Motorcycle suspension

The short answer is....NO

For novice and intermediate track days my advice is save your cash and service  what  you  have  by  changing the fork  oil  and  greasing  linkages  first. Then  set  the  static  sag,  and  ride  it. A  video  on  this  process  will  go  live  soon.

BUT, depending on your  riding   level  you  may  find  that  you  reach  the  limit  of  some  settings.

What  does  this  mean?

Depending  on  how  hard  you  brake,  and  the  combined  weight  of  you  and  the  bike  you  may  find  that  you  run  out  of  suspension  travel  and  the  forks  bottom  out.  When  this  happens  the  forks  can’t    dampen  the  surface  of  the  track  and  the  tyre  becomes  the  shock  absorber.  This  is  when  you  run  the  high  risk  of  the  front  pattering  and  ultimately  loosing  grip.  A  tyre  can  only  take  so  much.

I  encountered  this  on  my  first novice track  day  at  Donington.  The  forks  had  standard  springs  in  which  are  designed  for  “all  world” motorcycle  use,  they  were  also  progressive  springs.  This  means  that  the  spring  rate  changes  as  its  compressed,  for  track  use  its  recommended  to  use  linear springs  so  the  spring  rate  is  constant.  This  gives  you  a  predictable  fork  performance.

Modern  forks  (But  not  all)  can  be  controlled  by  adjusting  spring  preload,  tension,  and  the  rebound  rate.  We’ll  cover  these  in  the  future.

I  decided  to  speak  to  KTECH  and  they  advised  fitting  some  10.0nm  racing  springs  and  more  adjustable  rebound  adjusters.  I  then  found  a  KTECH  big  piston  kit  on  eBay  and  sent  just  the  internal  parts  off  to  them  to  be  machined.  The  big  piston  kits  and  rebound  kits  give  far  more  adjustability  over  standard.

My  next  track  day  was  again  at  Donington  so  it  was  a  good  back  to  back  test.  

When  braking  into  Foggy’s  and  Redgate  in  the  first  session  I  actually  had  too  much  travel  remaining  so  changes  were  made  to  the  preload  and  tension  to  get  the  fork  using  the  whole  stroke.

Suspension  settings  constantly  change  when  you‘re  getting  faster and  the  bike  requires  more  support.

You’ll  find  at  most  track  days  that  suspension  experts  will  offer  there  services  on  the  day  and  work  with  you  to  get  a  good  setting,  and  the  tyre  working  correctly.

Badly  tuned  settings  can  cause  hot  and  cold  tearing.  Again  we’ll  cover  this  in  the  near  future...

The  rear  shock  was  fully  serviced  and  I  had  the  spring  powder coated.  I  found  a  good  setting  (by  accident!)  for  the  rear,  and  I've  not  had  to  touch  it  yet,  but  that  will  change. 

The  only  other  suspension  modification  I  made  was  to  change  the  linkages  so  the  back  was  raised  40mm  to  put  more  weight  on  the  front.

For  your  first  few  track  days,  just  change  the  fork  oil  and  see  how  the  bike  feels.

The  best  tip  is  this.  Change  ONE  thing  at  a  time  with  the  settings  so  you  know  what  how  each  input  affects  the  handling.  Note  down  all  changes  so  if  you  need  to  you  can  go  back  to  a  base  setting.