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[Closed] An essential upgrade to all coil shocks?

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[#2838328]

[img] [/img]

well worth a read imho........
[url= http://www.southerndownhill.com/news/news/what-is-a-shock.html ]http://www.southerndownhill.com/news/news/what-is-a-shock.html[/url]
[url= http://simplybearings.co.uk/shop/p556262/AXK3552/AS3552+Budget+Needle+Roller+Cage+with+2+AS+Washers+35x52x4mm/product_info.html ]http://simplybearings.co.uk/shop/p556262/AXK3552/AS3552+Budget+Needle+Roller+Cage+with+2+AS+Washers+35x52x4mm/product_info.html[/url]


 
Posted : 10/06/2011 9:33 pm
 D0NK
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I struggle with long sentences can u summarise pls


 
Posted : 10/06/2011 9:40 pm
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Typical engineer. Wwwaayy too long. Whats the executive summary? The spring needs to twist so it can work properly?


 
Posted : 10/06/2011 9:41 pm
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surely all it can do is lower the spring rate very slightly (as the spring is no longer resisting both twisting and compressing movement, but instead just compressing movement)

i also don't understand how two could ever be needed?


Why two bearings? Well, essentially the main difference between running one bearing or two, is the ease in which the horizontal turn of the spring is accounted for. To say, one bearing will work fine, two will work better, as the movement is compensated for at both ends. In all honesty, we only ran the simulations with two bearings in, or none, and on my old race bike I only ever ran two bearings, as the weight gain was negligible (may as well just go for a short pee before your ride to compensate), but with the massive gains in rear grip available we felt it was silly to pass up on the opportunity.


 
Posted : 10/06/2011 9:47 pm
 D0NK
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thought it looked like a bearing so the coil could turn but figured it would be for easy preload settings or sommat (or it was something smaller and completely different) 🙂


 
Posted : 10/06/2011 9:47 pm
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2nd that retro


 
Posted : 10/06/2011 9:48 pm
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well ive just ordered 2 ill see if i can notice a difference

ill try 1 and 2 -see how it goes.......

basically without the bearing the damping profile looks like this [img] [/img]
which is bad

and like this with the magic bearings..........
[img] [/img]
which is smoother

because as at lower speeds the shock cant rotate so it deflects sideways and makes for a rougher ride
(at least thats what i think its saying)


 
Posted : 10/06/2011 9:54 pm
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with graphs.....


 
Posted : 10/06/2011 9:57 pm
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These things have been around for years for motorbikes, the concensus with serious tuners is that you can get it to show a difference on a chassis dyno but that there's no perceptible real world difference. Never tried it on a pushbike though, who knows, the results might be different.


 
Posted : 10/06/2011 10:03 pm
 LoCo
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It will make a difference, like putting a little grease on the ends of the spring, you'll get a definite result on a Dyno and it may feel a bit better on the trails, tempted to order a load 😉


 
Posted : 10/06/2011 10:04 pm
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Just ordered a set.
1 question - will this mean I'll need a heavier spring rate though??


 
Posted : 10/06/2011 10:57 pm
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not necessarily ... think of it more as reducing the stiction of the setup so that the transitions of movement and direction are smoother - esp at lower speed changes

This could mean that the sag travel is increased slightly for the same setting ( cause some stiction could count towards the resistance and sag when you sit on the bike slowly ) ... so with them fitted, you may need to wind the preload up a little to counter that extra bit of sag, but beyond that, its not going to be that much of a change.


 
Posted : 10/06/2011 11:24 pm
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Is that what it was about? I thought breast just telling to ride faster.

Actually, I like the theory. Can't hurt to give it a go.


 
Posted : 10/06/2011 11:39 pm
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You can just just mirror polish the ends of the coils like spring air rifle tuners have been doing for donkeys years.


 
Posted : 11/06/2011 9:59 am
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Nice one kimbers 😀


 
Posted : 11/06/2011 10:17 am
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well my bearings turned up

i can confirm that they weight 50g for both of em including washers

the do indeed make the coil rotate easier

and with 2 bearings it rotates easier than with one

havent actually ridden my bike yet though


 
Posted : 14/06/2011 10:16 pm
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IIRC K9 have been doing them for a while, the ones on K9 look like better sealed (i.e. cartridge ACB's rather than a needle roller and 2 washers) though? They also do them for forks.


 
Posted : 14/06/2011 10:41 pm
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I bought some here for my coil shock enduro but just managed to buy a new frame! oops. 😆

Anyone want to take a pair off my hands? £10 posted.


 
Posted : 15/06/2011 6:57 am
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Ridden it yet Kimbers?


 
Posted : 20/06/2011 10:40 am
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I'm using one of those needle bearing kits on both coil shocks - Patriot and 222.

Tried to fit both needle kits to the DHX 5, but the coil would not seat right at the chamber end, so down to one.


 
Posted : 20/06/2011 10:46 am
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What's the verdict then kimbers? Worthwhile?


 
Posted : 20/06/2011 10:54 am
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isn't this something that 5g of grease costing maybe 10p can fix?


 
Posted : 20/06/2011 10:54 am
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I predict this being like Ti springs being more sensitive (though admittedly at least there is some justification for this, I just don't believe for a moment that there will be any real world benefit).


