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Chain and sprocket replacement questions

romany

New member
My chain, and both front and rear sprockets on my 08 F650GS twin are shot. Over 40,000k so they owe me nothing.

I'd like to drop one tooth on the front sprocket to give me more low end power. Will my mid range power be affected? Top speed is not an issue as I'll never see it anyway.

If I drop a tooth on the front will I need to change the chain length?

There are a hundred chain and sprocket options out there in the wild world. Anyone got a preference? Or a good company to deal with? Aside from aesthetics is there any advantage to gold plated chains?

I'm currently on a medical leave so I thought, if I take my time and am careful, I'd make the swap myself. Never done this before so will appreciate all advice.

Thanks
 
Simple math, dropping from a 17 to a 16 will make about a 6% difference. So at any given speed and gear, the engine will be spinning 6% faster, it will pull stronger in every gear, but as you noted reduce theoretical top end. ( may actually increase real world top end)


Basic explanation is adding 60 rpm for every 1000 rpm. So where the engine was formally spinning say 5000, in the same gear and same forward speed it will be spinning 5300 rpm. Not really a big difference.

As far as chain NO same length. 1 tooth = 1 link, and links are in pairs.
 
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Changing the chain and sprockets on a 650/800 is very simple. Two bits of advice. Make sure you get the rear sprocket with the correct size bolt holes. Early models (probably yours) had 8mm rear sprocket bolts, later models used 10mm bolts. Second, loosen the rear sprocket bolts with the wheel on the bike and the chain still connected. They are pretty high torque and it's easier if you can lock the rear wheel in gear.
As stated, one tooth size in the front sprocket will not affect chain length.
Just FYI, I get my sprockets and chain from the Sprocket Center and can get a complete set for under $200. The two previous sets I got from them lasted 20K miles easily.
 
Nobody mentioned continuous chain factor :scratch Info I have is that "they" don't want a master link on anything over 60hp- been thinking about it but not sure if it's a real consideration. I bring this up because I think the swing-arm has to come off on a F800 to replace the "loop".
Perhaps someone has experience with this and can validate (or not) that "loop" theory.
OM
 
Nobody mentioned continuous chain factor :scratch Info I have is that "they" don't want a master link on anything over 60hp- been thinking about it but not sure if it's a real consideration. I bring this up because I think the swing-arm has to come off on a F800 to replace the "loop".
Perhaps someone has experience with this and can validate (or not) that "loop" theory.
OM

Total BS, there is a master link even in "continuous" chains, in fact every link is riveted in one way or another. Most modern "master" links are made to properly compress the o/x rings and can be done with a variety of tools, and just as good as a factory riveted chain.
 
Total BS, there is a master link even in "continuous" chains, in fact every link is riveted in one way or another. Most modern "master" links are made to properly compress the o/x rings and can be done with a variety of tools, and just as good as a factory riveted chain.

But there are two common types of master links - those that are riveted in place and those with a slide on clip. Insist on a rivet type and get the right tool to install the rivet type.
 
Total BS, there is a master link even in "continuous" chains, in fact every link is riveted in one way or another. Most modern "master" links are made to properly compress the o/x rings and can be done with a variety of tools, and just as good as a factory riveted chain.
Hmmm, I guess a clarification is needed- this is what is readily accepted as being a master link when you are talking motorcycle drive chains-

Nickel%20Master%20Link.jpg


I actually have the special tool used to compress the master link when reassembling an o-ring chain.
A quick search of whether to use/trust a master link on a high horsepower application/motorcycle didn't seem to help.
OM
 
Guess I should have clarified too, I haven't seen a clip type master link since my last trip to the farm store. As far as MC chains, I was under the impression that the clip link went the way of the dinosaur, when o-ring chains took over (about 1980).

So yes I agree, no clips.

BTW to peen a "rivet" type link, a set of new vice grips with sharp teeth, works really well. Most I have seen in the last 15 years have a shoulder to set the proper compression on the o/x rings, so you don't over compress them. A set of vice grips tightened with 1 or 2 teeth on the pin, then given a sharp rap with a hammer will nicely mushroom the pins
 
A buddy of mine puts a BB (from an air gun) on the end of the pin and smashes that with vice grips...
At least on the style link he was using it gave a good "flair" ...

I realize the clip style could disassemble it's self causing an issue, but in the many many years I've been riding dirt bikes I've never seen it happen. I've always put a blob of silicon caulk over the clip on my chains to keep them from snagging and closed end of clip in direction of travel.

I've not replaced the chain on my twin yet but wonder if staked is really needed. :scratch
 
Cool :thumb the main thing I was trying to point out to the OP is that it's a good idea to take a look at the actual routing of the chain. This is just in case the swing-arm had to be dropped out.
OM
 
I got ya...

The instructions for the F-twins does include the phrase "remove the swing-arm" ... :banghead

Only needed if you buy an endless (factory installed master link) chain. Unless you are buying it from a BMW dealer, the chain will have master link, thus NO swing arm removal necessary.
 
Only needed if you buy an endless (factory installed master link) chain. Unless you are buying it from a BMW dealer, the chain will have master link, thus NO swing arm removal necessary.
Not sure about that which brings me back to the 60 (maybe 50) HP "rule" on chains that are not endless.
My F800GS had a factory recall due to BMW being suspicious of the original chain that came with the bike. They replaced it with another endless (no master link) chain. I can't remember if they did the sprockets- the bike was low mileage- (3,800) when it went in for the recall.
All this has got me curious so.....from the Haynes manual Ref-18--
Drive chains for all but small bikes are continuous and do not have a clip-type link. The chain must be broken using a chain breaker tool and the new chain securely riveted together using a new soft rivet-type link. Never use a clip-type link, except in an emergency.


