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deebee4
Joined: 08 Jan 2011 Posts: 266 Location: Netherlands
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Posted: Sun Dec 07, 2014 11:21 am Post subject: Steering damper on a db4 |
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After 10 years of track riding with the db4 and gradually beefing up the power of the engine, it's now time to fit a steering damper.
And that's only to keep the front end calm under heavy accelleration out of the turns. Never really felt the need for it, never experienced a tankslapper or nerviousity on the db4 on track nor road. Other Italian bikes (Guzzi, Laverda) did provide me with that non-desired happening in the past, however.
Now I've got a 120 mm stroke Ohlins R&T steering damper, but it still seems a bit short. The distance from the forks from one side to the other seems too much for a 120 mm stroke. I could limit the fork movement by adding material under the plastic stops, but I'd rather see how it's looking on a db4 with steering damper. I know that a lot of db4ie did have one fitted when they came from Rimini.
So could you please help me out with pictures of the fitments and dimensions of the steering damper (body and rod lenght and stroke lenght)?
Best thing for a fully faired bike is to fit the damper body to the fork leg, because of crash protection, but it seems that there's also a lot of setups with the body bracketed to the frame boss.
So I hope you can help me out on this.
Cheers! _________________ Track riding on a Bimota: FUN! |
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2bims
Joined: 03 Apr 2010 Posts: 7289
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Posted: Sun Dec 07, 2014 2:10 pm Post subject: |
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Hi Deebee4........I've tried in the past with my Db4 to fit a damper.....as you say though...if using the welded boss on the left side of the frame...and the predrilled fixing point on the left lower yoke....it makes for a LONG travel on the steering damper lock to lock....Ohlins do make a long travel damper with a removable bracket....so that you can also adjust its length for fitting purposes.....
I've been looking for a while for a long travel cheapish Ohlins...but always get Outbid...new ones being circa 300plus GBP....I tried a cheap (real cheap) Chinese import model...that was the right length of travel...but quickly and quite literally threw it in the bin....it made one direction of travel feel power assisted...and the other direction like the wheels were buckled.....
To be honest...with the original Antera wheels I always sensed and felt a nervousness, twitchy light feel on the front end at speed.....but when I swopped the wheels for Dymags it all dissappeared...and I've done without looking for a damper since...albeit thats an expensive fix..... |
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deebee4
Joined: 08 Jan 2011 Posts: 266 Location: Netherlands
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Posted: Sun Dec 07, 2014 2:47 pm Post subject: |
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2bims wrote: |
Hi Deebee4........I've tried in the past with my Db4 to fit a damper.....as you say though...if using the welded boss on the left side of the frame...and the predrilled fixing point on the left lower yoke....it makes for a LONG travel on the steering damper lock to lock....Ohlins do make a long travel damper with a removable bracket....so that you can also adjust its length for fitting purposes.....
I've been looking for a while for a long travel cheapish Ohlins...but always get Outbid...new ones being circa 300plus GBP....I tried a cheap (real cheap) Chinese import model...that was the right length of travel...but quickly and quite literally threw it in the bin....it made one direction of travel feel power assisted...and the other direction like the wheels were buckled.....
To be honest...with the original Antera wheels I always sensed and felt a nervousness, twitchy light feel on the front end at speed.....but when I swopped the wheels for Dymags it all dissappeared...and I've done without looking for a damper since...albeit thats an expensive fix..... |
Thanks. For me it's just the landing of the front wheel back on the tarmac that can cause the dreaded tankslapper. Also some dampening will keep the front wheel better in the straight line direction when it's in the air.
No wheel swap planned, I'v got a Ducati 996 front wheel (lighter than the Antera) and a SB8R Antera rear wheel, both modified to fit and in black. The silver wheels are rain wheels now.
My lower yoke doesn't have the pre-drilled hole.... _________________ Track riding on a Bimota: FUN! |
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hnracing
Joined: 15 Apr 2012 Posts: 43 Location: Gothenburg Sweden
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Posted: Sun Dec 07, 2014 5:06 pm Post subject: |
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Here is the manual for Ohlins universal steering damper.
http://www.ohlins.com/Products/OwnersManuals/OM_07261-01.pdf
The kit SD166 for Ducati 1000SS is one with 140mm stroke. (SD004)
I use SD005 with 150mm stroke on my 1000SS trackbike.
/Henrik _________________ Monster 1100 -96 for the road / 1100SS for the track / DB4 new track project |
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2bims
Joined: 03 Apr 2010 Posts: 7289
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Posted: Sun Dec 07, 2014 5:09 pm Post subject: |
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Pre-drilled hole.......
