Author Topic: Fork oil for 45mm right side up forks  (Read 1604 times)

Offline Petrus Rocks

  • Gosling
  • ***
  • *
  • Posts: 358
Fork oil for 45mm right side up forks
« on: March 18, 2019, 03:51:38 PM »
I just transplanted a set of 45mm MG adjustable forks onto my 85 Tonti frame.  I see 485cc per leg as a spec but no height measurement.  Also MG calls for 10wt oil.  Anyone use something different? 
Pete

Online John A

  • Gaggle Hero
  • *****
  • *
  • *
  • *
  • *
  • Posts: 4907
  • No way to slow down...
  • Location: Hager city ,western WI
Re: Fork oil for 45mm right side up forks
« Reply #1 on: March 18, 2019, 04:05:29 PM »
actually I like to use motor oil.  I learned from some racing types that forks cant read so they don't know if you don't put in high zoot fork oil or not.  Ive been using 15/50.
John
MGNOC L-471
It is easier to fool people than it is to convince them that they have been fooled-Mark Twain
99 Bassa, sidecar
02 Stone
84 V65C
15 F3S Spyder

Offline Perazzimx14

  • Gaggle Hero
  • *****
  • Posts: 5974
Re: Fork oil for 45mm right side up forks
« Reply #2 on: March 18, 2019, 04:06:26 PM »
ATF also works a treat
2021 Moto Guzzi V85TT Guardia D'onore
2017 V7 III Carbon Dark #0008 of 1921
2017 Road Glide Special
2020 Kawasaki KLX300SM
2016 Suzuki Van Van 200

Rough Edge racing

  • Guest
Re: Fork oil for 45mm right side up forks
« Reply #3 on: March 18, 2019, 06:14:42 PM »
 Fairly big gap between 15/50 and ATF , usually described as a 7.5 weight oil....considering forks run much cooler than an engine or transmission...it's still a big difference...

Wildguzzi.com

Re: Fork oil for 45mm right side up forks
« Reply #3 on: March 18, 2019, 06:14:42 PM »

Offline Perazzimx14

  • Gaggle Hero
  • *****
  • Posts: 5974
Re: Fork oil for 45mm right side up forks
« Reply #4 on: March 18, 2019, 06:37:13 PM »
Fairly big gap between 15/50 and ATF , usually described as a 7.5 weight oil....considering forks run much cooler than an engine or transmission...it's still a big difference...

15/50 might be a bit excessive or have all dampening and slooooooooooooooooo ooo rebound. I've run straight 30w oil in the forks of my Eldorado with success.
2021 Moto Guzzi V85TT Guardia D'onore
2017 V7 III Carbon Dark #0008 of 1921
2017 Road Glide Special
2020 Kawasaki KLX300SM
2016 Suzuki Van Van 200

Offline Rick4003

  • Gaggle Mentor
  • ****
  • Posts: 508
  • Location: Denmark
Re: Fork oil for 45mm right side up forks
« Reply #5 on: March 18, 2019, 10:25:01 PM »
I just looked into getting some new fork springs for mine and Wilbers recommend 7.5w oil with their fork springs.
Moto Guzzi 850 T5 (850 sport) - 1985
Moto Guzzi Ambassador - 1967
Yamaha FZR 600 - 1996 - SOLD

Rough Edge racing

  • Guest
Re: Fork oil for 45mm right side up forks
« Reply #6 on: March 19, 2019, 05:08:08 AM »
 Pete, since the forks assembly on the bike now is from a heavier machine than your "cafe" Tonti, perhaps a slightly lighter oil might be better to prevent harsh dampening...Maybe 5 weight fork oil instead of the slightly heavier ATF.. I'm assuming the 45 mm forks were not under dampened on the original bike...
  For those interested, the 45 mm later forks on the 80's Tonti frame bike look very nice, a more balanced look with the large Guzzi engine...The original 35 mm forks look like they belong on a 250cc bike in comparison... :grin:

Offline Petrus Rocks

  • Gosling
  • ***
  • *
  • Posts: 358
Re: Fork oil for 45mm right side up forks
« Reply #7 on: March 19, 2019, 08:10:47 AM »
Good point Tony.




image uploader

Here's a before and after.  Steering stem triples, and bearings all fit right on.  Using the old Borrani rims I will have to make a spacer to center the wheels.  A simple bracket will allow me to use the old calipers.  I have a set of four pot Brembos that will go well with larger discs.

Offline Petrus Rocks

  • Gosling
  • ***
  • *
  • Posts: 358
Re: Fork oil for 45mm right side up forks
« Reply #8 on: March 19, 2019, 08:17:30 AM »
Didn't realize that was a such a crappy picture...


 

Quad Lock - The best GPS / phone mount system for your motorcycles, no damage to your cameras!!
Get a Wildguzzi discount of 10% off your order!
http://quadlock.refr.cc/luapmckeever
Advertise Here