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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Mon Jan 19, 2015 5:55 pm Post subject: Tesi 3D front shock |
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I have a question about the front shock. I've picked up a low mileage Tesi 3D and I'm going through the bike before I ride it. It seems the front end has some sag when sitting with no rider and I wanted to know if the shock uses air or nitrogen. The manual says 9.5 Bar of Air is standard. Thanks for any help on this. |
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brian
Joined: 22 Aug 2011 Posts: 3769 Location: Australia
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Posted: Tue Jan 20, 2015 12:01 am Post subject: |
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I'm no expert but I'm guessing you could use either. An advantage of the nitrogen would be that it's lighter and it would probably be drier than air. _________________ '99 DB4 #104, '96 SB6 #1165, '94 DB2 J #652, '99 DB4 #088, '08 VTX1800, '93 ZXR750R M1, '95 ZXR750, '95 ZXR750 Race Bike, '94 CBR400rr NC29 Race Bike, '94 CB250, '49 BSA C10 250, '61 BSA A10 650, '89 ZXR750, '91 Ducati 851 |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue Jan 20, 2015 12:44 pm Post subject: |
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nitrogen does not contain the moisture and other contaminants found in compressed air so, as you drive and the shock heat up, nitrogen filled shocks will fluctuate less in temperature and pressure than air filled while driving. The bottom line is, you will still see pressure changes with nitrogen but, overall, your shock will run cooler and at a more consistent pressure than if they were filled with air.
And now some NASCAR info on the 2
NASCAR Information
Fundamentally; air, oxygen and nitrogen will all behave exactly the same in terms of pressure change for each 10 degrees of temperature change. However temperature alone is not the whole story.
Ambient air contains moisture, nitrogen does not. If moisture is present it contributes to a greater change in pressure simply because at lower temperatures water condenses to become a liquid. The liquid form of water occupies very little volume and contributes only a negligible pressure to the tire. But at higher temperatures, such as those in a running tire, water evaporates inside the tire and becomes a gas which increases pressure in the tire.
Ambient air contains about 21% oxygen. Oxygen’s smaller molecular size allows it to permeate through the rubber of the tire. By inflating with nitrogen, which is much less permeable than oxygen, the pressure changes due to oxygen loss are greatly reduced.
The racing industry is correct; nitrogen is more predictable. Because nitrogen is dry it has no moisture to contribute extra pressure changes with temperature. Because nitrogen permeates out much slower than oxygen pressure changes due to that leakage are almost eliminated compared with ambient air.
What I dont know though...is what is used in the manufacture process...what Shock is on the bike? Manufacturer and model? The technical depts of the company should be able to help.....
I have a mountain bike with a FOX Vanilla Float air only system...separate HP connector...that I merely pump to correct pressure with air....but its merely a mountain bike and not a Tesi Bimota
Is it fitted with a "pull rod Extreme Tech" Unit??
I've tied several times before to "find" the company.....but being italian its difficult....as theres also a US software company by the same name...this company sells their gear so you could try and ask them....or email Bimota directly?
http://bellissimoto.com/ExtremeTechShocks.html |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue Jan 20, 2015 1:03 pm Post subject: |
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Got it now....most internet providers "block" the website as its called "extremeshox"......so could be construed as more risque than it actually is
http://www.extremeshox.com/en/company-profile
info@extremeshox.com
Email contact addresses contained above....they mention Bimota...as their shocks are used on DB5/6/7/8/9/10 and the Tesi.....so ask them the question...maybe in English and Italian (use Google Translate) |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue Jan 20, 2015 1:11 pm Post subject: |
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And finally....there is a Download section on their website for a couple of the service manuals for the Shox...and in English....but There isnt a specific one for the "pull Rod" unit on the Tesi
Heres the link anyhow....and yup....they say use Nitrogen only....they do say that their dampers are all geared to have low heat impact for expansion....so presumably all Nitrogen charged
http://www.extremeshox.com/downloads/manula-cross-eng.pdf
What is useful...is that in the downloads it tells you how to adjust low and high speed units...as fitted to your DB6...using a 5mm allen key for the low speed...and 15mm wrench for the high speed.... |
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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Tue Jan 20, 2015 3:10 pm Post subject: |
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Great Info, thank you! I've sent Extreme an email just to confirm nitrogen. |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Tue Jan 20, 2015 3:32 pm Post subject: |
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No worries.....next effort would be to Bimota if no answer (Italian companies are reknowned for ignoring anythiing and anyone not from Italy)....I presume you can at least link a tyre pressure gauge to it to check the pressure as is? Would give you a reference whether its low or not.....The Extreme Shox manuals do seem to indicate checking the pressure before every ride...which sounds Extreme in itself |
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Macx2
Joined: 03 Dec 2011 Posts: 44 Location: Wide Bay Queensland Australia
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Posted: Tue Jan 20, 2015 10:49 pm Post subject: |
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Jbuffa,
I tried to find out if there was a tool for adjusting the preload on the rear shock but got nowhere so will you let us know how you go? There has been some previous discussion on the high pressure for the front shock but I çouldn't find it and I'm not sure which forum it was on but I will keep looking.
Ian |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Wed Jan 21, 2015 12:24 am Post subject: |
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Macx2 wrote: |
Jbuffa,
I tried to find out if there was a tool for adjusting the preload on the rear shock but got nowhere so will you let us know how you go? There has been some previous discussion on the high pressure for the front shock but I çouldn't find it and I'm not sure which forum it was on but I will keep looking.
Ian |
What type of rear shock do you have? If its the extreme Tech Upgrade shock with red anodised remote body and gold locking ring ...its easy....one of the holes on the outside of the locking ring has an allen key grub screw that you unfasten....it locks on the thread of the main body...then I use a small flat blade screwdrive...short shaft...where the shaft is just smaller than the diameter of the hole...and use this as a lever to rotate the locking ring to adjust the preload....evidently when happy....retighten the allen key locking screw |
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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Wed Jan 21, 2015 1:53 am Post subject: |
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Thanks Ian. I'll let you know what I find out on the front shock. The rear on mine has a simple 8mm nut that walks the spring seat up or down. |
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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Thu Jan 22, 2015 3:28 pm Post subject: |
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I contacted Bimota Spirit and Bob confirmed Nitrogen. He also told me to put some miles on before I made any changes because the Tesi likes a softer front end. |
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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Thu Jan 22, 2015 5:32 pm Post subject: |
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Just received this from Extreme. Thanks 2bims for the contact info
Hi
Yes is correct to fill from main body , the small reservoir is only for hydraulic/damping purpose , you can use air or nitrogen , nitrogen is better but air is ok.
Regards
franco |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Thu Jan 22, 2015 9:19 pm Post subject: |
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Great stuff....and nice to see an Italian company responding to questions....Bimota should take a leaf from that book..... |
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Jbuffa
Joined: 06 Aug 2014 Posts: 64 Location: United States
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Posted: Sun Apr 19, 2015 7:12 pm Post subject: |
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Well I was finally able to put together a Nitrogen rig to charge my front shock properly. I'll have to revisit my riding impressions of the Tesi because when I put a proper gauge on the shock, I had only 87 PSI (originally I used a friends gauge that was pretty old and must have been dropped or abused). The manual calls for 137 PSI as the Standard setting. Just with a push test in the garage it felt harder, but the main thing was the rebound was much more responsive. I'll be riding on Wednesday when the weather let's up here in Atlanta. It did feel as if the front end was a bit droopy but I've never ridden a Hub steering bike before. I think it should ride much better now.
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