Rear shock size.

Thanks.

To summarise my previous threads....
I'm 65kg, nothing special in the skills department, but i find even at 250psi, (almost no sag, and way higher pressure than suggested for my weight) i'm regularly bottoming out the rear shock. Front too, but thats another story.

The 2013 model that does come in a 7.250 x 1.750 is not a 'complete' upgrade. Sure its got kashima and CTD settings, but in that size it doesn't come in an XV (high volume) version, and doesn't have the boost valve. No point when half of it is a downgrade.

^^^^ what he said. XV cans are designed to allow you to make the shock very firm at the start for pedalling efficiency but still use the full stroke on bigger hits... exactly what you don't like, it seems. I think a return to a normal shock air can volume might fix your problem. 250psi for a 65kg rider seems high. I have a normal volume on my Rize and run at 215-220psi for an 85kg riding weight (ie with hydration pack shoes and scone guard )

Thanks for the info. I was thinking something along those lines, but i guess since the stock shock is high volume, id stick with that.

Firstly im assuming something isnt quite right with this shock. Testing other similar models at lower pressures seems to give a totally different feel. Their shocks have much greater difference between the hard and soft settings. Even though they are heavier riders, run lower pressures they still don't bottom out. Riding speeds/styles are similar.

From what ive read about the replacement i want, the 'differences between the 3 settings are quite large.
So heres my logic... I'll probably run it at higher pressure as usual. This will make the 'climb' setting nice and firm. On rough terrain with no jumps I can run the 'descend' setting, and when the landings are going to be big, probably the trail setting. I guess with 3 settings rather than 2 I'll have more tuning options while riding.

Once the new one arrives, I'll definitely be sending the old one back and get it looked at since its still well under warranty. Why don't i just do that now? Because the bike shop quotes me some stupid time to get it back.

Once its been looked at I can feel confident selling it.

gods, that's brilliant! I'm trying it.

The mod appears to reduce the final air volume at the end of the stroke. This works, mate did the same and is also a trick used on open bath coil forks by changing the oil levels.

Just curious about the bottoming out. Are you landing with your weight back with the rear wheel hitting the ground first? Good on a hardtail to flat but not dual suspension.

I can bottom my 6" bike off a gutter by doing this or land 6 foot to flat without bottoming out by landing correctly front wheel first.

Landing too heavily back wheel first can prevent the fork from doing much as the head angle gets much slacker as you blow through your rear travel and the front hardly compresses, instead it try's to bend the fork. On a big slack bike this can bust your fork.

Front wheel first allows both the front and rear suspension to absorb the landing. I was taught to try and half compress the fork before landing the rear on a 6" bike.

Another question is do you have the shock rebound damping too slow? Over rubble and a quick sequence of bumps the shock will get stuck down because it can't extend fast enough meaning you run out of travel.

I err on the slow side for rebound on the rear so that it's less likely to punt me off the front over waterbar lips and after landings. Can't remember how many clicks off fully damped I run it, but it's further towards fully damped than fully open.

Doesn't surprise me to hear you're going OTB a bit if you are running rebound fully open

On the front I err on the fast side so that it doesn't pack down on consecutive fast hits, for the same reason. It also helps keep the front tyre in contact with the dirt better by letting it drop into the depressions instead of hanging up in the air.

They are tips I picked up from UK Dirt Magazine's downhill skills vid "Fundamentals" (circa 2004 or thereabouts). How far you take that will depend on your local terrain and the size of the drops. Bigger = more rebound damping.

Riding a mates bike (jacojoco) a little while ago I almost went over the front because I was totally not expecting the kick from the rear off the water bar lip. Only just managed to stop the bike rotating too far in the air , so the rebound setting does make a big difference. Needless to say I thrust the bike out in front a lot harder off the next jump!

Hope this helps. These are my two cents. Interested to hear others' thoughts.

The best book in my opinion is Mastering Mountain Bike Skills by Brian Lopez and Lee McCormack.

Basically covers everything. The writing style can be a bit annoying.

When it comes to drops it says fast drops to downhill land front first or slow to flat rear first. For small drops rear first can be okay as long as you do what it says and crouch and push the back down to reduce the drop height. They do show a dually for the first eg and a hard tail in the second.

For bigger drops to flat a mate taught me as I said before front first on a dually. He was a freak on a bike from NZ, sponsored by Specialized in DH and FR. This always gave me the softest and quietest landing.

Front first in each case means taking off with the bike level and once the back wheel has left the ground and airbourne slightly pushing the front down to land.

Never try and land until the back wheel is airbourne otherwise you will go over the bars.

Your rebound also is too fast. The fastest the back should be is the same as the front. This means if you are bunny hopping on the sport in a neutral position both wheels should lift off equally. Preferably the back end should be slightly slower than the front otherwise OTB's is more likely.

On a jump if you keep getting kicked by the back end it normally means you didn't compress the suspension going into the jump meaning the bike thought you went over a bump, tried to absorb it with the front and then the back and then sprung back front wheel and then back wheel. If you precompress the suspension into the jump the bike will boost into the air in control as the suspension doesn't soak it up.

How did the shim mod work out for you?

Its funny looking at my post above. After a post-ride clean and inspection yesterday i discovered i'd been running my rear shock for who knows how long on full fast rebound. Explains a few recent goofy offs and scaring myself off a couple of waterbars on the weekend :rolls eyes:

@Mez:
Glad you got something that works for you. Another thought is a skills class or two. The instructors can give you some guidance on suspension setup, and usually do at the start of the class. Will also help on learning how to handle drops and landings and help you replace any bad habits with better ones. I still do the drills I learned for a bit of fun and to help core strength and low speed bike handling.

Something I found interesting to try is to leave your shock pump connected and try to compress the rear suspension and see just how fast the air pressure rises for not much travel.
Not that this helps anyone here but it's an interesting experiment.

Yeah - I make sure to bash the needle against the stop as hard as I can while I'm doing it.

Oops - started a flame war.

Just pointing out that if you decide to learn basic pneumatic principles using your shock pump, be careful.

What does it all mean?

ROFL.

Yeah, completely useless.

I think somehow we are supposed to work out many newtons will be applied to the shock pump internals if we apply extra pressure to the shock while it is connected. Therefore demonstrating the destructive forces of compressing your shock while the pump is connected.

Who gives a fuck.