[Closed] Harsh rear shock after custom tune ??

and the banning has started

Good. There are some proper meanies on here.

PS how do you know when someone has been banned?

I get preferential information from the mods

Is it really the best thing to do to tune the shock for one type of riding event?

Do it on an entire trail with a variety of features, tuning for one very specific type of event will very likely make the shock horrific for any other type of event.

This is good advice, it's no good setting up a shock to work well on 5 percent of a trail when in reality you need it to work well for the other 95 percent of the trail.

Shock setup will always be a compromise until the advent of widely available electronic active suspension, it will still be a compromise even then...really.

If your shock was blowing through it's travel too easily and you had just put a few more psi into it then it would have cured the problem but the forks would have been less compliant over small bumps. . You have had them custom tuned by Mojo and that is what you now have so what is the difference ? Genuine question btw not meant as a dig .

Omg read the post ramseyneil.

I had the SHOCK tuned by mojo to cure it blowing through its travel.

I changed the forks for something slightly longer travel which in turn raised the front end of the bike for me too.

I did read the thread , I meant to say shock not forks . Fwiw I think you would have to ride some pretty rutted stuff for the shock to pack down so I suspect that Mojos advice is correct regarding the rebound and your problem lies elsewhere.

Get your forks set up at the same as the rear.......if they're not set up in tandem you're wasting your time .....differences on the front can make the rear feel good or bad and vice versa ......good luck ....its a time consuming proccess but you'll get there and be better at understanding it

The forks are fine. Still bedding In bit loads better than the Fox stuff they replaced.

Definitely the rear shock is packing down so the problem doesn't lie somewhere else.

As I've mentioned earlier I'm going to phone them tomorrow and ask their advice as technically the tune has cured what I ask them to set it to. I'm just not getting the slow rebound thing.

Yep you did say....but if there is too much rebound or pressure in the forks it will have an adverse affect on the rear...just saying......double check your sag on the front

Well if you are sure the rear shock is packing down then knock the rebound damping down a few clicks as has already been mentioned. How are you sure it's packing down ?

I'm not sure how the front sag/rebound affects what the rear is Doing to be honest.

How does that work then. ?

Ramsey Neil. .... I can feel it over a set of four root/bumps on a track. First bump is fine but it gets progressively harder until the last one where it feels like a hardtail. TheN a bit further down the trail it has recovered enough to work ok.

I understand about speeding up the rebound but was curious as to why mojo say run it almost fully slow.

Bloody hell - still going?

Renton, your shock is packing down. Speed up the rebound and play with as suggested by Toys19. Who cares what mojo said, they aren't you and don't ride your trials.

Fwiw TFT recommended 200psi in mine, which was fine for racing yet hard for everything else. I like my shock softer, so I ride at 165psi and the bike handled great in my experience / opinion.

Renton yes I started that topic for a bit of fun/I didn't want to put any negativity etc on a topic that you were seeking info/help on.

You are presumably a big bloke (riding XL's) working for the RAF- its all fun. I imagine in your work place theres a fair bit of banter and ribbing going on over the daftest stuff. Yes I too like to rinse through the occasional mountain bike frame but thats what happens when you buy secondhand and/or can't test ride first. The luxury of being able to buy something- not like it? Then simply shift it on for the same price or minimal loss .v. the rides you get out of it.

I've never been entirely happy on air shocks. Maybe its the rider weight or riding style? They just feel quite wooden to me.

I've had my current frame for 11months now. I've got the itch again but I'm clueless what to get next. I'd love a modern day Blur4x.

just get tinkering, have fun and keep posting.

At 6 foot I'm hardly big.

I found when i had a problem with my rear shock packing down it was seemingly caused by my forks having too fast rebound setting. As after much messing about i backed off the fork rebound and the rear settled down. As said earlier both need to be working with each other rather than against

Jeez... mean-spirited thread...

FWIW, all people can do is offer advice - without seeing the bike in action or riding it, it's nigh on impossible to say for sure what the issue is or even if there is one. As was stated earlier, what a lot of people think is 'right' is not actually right for performance which I'm guessing is what the OP asked mojo for. To put it another way, if you hopped on a pro's DH bike, you'd probably be surprised at how 'harsh' it was.

To the OP, are you sure it's packing down (in which case, yes, the rebound probably is too slow though again, this may not be adjustable with the dial depending on the shock and where in the stroke it's packing)? And even if it is, is it doing it everywhere or just on one particular bit of trail?

Suspension is a compromise. Many people have talked about setting sag and then checking that you're getting full travel on the biggest hits you ride. That's one way to do it but if you ride trails with lots of smallish rocks and roots and then one big bump somewhere, do you really want to tune the whole ride around that one big hit or should you get the suspension working for the rest of the trails and then deal with that one big hit for which the suspension may not be ideal? You may be much better off just slowing down a fraction for that one big hit and then having the suspension work really well for the rest of the trails.

