Ripmo AF Thread

PB Forum :: Ibis
Ripmo AF Thread
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Posted: Jul 21, 2021 at 13:59 Quote
WasatchEnduro wrote:
First ride on the CL this morn. I'll wait a couple weeks and give it a good shakedown before saying much as I'm only on easy trails right now due to some bruised ribs and a sprained wrist. I only added about 10-15psi to the Super Deluxe to maintain the same 30% sag and dropped from 2 to 1 volume spacers. I think Mammal charges harder and has the Ibis light tune which may be why he was running 3.5 and dropped to 2 positive spacers.

Anyways, no doubt I'd go the CL route if I were on coil (have run 2 different coil shocks during my 15 months on the bike and always wanted a little more support throughout and definitely more ramp up). The link is definitely more supportive and rampy and I can't wait to test it in slow, steep tech and some rock gardens to see how grip differs during the first half of the stroke.

Most of the stuff I ride this time of year is pretty steep and rough, and I think that's really where the CL shines. If I rode mostly smoother flowy trails, I'd probably just stick with the stock link. I'm now down from 3.5 to 2 volume spacers in the stock Topaz, with the same air spring/bladder pressure as before (180/190), and I doubt I'll be removing any more spacers at this point.

Posted: Jul 21, 2021 at 14:04 Quote
WasatchEnduro wrote:
Hey quick update on my rear fender and cascade link FWIW.

Yesterday I threw the CL on there and noticed the stock link is worn down a bit where it was constantly rubbing the rear fender. The rear fender worked perfectly except for grinding down the link a bit. Not sure if I'll try it again and just attempt to reposition a new fender some millimeters lower on the seatstay and/or protect the link with some tape where they contact or just go back to rubber mastic tape inside the well designed 'rock crusher' (or 'loam bucket' if you're in the NW).

First ride on the CL this morn. I'll wait a couple weeks and give it a good shakedown before saying much as I'm only on easy trails right now due to some bruised ribs and a sprained wrist. I only added about 10-15psi to the Super Deluxe to maintain the same 30% sag and dropped from 2 to 1 volume spacers. I think mammal charges harder and has the Ibis light tune which may be why he was running 3.5 and dropped to 3 positive spacers in his Topaz. I ran an off-the-shelf Topaz for a bit with a standard medium compression tune and was also running 2 pos (0 neg) spacers like in the Super Deluxe.

Anyways, no doubt I'd go the CL route if I were on coil (have run 2 different coil shocks during my 15 months on the bike and always wanted a little more support throughout and definitely more ramp up). The link is definitely more supportive and rampy and I can't wait to test it in slow, steep tech and some rock gardens to see how grip differs during the first half of the stroke.

And hey mammal, per your mtbr photos you need some protection for that link!

I wonder how it feels compared to the progressive coil spring. I have a 475-575 spring on mine and it ramps up real nice on big hits. From an engineering stand point, I think its better to let the coil spring take the brunt of the progression. I think that's what Casecade Links do, right? Just introduce more "bind" as the suspension compresses? Which puts more stress on pivot bearings/bushings.

Posted: Jul 21, 2021 at 14:48 Quote
bdreynolds7 wrote:

I wonder how it feels compared to the progressive coil spring. I have a 475-575 spring on mine and it ramps up real nice on big hits. From an engineering stand point, I think its better to let the coil spring take the brunt of the progression. I think that's what Casecade Links do, right? Just introduce more "bind" as the suspension compresses? Which puts more stress on pivot bearings/bushings.

Good point. A lot of coil riders have a progressive spring option that could work for them. That would be a nice test prog coil vs CL. I was on a burly 600# coil which gave me correct sag (close to 30) and when I tried a 575-700 prorate, the ramp at the end couldn't compensate for 35%ish sag and how fast it blew through initial travel. I was always riding in the 2nd half of the travel and whilst buttery it was just too soft.

Maybe in the absence of a test the armchair engineers can go at it.

Posted: Jul 22, 2021 at 8:15 Quote
bdreynolds7 wrote:
WasatchEnduro wrote:
Hey quick update on my rear fender and cascade link FWIW.

Yesterday I threw the CL on there and noticed the stock link is worn down a bit where it was constantly rubbing the rear fender. The rear fender worked perfectly except for grinding down the link a bit. Not sure if I'll try it again and just attempt to reposition a new fender some millimeters lower on the seatstay and/or protect the link with some tape where they contact or just go back to rubber mastic tape inside the well designed 'rock crusher' (or 'loam bucket' if you're in the NW).

