Author Topic: My 4500 mod unvailed. (Read 6650 times)

Ionit · « **on:** January 13, 2006, 12:51:44 pm »

It is my project for the next year but hopefully for much less. All of the geometry I plan on keeping. that means chainstay and both tube angles match the 4500. As you may conjure the rear travel will be a tad less. I am guessing total travel will be around three inches in back to match the crosslinks that I insist at keeping. Finding the magic spot for the rear shock eye was the most difficult process. I have to say, the linkage system demo was heaven sent. Before it I had intentions to do thing by trial and error. Thanks goes to whom ever found the program. Sorry please dive yourself credit. I will find that post ventually.
When using the program I modified a single pivot bike by changing the rear linkage points to simulate the x57 type linkage. then I tested different shock positions with the intent to up travel for a comparable frame. I think I can get a little over 3 inches without detracting from performance.

I was informed by Frankd3000 that this design benefit having a platform shock. Do others agree even if you have never tested one tell me your opinion.

Tell me what you think. I can always switch back to the simple swingarm. So you don't have be courteous. Let the criticism fly.

Frankd3000 · « **Reply #1 on:** January 13, 2006, 01:33:07 pm »

Bravo Ionit! I think, at the very least, it'll be an interesting project.

Questions galore;

Have you checked that the s/arm pivot's are the same width yet? I never checked Frank and compared with the 5000 frame I have.

You're obviously going to be using the s/arm that we got with the group purchase - what about a strut??? Judging by your pic it looks like you'll be using an early style?

I'll go out and get the Champagne bottle and put it on ice 'till you're done. [smiley=laughing.gif]

Oh, you have (e) mail.

Simon · « **Reply #2 on:** January 13, 2006, 06:45:05 pm »

Well Ionit I think I'm the one who posted the
linkage simulator demo though I can also link you to
a full programme (earlier version)if you wish,its what
I used on my project,
good to see new ideas BUT I don't know if your aware that design is exactly the same (I mean identicale) to the first Proflex carbon prototype bike (Oz style main frame 955 rear end),
there was a pic of the full bike built at a show on the old 855 heads site,hopefully Callum can dig out a pic for you,
anyway full marks if you pull it off as it will still be unique and IMHO stiffen up the rear end laterally very nicely indeed,should give a very fast ride [smiley=nod.gif].

Simon.

PS The s/arm and frame widths are the same (Terry checked his for the pivot mods we've done) so no worries there.

Simon · « **Reply #3 on:** January 14, 2006, 02:49:02 am »

Just checked,
you should get with a 1.5" stroke shock

69mm/2' 11/16" travel

with a 1.75" stroke shock

81mm/3' 3/16" travel

well thats what I make it.

Simon.

Ionit · « **Reply #4 on:** January 14, 2006, 02:58:11 am »

Yes. I'm using the S-arm from e-bay. The pivots thickness is the same. That is the first thing I tested when I got it.
The strut is the only component I worry about fitting. I was going to tackle that problem once I have the strut. The most important fitting to me is the dropout pivot on the far back of the swingarm. It needs to couple perfectly because it will be hard modifying either fitting for proper fit. I can handle the lengthening or shortening of the strut and by the looks of it with Andrew’s help the cone adapter is covered.
Hopefully those areas will be addressed without to much trouble.
If you can foresee any other problems please make me aware.
While I was changing pivot locations I determined having the shock's top picot about 2cm higher then the existing pivot will provide best results.

Oh Simon thank you very much for the demo link before. It was very helpful. Can you post the non demo link. It would be nice to save and export data.

Simon · « **Reply #5 on:** January 14, 2006, 03:03:14 am »

Look what I found

more info here
http://www.proflex.demon.co.uk/855headfeatures/bike97/

link to download simulator is here
you will need to translate and register,all straight forward before you can download the simulator.

http://www.mtbcomprador.com/

Simon.

Ionit · « **Reply #6 on:** January 14, 2006, 03:16:29 am »

Awsome. Thanks Simon.

I did see that design before in one of the magzines back when. I guess my idea isn't so unique anymore is it. I long but forgot about that concept at the shows cica 97.

Simon · « **Reply #7 on:** January 14, 2006, 03:29:41 am »

Quote

I guess my idea isn't so unique anymore is it.

