting at a discounted price for club members).

The pics I show don’t include the climbs where many are technical single track. Also, I hope to get better to be able to handle other SF bay area trails. When I get to the point of serious consideration of a new MTB, I am currently thinking of a 27.5 due to maneuverability.

Yeah - my new bike recommendation was 80% in jest, 20% serious. A dropper will make your current bike better for downhills.

Test ride some bikes before you decide. The geo on modern 29” bikes is super dialed where maneuverability is not a problem. (Except for the smallest frames, where many brands use 27.5).


Unless you’re exceptionally short, or ride DH on your rest days go for a 29er.

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