I found when i had a problem with my rear shock packing down it was seemingly caused by my forks having too fast rebound setting. As after much messing about i backed off the fork rebound and the rear settled down.

if you ride trails with lots of smallish rocks and roots and then one big bump somewhere, do you really want to tune the whole ride around that one big hit or should you get the suspension working for the rest of the trails and then deal with that one big hit for which the suspension may not be ideal? You may be much better off just slowing down a fraction for that one big hit and then having the suspension work really well for the rest of the trails.

I've never been entirely happy on air shocks. Maybe its the rider weight or riding style? They just feel quite wooden to me.

At 6 foot I'm hardly big.

All good advice above and an illustration of just how subjective suspension can be, it is very much a compromise.

At 6ft Renton you're bigger than most of the jockey-like test riders and pros that work in the bike industry.
I'm only 5-ft 9-inch but at nearly 90kg due to years of weight lifting i also struggle to get suspension working properly for me, air stuff seems to be designed for people around the 75kg mark which is why i still prefer coil forks and would happily run a coil shock on my bike if i had the funds currently (same frame as you but in medium by the way)...keep trying, there's loads of good advice on this thread, its opened my eyes to a few things i hadnt thought about either.

Deviant. How do you find your ctd shock in standard form. Does it use a lot of travel.

Renton, have you put a volume reducer in the shock?

I'm quite thankful that I'm average size and weight and neither slow nor properly fast nor prone to going HUGE off stuff - makes suspension tuning a lot easier! It still took me months to get my Pike really dialled in to match my CCDBa though...

Mine came with a Rockshox Monarch RT3 shock, it has three settings like the Fox CTD version, I just leave leave it in open/descend mode.

It requires loads of psi for my weight, not ideal and when funds allow I'll send it off for a tune to deal with a 90kg bloke. Had a Fox RP23 on a previous bike and remember having to run over 200psi to get the required 25% sag for my weight!

There is a Fox coil shock that fits our bike but I haven't found anyone on any forums running it yet to ask them about it....so it's probably not a good idea but it does get me thinking from time to time, the Trance is the first FS I've had that isn't single pivot so the characteristics have taken time to get used to but now I think it's great, it genuinely hugs the ground in a way single pivot designs don't/can't.....single pivots tend to hop around and be a bit more lively in my experience.

As said by several good posters in this thread, jot down what's been said about setting up your shock and play with the rebound, you should get it pretty much spot on. If that fails look to the fork, if the fork rebound is too fast it could be pushing back (so to speak) on the rear of the bike making it feel like it's packing down. You want front and rear compressing and rebounding together so the bike stays flat and true to its geometry.

Yep mojo put a volume reducer in as well on the tune.

If I keep the bike I may look at a ccdb inline or perhaps a monarch plus.

I'm no hero on my bike. I don't like jumping or steep stuff to be honest but I just want to go as fast as I can on stuff without feeling like the bike is holding me back.

Cheers.

I'm gonna do some experimenting with it over the next few rides.

Makes sense now about the fork. That's brand new and done 15 miles so far so it is still bedding in.

Have you phoned Mojo yet?

A bit late to party but will add my 2p anyway, most of it has all been said already by other people anyways ...

1) Ride the bike a for a few more rides to bed the shock in. Mojo will have used used seals and o-rings that will loosen up after a few rides. Re-evaluate how the shock feels after a few rides.

2) Regarding sag, you may want to experiment again to find the correct sag point for you. The shock has been retuned so will have different characteristics to before and you may find a different sag point suits you better. And don't worry too much about the pressure value, just put what ever gets you the required sag amount. Don't worry if this is different to what the chart says.

3) If the shock feels compliant over single bumps but harsh over repeated bumps and the o-ring is showing you used up a lot of travel then it is likely the shock is packing down. Decrease the rebound damping a little bit and try it again and repeat if needed.

4) The settings from Mojo are only suggestions. Everyone is different and will prefer different things so don;t be scared to experiment and move away from those settings.

5) go have fun ./..

I have deviant's stats and run well over 200psi in my ctd. Did not get in fully dialled before winter came, but without asking, mojo put a spacer in which gave more support nearing the end of the travel. What I have found is setting the rebound up by purely dropping off a curb and controlling the rebound it was 4 clicks off slow. Out on the trails I've now settled on 5 from fast, and just need to be a little careful on slow repetitive drop downs ie steps. In other words difficult to get it set up perfectly for everything. Sounds obvious but if your forks are not set up correctly the bike will feel poor regardless what is running at the back.

I had my CTD TA push tuned @ TF and they got it right, for me, straight out of the box. Might have helped that they also custom tuned my 5th Element so had a bit of background to work with?
I'm just under 6' but am 14.5st with riding kit on and run my shock with about 220psi in. Took me a while to get used to an air shock after the coil but I'm 100% confident in it performing better than the older air shock ever did. I also found that playing with the fork (RS lyrik) settings a bit actually helped with the feel of the rear shock as both were working together so definitely worth playing with both.
The C mode feels like I'm riding a hard-tail with very little bob and D feels bottomless.
Hope you get it dialled in right. I can take some time but the effort to get it working right (front and back) is worth it.

