Rockshox reverb seatpost

[Ans and Sue]

I need some input/advise ???  Bought new bike with first EVER dropper seatpost.  Me legs are very short so I can never fully extend it.  So when not fully extended, so I can reach pedals, there is some movement down when I sit on the saddle. About 4-5mm.  is that normal or not?  Must it be bled? etc. I would rather get it sorted sooner than later if that is necessary. Thanks Ansi

[AlanD]

There shouldn't really any movement downwards. All dropper posts have some side to side play which is normal.

 

Check the that air pressure is correct. The valve is at the bottom of the seat post (will have to take is out the seat tube obviously). If that is correct and you still have downward movement then a bleed might be in order.  

[Bizkit031]

If I were you I would have it looked at ASAP because Cape cycle systems the agents for Rockshox are quick to blame the customer for problems with Reverbs and don't want to except responsibility if anything goes wrong with them.

[Ans and Sue]

There shouldn't really any movement downwards. All dropper posts have some side to side play which is normal.

 

Check the that air pressure is correct. The valve is at the bottom of the seat post (will have to take is out the seat tube obviously). If that is correct and you still have downward movement then a bleed might be in order.  

what should the pressure be??

[AlanD]

what should the pressure be??

It's says by the valve, 250psi. If you hear it losing air after you have pumped it up then one of the air seals has gone and would need a service. I hope this is not the case as it can get pricey.

 

If there is side to side play, the bushings in the tops cap are stuffed and you would need replace the entire tops cap, again, pricey.

[Amberdrake]

If its a stealth post the air cap is under seat.

Check the amount of drop on the post (100mm,125mm,150mm) and consider replacing it with less drop so you can use it at full extension.

Good luck

[100Tours]

A few thoughts

 

- properly set up the seatpost should be rock solid when you sit on it. (side to side movement excluded - some side to side seems normal).

- if the seatpost is sagging then it either needs bleeding or the seatpost is clamped too tight in the frame. I've had issues on my gf's post when the set clamp was too tight (seat felt sticky and had dead spots along the length of travel). Back half a turn fixed the issue. If that doesn't fix it then bleeding doesn't look too difficult but maybe get the shop to do it for you.

- is the seatpost a 100mm or 125mm dropper? if it is 125mm this is better suited to bigger bikes. Think about swapping it with someone on the hub for the shorter version - it is important that you extend the seatpost to full length on regular occassions and don't run it half way up all the time. (based on posts on other forums)

[Ans and Sue]

It's says by the valve, 250psi. If you hear it losing air after you have pumped it up then one of the air seals has gone and would need a service. I hope this is not the case as it can get pricey.

 

If there is side to side play, the bushings in the tops cap are stuffed and you would need replace the entire tops cap, again, pricey.

thanks Alan.  But this is a brand new dropper. Bike came with it. Hence my concern.  I had one ride with the bike so far and that problem existed before the ride No side to side.

[Ans and Sue]

If its a stealth post the air cap is under seat.

Check the amount of drop on the post (100mm,125mm,150mm) and consider replacing it with less drop so you can use it at full extension.

Good luck

thanks. I will check the air pressure tonight.  My legs are unfortunately just too short.  The post is at its lowest.

[JXV]

The seat is not spongy because of low airspring pressure. It is more likely that some air has leaked into the oil space above the internal floating piston that locks the seat in place. Topping up airspring pressure and bleeding the remote line probably won't fix this. It needs to go in for a proper service.

 

If this is a new bike and post then it is likely still under warranty and these issues should get fixed at no cost to you.

 

It is not ideal that the post is too high for you when fully extended. Normal setup is to leave the post fully extended, then set the saddle height to your optimum pedalling position using normal seatpost clamp. Any salesman that advises otherwise is not being truthful. You should only be using the dropper to get the seat out the way on steep descents or tricky terrain when in standing position on the pedals. Since you have short legs a post with shorter travel may be more suitable for you.

 

Tip for the Reverb: Do not ever lift the bike by the saddle or hang it from the saddle in a bike rack.

 

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Edited October 31, 2016 by JXV

[Goblin]

You should be able to fully extend it, if you cant its the wrong size for you.

Try replace with a smaller one.

[igg]

Tip for the Reverb: Do not ever lift the bike by the saddle or hang it from the saddle in a bike rack.

 

Is this reverb specific, or any dropper?

I sometimes hang my bike by the saddle when I'm wrenching. It's a KS Lev and I only do this at full extension.

[JXV]

Dunno about other posts but the Reverb can apparently suck air in if you put the post in tension. I think recent models have revised IFP seals but I have an early Reverb Stealth and experienced this twice. Now fixed and it hasn't recurred. I'm careful not to lift the bike by the saddle.

 

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Edited October 31, 2016 by JXV

[AlanD]

thanks Alan.  But this is a brand new dropper. Bike came with it. Hence my concern.  I had one ride with the bike so far and that problem existed before the ride No side to side.

If its brand new and still under warranty I would then take it back straight away, maybe you can get them to swop it out for something a bit smaller like the 100mm assuming you don't have this one already.

If they replace it for you with a brand new, consider selling it and get a nice cable actuated dropper. Easier to maintain, no bleeding and half the trouble's. Just a thought,

[AlanD]

Is this reverb specific, or any dropper?

I sometimes hang my bike by the saddle when I'm wrenching. It's a KS Lev and I only do this at full extension.

I try hard not to lift my bike by the saddle either. I have the 2016 Giant dropper and also heard you can suck in air this way. Rather safe than sorry.

[droo]

New bike means warranty. Send it back. If there's play at the top of the stroke there's air where there shouldn't be.

 

Careful of the cheap and cheerful ones - they're usually disposable. You can't change the wiper seal on the Giant one, which means when it wears out you bin the post. The Reverb may give issues from time to time, but at least it's serviceable.