Trek Rail 9 2021 - replacement dropper post suggestions

[Dhmorelia]

Hi everyone,
I have a Trek Rail 9 2021 (medium) and I'm constantly frustrated with the stock Trek dropper on the bike. It seems a little slow to extend and I need to place pressure on the middle or front of the seat to get it to drop. It won't drop easily if I place weight towards the back of the seat. Online comments seem to indicate that this is quite normal for the Trek dropper post. FYI regularly clean and re-grease (Sram butter) the dropper seal collar. This helps a little but doesn't last long.

I've started looking for a replacement. Brands such as Oneup, BikeYoke and Rockshox Reverb (AXS maybe). Happy to consider other brands etc.

The distance from the top of my seat post clamp to the seat rail is approx 200-210mm (the approx distance is because I may need to change my seat soon and the new seat will possibly be thinner than the current one).

Any advice would be appreciated.

 

[dixie600mhz]

The one up and bontrager are nice in that you can add a shim to limit the extension. So if you need 162mm you can buy the next dropper up (say 175mm) and shim it to exact fit. The reverb cannot be shimmed. I sold a reverb last year to get the one up. I've had no issues with one up or bontrager. The other highly rated I haven't tried is the fox transfer. It gets good reviews. Don't think you can shim the fox either tho but am not sure.

 

[KennyB]

There is a neat sizing app on the One Up web site.

 

[Ushtang]

Reverb AXS here. 2 years of use so far and no issues, haven't needed to service or purge air. They are spendy for sure, but has been worth it for me so far.

 

[Philly G]

Highly recommend the Loam dropper from PNW Components. Of all the droppers with adjustable travel, the Loam is the easiest to adjust - can literally do it trail side without tools - and also has the most adjustment - 25mm in 5mm increments. Also their customer service is second to none.

 

[Husky430]

On the budget side of things, I've had a Brand X on my bike for about 18 months now with no dramas and Chain Reaction have them at 20% off at the moment so really great value.

 

[datonetti]

RockShox AXS

 

[Seabird55]

i've been happy with the 180 one up. i'm on a 2021 rail 7 medium and no issues on fit

 

[DeRailled7]

often if a dropper post is slow to drop or raise, or if like in your case you find it difficult to lower it, it could be that your post clamp is too tight. If it’s too tight it will deform the post and squeeze the internal mechanism. Problem is, if you don’t tighten it hard enough the post will slip down. A good solution is to use anti-slip grease on the post, something like Fiber Grip from Finish Line. That’s what i now use and it solved that problem for me. Having said that i also find the TranzX dropper post that came with my Rail 7 a bit slow as well. The extension/drop speed can’t be adjusted, unlike my Reverb on my other bike. It’s also too short to my liking. I will be buying a longer OneUp V2 dropper post. One advantage of the OneUp is that the maintenance is cheap and easy. Just need to change the internal cartridge. Don’t even need to take it to the shop.
cheers

 

[GrandesRoues]

I have a "Revive" dropper, and it works beautifully.

 

[Norcalsl]

Reverb AXS.

 

[MOTO13]

often if a dropper post is slow to drop or raise, or if like in your case you find it difficult to lower it, it could be that your post clamp is too tight. If it’s too tight it will deform the post and squeeze the internal mechanism. Problem is, if you don’t tighten it hard enough the post will slip down. A good solution is to use anti-slip grease on the post, something like Fiber Grip from Finish Line. That’s what i now use and it solved that problem for me. Having said that i also find the TranzX dropper post that came with my Rail 7 a bit slow as well. The extension/drop speed can’t be adjusted, unlike my Reverb on my other bike. It’s also too short to my liking. I will be buying a longer OneUp V2 dropper post. One advantage of the OneUp is that the maintenance is cheap and easy. Just need to change the internal cartridge. Don’t even need to take it to the shop.
cheers

Thank you!! I consider myself a bright man, but my dropper was working like crap and I didn't know why. I lubed the cable etc.... Wouldn't raise or lower smoothly at all. I was ready to junk it and buy a new one. Ummm, I tightened the seat post clamp to tight. Now, it works perfectly. I never even thought of the clamp being overtightened.

 

[Richiefromboston]

AXS only issue is the battery dies a lot. Never think to charge my dropper post, but im learning otherwise its worthy.

 

[js71]

Bike Yoke on mine. Flawless.

 

[Ushtang]

AXS only issue is the battery dies a lot. Never think to charge my dropper post, but im learning otherwise its worthy.

I've actually have not experienced this. I was riding 1 - 2 a week involving 1hour long rides and I can usually go a little over a month without charging the battery.

 

[Richiefromboston]

I've actually have not experienced this. I was riding 1 - 2 a week involving 1hour long rides and I can usually go a little over a month without charging the battery.

I LITERALLY JUST CHARGED UP MY NEW SPARE FOR MY DROPPER, NOT SURE THE DEAL BUT ITS FAILED MORE THAN 4 TIMES IN 5 MONTHS, IS WHAT IT IS.

 

[MOTO13]

Ok..it's official. The Trek Rail dropper post is the biggest pile of shit ever put on a $7k emtb. My second cable broke the other day...even after I re-torqued the dropper, it constantly still gets stuck when trying to raise it. I thought I had overtightened it previously, as it worked for about a day when I slightly loosened the clamp. Fuck no, it still got stuck in the middle of the woods several times and wouldn't raise the other day. I removed the cable and said fuck it. This pile of shit is getting replaced.

