Is this Chain Length Right - Gen2

[AlanK]

Hi, so I took my bike to BMW dealer for service and MOT and have a few concerns when I got it back, not least ?150 for fitting chain and sprockets I supplied.

What is most concerning for me though is I supplied the brand new chain in box at 120 links as it comes, and they fitted this as was. My sprockets were -1+1 so not a massive difference expected but when I picked up the bike my chain adjusters are wound extremely far out and the axle as you can see is sitting a lot further back than it has ever been.

I counted 120 links but believe OEM is 118 - I have raised this with them but they want me to come in and speak to them as "there are aspects I should be considering rather than just the length so want to discuss this"

I am far from technical so its going to wash completely over my head hence this post - to me the wheel should be a lot further in and whilst ratio change will have affected this slightly so it wont be exactly where stock sits, it shouldn't be this far out on brand new chain.

Any pointers would be massively appreciated - should I accept Im in the wrong and this is ok or am I right to be concerned?

 

[bmwbadboy]

I've been using 120 chain on track since day 1. No issues what so ever. Some people here used 118 but found the bike wheeling too much out of slow corners.

What is your concern exactly?

 

[AlanK]

This is just for road use and its a brand new chain etc.

I just expect it will stretch some and will be very soon at the point it cant go any further. Given the chain that came of after 10K was a good 1-2cm further forward than this its looks wrong to my untrained eye. Then there is the aspect of what if any difference this change in wheelbase will make for road riding but that is probably getting into details I may well never notice.

 

[Flyingscotsman]

The gen 2 chain is 118 links

 

[alex]

118 is std.
604-608mm of swingarm length is ideal.
The longer the swing arm the more stable the bike should be, but at the cost of nimbleness.

If the length is in that ballpark I'd not worry.

- Alex

 

[AlanK]

The gen 2 chain is 118 links

yeah so I gather which is again why I think they have stuffed up this job - but on the phone to them they are saying there is more to it than that due to my non standard gearing and I need to take into consideration bla bla bla bla -

I think it sounds like waffle and I have a chain that has no room for adjustment due to said waffle but want to be sure of myself before going up. Certainly the axle position suggests there is a waste of 50mm space in front of it when it sits like this from new.

 

[oldwobbler]

If you are going to run out of chain adjustment before the chain needs replacing then its wrong.

 

[Monners]

120 links makes for a much better bike. It's true that stock is 118 but my advice would be to stick with 120. If you go -1/+1 and keep the 118 links you have slightly shortened the wheelbase which the BMW definitely does not need. Even at 120 the bike turns like a 600 so there's no need for the short wheelbase and it will make it friendlier at maximum revs.

 

[AlanK]

I doubt I would notice the difference so happy to go with recommendations from people that can actually ride, unlike me and my 450 miles last year :drunk:

Struggling to actually measure the swing arm length accurately to see what it actually is

Just will it actually last before I run out of adjustment given how far back it is. Not sure how much a 3d chain will stretch in use.

 

[imperialblue63]

ive just fitted new chain and sprockets on 2014 model and my adjusters sit just about on line 3 to me yours looks wrong mine was all standard links and sprocket teeth,my axle nut is a lot further forward,not sure wether this helps any .

 

[Monners]

Its fine @alank . What the dealer is trying to explain to you is actually good advice for your gearing, the bike is better and easier to ride with the longer wheelbase. Many dealers will just put the standard link on because they dont want to deal with all the questions from customers who have been freaked out by answers on the internet. The ironic thing is everyone has an internet spaz out about a non standard chain length that makes the bike easier to ride and yet they are happy to change the gearing to something non standard with the stock chain length and give themselves a shorter wheelbase that makes the bike less stable. The shorter wheelbase is quite rideable and many use it but the BMW works best with the longest wheelbase you can manage with whatever gearing you are using; usually 16/44 or 43 (stock is 17/45). Its worth baring in mind that the superbike racers often add even more length to the swingarm to get more wheelbase to help handle the power.

 

[alex]

Just remember that will a longer lever you work the spring harder.

 

[AlanK]

Cheers guys - if its not going to end up with me needing a new chain in only a few months then will leave well alone.

 

[Gobert]

Its fine @alank . What the dealer is trying to explain to you is actually good advice for your gearing, the bike is better and easier to ride with the longer wheelbase. Many dealers will just put the standard link on because they dont want to deal with all the questions from customers who have been freaked out by answers on the internet. The ironic thing is everyone has an internet spaz out about a non standard chain length that makes the bike easier to ride and yet they are happy to change the gearing to something non standard with the stock chain length and give themselves a shorter wheelbase that makes the bike less stable. The shorter wheelbase is quite rideable and many use it but the BMW works best with the longest wheelbase you can manage with whatever gearing you are using; usually 16/44 or 43 (stock is 17/45). Its worth baring in mind that the superbike racers often add even more length to the swingarm to get more wheelbase to help handle the power.

In my short period of owning a S1000RR I've found the 604 > 608 I seen quoted in a few places too short. I've tried both 16/46 to get in the 604>8 range and 16/45 and the bike feels easier to ride with the longer wheelbase. I tried 16/46 at Oulton yesterday for a couple of sessions and it was more of a handful than normal. Changed to a 45 rear and I was faster right away with less drama - even managed to knock over a second off my PB.

 

[Monners]

Cheers guys - if its not going to end up with me needing a new chain in only a few months then will leave well alone.

Just to add - if you did want to shorten the chain; all you/the dealer would need to do would be to grind those extra links off and put a new chain-link in which are only a few quid.

 

[AlanK]

So back at dealer today to be told by a other mechanic that it is far too long for a new chain and should be shorter. Excuse now is they wouldn?t cut a customers chain but no answer to why they wouldn?t ask before just sticking it on.

 

[AlanK]

I guess my question is how long chain will actually last before it can?t be adjusted anymore?

 

[Flyingscotsman]

You could always cut a link out if and when you run out of adjustment.

 

[Monners]

You have a 16/46 sprocket set (stock is 17/45 for gen 2/3 and 17/44 for gen 1). This is a really big rear sprocket so you will never run out of adjustment. I have a 16/43 with 120 link chain at the moment and whilst it is borderline after three days max revs at Mugello, it has not stretched out of adjustment range.