I have some Magura Menja 2009 130mm forks and I am having a few problems setting them up.
If I have the forks set up plush enough to roll nicely over roots etc. then they seem prone to dive. This is quite noticable if I have to slowly ride down steep steps/drops, where the fork can compress so much it feels like i'm about to go over the bars! (and yes, I know how to ride to avoid this, but I have to change riding my style significantly with these forks)
Alternatively I upped the pressure recently but then lost all sensitivity from the forks.
I realise that the forks are sensitive to small changes in pressure, and that I will probably have to compromise to some degree. However, I have heard of a couple of tricks to tune them - namely adding oil to the air chamber to make the spring rate more compressive, and increasing the weight of the damping oil.
I like the idea of making the forks more progressive, but I have also heard that over time the oil migrates and makes the problem worse, so this seems like a bad idea to me. Has anyone had any experience of doing this? Is it possible to remedy the oil migration with a service?
Increasing the weight of the damping oil sounds simple enough, but I am not sure what the effect will be. I imagine it will reduce brake dive etc. but will it reduce bump compliance at the start of the stroke? Has anyone done this?
I realise this isn't really a specifc question or questions, but any advice on the matter would be greatly appreciated. I suppose I am more likely to try changing the damping oil, so any advice on that matter would be great.
Thanks!
I had a similar issue with my Durins. I am a heavy guy and was running them at high pressure around 90 psi.
I added around 10 ml of heavy oil to the air chamber (Fox float fluid) if it migrates it will just end up in the lower leg which has the same oil in it anyway (well it does on mine). I haven't noticed any problems and it did lower the volume of the air chamber and helped them ramp up a bit. I now run them at 80 PSI and I'll freely admit they are not the plushest forks on stuff like roots and things when seated but they don't dive too much and they track the ground well without pinging off things. I run mine with around 15mm of sag when I'm up on the pedals and they work well enough. I get full travel and my wrists seem to not take a pounding so they are working. I do notice the lack of small bump movement but I run 2.4s and they do that job.
I also run the rebound very fast maybe two clicks out from off.
Not tried changing the damping oil but have pissed about with using the adjustable lockout as a compression control. To be honest I prefer them as is.
They are very linear forks so you may have to accept that to get the ride you want you may have to run them with slightly higher pressures. I have found as little as 3psi is a noticable change.
The oil in the air piston thing is mre aplicable tot he 2007 ones, 2008 onwards had a smaller air volume to start with.
Perceverance is the key, it took me a while to find the right settings but now they are awesome forks!
Have you done a lower leg service? Pullt he rebound adjuster off (takes some pulling), undo the bolts on the bottom of the legs and pull the lowers off. Remove the foam rings from under the seals and soak in fork oil (I used 15 wt) and re-fit. Smear the area between the seal and foam ring with plenty of rock'n'roll super slick grease. This gives them even more small bump sensitivity.
Also try running the rebound faster, you might think they are diveing, but it could be that they just arent recovering quick enough.
They still dive under braking and in berms, but front end grip it phenomenal!
I've the same issue. Was gonna try some more oil in the air chamber. Up to 23ml is apparently recommended?
With that and the lack of an oil seal (compared to other forks) allowing oil to slowly leak out onto the stanchions (a fetaure - not a fault!) I'm thinking of flogging mine and going back to Rockshox....
I had them serviced fairly recently, so they are should be performing as the Magura intend. I must say I really like the suppleness and grip they give, over the first ~50% of the stroke.
Reading through the Magura forum again it does seem that most people adding oil to the air chamber have 2007 forks, but these guys did it with a 2009 fork as far as I can tell:
http://www.bikefix.net/2009/06/bikefix-exclusive-review-magura-menja.html
although they added a pretty small amount of oil (5ml).
I cant see how the oil would leak out of the air chamber, It's airtight after all? Had the cap off mine and it looks like its still in there from around 6 months ago..
As for the seals I've had mine apart monthly and the insides of the legs and the seals are clean and not allowing dirt in. A little oil on the sanctions is not a problem as far as I can tell, at least everything is nicely lubed.
Think i'm gonna go the whole hog and both replace the damping oil and add a little to the air chamber. Not sure what weight of damping oil to use though. They are originally specced with 5wt, and I read on post where a guy used 15wt and claimed a 'subtle but noticable' difference. Maybe 10 or 15wt...
Before you change the damping oil try running the sag at 20% when you're standing on the pedals, run less rebound damping and stick 5ml of oil in the air chamber. Really worked for me.
Not sure changeing the oil will help, you'll just end up with the adjuster set in a different place.
IMO it needs a second stage on the rebound damper to decreace the single stage pressure drop, and maybe a high speed port covered by a shim so that it rebounds quicker but doesn't top out. At the moment the single stage variable orrifice (presume thats what it is) seems limited by cavitiation. Thats my thoughts on the 2007 model anyway. Its good in use, but occasionaly it feels a little out of its depth.
A little oil on the stanchions is not a problem as far as I can tell, at least everything is nicely lubed.
It's not what I would call a little? Lube ain't required on the outside of the dust seal - just inside. Any lube outside just mixes with dust & muck to form a nice grinding paste. Enduro fork seals do a kit with seperate oil seal: [url] http://www.enduroforkseals.com/id264.html [/url] Not too expensive so might try that?
I serviced mine myself - pretty straight forward to do a full oil change etc. Maybe I'll try tweaking some more while I save up....?