Ok.. I wanna attempt to be the voice of reason here..

mojo advised that they returned the shock with the rebound turned really slow due to the work they did on the internals..
they warned that you would have to set your rebound with that in mind.. So instead of adjusting your rebound from the middle as you would usually, you're setting it from slow and speeding it up til you're happy..

It's all there in black and white.. Snot rocket science

It is interesting what custom tunes do I recently had my shock tuned to give a bit more small bump compliance that I always thought it lacked. My bike has always felt a bit like a DH bike but now it really has a magic carpet feel to it which suits the bike and most of the trails I ride. Unfortunately I'm not sure it is actually what I want from a bike anymore.

Hmmm. Sending my shock off this week for a service (Fox Brain thing off my FSR). I was considering having it custom tuned, but not sure it's a good idea now! Might be simpler to just leave it standard!

I just got an advert for roast dinners at a Toby carvery when I clicked on this thread. Just the ad, nothing else! I don't know what they're trying to say...

EAT MORE MEAT!

I've read all that and I'm still not clear what the sag on the shock is.

Set up the sag. Don't go one what psi you had before, start from fresh and set the sag up and adjust that first.

Mojo don't say they are running the shock slow. They are saying that the adjuster is set to nearly slow because they are using the shim stack to adjust rebound. It could be that it's setup fast, but with the adjust set to near slow.

Worry about getting the sag right first, then worry about rebound.

They are saying that the adjuster is set to nearly slow because they are using the shim stack to adjust rebound.

You might want to go back and think about that comment

Probably. But my head is hurting and beyond thinking atm.

Anyway, my point is set the sag up first. 🙂

Ok so I've just spoke to mojo and they explained what has been done to the shock. (Firmer compression a d volume spacer)

I explained about the packing down and he said about setting the sag (I told him I just put the same.e pressure in as before)

He said set the sag for about a third of the shock strike a d maybe speed the rebound up a click or two.

Going out tomorrow a d will have a play.

It will feel harsh because you are running the same psi. If you have a volume reducer, you won't need as much air to get the same sag.

It's threads like this that make me wonder if there's any mileage in places like Mojo running 'setup my bike' days.

Group of people turn up, someone who knows what they're doing helps them get a base setting, they ride a section of trail, describe what they are feeling, expert makes suggestions for changes and repeat? Even adding volume spacers etc durign the day might not be that much of a problem if ratio's of number of entrants/support staff are ok?

Yay for the Telephone! 😀

Renton say Mojo firmed up the compression also - Renton did they state whether that was he high speed or low speed compression, because if he asked for better small bump sensitivity why would they firm that up?

Renton fyi the high speed is the one that's reacting to the sudden small impacts, it's possible that's part of the issue, but please sort out the sag and rebound before we get to that point. FWiW the low speed compression is the one that firms / stops the shock collapsing during bigger dips/whoops in the trail and the one that's affect by your ctd lever ("Trail" mode is just a firmer low speed compression setting than "Open")

It's threads like this that make me wonder if there's any mileage in places like Mojo running 'setup my bike' days.

I stick air in then a fair few rides later I'll use a tyre lever to let some air out.

Once I let out a tad too much before a bum-on rear tyre cheeky descent. Boy that descent was tricky 😀

Thats the sum-part of my tuning!

[i]I stick air in then a fair few rides later I'll use a tyre lever to let some air out.

Thats the sum-part of my tuning! [/i]

It's threads like this that make me wonder if there's any mileage in places like Mojo running 'setup my bike' days.

😉

hora - Member

I stick air in then a fair few rides later I'll [s] use a tyre lever to let some air out [/s] get a new frame

Just been sat on the khazi reading MBR and their ' test' of the current Trance 27.5 3 , I'm vaguely interested, because I should have my SX sometime over the next three weeks........
Apparently this model hasa RockShox Monarch R rear shock, however they state.........

"We noticed that the 'o' ring never reached the bottom of the shock body and while this is perfectly normal on the Trance, you do need to factor it in when setting the sag, otherwise the suspension will be way too soft".

Not entirely sure what they are on about if I'm honest. Not certain either, whether they are on about Trances in general.

I have no idea how the shock varies in dimension or stroke length ,to yours, Renton, but just might be a point to note.

he said about setting the sag

Just thought I would come back and update this thread.

I've done a bit more riding on the bike now and in fact have just got in from a ride.

Needless to say I think I'm getting used to it having sped the rebound up a click or two.

I've gone second fastest on one segment and knocked 37 seconds ofF another segement.

It seems to climb like the proverbial mountain goat to which is a bonus.

However the one downside is that it has started leaking again so needs to go back to mojo.

Thanks to you all that posted some helpful info on this thread.

Before sending it back pump it up and put it in some water. Probably won't help but will save you from sending it back should it just be something like a bit of dirt in the valve

Legend its leaking oil mate not air sorry should of made that clearer.

It's been repaired once under warranty.