Front fork travel

discussions specific to the 906 Paso
Post Reply
User avatar
Giscard
Posts: 126
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Front fork travel

Post by Giscard »

Hi. I have just replaced my tyres, thanks to MC Reifenservice, Alfred Schenk for rhe new Shinko's. While I was at it I did the wheel bearings and thought I would change the fork seals.
All seemed to go OK. At a suggestion, I think on here, I used 7.5W oil instead of the 5.0W oil.
When I got the forks back together I pressed down on the stantion with my full weight and I could get it to compress to about 3cm. At that point it felt solid, so I was not totally happy with it.
Anyway I put the forks back into the bike and eventually took it for a tentative ride. All felt ok on the the roads that were not full of potholes. However I I did go over a fairly deep pothole and it was really uncomfortable through my wrists.
I now have the forks off the bike again. Before I take them apart (and fit new fork seals!) to see if I have put anything in upside down etc has anyone any suggestions. Should I go back to the 5.0W oil, would I expect more than 3cm of travel with me physically compressing the fork.
User avatar
Giscard
Posts: 126
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Re: Front fork travel

Post by Giscard »

Ok I decided to just drain the oil and change it for 5W to see if that will make them a little softer. I took the spring out and checked the "stroke" and it was close to the 4.9 inches in the manual so all seems ok there. I think I was just surprised at how hard the suspension felt on a road covered in pot holes.
Mc tool
paso grand pooh-bah
Posts: 1957
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Riverton New Zealand

Re: Front fork travel

Post by Mc tool »

Hi , how much fluid did you putin there. If there is to much the forks wont fully compress ' :)
I wish I was young again............Id be heaps smarter than last time
User avatar
Giscard
Posts: 126
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Re: Front fork travel

Post by Giscard »

Good point. The amount of oil is the thing that is worrying me slightly. I filled the forks to the recommended 180mm from the top. However, the manual said "perform the oil filling with barrels at end of stroke inside the slidings and without springs and spacers. I took this to mean that the slider was pulled out as far as possible but I am now thinking that the slider should be pushed in as far as possible. Please can someone confirm which it is as I am starting to feel a bit stupid.
Mc tool
paso grand pooh-bah
Posts: 1957
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Riverton New Zealand

Re: Front fork travel

Post by Mc tool »

Measure fluid level with forks compressed and springs and spacers removed . :)
I wish I was young again............Id be heaps smarter than last time
User avatar
Giscard
Posts: 126
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Re: Front fork travel

Post by Giscard »

Thanks McTool. You have confirmed what I eventually thought was the problem. When I was adding the oil to the forks that I had extended, I thought this is a lot of oil. It's a pity I didn't stop and reread the instructions. I still think they are ambiguous, but that's down to me. :banghead:
Onward and upward.
Looking forward to a much smoother ride.
User avatar
higgy
paso grand pooh-bah
Posts: 3369
Joined: Tue Jul 29, 2008 9:50 pm
model: 907 I.E.
year: 1992
Location: Hilltown,Pennsylvania
Contact:

Re: Front fork travel

Post by higgy »

:banghead: unfortunately in most shop manuals some things are assumed as previous knowledge
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
Electrocuted Birds Are Bursting Into Flames and Starting Wildfires :roll:
88 750
90 906
92 907ie
Mc tool
paso grand pooh-bah
Posts: 1957
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Riverton New Zealand

Re: Front fork travel

Post by Mc tool »

higgy wrote: Fri May 23, 2025 8:32 am :banghead: unfortunately in most shop manuals some things are assumed as previous knowledge
Gets worse as you get older too , Im surprised at all the knowledge I've forgotten ......or only thought I knew......previously :D :lol:
I wish I was young again............Id be heaps smarter than last time
User avatar
Giscard
Posts: 126
Joined: Thu Apr 28, 2011 2:56 pm
model: 906 Paso
year: 1990
Location: Cardiff UK and Dordogne France

Re: Front fork travel

Post by Giscard »

higgy wrote: Fri May 23, 2025 8:32 am :banghead: unfortunately in most shop manuals some things are assumed as previous knowledge
So true. All my other bikes are from the 50's and 60's. With their fairly basic front forks, it is usually put in a certain amount of oil with no concerns about stantion position. Ah well never too old to make mistakes, and hopefully with advice, to correct them. :lol:
Post Reply