Not sure changeing the oil will help, you'll just end up with the adjuster set in a different place.
Are you sure? I assumed they had compression damping too, just that it was not user adjustable. If they have no compression damping whatsoever then you're right, changing the oil will make no difference.
Anyone know whether they have compression damping?
Menjas do have compression damping as they have a lockout. The guys at Magura UK are pretty clued up on their gear perhaps a call to them might help?
Just checked and they do have compression damping, it's just not adjustable, so changing the damping oil would affect the forks compression behaviour.
Still better off trying the more straighforward fixes first as a few have said.
Sure. I have tried a few levels of sag and rebound damping (have had the forks for months now), so will buy some 10wt oil and add a little to the air chamber. I will have a go with that and see how I get on, and can always swap out the damping oil at a later date if I feel like. I guess increased compression damping could kill the small bump plushness.
Thanks people.
Let some air out of your front tyre? Maybe? Sounds cheap, give it a go, what's the worst that can happen?
130mm forks, right? Then presumably you've got these because you want them to do what? Give you five inches of plush root, and pebble eating action? Mind that gnarly pot hole, dude...
Set the fork up for where you need them working at their very best which is for most people; fast downhill. Everything else, **** it, bend your arms...
Eloquently put!
I agree.
Give you five inches of plush root, and pebble eating action?
Well, you may take the p1ss but having a plush fork at the start of the stroke gives a lot more traction for cornering in rough stuff. If I wanted a rock hard fork that only compresses under jumps i'd buy a dirt jump fork!
BTW next time just say 'MTFU', its quicker 😉
The compression damping is shocking though, I presumed it was a orifice plate? The lockout acts on high speed damping first (if you turn it halfway the forks bobs as much as normal, but wont react to the trail) so increacting the oil viscocity would only exacibate the problem.
The damping is active whether or not you have the fork locked out or not - lockout is a seperate issue.
Don't put 10wt oil in the air chamber - use a heavier lubricating oil. Light suspension oil will migrate rapidly to the lowers - I've tried it. Magura won't say what suspension blood type 5 is. On inital inspection it was a thick oil, not runny like suspension fliud. I've had good results with synthetic engine oil.
I used fox float fluid mostly because I bought a litre of it. It's 45 wt engine oil I think. I use it in the lowers too. Seems fine but I don't over analyse. Also I have Durins and they are different.
If a fork has damping, it will act on both rebound and compression. They may be separate circuits and whether the damping is adjustable or not is another matter.
Adding higher weight damping oil will increase the compression damping and reduce the diving. The rebound adjuster will need adjusting to suit as it too will now be slower for a particular setting on the dial.
mad pierre (or anyone) if you are thinking of selling your maguras let me know as I'm looking for a pair.
Cheers
Hmmmm.... how much you looking to pay. Mine are I think 09 and in very good nick.
joolsburger, fox float fluid is 85w gear oil (Torco to be pedantic)
i had this issue on a set of 2010 Magura Thors and just couldnt get the fork setup correctly no matter what i tried.
in the end i got rid of them and got some DT Swiss forks which are way better.
madpierre - can you drop me a mail re forks, I've got a budget and will mail you back with what I've got
ss, works well enough oil is oil it gets "airbourne" apparently.
FYI SAE for gear oil is different to SAE for engine oil, confusingly. From wikipedia:
Note that the SAE has a separate viscosity rating system for gear, axle, and manual transmission oils, SAE J306, which should not be confused with engine oil viscosity. The higher numbers of a gear oil (eg 75W-140) do not mean that it has higher viscosity than an engine oil.
Ok, for the record I added 7.5ml of thick oil to the air chamber (a fair amount, I know).
The fork now behaves totally differently. I can now get good small bump ground-tracking at the start of the forks travel, but without the fork blowing through its travel very easily. This makes the bike handle totally differently (for the better), because when I get over the front end or on bermed corners the fork is much less prone to diving.
I have only had one ride on it so far, so judgement is reserved. I nearly, but not quite, reached full travel a few times which seems about right to me. If I never reach full travel I might drop a few psi or suck out 2.5ml of the oil.
I find it a bit odd that the Menja is specced the way it is, I think I remember hearing (reading?) a Magura guy say that it is designed not to move until it hits a sufficiently large impact, and then to move a lot(!). I'm pretty sure this is the definition of blowing through travel! A bit of a shame, because the suppleness of the fork is really nice.
Oh well, thanks all for your help.
How do you add oil to the air chamber? And importantly, how do you remove it if you decide you don't like it? Is it a matter of unscrewing the schrader valve core or do you undo the whole valve.
I have a 130 Menja fork, which used to be a 100 until Tony from Magura upgraded it for me, but after he did that the DLO didn't work, which isn't much of a problem, because I never used it anyway.
You let all the air out the fork (IMPORTANT!) and compress the fork. Then you remove the top of the left fork leg with a big spanner (not just the valve). Using a syring insert the required amount of oil into the fork leg.
If you want to remove the oil you need a long enough syringe to get it out again! It probably doesn't matter if a miniscule amount remains behind.
Stuff syringes. Dip a straw or the middle of a biro into the oil, put your finger over the end, remove.
If you want to remove the oil you need a long enough syringe to get it out again!
Or you could just tip it upside down!!
Mine are better since I serviced them and added some oil to the air chamber but still ain't as good as the Pikes they replaced so they are for sale. Email in profile if you're interested.