Dog bone leverage ratio?

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HisNibbs · #1 Post by **HisNibbs** » Thu Aug 23, 2012 9:31 pm

Any one done a comparason or has measurements on the Mile and Falco swing arm and linkage pivot points?

Reason for asking is that I'm now questioning whether when replacing the Falco shock with a Mille item, one should also use the Mile linkages.

My bike has the 2001 RSVR Ohlins and "long" dog bone linkages that go with it. It has always been on the firm side. I have just had the shock rebuilt at Rev's who also put a slightly softer spring in and I've had a chance to play around with things.

First thing I noticed when going back to standard shock and linkages was that there was more sag available and that there wasn't a lot of difference regarding firmness in the ride. Yes the blue shock was a little harder on the kidnies but what I realy noticed was the drop in ride height.

While getting the old bearings out the RSVR linkages I had a go with the Falco linkages and the rebuilt RSVR shock. Now that when first fitted had a lot of sag which I was comfortably able to reduce to 20mm or so with a further 15 to 20mm when sitting on the bike. Figures which off the top of my head are reasonable and the ride was noticably more compliant and certainly felt a realistic option for the future. I didn't try it two up but I recon it might be a little soft for spirited two up work. I then put the RSVR dog bone and linkages in this immediately hiked the ride height 5 - 10mm or so and removed nearly all Sag (maybe 5mm left). I backed of the Pre load to get 10 -12 mm with another 15mm or so with me on board. Definitely felt firm when I took it out.

I'm suspecting that the linkages are designed to work optimally with the swing arm and that the Mile ones are sub optimal when used with the Falco. Mind you if the relationship of the pivot points on the two arms are the same that theory'd be bollox.

Revs have offered me a set up session which I'd like to take them up on but It's a long motorway haul to get there and which linkages should I fit...

Oh and any one care to lend a swing arm removal tool at some point?

D-Rider · #2 Post by **D-Rider** » Thu Aug 23, 2012 9:45 pm

My understanding is that the Mille and Falco rear suspension geometry is essentially the same - this is why the mille stuff works on the Falco.
I've never taken the measurements myself but I believe it's true. The fact that the early milles shared triangles and dogbone with the Falco supports this too.

I know Mango runs his ohlins with Falco linkages but has had his shock re-sprung and re-valved to suit.

randomsquid · #3 Post by **randomsquid** » Fri Aug 24, 2012 1:11 pm

I have no idea at all about suspension setup, but a couple of observations.

Revs rebuilt a yellow spring shock for me and fitted a harder spring.
They fitted the shock with an age appropriate RSV linkage that I bought.
I asked him to keep the back the same height if possible as I have short, fat, hairy legs.
Even with the ride height adjustment wound off it is still higher than the falco setup.
He seemed really pleased with the way the back felt after he'd put it together.
I can't ride well enough to test the limits but it's a vast improvement.

#4 Post by **mangocrazy** » Fri Aug 24, 2012 9:01 pm

Hi Keith,

As Andy says, I run an '02 aftermarket RSV Mille Ohlins shock with Falco linkages (and a Falco swingarm). Initially I tried it with the RSV linkages but a) it was punishingly firm and b) the dogbone rubbed on my newly-painted hugger.

So I decided to try the road less travelled and make the RSV shock work with the Falco linkages. At first I went with what I assumed was the Blue Sachs spring rate - an 800lb/in spring. That was definitely too firm and just as bad (if not worse) than the RSV linkage setup, so I replaced it with a 700 lb/in spring which is just about spot on. It's taut and precise for solo use, and nicely compliant for two-up, even when 'pressing on'. I do have the remote preload adjuster version of the shock, which makes it very easy to adjust preload when switching between solo and pillion.

The next thing to get sorted was the valving. John at Revs put a Falco-specific valving setup on it at the same time as I had the 700 lb/in spring fitted. That worked well enough for me and Mrs Mango to do a 2000 mile round trip to the South of France with no problems at all.

However when we got back and I put some solo miles on it, it felt like the compression damping was still much too aggressive (something I've found is a characteristic of Ohlins shocks as delivered from the factory) and I asked John to drastically reduce the compression damping. This was done earlier this year and when it came back it felt just about spot on. John had reduced the compression damping by around 50% (or so he told me) and now it feels just about perfect. You can feel the bumps (but not get kicked out of the saddle by them) at lower speeds, but as you go faster it all just blends into a smooth yet precise sensation.

It has to be said that I put a set of Oz wheels on at the same time as I got the revalved shock back from John, so that will doubtless have an effect, and also fitted a set of Dunlop Sportsmarts (which are great). But the bike has now got to the point where I'm not thinking about fiddling with the suspension, but just enjoying riding it.

As for frame, shock and swingarm mounting points, I think what Andy says has the ring of truth. Early Mille and Falco used identical linkages/dogbones and the 01-03 Milles only used the revised linkages and spring rates/valving - no other geometry changes were made, so Falco and early Mille suspension is basically interchangeable, as long as you match it correctly.

HisNibbs · #5 Post by **HisNibbs** » Fri Aug 24, 2012 9:52 pm

Thanks for the replys.

It actualy felt very good with the Falco linkages and the Mile Ohlins shock. I'm not as heavey as some so it may not be an option for every one. I think I can get one of my daughters on board and just about fit the Falco solo "norm".

I'm back to the complete Mile shock and linkage set up and have backed off the compression damping a fair bit from the factory defaults John set.

Aladinsaneuk · #6 Post by **Aladinsaneuk** » Fri Aug 24, 2012 10:41 pm

keef is a slimmed down racing snake....

there is always one skinny bugger that makes the rest of us look fat !

D-Rider · #7 Post by **D-Rider** » Sat Aug 25, 2012 8:08 am

..... and there's always some lardy sod that makes the rest of us look slim ..... though I'm concerned that as I've not noticed who that is, I may fulfil that role ......

Aladinsaneuk · #8 Post by **Aladinsaneuk** » Sat Aug 25, 2012 6:15 pm

so many bullets.....