HTH
Gary
 
Clips:)

Cannot count all my miles of my past riding chain driven bikes with clip type master links. Never had one fail. That said, one MUST be really careful installing these clips and its not to be taken lightly, as it will eject itself quite easy if put on with haste! Also, one of our best among us has lost a chain in recent years. Paul will add to this maybe, as he spun one chain out the back riding down the highway on tour. Im not sure what he used, but has much opinion obviously with an experience in his past. ME, I will not be afraid of a clip link, as long as I AM the one putting it on. Im not trusting anybody to do this. Its old school, clip links, but still available and safe, imo. Know your skill set, before attempting this job and take good care doing it:). Randy
 
Cannot count all my miles of my past riding chain driven bikes with clip type master links. Never had one fail. That said, one MUST be really careful installing these clips and its not to be taken lightly, as it will eject itself quite easy if put on with haste! Also, one of our best among us has lost a chain in recent years. Paul will add to this maybe, as he spun one chain out the back riding down the highway on tour. Im not sure what he used, but has much opinion obviously with an experience in his past. ME, I will not be afraid of a clip link, as long as I AM the one putting it on. Im not trusting anybody to do this. Its old school, clip links, but still available and safe, imo. Know your skill set, before attempting this job and take good care doing it:). Randy

I have had four eventful experiences with clip style master links on BMW 650cc bikes:

1. Trip to Deming, NM - riding through El Paso. My F650 Funduro spit the chain. I found a shop, bought a master link, reinstalled the chain and Voni and I proceeded to Deming. This was a chain I had installed about 5,000 miles previously.

2. Trip coming home from Deming, NM the next day. Voni's F650 spit the chain going down I-10. Stashed the bike inside a ranch fence, rode two-up home, went back the next day with a new chain. The chain that spit the ML was installed at the Honda dealership in Lawton, OK on a trip from Albuquerque, NM to North Carolina. It had about 6,000 miles on the chain. Two bikes, different installers, not infant mortality, same trip within two days! What are the odds?

3. Summer travels on my F650 Dakar. We stopped to get a face shield in Sturgis, SD. As I was buying the shield, and Voni was buying some gloves, she asked me if I had a spare master link for my bike. I said "no" and bought a whole spare chain. Right at 24 hours later riding between East Glacier and Browning in Montana my bike spit the chain. This chain had been installed by the previous owner and was virtually new when I bought the bike. It had about 3,000 miles on it when the ML fell off.

4. Riding an F650 on a tour in southern Africa, I noticed one morning that the clip was off the master link but that the side plate was still in place. The tour guide did not have a spare link, or a spare chain. I had to improvise. The office at the lodge had a paper clip, so I used the paper clip to "figure 8" safety wire the side plate so it couldn't move sideways. I kept my eye on it and rode it that way for the next 6 weeks.

I know a lot of riders who tell me they have never had any problem with clip type links in many many miles. I believe them. I smile, then laugh, and then just say, "I have".

So I don't use them. If I had been paying attention to the chain when I bought the F650 Dakar I would have replaced the link with a rivet type. But I was busy dealing with the wrong cam timing, drilled air box, drilled cat-con, and a few other issues so never gave the new chain much thought. Had I noticed the clip style link I would have obtained some safety wire or a paper clip before I ever rode it 350 miles home. :)
 
I have one friend who lost a master link. Chain wadded up around the drive sprocket and destroyed the transmission on his Wee Strom. Expensive mishap since it required a 500 mile tow.
 
I have one friend who lost a master link. Chain wadded up around the drive sprocket and destroyed the transmission on his Wee Strom. Expensive mishap since it required a 500 mile tow.

I actually know a couple of folks who have had holes punched in the engine case when a chain lost a master link or broke.

On the F650 Dakar motor BMW has a stiff plastic sprocket cover that has an inner shroud around the sprocket, then an air gap, then the outer front of the cover. When my chain let loose it broke the inner shroud into chunks and cracked the outer cover. But this protected the engine case from any damage.
 
Hard to tell, but I don't think this bike is running a clip on the master link...

There really isn't any inherent weakness in a clip master link, it is as strong as any other link. The disadvantage is that the clips can become dislodged, allowing the side plate to fall off and thus the chain fails. The video is good to show what the chain goes through, and not just on a drag bike, any chain does that and think about riding the twisty's where the chain switches from slack to tension every time you accelerate and decelerate which can be several times per minute.

The clip does not actually have any forces on it from transferring power, but centrifugal forces as it rounds the sprockets and as the chain "whips" in normal operation gets g forces applied to it. That is why they are as light as possible. Also stones, sticks or other debris is always assaulting the bike and there is always that 1 in a million chance the clip can be dialoged.
 
On my other bikes I've always cleaned the oil and grease off of the master link and then slathered on a low profile blob of silicone caulk or sealant.
It peals off when needed and I figured it would help keep the clip in place.

I don't know if it helped or not, but in a lotta years of trail riding I've never lost one ...

(all lower HP bikes than what we are talking here though)
 
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