First ride on the CL this morn. I'll wait a couple weeks and give it a good shakedown before saying much as I'm only on easy trails right now due to some bruised ribs and a sprained wrist. I only added about 10-15psi to the Super Deluxe to maintain the same 30% sag and dropped from 2 to 1 volume spacers. I think mammal charges harder and has the Ibis light tune which may be why he was running 3.5 and dropped to 3 positive spacers in his Topaz. I ran an off-the-shelf Topaz for a bit with a standard medium compression tune and was also running 2 pos (0 neg) spacers like in the Super Deluxe.

Anyways, no doubt I'd go the CL route if I were on coil (have run 2 different coil shocks during my 15 months on the bike and always wanted a little more support throughout and definitely more ramp up). The link is definitely more supportive and rampy and I can't wait to test it in slow, steep tech and some rock gardens to see how grip differs during the first half of the stroke.

And hey mammal, per your mtbr photos you need some protection for that link!

I wonder how it feels compared to the progressive coil spring. I have a 475-575 spring on mine and it ramps up real nice on big hits. From an engineering stand point, I think its better to let the coil spring take the brunt of the progression. I think that's what Casecade Links do, right? Just introduce more "bind" as the suspension compresses? Which puts more stress on pivot bearings/bushings.

I can't comment on the difference in feeling between using a progressive spring vs. a more progressive leverage ratio , but the latter shouldn't be considered as "binding". A progressive leverage ratio results in a higher rear wheel force required to move the shock a given distance, while a progressive spring will be pushing back harder over that same amount of travel. In an apples to apples situation, these forces around the pivots/frame/hardware etc. are being balanced between the wheel and shock, so those pivot/frame components would effectively be "feeling" the same thing in both cases.

Posted: Jul 22, 2021 at 9:50 Quote
If there is anyone in the upstate NY area looking for a Ripmo size large there is a guy in Latham that has the GX build in his shop. Looked at it yesterday just felt it was more bike than I really need. High Adventure Ski & Bike, $4299. Check it out!

Posted: Jul 22, 2021 at 10:29 Quote
As far as ride goes, there is a pretty distinct difference between progression added through the linkage and progression added at the shock. This can be broken down into a few different things: spring rate as felt at the wheel, potential energy the spring can store, and the difference in spring force between top and bottom of travel.

Starting with potential energy that the spring can store, a progressive linkage enables having a higher spring rate without having the bike sit too high in travel or feel harsh off the top. This increases the amount of energy that the spring stores when compressed. As a result the damper doesn't have to do as much work so the issue of running more than you want just to keep the shock off the bottom isn't as prevalent. I think we all know the feeling of being hesitant to add damping because the bike feels really good over the small stuff but knowing it needs to happen to keep from blowing through travel as quickly. Interestingly, a 550 spring can store more potential energy than a 500-610 progressive spring too.

Then if you look at spring rate as felt at the wheel, a more progressive linkage keeps the ramp up smooth and doesn't have that end of travel wall feeling. A progressive spring or shock with lots of volume spacers gets pretty stiff at the end of travel. There is a misconception that anything progressive will ride deeper in its travel. That is the case for progressive springs and volume spacers, since they like to sit up against that end of travel wall, but progressive linkages actually like to sit higher in travel. Also, lower spring rate or shock pressure doesn't make better small bump, it's how that is felt at the wheel. If you aren't changing linkages those happen to go hand in hand, but with a more progressive link a stiffer spring can easily feel more supple off the top. So no matter what bike you're riding, don't fixate on a pressure or spring rate number... Lower isn't necessarily better, it's how that translates to the wheel that matters.

Lastly, the difference in spring force between top and bottom of travel is directly related to the difference in rebound speed between the top and bottom of travel. If you look at something like a Super Deluxe with the megneg installed, you can get pretty large shock forces at the bottom of travel. Yes this keeps you from bottoming out often, but it also means the shock rebounds significantly faster near the bottom of travel than it does at the top of travel. Set up wise, this makes tuning rebound hard. You get stuck between slow rebound at top of travel with reasonable rebound at bottom out or reasonable rebound at top of travel and fast rebound at bottom out. Running a more linear spring keeps rebound speed more consistent since there isn't this massive difference in shock force. Now you might be thinking, what about high and low speed rebound? Can't that be used to negate this? It actually can't because the suspension is often still loaded up while rebounding. If you look at a g-out, for example, you can be near bottom of travel but with a very slow rebound speed. Conversely, you might be deep in travel over large roots and the wheel is rebounding quickly since it's unsupported as it rolls over the back side of the roots. Long story short you still end up stuck between those two rebound scenarios even if you have HSR and LSR.

Now for stress, yes there will be more stress on the pivots at bottom of travel. That's inherent when adding bottom out resistance. That said, shock loading from a harsh bottom out is orders of magnitude higher than the loading at bottom of travel with no bottom out. That shock loading is what really breaks stuff. I've heard people say something along the lines of "you can only push down on the pedals so hard before your feet come off". If you're only pushing down on the pedals for a very short period of time you might be surprised how high that number can get though. Just think what you could get a scale to go up to if you jumped on it for all it's worth.

Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.

Posted: Jul 22, 2021 at 10:40 Quote
Kmccann137 wrote:
So after many upgrades to my RAF the only thing left is the rear hub engagement. Has anyone figured out how we can upgrade this Ibis hub engagement?

I recommend DT Swiss' spoke length calculator. The ibis rims have an ERD of 603 and the s35 logo wheels use 293mm spokes. I don't remember how long the nipples are, I sold mine that came on my RipmoAF and built some new ones up with a hydra rear and dt swiss 350 front.

Ibis uses speedtuned hubs but I can't find the dimensions for the wheel building calculations, still all you need to know is the dimensions of the new hub and the fact that you have 293mm spokes.

I've built a lot of wheels and I recommend not reusing aluminum spoke nipples and to use brass. It's a bummer when the aluminum ones break and both are cheap.

As for hubs, the Bitex BX211R is a great cheaper alternative, it has 56 POE and same dimensions as the i9 Hydra so you could reuse half the spokes and you'd need 291 or 290mm ones for the drive side. The DT Swiss 350 Boost 32h would also give you the option to upgrade to 54 POE and you could reuse all the spokes. +/- 1mm is usually fine, you can also compensate for spokes that are 2mm too short with 2mm longer spoke nipples.

Posted: Jul 22, 2021 at 10:44 Quote
Kmccann137 wrote:
Yes I agree this bike has a lot of pedal kick back especially if you don't have your weight over the rear axle on high compressions. I actually wanted to try to quiet the bike down because I'm not sure where this metal sound is coming from but I think its the chain and hub movement causing it.

I started running a hydra on my RipmoAF this year, since then the bike seems to have trouble using all the travel (topaz w/ no spacers or one negative, 195psi in can, 190 in main, I weigh 195lbs). It could be that I'm not riding as hard due to a herniated disc this spring but it's good to know others have thoughts on pedal kickback with the RipmoAF and Hydra combo. My next wheels will probably either have Bitex hubs (56 POE) or dt swiss 350s where I can start with 16 or 36 and upgrade to 54 if needed.

I'm also getting a Jade X so curious if that setup will help and/or how it will feel with a Hydra. I'm debating between the 525-650 prorate and a 500lb linear one.

Posted: Jul 22, 2021 at 10:52 Quote
CascadeComponents wrote:
As far as ride goes...
Thanks for the detailed break-down, that's a good thought process to go through.

With regards to stresses with a progressive link vs. progressive spring, if the spring tends to ramp up less smoothly than the link (sit up against "the wall"), then the link will deliver that loading in a smoother manner.

Posted: Jul 22, 2021 at 11:03 Quote
CascadeComponents wrote:
Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.

Fascinating. I came on here looking for RipmoAF spring weight recommendations since I'm getting a Jade X and now I'm thinking a 550lbs linear spring (I'm 195lbs before gear) and a cascade linkage could be the ticket for me. Either way trying out a new setup and seeing how it goes will be fun! So many combinations to play with :-)

Posted: Jul 22, 2021 at 13:38 Quote
CascadeComponents wrote:
As far as ride goes, there is a pretty distinct difference between progression added through the linkage and progression added at the shock. This can be broken down into a few different things: spring rate as felt at the wheel, potential energy the spring can store, and the difference in spring force between top and bottom of travel.

Starting with potential energy that the spring can store, a progressive linkage enables having a higher spring rate without having the bike sit too high in travel or feel harsh off the top. This increases the amount of energy that the spring stores when compressed. As a result the damper doesn't have to do as much work so the issue of running more than you want just to keep the shock off the bottom isn't as prevalent. I think we all know the feeling of being hesitant to add damping because the bike feels really good over the small stuff but knowing it needs to happen to keep from blowing through travel as quickly. Interestingly, a 550 spring can store more potential energy than a 500-610 progressive spring too.

Then if you look at spring rate as felt at the wheel, a more progressive linkage keeps the ramp up smooth and doesn't have that end of travel wall feeling. A progressive spring or shock with lots of volume spacers gets pretty stiff at the end of travel. There is a misconception that anything progressive will ride deeper in its travel. That is the case for progressive springs and volume spacers, since they like to sit up against that end of travel wall, but progressive linkages actually like to sit higher in travel. Also, lower spring rate or shock pressure doesn't make better small bump, it's how that is felt at the wheel. If you aren't changing linkages those happen to go hand in hand, but with a more progressive link a stiffer spring can easily feel more supple off the top. So no matter what bike you're riding, don't fixate on a pressure or spring rate number... Lower isn't necessarily better, it's how that translates to the wheel that matters.

