1200Sport front suspension questions

[ohiorider]

Well, that's something! At least you were able to dig up the reference to the elusive 480ml quantity. I think this is a Marzocchi fork ..... maybe I'll try a post on their site (if they have one.) We're at a disadvantage, since as far as I know, the 1200 Sport is the only CARC Guzzi to use this particular set of forks. 80ml (2.7 oz) would add up to another 2 1/2 - 3" of fluid in each fork leg? Bound to make a difference.

Whatever happened to the good old days where there was a small plug on the bottom of each fork leg to drain fork oil? My old R100GS has that feature.

Tom, you'll have to educate me re: at what stage of the rebuild process is fork oil poured into the Sport's fork legs? I was too cowardly to dig into them myself when they needed seals, so I took them to a good Triumph/Ducati shop where I knew the lead mechanic. He's quite familiar with our type of fork and did a nice job of replacing the seals

 

[toma nova]

Tom, you'll have to educate me re: at what stage of the rebuild process is fork oil poured into the Sport's fork legs? I was too cowardly to dig into them myself when they needed seals, so I took them to a good Triumph/Ducati shop where I knew the lead mechanic. He's quite familiar with our type of fork and did a nice job of replacing the seals

Bob,

The fork oil goes in after the spring and spacer have been bolted to the pumping rod with the fork cap and that whole unit has been bolted to the wheel holder with the retaining bolt from underneath. The slider can be slid all the way down and you pour the new oil over the spring, then slide the slider tube up and screw the fork cap on.

Can you ask your mechanic how much oil he put back in, assuming he drained it to change the seal? It's possible he did not remove the cartridge or the retaining bolt and only unbolted the fork cap to get the new seal on, which would let him keep the old oil in.

Thanks,
Tom

 

[ohiorider]

Tom, I can ask, but probably a lost cause, since it was nearly 2 years ago when he replaced the seals. It might make sense to ask him how he does similar forks on other bikes (Triumph and Ducati.) He also wrenched on Guzzis for a few years, but has been 'out of touch' with them since the CARC bikes came out. He is more than willing to share information if I catch him at a slack moment (not often)

 

[GTM®]

There's only way to get the fork oil in per my earlier post, the assembly *has* to be fully together, with the tube slid down to allow the oil fill. Pump to insure the oil has made its way into the assembly, and air out. It's been a few years since I did a fork kit on a 12S. From memory, ~480-500 sounds about right. I also do 500ml in the Norge forks.

 

[toma nova]

Bob, I took your suggestion about contacting Marzocchi - a couple of phone calls and I at least have someone in LA sending an email to the factory for the spec. We'll see what Italy has to say early next week. I forget that it's often easier to make a call than spend time and effort on the intarwebs.

Todd, 480 is almost to the top of the slider tube (when it is slid down all the way with the entire cartridge assembly installed) - it just looks like too much oil and is nowhere near 120mm of airspace.

I'll road test it this weekend and report any unusual findings!

Thanks,
Tom

 

[GTM®]

Tom, let me save you the time. I know all of the players at (the now closed) Marzocchi U.S. location. They moved all of their bicycle product to Long Beach. The minuscule motorcycle stock went to Ty Davis. Don't hold your breath on getting a timely or decent response. The OEM Guzzi product lives in the hands of the factory, so Marzocchi will likely tell you to contact the dealer. I take it you didn't measure the drain oil?

 

[toma nova]

Tom, let me save you the time. I know all of the players at (the now closed) Marzocchi U.S. location. They moved all of their bicycle product to Long Beach. The minuscule motorcycle stock went to Ty Davis. Don't hold your breath on getting a timely or decent response. The OEM Guzzi product lives in the hands of the factory, so Marzocchi will likely tell you to contact the dealer. I take it you didn't measure the drain oil?

I talked to Ty and he said he'd email the factory. He didn't seem too fazed by the question...

Nah, I disassembled the right fork (good seal) by removing the retaining bolt first which resulted in oil spilling all over me and the floor. The left fork had been leaking for a long time so who knows how much oil I had washed off the caliper and wheel.

I've got everything buttoned up with 480ml and will go with that until either something hyro-locks or I see an accurate number. I'm not really that worried since now I know that forks are really pretty simple inside (mechanically simple, I know that tuning is a black art I'll never master!).

Thanks for the information,
Tom

 

[ohiorider]

Tom - thanks for fixing the Race Tech links on damper and cartridge forks. Think I'll print it out, sit back with a coffee, and try to learn something.

Bob

 

[ohiorider]

Tom, let me save you the time. I know all of the players at (the now closed) Marzocchi U.S. location. They moved all of their bicycle product to Long Beach. The minuscule motorcycle stock went to Ty Davis. Don't hold your breath on getting a timely or decent response. The OEM Guzzi product lives in the hands of the factory, so Marzocchi will likely tell you to contact the dealer. I take it you didn't measure the drain oil?

I talked to Ty and he said he'd email the factory. He didn't seem too fazed by the question...

Nah, I disassembled the right fork (good seal) by removing the retaining bolt first which resulted in oil spilling all over me and the floor. The left fork had been leaking for a long time so who knows how much oil I had washed off the caliper and wheel.

I've got everything buttoned up with 480ml and will go with that until either something hyro-locks or I see an accurate number. I'm not really that worried since now I know that forks are really pretty simple inside (mechanically simple, I know that tuning is a black art I'll never master!).

Thanks for the information,
Tom

Tom,

How is she riding with 480cc of fork oil in each side? Curious owners want to know! :cheer:

 

[GTM®]

Also, I found the spec on the Cali 1100 cartridge forks, and it specs out at 485ml, so that should be close.

 

[toma nova]

Tom,

How is she riding with 480cc of fork oil in each side? Curious owners want to know! :cheer:

Bob,

A quick one-hour ride last weekend showed no issues or problems. PR3s and EBC HH pads are awesome!! I'm out of town for a couple of weeks and it's blazing hot here, so no more testing until mid-August at the earliest.

I'll post some feedback after a few hundred miles.

Tom

 

[StewNic]

I'm not going (totally) crazy!

I found the reference to 480cc in the 1200 Sport 4V service manual.

However, that version of the SM still shows the B11 forks and calls for measuring the airspace - not an option on 12S forks since they're all bolted together before adding the oil.

So, I'd still like any guidance on which volume I should use. Trial and error is not a great option since removing the forks is time consuming.

Thanks for any wisdom,
Tom

Tom

Last year I changed the fork oil on my 2007 1200 Sport 2v and had the same dilemma.
I measured the quantity of oil that came out and it was approx 500ml per leg.
I refilled with 480ml per leg with Putoline fully synth 7.5wt and the forks work a treat, the difference of 80ml to mind would lock the forks out if incorrect.
I would suggest that 1200s 2v manual (regarding forks) was not updated from the Breva. The forks on the 4v are the same (or very similar) to my knowledge to the 2V and from my own experience is the correct quantity.

 

[dragonknee]

So, reviving a old thread and in the future where we are now this stuff is still all witchcraft and blackarts.
I guess what I'm wondering is if the Norge and Breva forks could be made to work better for cheaper on our Sports or that doing the cartridge forks on the 12s is the answer...