 

[Richiefromboston]

Ok..it's official. The Trek Rail dropper post is the biggest pile of shit ever put on a $7k emtb. My second broke cable the other day...even after I re-torqued the dropper, it constantly still gets stuck when trying to raise it. I thought I had overtightened it previously, as it worked for about a day when I slightly loosened the clamp. Fuck no, it still got stuck in the middle of the woods several times and wouldn't raise the other day. I removed the cable and said fuck it. This pile of shit is getting replaced.

At least its just your dropper, My 9.8xt after 500 miles is useless as the motor mount bracket bolts sheared right off. and it was 10K

 

[MOTO13]

My motor is constantly cutting out too. It will suddenly stop assisting for a second or two and then suddenly it just works again...sometimes the Kiox and motor will go completely dead and then I have to stop and turn it back on. I love the bike when it works, but not super impressed with these problems

 

[Richiefromboston]

My motor is constantly cutting out too. It will suddenly stop assisting for a second or two and then suddenly it just works again...sometimes the Kiox and motor will go completely dead and then I have to stop and turn it back on. I love the bike when it works, but not super impressed with these problems

Never had those issues, but "waiting" to find out if I can get new bolts sucks. its winter/fall in new england and yesterday was a perfect day to ride, not many of those left.

 

[MOTO13]

Can't you make a bolt? You know, cut one down or file the head etc...? It's just a motor mount bolt, surely you can get something close enough to be able to ride it????

 

[ckkone]

Just got a 175mm Fox Transfer I have a large frame.

 

[Richiefromboston]

Can't you make a bolt? You know, cut one down or file the head etc...? It's just a motor mount bolt, surely you can get something close enough to be able to ride it????

I did, but the beauty of the bolt shearing off is, some of it is stuck in the motor casting itself. Now being an m5 its tiny, so I replaced all I could and used epoxy to hold the one that sheared off in place like a pin(instead of a bolt) all Icould do. this SUCKS slightly over 500miles and this happens? 10000.00 bike Iwouldnt expect this. Now Ive built (recently) Motrcycles Hardcore intercontinetal land cruisers. Im good with mechanical undertaking. This setup by trek isnt awesome. and not having my bike SUCKS

 

[Doomanic]

My motor is constantly cutting out too. It will suddenly stop assisting for a second or two and then suddenly it just works again...sometimes the Kiox and motor will go completely dead and then I have to stop and turn it back on. I love the bike when it works, but not super impressed with these problems

Check the state of the battery connection on the bike. The notorious Trek battery rattle wore groves in mine and it got so bad that it would turn on then off and keep doing it for as long as the battery was connected.

 

[Stihldog]

Re; the battery cutoff. There was a suggestion in this forum for a possible solution. The bracket in the lower battery compartment seems to be the culprit. It was suggested to move this bracket a few mm which may reduce the slack or battery rattling which may cause a better connection. I’ve only occasionally had the power cut-off but I was able to ride through it until the power returned (it’s like throwing out an anchor for a few seconds). This only happens about 1-2 times a ride but never on a steep rocky climb.
Re; da dropper. I’m switching over to the AXS reverb. I’m pretty sure it’s somewhere in a container, on a ship, off the coast of North America. I’m on my second Bontrager 150mm dropper. One was warrantied and the current one is borrowed …and it sucks too.

 

[Dhmorelia]

Hi everyone,
Just following up on how I went with this. I service the Bontrager dropper and it improved enormously. Much smoother and didn’t bind as much in use when I place my weight to the back of the seat. I found that it needed relatively regular services especially after dirty rides (I clean the bike after each ride). This was a bit annoying.
I decided to upgrade to the Bikeyoke revive. While planning to do this, the Black Friday sales happened and I could get a15% discount on an already well priced Reverb AXS. So I ended up with the Reverb AXS 150mm on my medium Rail and couldn’t be happier.
thanks for everyone’s advice.

 

[Hamina]

Hi everyone,
Just following up on how I went with this. I service the Bontrager dropper and it improved enormously. Much smoother and didn’t bind as much in use when I place my weight to the back of the seat. I found that it needed relatively regular services especially after dirty rides (I clean the bike after each ride). This was a bit annoying.
I decided to upgrade to the Bikeyoke revive. While planning to do this, the Black Friday sales happened and I could get a15% discount on an already well priced Reverb AXS. So I ended up with the Reverb AXS 150mm on my medium Rail and couldn’t be happier.
thanks for everyone’s advice.

I agree with this. I've serviced my Rail 5 post approx. 4 times fully during the last 2 years. Most of the problems are solved by this. In winter time the mud and water will freeze and the mechanism will stop working in the bottom of the post.

Changing to Aliexpress dropper remote was also a small gamechanger because it has a big bearing in it.

The best argument for AXS is that you don't have to remove anymore the motor to service the dropper post. The price is still ridiculous for such a mechanically simple product.

 

[The Hodge]

I've a Crank Brothers post on my Whyte..which has been flawless so far ..I'm giving a good bit of credit for this to the fact that the post gets a squirt of Juice Lubes after cleaning the bike / prior to every ride .
Work the post up & down a few times & wipe off the excess..

 

[MOTO13]

I ditched the stock dropper on my 9.7. Now I have an SDG dropper...buttery smooth. Boy, that stock dropper on Rail's is a real beauty. Trek sb ashamed to put a POS like that on their bikes.

 

[Dhmorelia]

I agree with this. I've serviced my Rail 5 post approx. 4 times fully during the last 2 years. Most of the problems are solved by this. In winter time the mud and water will freeze and the mechanism will stop working in the bottom of the post.

Changing to Aliexpress dropper remote was also a small gamechanger because it has a big bearing in it.

The best argument for AXS is that you don't have to remove anymore the motor to service the dropper post. The price is still ridiculous for such a mechanically simple product.

I agree. Minimising cabling and motor complications was a major factor in choosing the Reverb AXS.