Chain adjustment

Beilby · Post by **Beilby** » Thu Jul 21, 2005 10:02 am

I feel horrifically noobish for asking this - especially as I've owned my paso for 8 years - but I am having trouble adjusting my chain.

Spot the non-mechanic, sheyar. I haven't needed to do it for the last year or so, and I am just stressing about the order of loosening things off because my mechanic has done it all up quite tight, and I've left it far too long to adjust it.

I've loosened of the end caps each side, but the axle bolts are looking immovable. Do I just turn harder? And, they are not a reverse thread, on either side, are they?

Hopefully at least my awesome display of ignorance has given some of you a chuckle.

fasterdammit · Post by **fasterdammit** » Thu Jul 21, 2005 1:31 pm

Ah, let's see ... I haven't done it on a 906, just my 750 but I believe their mostly similar? Somebody correct me if I'm wrong, but Beilby, you will know right off the bat if something in my description doesn't fly.

Now, if the 906's axle carry is just a slider in the swingarm, then nevermind, all this is rubbish, but it sounds like we're going to be looking at the same thing.

It's been a couple months, but as I recall, there are a couple bolts in the swing arm that hold the concentric in place. The concentric is the circular piece in which the rear axle sits. The rear axle is off-set from the center of the concetric, so that as you rotate the concentric, the rear wheel essentially moves around in a circle along the plane of the two wheels. Doing so can slightly later your rear end ride height along with (obviously) chain tension.

Anyway, loosening the concentric stay bolts should allow you to rotate the concentric in the swing arm. There is a socket large enough to accommodate the nut in the standard toolkit, but as I recall it was something like an 18mm or maybe larger? Suffice to say though, and I imagine especially if it's been a while, your best bet is to fashion some sort of lever to break free the concentric and rotate the whole unit. If it's been 8 years? :umm: ugh Just remember, bend at the knees, let your legs do the work. This isn't something you can do sitting down. Might want to have somebody hold onto the bike, too.

But once you've broken it free, it shouldn't be too difficult to rotate.

I seem to recall that there are two sizes of sockets you can use; the larger one is for turning the concentric, the slightly smaller one is for loosening the axle nut itself - not something you need to do if you're just going to adjust your chain or ride height. I'm thinking the concentric adjustment is on the left as you sit behind the bike looking forward, and the axle nut is on the right side. Caveat: I forget excatly - however the bike is out in the parking garage, so I will go check at lunchtime.

lceriani · Post by **lceriani** » Thu Jul 21, 2005 5:15 pm

I own a 750, but if the mechanism is the same I suggest you a little trick: the procedure described in the shop manual works well, but it's all FAR easier if the rear wheel is free to rotate.

Personally I use a home-made rear wheel stand, but before it I used to put something under the bike center stand to raise it enough to let the wheel rotate...

LC

Beilby · Post by **Beilby** » Thu Jul 21, 2005 5:15 pm

Hm, yes - so what you are saying is I do just need to get greater pressure onto the main axle bolts.

Yes, I have the eccentric (concentric?) axle setup you mention. On the right hand side there is a much smaller sized Allen key set inside the larger main bolt. I seem to remember that once I have loosened things off, I use that smaller inset Allen bolt to do the adjustment.

But the standard setup includes no reverse threads huh? I am worried that if I get harsh on the axle and force it I will strip threads by going in the wrong direction.

Beilby · Post by **Beilby** » Thu Jul 21, 2005 5:17 pm

lceriani wrote:the procedure described in the shop manual works well, but it's all FAR easier if the rear wheel is free to rotate.

Mmm, I would love to see this description. I have no manual of any sort.

With the bike on the centre-stand the wheel sure is free to rotate - or did you mean to say it is better if the wheel is not free to rotate?

lceriani · Post by **lceriani** » Thu Jul 21, 2005 5:26 pm

On my bike the center stand is not enough to let the wheel rotate... if on your bike it rotates, that's perfect!

(maybe my center stand doesn't work perfectly....)

you can find some shop manuals on the download section of this site:
http://ducatipaso.org/modules.php?name= ... load&cid=2

if you don't find your model, you can have a look at other Pasos...

LC

Beilby · Post by **Beilby** » Thu Jul 21, 2005 8:09 pm

Wow! Fantastic - what a great site.

My thanks to both of you.

lceriani · Post by **lceriani** » Fri Jul 22, 2005 7:54 am

Thanks should go to Mike... "keeper of this madness"!

mike · Post by **mike** » Sat Jul 23, 2005 5:00 am

lceriani wrote:Thanks should go to Mike... "keeper of this madness"!

hehe thanks and we got more goodies coming... recently donated was a 906 shop manual! now we'll have all the goods

now if only i had time to get to the 'fiche printer we'd have 906 and 907 parts catalogues too!

qldman36 · Post by **qldman36** » Sat Jul 23, 2005 1:44 pm

Mike,
If you have the capabilities to copy fiche cards to format that you can post in archives,i have 750n906,907 paso and most other pre'92 model Ducs that i could lend you to copy.
750 is Europa dated '88,907 '91,'92.906 of course only one year'89.Have 750 F1,851,888,900ss,superlight,etc,etc.
PM me if of interest,Carl

Post by **jcslocum** » Sat Jul 23, 2005 3:15 pm

CAUTION!!

If this is your first time doing this adjustment do NOT overtighten the chain. Doing so can have disastrous results.

It much better LOOSE than tight.

mike · Post by **mike** » Sat Jul 23, 2005 6:21 pm

qldman36 wrote:Mike,
If you have the capabilities to copy fiche cards to format that you can post in archives,i have 750n906,907 paso and most other pre'92 model Ducs that i could lend you to copy.
750 is Europa dated '88,907 '91,'92.906 of course only one year'89.Have 750 F1,851,888,900ss,superlight,etc,etc.
PM me if of interest,Carl

I have the capability, but it is VERY time consuming and costs $.20 per shot. Most big university libraries have microfiche printers.

I have USA fiche 1987, I'm not sure what the 906 and 907 fiches are have to dig 'em up in the archives.

steele · Post by **steele** » Sun Jul 24, 2005 11:17 am

What ever you do dont overtighten it

qldman36 · Post by **qldman36** » Sun Jul 24, 2005 3:14 pm

Mike,
Don't need nor want copy for myself,assumed by your wording that you did not have all three models on fiche for putting in archives.Was offering them to you to copy before i put the 19 Duc fiches i have on Ebay.
Carl