Rockshox Monarch RL... Doesn't fully extend?

[Gionnirocket]

Odd situation... Or I'm just clueless on this.
Purchased a new seatpost mounted rack and I wanted to check clearance with the rear suspension so I let the air out of my rear shock.
Looked good so I put back the 160 psi that was in there.
On my first ride about 10 mi in I herd a little tire rub and on inspection the rack was on the fender and the shock was depressed. I tried adding some air and went up to 250 psi and got some clearance so I locked the shock in that position and finished my ride.
This morning the shock was fully extended so I checked pressure and it was holding at 250 psi so I left the pressure as is but unlocked the shock so I'd have some suspension.
On today's ride the same thing happened about six miles in so I messed with the pressure until I got some clearance and then locked the shock again and made it home.
So once home I started from scratch and set both the rebound and lock fully counter clockwise and open. Bled all the air and then proceeded to add 150 psi. Exercised the shock 5 times to equalize and then checked pressure again. Holding a 150 psi but it wasn't fully extended so again I went up to 250 psi and still not fully extended...
So is my shock busted or am I?

 

[PCeBiker]

I've got the same shock but you may have a separate air tank?

I'm cuhttps://a.co/d/bWmOvH9rious as hell as to what's going on inside, but it ain't broke yet and I've managed to leave it alone.

I did find a couple of rebuild kits that might fix whatever problem you gots goin on?

https://a.co/d/bWmOvH9

https://a.co/d/4J8K9sQ

I watched a video where the guy took a similar shock apart, and found that there was NO Oil on the other side of the air valve, like there's supposed to be.

I kinda looked into what oil I could use to squirt some into the port as a preventative measure, but decided to climb out of that 🕳 and wait for it to "Break" before I fix it.

I'm assuming that oil leaks past a seal then the seal will stop sealing?
That could be what you've got going on?

Apparently it's a common problem.
I don't know where the oil ends up, but it doesn't leak out anywhere as far as I know?
Or maybe it's just so slow that it isn't noticeable?

If you're brave, you could remove your valve core and put a few drops of whatever oil is needed? (I'm guessing regular fork oil will work?)



Then you could replace the Schrader Air Valve with a Schwalbe Presta Click Valve to turn your shock into a Quality Shock.

 

[PCeBiker]

Apparently my shock is the "Debonair" version that has a softer ride and a fatter plunger with more air volume or something like that?

 

[PCeBiker]

I'm assuming that oil leaks past a seal then the seal will stop sealing?

From what I think I remember,..
There is supposed to be an equal amount of oil above and below the seal on the other side of the air valve.

I figure that you could lose some oil past the valve core every time you let any air out?

The oil above the seal can leak down past the seal to the bottom chamber because of grabity, but not necessarily leak out of the shock itself?

You could probably install your shock upside down to get grabity to get the oil to leak back to where it came from?

Perhaps a semi-annual shock inversion could keep the oil from running out on one end?

 

[PCeBiker]

Eighty fricken bucks for a full rebuild kit !!??
It does come with tokens so can see how high I can stack it when I play in the rock gardens though.

If mine craps out, I'm going to invest the Eighty Bucks into an air tank and and 48V electric air valves and learn to pronk my e-bike.
I've already got a 48V compressor.

I can work it like a hydraulic low rider.

That'll be ShitLoads OF FUN !!!

I had a pogo stick when I was a kid, and could bounce on it until I got bored without putting my foot down.

I had one Exactly like this,..

I took the frills off, cuz those are for girls.
The rubber foot that you bounced on just slipped over the hollow end of the metal tube without a fender washer or metal end cap, so the metal punched through the rubber.

I had to bounce Really Carefully, especially on the concrete basement floor, because the metal on concrete would slip out from under me in a microsecond.



I'm sure that I could learn to bounce on two wheels if I get the front and rear air shock fill rates figured out?

I could probably do a fully powered back-flip without putting my foot down or even grabbing the handlebars if I get some practice in.

 

[Gionnirocket]

Thanks

I just checked it and it's slowly extending again. I have the bike suspended off the ground with the rear dangling
I don't know if mine is a solo air or debonair but curious... How much piston shows on yours from the air chamber to the first 20% sag hash mark?
Mine is 3/8 in. now... Not exactly sure what it should be.
Odd thing is... When tested at home both days before the ride it seemed fine... Same goes for the initial 10 mi ride yesterday and 6 mi ride today. Like it extended less and less with each compression till it bottomed out the rack on to the fender. And know it's slowly extending again.
That's some super slow rebound

edit: Yeah... Did some reading and some video and it seems common with the Monarch. Might need some lube... Might need to be serviced.
I'll probably start with the 50 hour service kit. Considering I have over 5500 mi (5500mi/15mph=366 hours+) on it I guess I can't complain

You may want to read this one....

