K2 / Proflex Riders Group

General => Tech Forum => Topic started by: orange on January 03, 2007, 02:48:14 am

Title: Rear elastomer size/shore for 753?
Post by: orange on January 03, 2007, 02:48:14 am
I've got a source for cheap new elastomers (see sticky above for parts) and I want to replace the old hard elastomer on my 753. The current dimensions are 56mm long by 40mm OD and 13mm ID (friction damped remember).

Anybody know what that would have been when fresh and new?

Also what 'shore' rating should I go for? I am 13 stone.

This guy may not have them, but it's worth asking.
Title: Re: Rear elastomer size/shore for 753?
Post by: Simon on January 03, 2007, 07:06:13 am
Lol thats 182lbs to those across the pond,
14lbs=1 stone

according to my K2/Proflex spring chart
they recommend a 50 rating for a rider weight
of 140-180lbs and 60 rating for 160-200lbs
this is for 14" frame using a single elastomer,
larger sized frames (16" 18" and 20")its recommended an upgrade to
twin elastomers 150-190lbs 40/60 180-220lbs 50/70

Simon.
Title: Re: Rear elastomer size/shore for 753?
Post by: orange on January 03, 2007, 08:27:13 am
So if it's a 20" frame (which I think it is), I'll need a 50 and a 70 - will they be 30mm each in length approx and do they all have the same internal diameter?

The old one is wider than the ones I've peeled off ODS etc. at 13mm ID. How crucial is the ID or can you force on a narrower one and accept that you'll get more friction damping? Or is that not a good idea?
Title: Re: Rear elastomer size/shore for 753?
Post by: Ziggy on January 03, 2007, 08:27:46 am
What does your chart say for someone who's 154lbs, on an 856 (ODS) & the Vector-1 (Elastomer on a stick!) that's on the front?

Cheers!  :)
Title: Re: Rear elastomer size/shore for 753?
Post by: Simon on January 03, 2007, 09:24:38 am
Quote
So if it's a 20" frame (which I think it is), I'll need a 50 and a 70 - will they be 30mm each in length approx and do they all have the same internal diameter?

The old one is wider than the ones I've peeled off ODS etc. at 13mm ID. How crucial is the ID or can you force on a narrower one and accept that you'll get more friction damping? Or is that not a good idea?


From what I've had in the past the heavier one had
a narrower I/D,I didn't have any problems fitting them,don't forget you will need a spacer plate between them,

Simon.

Title: Re: Rear elastomer size/shore for 753?
Post by: Simon on January 03, 2007, 09:31:21 am
Quote
What does your chart say for someone who's 154lbs, on an 856 (ODS) & the Vector-1 (Elastomer on a stick!) that's on the front?

Cheers!  :)


Rear for a 856
120-160lbs = 100 top  80 bottom
140-180lbs = 120 top 100 bottom
Front vector1 upgraded to duel mcu's
120-160lbs = 60/40
140-180lbs = 70/50

Simon.

Title: Re: Rear elastomer size/shore for 753?
Post by: kiwi on January 03, 2007, 09:39:18 am
Quote
What does your chart say for someone who's 154lbs, on an 856 (ODS) & the Vector-1 (Elastomer on a stick!) that's on the front?

Cheers!  :)

spring chart (http://k2bikes.com/tech_library/pdfs2/98/98springratechart.pdf)
There was a fantastic old chart which i am sure I have a copy somewhere but in the meantime take a look at the k2 site at athe link,there is some good stuff there still!
Title: Re: Rear elastomer size/shore for 753?
Post by: kiwi on January 03, 2007, 09:41:16 am
I am not 100 per cent sure that the proflex numbers were the shore hardness or not.
Title: Re: Rear elastomer size/shore for 753?
Post by: Ziggy on January 03, 2007, 10:52:57 am
Quote
I am not 100 per cent sure that the proflex numbers were the shore hardness or not.


I'd be tempted to say 'not'...

I'm currently running 70/70 on the front & rear, & it's definately too hard on the front, but probably a bit hard on the rear too.  It should be way too soft on the rear according to Simon's figures (thanks for that btw!).
Title: Re: Rear elastomer size/shore for 753?
Post by: orange on January 03, 2007, 05:59:15 pm
This guy says he has plenty of elastomers but only in 10, 30 and one or two 40's - if I had 2 40's would that be too soft for my 753 or could I just about get away with it? These are the numbers stamped in the elastomer - are we talking the same units here?
Title: Re: Rear elastomer size/shore for 753?
Post by: kiwi on January 03, 2007, 08:06:42 pm
Quote
This guy says he has plenty of elastomers but only in 10, 30 and one or two 40's - if I had 2 40's would that be too soft for my 753 or could I just about get away with it? These are the numbers stamped in the elastomer - are we talking the same units here?


thats what i am querying too.I dont think the number stamped on the elastomers are the same "units" as shore...I have absolutely no reason for this,,i just am not sure.
Title: Re: Rear elastomer size/shore for 753?
Post by: orange on January 03, 2007, 10:36:24 pm
Can we take 10 to mean softest and 40 to mean hardest then? Do we know if those numbers on the elastomers came in any other values than 10, 30 and 40?
Title: Re: Rear elastomer size/shore for 753?
Post by: oldgit753 on January 03, 2007, 11:07:40 pm
I have just gone back to riding my 753 after a five year lay off and after a request here in the forum got a single replacement elastomer from SLIM, also through this forum.

It is white, with a 45mm length, 40mm diameter and 13mm ID. Have been out on the bike twice since fitting the new elastomer at Christmas and it works a treat. I'm 200 lbs by the way, and the compression in the elastomer is very good and there's no noticeable rebound problems.
Tony
Title: Re: Rear elastomer size/shore for 753?
Post by: orange on January 03, 2007, 11:41:41 pm
Ah, I might try Slim then, how much was it? Also when I measured mine it was 56mm long (40mm OD and 13ID are the same as yours it seems) - how come yours is shorter?
Title: Re: Rear elastomer size/shore for 753?
Post by: kiwi on January 04, 2007, 08:48:24 am
the proflex numbers went much higher than that(40) I think one of my rears was a 120.See simon post above he gives the rates for differents rider weights,and 120 is there! [smiley=nod.gif]