Lastly, the difference in spring force between top and bottom of travel is directly related to the difference in rebound speed between the top and bottom of travel. If you look at something like a Super Deluxe with the megneg installed, you can get pretty large shock forces at the bottom of travel. Yes this keeps you from bottoming out often, but it also means the shock rebounds significantly faster near the bottom of travel than it does at the top of travel. Set up wise, this makes tuning rebound hard. You get stuck between slow rebound at top of travel with reasonable rebound at bottom out or reasonable rebound at top of travel and fast rebound at bottom out. Running a more linear spring keeps rebound speed more consistent since there isn't this massive difference in shock force. Now you might be thinking, what about high and low speed rebound? Can't that be used to negate this? It actually can't because the suspension is often still loaded up while rebounding. If you look at a g-out, for example, you can be near bottom of travel but with a very slow rebound speed. Conversely, you might be deep in travel over large roots and the wheel is rebounding quickly since it's unsupported as it rolls over the back side of the roots. Long story short you still end up stuck between those two rebound scenarios even if you have HSR and LSR.

Now for stress, yes there will be more stress on the pivots at bottom of travel. That's inherent when adding bottom out resistance. That said, shock loading from a harsh bottom out is orders of magnitude higher than the loading at bottom of travel with no bottom out. That shock loading is what really breaks stuff. I've heard people say something along the lines of "you can only push down on the pedals so hard before your feet come off". If you're only pushing down on the pedals for a very short period of time you might be surprised how high that number can get though. Just think what you could get a scale to go up to if you jumped on it for all it's worth.

Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.

Ordered my link a few days ago. Can’t wait to experience every verb and adjective contained in the tome I just read Smile

Posted: Jul 23, 2021 at 6:30 Quote
CascadeComponents wrote:
Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.

That's great to read, I've be weighing up whether to get one as I've been struggling of late to get the balance between having the shock feel supportive when pedalling/in the mid stroke and not bottoming out. I've been experimenting with switching the bands on my Topaz between the positive and negative chambers and the bike rides really well with 2 neg and 1 pos but then on bigger impacts I'm blowing through the travel and bottoming out (these aren't huge hits either), so then I go to 2 pos and 1 neg which provides that extra progression for the bigger hits but then the bike feels like it's wallowing and sitting a bit deeper and then I'm getting at best 3/4 of travel. So the cascade link sounds like it could really help me get to that sweet spot with the added bonus of another 3mm of travel too.

Posted: Jul 23, 2021 at 7:27 Quote
I put in a pre-order for a CL too, excited to try it.

Also, as for Topaz volume spacers, I had fun playing with those last year and found the bike more planted without the negative ones and more playful with them. A few weeks ago I added one and must have not had all the o-rings on right and the shock's shaft sucked into the shock and was stick at min travel so I had a super low and slack hardtail for my descent...ridable but not optimal. When I went to fix it the shock started leaking oil. Fortunately DVO said they'd fix it so I'm sending it in and getting a Jade X to ride in the meantime. Hopefully others don't make the same mistake I did with not checking and lubricating the washers

Posted: Jul 23, 2021 at 8:30 Quote
muggomagic wrote:
CascadeComponents wrote:
Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.

That's great to read, I've be weighing up whether to get one as I've been struggling of late to get the balance between having the shock feel supportive when pedalling/in the mid stroke and not bottoming out. I've been experimenting with switching the bands on my Topaz between the positive and negative chambers and the bike rides really well with 2 neg and 1 pos but then on bigger impacts I'm blowing through the travel and bottoming out (these aren't huge hits either), so then I go to 2 pos and 1 neg which provides that extra progression for the bigger hits but then the bike feels like it's wallowing and sitting a bit deeper and then I'm getting at best 3/4 of travel. So the cascade link sounds like it could really help me get to that sweet spot with the added bonus of another 3mm of travel too.

Muggomagic - I ask because I’m thinking about switching from 2N / 1P to 1N / 2P for the same reasons you did: have you played around with the pressure at all to get that last 1/4 of travel?

Posted: Jul 23, 2021 at 20:43 Quote
canned-slammin wrote:
CascadeComponents wrote:
Hopefully that all makes some sense and sheds a little light on what actually is driving the links to be the way they are.


Muggomagic - I ask because I’m thinking about switching from 2N / 1P to 1N / 2P for the same reasons you did: have you played around with the pressure at all to get that last 1/4 of travel?

Yes and if I drop the pressure a bit I get a lot of movement under pedalling and I’m also sitting at around 35% sag which isn’t good, then the front and rear feel really unbalanced.
I did think about getting someone I know to 3D print some half and quarter sized bands to see if I could fine tune that (which I may still get done) but I’ve made my mind up to order the CL as I think it’ll get the bike exactly where I want it.


 
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