NSMB.com - Care for your RockShox DebonAir

RockShox' DebonAir air can changed how a lot of riders thought about air shocks - but many have had a frustrating but easy to remedy issue...

nsmb.com

 

[PCeBiker]

That's some super slow rebound

Maybe the rebound valve port is clogged or something?

edit: Yeah... Did some reading and some video and it seems common with the Monarch.

I didn't want to do too much research because then I might not be able to resist the urge to take mine apart to investigate.

You may want to read this one....

NSMB.com - Care for your RockShox DebonAir

RockShox' DebonAir air can changed how a lot of riders thought about air shocks - but many have had a frustrating but easy to remedy issue...

nsmb.com

That's a different shock than mine.
I don't have the air can.
I don't know if that makes any difference??

This is from my ebikes' website,..

I don't know if mine is a solo air or debonair but curious...

I'm not sure what that means, but my understanding is that the Debonair has a fatter plunger with more volume, so the ride is more cushioned and less harsh.

A mountain biker would probably prefer the smaller volume option to feel more responsive?

I've got both my forks and shock rebounds turned all the way to mushy and I've got more than six inches of travel up front.

How much piston shows on yours from the air chamber to the first 20% sag hash mark?

I will take some pictures and post them.
Assuming that you have the same shock.
One thing I learned is that there's A LOT of different specs for the different shocks available.

 

[Mike TowpathTraveler]

I have that same shock on my H-Bike Full FatSix (110mm travel....not sure what your travel is). After reading your post last night, I looked into the Rock Shox Monarch RL rebuild PDF on their website. I like to think I can take care of alot of issues on my rig, but taking this shock apart & putting it back together requires some special tools and a vice & strap wrench. Then again, to service it would require the trust of some bike mechanic who hopefully has that experience to rebuild the shock with new seals, etc.

Personal observations along the way: When the air temp drops in a big way (say from warm to cold), I can tell my shock pressure dropped and is in need of air cause the front derailleur (2X set up on my front chainring) will have chain rub when the shock depresses and rebounds. I think I run about 225-250 psi in mine. My riding is mainly local roadways, flat canal towpath trails and NJ Pine Barrens sand roads. No air, no jumps, at the most, mild dips or roadside cracks or pot holes I missed due to daydreaming...

I first set up my back with a rear bikepacking bag and carrier. Quickly grew not to like it as it felt like the tail (bikepacking bag and carrier) wagging the dog (me) when I stood on the pedals and pedaled hard. I could only tighten that carrier so much on the seatpost! Any deep ruts that got the shock doing it's thing resulted in that fat bike tire hitting the bottom of the carrier/bag. No good.

The solution was an Old Man Mountain rack that was attached to the rear stays at the top (just to steady it, not to support the rack load) & the rack bottom stays held in place with a Robert Axle Project thru-axle. In this set-up, the entire rack with load, moves up and down with the rear frame triangle, unlike a seat post rack. It's a bit pricey but once in place, it's there forever. Drawback? To fix a flat on the roadside, you have to physically disconnect the vertical rack stays from the thru-axle. Just a minor thing, really.

 

[PCeBiker]

I will take some pictures and post them.
Assuming that you have the same shock.

Here's a couple pictures.
I'm pretty pretty sure the shock is as fully extended as it always been.

I've got 3800 km on the shock with my preload set to ~25%.
I forget what my pressure is.

I found out that I lose about 20 PSI when I unscrew the shock pump, so I add 20 PSI when I set it.

Losing 20 PSI isn't that bad considering there is such a small volume of air at about 200 PSI.

I carry my shock pump with my e-bike and it works great as a tire pump with its high volume long throw handle.
I don't bother carrying my 48V compressor or CO2 inflator with me anymore.
The only issue with the shock pump is the longer handle that makes it a little more difficult to fit on the ebike.

 

[PCeBiker]

The solution was an Old Man Mountain rack that was attached to the rear stays at the top

I looked into that rack, and it wouldn't fit my fat bike with a hub motor.

I ended up with a Topeak rack that attaches to the rear stays,..