Thinking about it I might be getting that wrong........Its the Db1 that has both a boss on the frame and a predrilled hole on the lower yoke......so I fitted a SD to that that works well........The Db2 comes with one already attached across the forks which works well....and the DB4 I had to source a fork clamp for the front fork to align with the frame boss..... |
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deebee4
Joined: 08 Jan 2011 Posts: 266 Location: Netherlands
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Posted: Sun Dec 07, 2014 6:01 pm Post subject: |
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Thanks, Henrik. That manual came with the steering damper I got to try if it would fit. But now it's digital and that's always nice. _________________ Track riding on a Bimota: FUN! |
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deebee4
Joined: 08 Jan 2011 Posts: 266 Location: Netherlands
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Posted: Mon Dec 08, 2014 2:20 pm Post subject: |
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Looking into the possibility for a setup like on the db2. That is in front of the forks.
Reading the db2 (corrected) naked thread I realise now why the Rinimi people did opt for a long steering damper frame mounted. The projector headlight builds to deep towards the headstock, occupying the place for a steering damper in that area.
Since I don't have a headlight fitted maybe I can fit one there.
But nevertheless I would like to get some pictures and data about of the steering damper on a db4. _________________ Track riding on a Bimota: FUN!
Last edited by deebee4 on Mon Dec 08, 2014 8:46 pm; edited 1 time in total |
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2bims
Joined: 03 Apr 2010 Posts: 7289
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Posted: Mon Dec 08, 2014 3:10 pm Post subject: |
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Did you mean DB2? And not DB4? DB2 has a nice sturdy bracket on the steering head for the main mount and then goes across to the right leg from recollection, with the mount for the SD bolt being at the front face of the Fork...makes for a nice short light stroke and damper being needed...and that can be adjusted.....side mounted Db4 on the existing frame lug means the adjuster end dissappears beneath the side fairing panel....so cant be adjusted quickly........The front instrument/headlight bracket assembly on the DB4 is plain black painted steel...as I looked to drill and fabricate a central hole on this bracket to fit a short ohlins damper I had on DB4...but wasnt sure about the structural strength of the plate steel.....Didi you want piccies of the DB2 arrangement? |
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2bims
Joined: 03 Apr 2010 Posts: 7289
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Posted: Mon Dec 08, 2014 3:36 pm Post subject: |
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Anyhow....heres some piccies of the DB2 arrangement...that also shows the damper with the deeper DB4/Vdue projector beam assembly in place...didnt bother the damper...it was the speedo drive from the clocks that got blocked initially.....
And on here you can more clearly see the right side mounted bracket on the fork leg....between upper and lower yokes...
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deebee4
Joined: 08 Jan 2011 Posts: 266 Location: Netherlands
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Posted: Mon Dec 08, 2014 8:54 pm Post subject: |
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2bims wrote: |
Did you mean DB2? And not DB4? DB2 has a nice sturdy bracket on the steering head for the main mount and then goes across to the right leg from recollection, with the mount for the SD bolt being at the front face of the Fork...makes for a nice short light stroke and damper being needed...and that can be adjusted.....side mounted Db4 on the existing frame lug means the adjuster end dissappears beneath the side fairing panel....so cant be adjusted quickly........The front instrument/headlight bracket assembly on the DB4 is plain black painted steel...as I looked to drill and fabricate a central hole on this bracket to fit a short ohlins damper I had on DB4...but wasnt sure about the structural strength of the plate steel.....Didi you want piccies of the DB2 arrangement? |
Thanks for the pics. If I decide to try to fit a short SD in the front I would give it its own sturdy bracket, not using the steel support (that did bend during the latest crash). If possible I could bolt the bracket to the two bolts holding the headlamp support to the headstock, thats sturdy enough.
A long SD on the LH side: if I can fit the damper body to the fork leg and the damper rod to the frame I can adjust it easily too. But I think I would need a 140 mm stroke damper and then fitting a long body to the fork leg is somewhat less elegant.
Looking at various db2's I'm starting to like them more and more.... _________________ Track riding on a Bimota: FUN!
Last edited by deebee4 on Tue Dec 09, 2014 7:30 am; edited 2 times in total |
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polyesterpig
Joined: 30 Jan 2011 Posts: 76 Location: California USA
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Posted: Tue Dec 09, 2014 4:58 am Post subject: |
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If you look at these pictures you can see where a damper mounts. One end clamps around the fork slider @ the other end attaches to the welded bung on the frame. I will try to measure my damper for you. _________________ 2002 Cannondale E440
2003 Cannondale Super Mono 440
(3) 2003 Cannondale E440R
2010 Ducati Hypermotard evo SP
2000 Bimota DB4ie BiPosto |
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