Bimota Forum

[SpikeC]

Can anyone tell me what the static sag should be for a road going DB5R?
I am confused by the manual stating that the spring preload should be 6.5 mm. The rear of this bike feels awfully firm. My previous bike was a Ducati monster M1100S with an Ohlins on the back, and it was really stable butt also nicely compliant.
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Spike C.
Portland, Oregon, USA
2008 Bimota DB5R
1965 Triumph T100SC

[CNC]

I also found this data confusing... It is actual preload in the spring itself which is kinda hard to measure. You must unscrew nuts on rear shock and then start from position when nut starts to compress the spring. Bike must be lifted (spring released). But that gives you just factory starting point. So I set up the bike according "universal" approach:
- sag without rider 10-20mm
- sag with rider 25-40mm

This is measurement vertical from wheel nut to some point on frame. I used medium numbers (15/33mm) and it is perfect for me. If you are a little heavier, you'll be then somewhere around 12/37... and if lighter, you can set it softer 17/30. Test with your gear on (helmet, boots, leather...)
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Bimota DB7, Bimota DB5 Mille, Ducati 916, Ducati M900, Benelli Tornado Tre

[2bims]

I concur with CNC on that one,I use the 25-40mm range also, CNC has the Mille early Db5 which also has Ohlins front and rear same as Db5R as yours and mine Spike.....Back end should squish down when your on it for this compliant ride that youre talking about, notoriously the ohlins are set over hard drilling every bump on the road into your own rear end, but slacken off the preload adjuster on rear spring, with a suitable Ohlins ring spanner if you have one, and you'll find that you can get squish on the back end that still leaves the spring some tolerance to be able to compress to soak up bumps rather than be close to its limit on compression.....Or just be like me and carrying too much onboard weight meaning the spring always is doing a job.....I will teel you that both the front and rear units are better and more obliging to set up than the Marzocchi fronts and Extreme Tech rears fitted to the other Db5'Db6's...these dont seem to change no matter what you do with them....

[SpikeC]

Ok, I found that the length of the stock spring should be 150mm unladen, according to some charts that I found, so the starting point for preload should be a spring length of 143.5mm. That works out to 5 5/8" uncompressed, And after unwinding a bit that is where it's at. With just the weight of the bike on it is a hair over 14mm. I will need to get a helper to see just where it is with me on it. I have the original tool kit and it has a shock spanner, butt it is a bit too bulky to access the rings with the body work on, a spanner from an old BMW K1200RS works perfectly, tho!
I weigh just over 160# with street clothes on, so probably around 175 or so ready to ride.
Many thanks for the help with this!
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Spike C.
Portland, Oregon, USA
2008 Bimota DB5R
1965 Triumph T100SC