 
Posted : 20/06/2011 10:57 am
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isn't this something that 5g of grease costing maybe 10p can fix?

I'd guess not, the pressure between spring and collar is probably in the order of 1500psi, show me a grease that maintains and adequate film thickness at that pressure and still be lubricating!

Thats not to say you need the grease either, but it wont do the same job.


 
Posted : 20/06/2011 11:09 am
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But this backs up the idea that ti is more sensitive. As there are fewer coils for a given spring weight, the angle of the coil is steeper and therefore it needs to twist less to over come this inherent stiction. Well, that's the theory, not sure I notice it.


 
Posted : 20/06/2011 11:13 am
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these are completely pointless.

imho they're worse than powerbands - at least those are obviously bobbins and easy to dismiss.

but these bearings - however pointless they are - do stand up to a certain level of scrutiny: coil springs DO 'wind up' under compression.

they're still pointless though.

sorry.


 
Posted : 20/06/2011 11:24 am
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You would notice the difference in Ti vs Steel... but only if you've just shelled out £100 for the Ti spring 😉


 
Posted : 20/06/2011 11:29 am
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Well, I thought I'd give it a go. I've got a 190 x 50 dux 5.0 with a 750 spring on it. There isn't actually enough space to fit them in it seems. I'm not in the mood to mess about with spring compressors to get them in. I even bought the branded ones rather than the budget.

Anyone fancy trying a set? Ten quid posted. Drop me a line, gmail address with the same username.


 
Posted : 22/06/2011 7:44 am
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A friend has tried them - says there is a slight but noticeable difference.

I read that it changes the sag, 2 bearings changes it more than 1 so 2 makes a difference- but it was only by a couple of %.

"2:1 leverage ratio Maelstrom using a 190lb coil, i get 32% sag. With one of these bearings above the coil i get 36% sag. With a bearing above AND below i get 40% sag."

I've fitted mine to a glory and can't actually see the bearing rotate at when I bounce up and down - not ridden it mind.

Still, its called a Needle Thrust roller bearing - or axial load bearing whats coller than that ?

I'm sure flange fits in there as well.


 
Posted : 22/06/2011 8:46 am
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To take it a stage further we ran the [url= http://www.hypercoils.com/Products/Hyperco-Hydraulic-Spring-Perch.aspx ]Hyperco Spring Perch[/url] on race bikes in Superstock as they reduce stiction in the shock by reducing side loading. They use hydraulics to achieve it.

The bearings above are more commonly used on motorbikes to make setting the preload easier as it allows the preload collar to move more freely.


 
Posted : 22/06/2011 10:04 am
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email sent to onzadog


 
Posted : 22/06/2011 10:15 am
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I ordered some of these to try but I got an email saying my paypal payment didn't go through.

Which is utter bollocks as I bought 3 other items on the same day.

Look forward to seeing what other riders think 😀


 
Posted : 22/06/2011 10:28 am
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Any update on these?


 
Posted : 23/08/2011 11:27 am
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I just ordered some again after buying an ironhorse sunday and I've spoken too a few companies, aparently it works well!

You can get specific kits and springs to go with them, but I will just use the standard ones and put loads of grease in them for now!


 
Posted : 23/08/2011 11:29 am
 LoCo
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Personally I'd like to see some that are actually sealed against dirt, even the exspensive ones with a sleeve aren't really sealed properly, just concerned they'll become sticky quickly and seize fairly soon after, unless you're stripping, cleaning and greasing on a regular basis.

Will look into it further when have time.


 
Posted : 23/08/2011 11:32 am
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toons - Member

Any update on these?

nope, they're still completely pointless.


 
Posted : 23/08/2011 11:34 am
 LoCo
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Not sure completely pointless, however they would probably be the last thing I'd fit in the quest for the 'ultimate' in shock performance, after the shock had been stripped, tuned, Ti spring fitted e.t.c.


 
Posted : 23/08/2011 11:40 am
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Yes, yes I can read and understand the graphs and engineering principles.

Let's cut to the chase here, will it turn a complete Beadlehands numpty (ie, me) into Steve Peat or won't it?


 
Posted : 23/08/2011 11:49 am
 LoCo
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Yes oh course* 😀

*this may not be true


 
Posted : 23/08/2011 11:50 am
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I bought a bike, and it had some on it. I took them off.

Couldn't tell any difference. Waste of money*.

*scientriffic research suggests they will make you eleventythree percent faster*


 
Posted : 23/08/2011 11:59 am
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Do they work on air shocks?


 
Posted : 23/08/2011 12:00 pm
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Do they work on air shocks?

I hope that's a joke.


 
Posted : 23/08/2011 12:02 pm
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They are not quite as effective on air, only an eleventytwo percent increase in speed has been noted.

However if you combine them with the needle bearings to replace your bushes and liberally coat the lot with snake oil, you can expect similar levels of performance as a coil.


 
Posted : 23/08/2011 12:04 pm
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So...I need snake oil and I'll get an eleventytwo percent increase in speed?

Can you buy it in Evans?


 
Posted : 23/08/2011 12:11 pm
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Do they work on air shocks?

they'll definitely be just as effective on an air shock...


 
Posted : 23/08/2011 1:07 pm
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