Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


custom swing arm

Reply to topic
Bike Chat Forums Index -> The Workshop
View previous topic : View next topic  
Author Message

steven_191
Nearly there...



Joined: 31 May 2009
Karma :

PostPosted: 16:52 - 27 Feb 2011    Post subject: custom swing arm Reply with quote

for my project i think alot of hassle would be avoided by having a custom swing arm made.

im just wondering what materials are they normally made from.

i know the cagiva mito and aprilia rs125 are cast aluminium but then again there is alot of metal there.

arent some mild steel box section?

the problem i need to overcome is allowing enough space for the right suspension travel, the chain on the right hand side and the linkage actually being able to work.
speaking of linkage. am i right in thinking its job is to reduce the motion on the shock compared to the motion on the wheel. in which case its a reduction ratio.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

steven_191
Nearly there...



Joined: 31 May 2009
Karma :

PostPosted: 16:57 - 27 Feb 2011    Post subject: Reply with quote

i dont really even need a linkage do i?

alot use the top brace or where the sides link together in front of the wheel as the shock mount. mounting it this far forward still reduces the shock travel
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

G
The Voice of Reason



Joined: 02 Feb 2002
Karma :

PostPosted: 20:29 - 27 Feb 2011    Post subject: Re: custom swing arm Reply with quote

Most swingarms are steel. Regularly considerably heavier than the frame it's self.
 Back to top
View user's profile Send private message You must be logged in to rate posts

woodyfjr
Scooby Slapper



Joined: 25 Jan 2006
Karma :

PostPosted: 21:03 - 27 Feb 2011    Post subject: Re: custom swing arm Reply with quote

steven_191 wrote:

Speaking of linkage. am i right in thinking its job is to reduce the motion on the shock compared to the motion on the wheel. in which case its a reduction ratio.


Very close the linkage is too increase the effectivenes of the shock in relation to the swingarm travel.
____________________
If you don't pay your exorcist you can get repossessed.

If you have to rev it! Don't Buy it!
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts

steven_191
Nearly there...



Joined: 31 May 2009
Karma :

PostPosted: 23:36 - 27 Feb 2011    Post subject: Reply with quote

CHR15 wrote:
Quote:
for my project i think alot of hassle would be avoided by having a custom swing arm made.


budget at least £500 for having a swingarm made.


Very Happy maybe not then

i was considering getting the materials and tacking them together myself then having them properly welded.

on a brighter note though, it may be that the honda cbr 600f swing are is a few millimeters away from being just what i want.

just waiting for some measurement info before i decide. looks like the older steel type is very close but if the more modern ally type is close and lighter i might settle on one of them
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

steven_191
Nearly there...



Joined: 31 May 2009
Karma :

PostPosted: 23:40 - 27 Feb 2011    Post subject: Re: custom swing arm Reply with quote

woodyfjr wrote:
steven_191 wrote:

Speaking of linkage. am i right in thinking its job is to reduce the motion on the shock compared to the motion on the wheel. in which case its a reduction ratio.


Very close the linkage is too increase the effectivenes of the shock in relation to the swingarm travel.


its still a reduction though right?

talking to a guy the other day at hagon and a bit of research online led me to believe that a shock at the end of the arm effectively gives you a 1 to 1 ration of swing arm/shock travel. this creates alot of movement in the shock which causes the oil to heat up and froth and become useless.

reducing the shock travel in relation to swing arm travel reduces this.

so then how do you know when enough reduction is enough?? i suppose copying 99% of other bikes would be the way to go
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

woodyfjr
Scooby Slapper



Joined: 25 Jan 2006
Karma :

PostPosted: 09:46 - 28 Feb 2011    Post subject: Reply with quote

(am i right in thinking its job is to reduce the motion on the shock compared to the motion on the wheel. in which case its a reduction ratio) the opersite.

If you think about where the shock is mounted on a modern bike in relation to a twin shock the shock would have a very short stroke.

eg: If the swingarm shock mount was say 24" away from the pivot point and say it had 8" of movement, then you fitted a shock say 12" away from the pivot you would only need it to move 4" to get the same swingarm movement.
However the shock would over heat as its doing the same work but in half the distance so this where linkages come in.

The linkage (gearing) increases the shock stroke length to allow more damping control so it would compress at a slower rate than the swingarm.
____________________
If you don't pay your exorcist you can get repossessed.

If you have to rev it! Don't Buy it!
 Back to top
View user's profile Send private message Visit poster's website You must be logged in to rate posts
Old Thread Alert!

The last post was made 15 years, 113 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT + 1 Hour
Page 1 of 1

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 

Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.10 Sec - Server Load: 1.47 - MySQL Queries: 14 - Page Size: 55.07 Kb