It wasn't until after I ordered it that I realized it doesn't fit a fat bike, but I managed to spread it open WAY Past Spec and it's been fine.
I've got clearance with my 27.5" X 2.8" tires, but a 4" tire probably wouldn't fit?

I won't be putting my 14# battery in the trunk bag though.

 

[Mike TowpathTraveler]

Yep, the Robert Axle thru-axle will not work for hub drives...... or skewer axles, for that matter, too.

The OMM Phat Sherpa I got for the H-Bike required that I bend out the downstays so it would fit the OMM through-axle mount brackets.

Not sure what this site has done lately in regards to accepting photographs, but the photos I used to post here with no problems no longer can be posted due to their being "Too big for the server to handle"........

 

[PCeBiker]

Yep, the Robert Axle thru-axle will not work for hub drives...... or skewer axles, for that matter, too.

They should make clamp-on/bolt-on attachments to fit the swing arm or chain stay or whatever it's called.
Some kind of universal clamp on attachment.

I bought a $40 steel rack thinking maybe I could attach it somehow.
It's got the cheap universal chain stay attachments,..

They could re-engineer them to not be cheezy crap.

Something kinda like these, with proper rubber/plastic inserts for different frame dimensions.

Not sure what this site has done lately in regards to accepting photographs,

Yeah, I had to learn how to reduce the size of my pictures.

 

[PCeBiker]

,.. After reading your post last night, I looked into the Rock Shox Monarch RL rebuild PDF on their website.

I just skimmed through that PDF.
Holy Crap !!
There's a lot going on in there.

If I ever take mine apart, I'll replace it first.
Apparently the shock isn't good enough anyway, because it only has rebound adjustment and lacks compression adjustment.

 

[Gionnirocket]

Thanks guys!
Ok... So I have a spare shock so I replaced the funk'd one and ordered a 50 hour maintenance set of O_rings and oil.. I have a tub of Slickoleum so that will be my dynamic grease. Yes the repair manual is at first intimidating... but remember that's a complete repair/rebuild guide which I don't think necessary at this time.
As for specialty tools... I've got a strap wrench... and used a ratchet socket and threaded rod/nuts/washers to fashion an eyelet bushing removal tool which worked well, though I did order one of those as well. As for the soft jaw vise, I'll use some oak blocks.
When the O_rings and oil arrive I'll open the biAtch up and see what I see.



As for the shock it's a base model Monarch RL/SoloAir/51mm stroke. It seems well fitted to the geometry and has worked really well (up until now)
Like I said, over 5500mi on it and I find it's performance is more than adequate. The bike is an SUV and that's how it's ridden. The bike doesn't excel at anything but does all I need it to do very well.

Now to the rack...
My bike came with a functional rear triangle mounted rack.



But with just the added weight of some bare tools, water bottle, etc... the unsprung weight made the rear suspension behave like a whale tail. With it removed the bike feels much more nimble. I know the seat post rack has its draw backs as well... but I feel the ride is noticeably better.
I think bike geometry and riding style play a part in the equation so different (shock) strokes for different folks

 

[Mike TowpathTraveler]

@Gionnirocket: Great stuff! Please consider doing a rebuild thread with lotsa pics!

 

[PCeBiker]

I finally read through that MSMB.com link and realized that a simple service is really quite easy to do,..

So I think that I'm going to order at least the 50 hour service kit, or maybe I can buy just the 3 O-rings that I'd need, or maybe all I need to do is a quick lube job, with no replacement parts at all?

I'm going to start with buying some Slickoleum.
I've already got a vise and strap wrench, and it sounds like I can get it lubed up in about 20 minutes?

... and used a ratchet socket and threaded rod/nuts/washers to fashion an eyelet bushing removal tool which worked well, though I did order one of those as well.

Did you remove your bushings to install them in the replacement shock?
Could I just leave mine installed and still get my shock apart to grease the air can?

As for the shock it's a base model Monarch RL/SoloAir/51mm stroke.

I still don't know exactly what shock I've got other than it's apparently a Debonair, but I'm thinking that it's the same as your shock as far as those 3 seals, and greasing the can are concerned?
Does that sound right?

I might even be able to simply remove just the one end of the shock from frame and pull it apart with it still installed?
Then I might not need to use the vise or strap wrench?

It seems well fitted to the geometry and has worked really well (up until now)
Like I said, over 5500mi on it and I find it's performance is more than adequate. The bike is an SUV and that's how it's ridden. The bike doesn't excel at anything but does all I need it to do very well.

