K2 / Proflex Riders Group

General => Tech Forum => Topic started by: Simon on January 15, 2005, 03:39:17 am

Title: Revised anchor point
Post by: Simon on January 15, 2005, 03:39:17 am
You'll all be getting fed up with my floating brake saga soon  [smiley=laughing.gif] but I'm sure I've sorted it now,on the advice of Brian from brake therapy I've again lowered the anchor point on the frame (it now has multiple mounts so I can adjust it,not using the slot that can be seen),I tested this with a straight torque rod and everything seemed great,just hoping for some decent weather  [smiley=upset.gif] for a proper test,as everything seems sorted, I shortened the rod and added a kink for extra clearance (the longer rod was using up to much brake hose length),I also re-shaped the frame anchor end to a more circular appearance,think it looks pretty good now ??? :P
Simon.
(http://idriders.com/proflex/galleries/Simon/PHTO266.jpg)
(http://idriders.com/proflex/galleries/Simon/PHTO265.jpg)
Title: Re: Revised anchor point
Post by: Scott on January 15, 2005, 04:36:48 am
Good looking work, Simon!   And how has the Risse performed for you?

Cheers,
Scott
Title: Re: Revised anchor point
Post by: Simon on January 15, 2005, 04:42:02 am
Quote
Good looking work, Simon!   And how has the Risse performed for you?

Cheers,
Scott


Thanks,
The Risse's has performed great but it did blow an internal oil seal just out of warranty (typical).
Simon.
Title: Re: Revised anchor point
Post by: Matno on January 15, 2005, 08:14:56 am
At least you can replace the seals on a Risse yourself, right?
Title: Re: Revised anchor point
Post by: Carbon_Angus on January 15, 2005, 08:36:13 am
let us know when you have ride time on it.

aesthetically  :P your second version looked better (IMHO) although this one does mimic the swingarm.

going back a wee bit....the aluminum swing with the needle bearings has more lateral stiffness than orig. carbon swingarm with the "oldstyle" bearings ???

[smiley=beer.gif]



Title: Re: Revised anchor point
Post by: Simon on January 15, 2005, 09:12:19 am
Quote
At least you can replace the seals on a Risse yourself, right?

Yes some but unfortunatly not the 1 required (again typical),I probably could of if I had the special tool (or made 1) to undo and split the air chamber,I had an internal leak between the air chamber and the damper.Plus the cost of a rebuild kit over here wasn't much less than getting a specialist to do it,elected to have them do it.
Simon.  
Title: Re: Revised anchor point
Post by: Simon on January 15, 2005, 09:20:56 am
Quote
let us know when you have ride time on it.

aesthetically  :P your second version looked better (IMHO) although this one does mimic the swingarm.

going back a wee bit....the aluminum swing with the needle bearings has more lateral stiffness than orig. carbon swingarm with the "oldstyle" bearings ???

[smiley=beer.gif]





Ah I can still go back 2 the second version as that mounting point is still there plus 2 others,but you're right doesn't look quite as good just trying to make it look the best I can in its optimum performance position .
Yes I find the aluminium s/arm is laterally stiffer though it came from a needle bearing version bike the pivot eye's are still the same as the convensional bush system just the inserts are different,fitting an al s/arm from a needle bearing bike would be a straight forward fit using bushes, but an al s/arm fitted to a carbon frame requires major mods for clearance,as you know my al s/arm pivots are reamed out and are running on 4 sealed precision bearings not bushes or an internal needle bearing, [smiley=beer.gif]
Simon.
Title: Re: Revised anchor point
Post by: jinder on January 16, 2005, 06:11:56 am
AWESOME!!!!!!!!!!  That looks wild!
Title: Re: Revised anchor point
Post by: StoereVent on January 18, 2005, 06:51:09 pm
Simon,



this must be a stupid question, but why didn't you attach the piece where the brake is mounted on directly to the swingarm instead of fixing it with a rod to your frame?



(like OP did : (http://idriders.com/proflex/galleries/Old_Proflexer/Bike%20Side%20View.jpg))



Jeroen.
Title: Re: Revised anchor point
Post by: Simon on January 19, 2005, 03:58:25 am
Quote
Simon,



this must be a stupid question, but why didn't you attach the piece where the brake is mounted on directly to the swingarm instead of fixing it with a rod to your frame?



(like OP did )



Jeroen.

What like this [smiley=laughing.gif]
(http://idriders.com/proflex/galleries/Simon/Phto217.JPG)
Ummm well yes it could be (stupid) but maybe you haven't heard of a floating brake system,
first why haven't I attached it like Op's,checkout the above pic, I've already done that and also for my son Mega-Oz,
It was time to move on, this system put simply tries to isolates braking forces acting against suspension action,if you look closely the caliper bracket moves in an arc around the disc as the suspension compresses,at lot depends on getting the geometry correct hence the numerous mods,checkout the past postings and related drawings in my gallery to understand things more.
you could also have a look here for some info
http://www.therapycomponents.com/FLOATING%20BRAKE.htm
Simon.
Title: Re: Revised anchor point
Post by: Old Proflexer on January 19, 2005, 01:29:48 pm
yes, the idea of attaching a portion of the the caliper to the main frame allows the suspension swingarm to move freely while the brake calipers braking forces are more independant of of that motion.  if the whole thing is attached to the swingarm, it defeats the purpose of allowing the caliper to 'float' around the motion of the arm as the whole unit would then move with the arm.  the unit pivots at the axle clamp area and keeps the caliper in line with and over the rotor under normal arm motion when riding.

i should have paid more attention in my physics and engineering classes way back when in school.  somebody correct me if i'm wrong.  

but hey, in my book, any discs are better than no discs.

good show simon,

OP
Title: Re: Revised anchor point
Post by: StoereVent on January 19, 2005, 06:21:00 pm
Simon,

It seems that I never took notice of the difference between the normal and the floating system. Now I know the difference, I understand you better. I guess the reason I never had to bother about it comes from the fact that I'm a HS33 user.

By the way: is the benefit of the floating system enough to compensate the increasing weight, or is it more that the fact of having a braking system that doesn't affect the suspension (so a more 'pure' system) is the main goal?

Jeroen.
Title: Re: Revised anchor point
Post by: Simon on January 20, 2005, 04:02:37 am
Jeroen, weight here is not really an issue, with every thing bar the bearings being aluminum or titanium I've only added 150/200g according to the trusty kitchen scales,bike still weighs in at 25lbs,not bad with full disc's,a floating brake system,4" travel forks,its a more or less a do most things bike that can (has) raced,now has a far improved braking system over the normal problems associated with single pivot bikes.
Simon