Oh yes it is,
yours will be built tested and used and there wont
be another one,thats unique enough for me

,

Simon

Ionit · « **Reply #8 on:** January 14, 2006, 04:55:17 am »

Here is the first update.
The clamp thickness on the swingarm is thicker by about .5mm but it still assembled beautifully.

If anyone has a strut that accomodates this style arm for purchase give me a shout. looking for the x57 typs brace that reaches from frame to dropout. It will be around 19.5 inches but the length I can modify so any x57 type will do.

shovelon · « **Reply #9 on:** January 14, 2006, 06:22:10 am »

Excellent, excellent, excellent! What a great idea.

I think the first thing you will notice when completed is a considerable reduction in swingarm flex. The strut in my opinion really stabilizes the rear wheel from twist and flex. And I am harboring the belief that the x57 swingarms are more stout.

And the 4500 has that lowered pivot for a more active suspension. You could definately benefit from a platform shock if you can adapt one.

You can shorten your strut pretty easily. The joints are bonded. To disassemble from the shock mount, just heat gently over the kitchen stove untill the glue melts. But make sure the air pressure does not build up too much inside that it launches the strut when the glue melts. Trim and rebond with whatever(JB Weld works).

Lengthening could be done by bonding a sleeve below the upper joint. The upper mount slides into the tube about 1/2 to 5/8 inch. So cutting the the tube maybe 1 inch below the upper joint and and bonding an oversize sleeve would work. Be carfull, the tubes are only about .5mm wall.

Or better yet, dissemble and reassemble with carbon tubes. [smiley=nod.gif]

It's going to look great. Again, what a great idea.

Terry

Frankd3000 · « **Reply #10 on:** January 14, 2006, 02:51:11 pm »

Well look at that - it's on! Coooooool!

Okay, another Q - since you'll be changing where the shock mounts to the frame plate, what are you going to do about the location and mounting?? I'm sure you've noticed already that the shock's stock location is where it is because it's buried in the "V" of the seat/top tube's junction, right? If you're going to move it up then you'll have carbon (frame) in the way.

Input?

Also, this means you can run a ball bearing conversion on that, right? (still gotta look at Frank to see if I can do it or not)

Originality - well, I can speak from personal experience with this one. I was all set and ready to "do something special" when I joined up here. Heck, look at my username! Then I saw Simon's project and fell apart when I saw he did exactly what I had in mind. (damn, it's gorgeous!) Anyways, wether ProFlex made one or not, I certainly think the cudos goes to you for building one of your own. You're really taking the best of everything and rolling into one FINE package. Also, you're DOING it, not just hacking something up or being a big company and calling it a prototype.

I say it's a proud piece to build.

Not many people build prototype's.

kiwi · « **Reply #11 on:** January 14, 2006, 06:14:36 pm »

great idea...the shock can mount to custom pltes fixed to the frame,dont do anything to the strut itself until you get the shock,cos you will prolly have to massage the length of the shock anyway via an adapter from shock to 957 strut.I am sure that fabing a stut from scratch wouldnt be hard for guys of your calibre....

Ionit · « **Reply #12 on:** January 15, 2006, 07:26:15 am »

Ha. thanks Kiwi. But sometime my enthusiasm surpasses my actual skill in practice. My comfort dismantling it kind of scares me. The tip you gave me is a good one. I shall wait until I have the hole strut and shock assembly before I start chopping things. I still have the CF side plates and can move them around slightly for correct positioning.
I followed Dominic's instructions to take those off with the rest of the cable system bits. I think I will leave them off for good and redistribute them.

Colin · « **Reply #13 on:** January 16, 2006, 08:59:03 am »

Thought................

........comparing my 857 beside my 5500, the shapes of the swing arms are different......

Because of the lower mounting point on the 5500, the swing arm comes up higher before going horizontal, I think this is to clear the chainrings...........

.......with the lower pivot and a "low rise" swing-arm, you might foul the chain-ring..............

...........or on the other hand, you might not!

Ionit · « **Reply #14 on:** January 16, 2006, 11:26:36 am »

Good thoughts colin. I will check this.

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Author Topic: My 4500 mod unvailed. (Read 6650 times)