Author Topic: 856 with rock-shox bar rear (Read 4273 times)

Juanpablo · « **on:** July 28, 2005, 05:49:51 am »

I buy a rock shox bar to fix the problem with my old rear girvin ODS. The measure of rock-shox eye to eye is 200mm and the stroke measure is 50mm. I made a adaptor and all joint measure about 220mm (since the upper eye eyelet to the base of the adaptor. I have a Girvin Elite fork. My question is:
Is so large this shock for my bike???

Proflex forever from Andalucia.

Simon · « **Reply #1 on:** July 28, 2005, 06:18:37 am »

I'd says yes its to long,but can you post some pictures of what you intend to do so we can give you a better idea of what can be done.
Simon.

Juanpablo · « **Reply #2 on:** July 28, 2005, 07:48:35 am »

Sorry,I know that my english is too bad, but thanks for your help Simon
I made a adaptor with a provisional shock. This joint measure 200mm (upper eye-base of adaptor). You can see in: http://idriders.com/proflex/files/adapter856.JPG
I want to put a new shock, and I made a smaller adaptor, but the join (adaptor-rockshox) measure 220mm. Do you understand that I try to made??? Is posible??? any other ideas?

.
Many thanks, Juan Pablo

Proflex forever from Andalucia

Simon · « **Reply #3 on:** July 28, 2005, 09:25:55 am »

Quote

Sorry,I know that my english is too bad, but thanks for your help Simon
I made a adaptor with a provisional shock. This joint measure 200mm (upper eye-base of adaptor). You can see in: http://idriders.com/proflex/files/adapter856.JPG
I want to put a new shock, and I made a smaller adaptor, but the join (adaptor-rockshox) measure 220mm. Do you understand that I try to made??? Is posible??? any other ideas?.
Many thanks, Juan Pablo

Proflex forever from Andalucia

Hi JuanPablo
OK I think I understand,the standard measurement from the centre of the top shock bolt to the base of the strut is around 195mm,with your adapter if the measurement is 220mm from the top bolt to the adapter base then thats way to far (in my opinion), the 200mm setup in your picture looks great,I'd say using a Shock with an eye to eye of 165mm with the adaptor your showing in the picture would workout great (again in my opinion),
Simon.
Ps very nice looking adapter [smiley=nod.gif]

shovelon · « **Reply #4 on:** July 28, 2005, 01:54:14 pm »

Super nice adapter there JP. I like how you tapered in the sides.

So ride it and see for yourself how well it works. How does it measure up side by side with the ODS?

Terry

Juanpablo · « **Reply #5 on:** July 28, 2005, 09:40:53 pm »

The provisional shock measure 165mm, and I made a adaptor a little bit bigger, The joint win 10mm compare with my old ODS.
Its not necesary to be a expert, beleive me. Only its necesary a cube of aluminium, a saw, a file, and patience. The last one is very important.
I feel positive sensation, over all in harder downhill. The rebound is to hard, but I think that the problem is the cheap shock.This is the reason because I buy a new shock.
I made other prototipe adapter, smaller, and I reduce 10 mm the measure of the joint(necesary for the larger rockshox), in the other hand, when I sit on my bike, the shock will reduce about other 10mm, and the efect it will be similar at the actual shock.
What do you think about it???

Proflex forever from Andalucia

Sprucey · « **Reply #6 on:** July 28, 2005, 09:44:03 pm »

I think is great how simple that adapter is - by that I mean the "design concept".

I have been wanting to make an adapter and was thinking along the lines of some sort of machined tube to insert the shock eye and then pin it through (similar to some we have seen previously on the site) - complicated and difficult to do unless you are a precision engineer.

JPB's adapter is simplicity itself and I cannot see any reason why it would not work? (Am I missing something? The bottom shock eyelet cannot move sideways or vertically, can it?)

The cone on my ODS (kindly given to me by Simon) is removable and would fill the hole in the strut to stop the bolt moving no problem if I used this sytem.

The irony, is that I have just had a cone shaped hole machined into my 855 strut by a local engineer to accept the ODS unit!

Sprucey

Juanpablo · « **Reply #7 on:** July 28, 2005, 11:42:14 pm »

I thinked about this when I made this adapter.It can move a little to side, but all the rear structure of my proflex dont allow move to side. I work in this and maibe I can make something about this.Your Althought I say that the present adaptor work well. If is posible, send me any photos about new ideas.
Ps: Thanks Sprucey, your idea look like very good, but difficult to made.
Proflex forever from andalucia

will · « **Reply #8 on:** July 29, 2005, 01:20:29 am »

Agree with Sprucey... it's a beautifully simple solution.

Unfortunately, I also just finished a hack job on my rear shock adaptation. I tapered the end of a "normal" shock to fit the cone recess, then I drilled it and tapped it to accept the end bolt. [smiley=furious.gif]

Basically, I permanently disfigured a new shock to fit when an adapter like Juan Pablo's would have saved many hours and a few tears.

Live & learn...

Simon · « **Reply #9 on:** July 29, 2005, 01:24:50 am »

One problem you will encounter if you raise the back of the 856 to much,it messes up the dig in performance of the suspension,it also increases the suspension induced lockout of the cranks,
tried all this and can say don't raise the back to much,
checkout page2 of my gallery to see what I've done and how I've overcome this,its abit more extreme than what you've done but the principles are the same,
Simon.

kiwi · « **Reply #10 on:** July 29, 2005, 11:31:31 am »

beautiful idea and as spruceys says the old ods cone can be bolted through too to add rigidity.Looks as though yo can reduce the height to come back to 210 mm from eye to end of cone.As sprucey says the cone will come off te original non ods and ods units.

Juanpablo · « **Reply #11 on:** July 31, 2005, 08:03:07 pm »

Yes, I think that it is the solution, I want to make this.
I will send you a photos when I finish it.
Many thanks.
Proflex forever form Andalucia

rapiddescent · « **Reply #12 on:** August 02, 2005, 08:32:47 am »

I was thinking - just remove the cone from the top of the strut (it does come out) - but then sprucey took the words out of my mouth. A nice tapered end would fit flushly.

We have noticed in testing that there occasionally is a lateral loading on the end of the shock - presumably this is why they changed the fitting design from the 855 to the 856. The 855 doesn't have the cone and suffered failures in this area. It is worst on the 14" frames which I am positive don't actually have the right geometry for the shock at all.

nice work.

callum
rds

sammydog · « **Reply #13 on:** August 02, 2005, 11:49:48 pm »

So how long should we be looking eye to eye. I made something previously (I think there is a photos here somewhere) but haven't really checked to see how much I may have altered the intended eye to eye.

I'm building my second proflex back up as a single speed, so I wouldn't mind getting it right.

guman · « **Reply #14 on:** August 03, 2005, 08:41:10 am »

It is almost the same as the adapter I made in 2002! You can find the picture in the "Files" under "Guman"( Is it strong enough?). It was! There is also somewhere another pic of another adaptor I had made for me some years ago. It is more complicated but it gives me more confidence because there is no gap between the shock and the frame.
The only problem with the second adapter is you have to cut off the shock!! I used a Foxshock, an old model, wirhe the new shocks you have to be carefull or oil or gas may escape and your nice shock is wasted.
Maybe I can come to Andalucia next year to show you? Iy' not soooo far from Belgium (ahem)....

BTW, today I saw in a Belgian magazine that K2 finally is selling spareparts (elastomers ed).

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Author Topic: 856 with rock-shox bar rear (Read 4273 times)

will

guman