I've got 3800 km on my bike now, but it's all been very light use on the forks and shock. A lot like highway miles on a car, so I might be able to just grease up the air can?

PS,.. I thought that this thing was the air can,.. ??

It looks to me like a can full of air?
I don't know what it's called?

Now to the rack...
My bike came with a functional rear triangle mounted rack.

My bike came with a similar rack, but it was also using the fender as a rack support, but the fender/frame attachment point was a slotted hole that allowed movement, and the rack broke after a month of having my #14 battery strapped to it.

But with just the added weight of some bare tools, water bottle, etc... the unsprung weight made the rear suspension behave like a whale tail.

The same thing happened to me, and I got a speed wobble with the battery mounted on the rear rack. (But only when I rode no-hands.)

That's when I managed to attach my second battery to my top tube, but I had to carry my tools and water in my pockets, so I bought the Topeak rear rack for a few tools, snacks and water.

I used to have a heavily loaded tool bag, but realized that I didn't need to bring the kitchen sink with me for my regular rides, so my tool bag is much lighter now.

With it removed the bike feels much more nimble. I know the seat post rack has its draw backs as well... but I feel the ride is noticeably better.

I could have got a seat post rack, but my suspension seatpost really reduces my clearance, and I don't like how they hang off the back bouncing around and torquing on the seatpost.
The same thing was going on with my original rear rack.

I think bike geometry and riding style play a part in the equation so different (shock) strokes for different folks

Yeah, it gets pretty involved.
I remember studying that in Gr.12 physics class.
We were doing experiments with syringes and the P V T theory, and it was bugging me, so I asked the teacher if it takes the same amount of work to compress a volume of air to nothing, regardless of the cylinder diameter and stroke length.

He didn't have an answer for me right away, but corrected my question and said to compress it to liquid andvtgen said, "yeah, it sounds like somebody is getting something for nothing".
He looked into it and answered me the next day, and said yes. It takes the same amount of work to compress any volume of air into a liquid.
(Sticky binding seals, aren't included in that equation.)


My rides 98% flat gravel roads where my forks and shock barely move at all.
It's just the occasional pot hole that works the suspension, so it's had Very Light use.

I'm pretty sure that I can get away with a simple 20 minute lube job without replacing anything.
That's of course if I don't screw up and have to replace the shock.

Then my bike is outta commission for a month or two will I fix was wasn't broken in the first place.

 

[Base]

could not discribe better:

{The Piggyback acts as an additional oil reservoir for the damper. This extra volume helps keep the oil cool during longer or heavier trails/higher speeds. By reducing overheating, the damping continues to perform better and therefore more reliably, even during intense descents or technical rides.}

 

[PCeBiker]

{The Piggyback acts as an additional oil reservoir for the damper. This extra volume helps keep the oil cool during longer or heavier trails/higher speeds. By reducing overheating, the damping continues to perform better and therefore more reliably, even during intense descents or technical rides.}

Ohh, OK.

I thought it was full of air?
I remember my dirt bike had a reservoir, but I think it was full of nitrogen?

I thought that can was full of air so you could add more air volume without using a bigger shock?
Then you could adjust the PSI and air volume amounts to adjust the ride quality.

I remember on my dirt bike, I could adjust the amount and viscosity of the fork oil, as well as the fork air pressure to adjust ride quality.

The oil was for the initial movement of the fork.
The "compression" and "rebound" adjustments I guess?

 

[PCeBiker]

I was searching for the 5cc blister packs of oil, and these,..

So the Air Spring is replaceable/upgradeable.

It seems like there's mostly just a difference in length, but the manufacturing date is part of it too.

You may need to know the name of the QC guy who assembled it at the factory, so you can ask him exactly what part he used.

 

[Gionnirocket]

I don't think I'm going to do.. or need to do a full rebuild.
If things look good inside I will clean an lube. If see wear I'll replace the o_ring maintenance set too.
I have a spare shock so I can experiment here to find the issue without losing ride time. They call for 50 hour O_ring replacement but I had well over 300 hours without issue. Might be a good idea to set a 200 hour cleaning and relube schedule.
Anything interesting I'll pic and post but I don't have the bandwidth these days to do a detailed rebuild thread.
Anywho.. There's a handful of videos out there already.
I found this one particularly well done..

@PCeBiker ...yeah the bottom bushing needs to be removed from the eyelet to allow clearance for the main air can removal.

Really nice day here so I'm headed out for a ride. . .