Best $46 mod...45T rear sprocket!

[bradvanhorn]

Originally Posted by fennell

Its slightly better than stock, and yes it can wheelie more but all humans have a handy wheelie control device on the end of their right arms Its still too tall with 18/45 imo.

The bike feels flat and boring to me with the stock gearing, the 17/43 (very similar to 18/45) was a little better, but still didn't feel like a thousand should, i was still disappointed in the difference from the 675.
Now with 17/45 it actually has proper punch like a big bike should.

Hmmm, I'm going to try a 45 rear (+2) first. I'm interested in trying the 520 conversion (to help the weight loss program) but I definitely won't do that until I've sorted the sprocket size preferences.

[lxtoploader]

Where is a good US source for a afam or renthal aluminum 44t rear sprocket? Thanks, Andy

[Herbus]

Well I've enjoyed reading this thread instead of doing work all morning. I was hoping to sanity check what I'm now planning to do...

Running an '07 S3, the chain and sprockets are well past their time so I'm thinking I move to a 18T (stock) front and 43T rear (which is stock for the later model S3's anyway). So this way I'm moving to "current standards". I also am not interested in having the wheel pop up on a whim in 1st and 2nd... a touch more pull (whether I notice it or not) moving from 42 to 43 will be enough for me.

Variables I can't account for are...
- The stock '07 chain is 106 links, so if I move from a 42T to a 43T is there a way to know what length I'll need?
- The later model S3's with the 43T also have a 190 profile rear tyre I think... I believe mine's 180... is having the 180 going to factor into the chain length I need?
- If the speedo is around about 6% high at stock, me moving to a 43T probably doesn't justify messing with the speedo calibration at all... my speedo will still be, what, 3-4% above actual speed... my odo will be a teeny bit off, showing less km's than I've actually done, but only slightly... is that correct?

I think I'll go with a 520 conversion too... not expecting any great change from it, but it sounds like a positive move and with the quality of chain/sprocket I'll get (DID, steel teeth etc) I don't expect I'll have any premature wear issues.....................

Thank You

[DEcosse]

Originally Posted by Herbus

...The stock '07 chain is 106 links, so if I move from a 42T to a 43T is there a way to know what length I'll need?

A general rule of thumb is 4 extra teeth, fit 2 links (you must fit links in pairs)
Simple way to think about it is that if sprocket has four extra teeth, the chain goes around approx 1/2 of the circumference on the sprocket, so in this case two extra teeth or two links.

For one extra tooth, you would need 1/2 a link's pitch in actual length - moot - std 106 will be fine
(I actually helped friend fit 45 to std 106 chain - it was close to the limit of adjustment but in spec - if changing chain also, definitely go +2 links)

The later model S3's with the 43T also have a 190 profile rear tyre I think... I believe mine's 180... is having the 180 going to factor into the chain length I need?

No

If the speedo is around about 6% high at stock, me moving to a 43T probably doesn't justify messing with the speedo calibration at all... my speedo will still be, what, 3-4% above actual speed... my odo will be a teeny bit off, showing less km's than I've actually done, but only slightly... is that correct?

You're counting wrong way - going to larger rear sprocket than stock makes error worse, not better.

[SpeedJunkie1050]

Herbus, if you're going +1 on the back you shouldn't need any more links if you buy a new chain.

Can anybody tell me whether a 108 link chain would be suitable for a +3 rear sprocket before i order it? (or should i be going for a 110 bearing in mind how much slack these S3's like?)
EDIT: DEcosse, you're good! Answering my question before i've even asked it! Thanks!

[Ben_]

Can confirm a 46T will not fit with standard chain; at least 2 extra links needed.

[outlaw]

Hi, if you dont want the front wheel to come up, why not fit a 19 front sprocket and a 42 on the rear, it drops the revs by 600 in top gear for motorway riding , i tryed it when i had a few long trips to do,, then went back to 18/45 to use around town,

[Tal]

Did the upgrade today..can't wait for warm weather..

[notowman]

I prefer -1 in on the front sprocket. Does anyone feel that does not accomplish the same thing?

[oldrnslwr]

I went -1 on the front also. $23 and 10 minutes, nice change. I didn't read all 30 pages of this thread, but it works for me. No clearance issues at all.