F650 General Chain and Sprockets FAQ

compiled & edited by Kristian #562
updated 22 Feb 2003 by Spakur#1117
Please read the Disclaimer before attempting any work in this FAQ.
Last updated: 16 May 2006, by Winter #1935

For other related FAQs:


The stock DID 520V on our F650's is a good chain, but fails in a couple areas. One is that according to DID's website the 520V is rated for an engine up to 400cc. The second failing of the chain is that it's wear resistance and tensile strength are nowhere near the standards needed for our F650's.

Consequently, above 10,000 miles the original stock chains will start stretching excessively and constantly be out of adjustment. When this happens it's time to change the chain. If you do this soon enough, you may not have to change the sprockets. But keep in mind, common good practice in motorcycle maintenance is to change the sprockets with installation of a new chain.

Note: Many old links to chain related websites have been removed from this FAQ simply because they were no longer working and "alternative" links could not be identified. If you have any website links for this FAQ, please contact the FAQ master.

Maintain Your Chain and Sprockets
Your chain (and sprockets) are exposed to all sorts of forces in all sorts of conditions. Your chain needs to bend around the sprockets, and over time the wear of metal on metal will change the shape of the sprockets. With proper care your chain and sprockets will last longer. The main advice is to ensure you lube your chain on a regular basis (every tank of fuel is a good time). On a regular basis also inspect the condition of your sprockets and replace them as required.

About Chains

Chain Specifications

You need a 520 type chain for the F650 model bikes. 520 means 5 eighths of an inch between the pins and 2 eighths of an inch (i.e. 1/4") between the plates. There are some good ideas in the Chain and Sprockets FAQ on how to ensure you have the correct chain length. You can also check the 15T and Other Sprockets FAQ for a table containing the number of links you will need on a bike with different sized sprockets. However, for a stock 47T/16T sprocket setup (on all bikes), you will require:

Most chain manufacturers recommend a maximum engine capacity for their chains. For the F650 you want a chain rated to at least a 650cc capacity, or a little bit more.

What Chain Size #'s Mean

by Mark #217, 14-Sep-01

The first two numbers in a chain size are the length and width of the link in increments of 1/8. So a 520 chain is 5/8 long and 2/8 (1/4) wide. It only gets a little complicated with say a 525 chain. This chain is 5/8 long and 2.5/8 (two and a half 1/8's) wide----which figures out to 5/16.

Can I use a 525 chain instead of a 520?

Chain Selection - Hints and Tips

Master Links: Clips or Rivets

This is a perennial discussion. The warnings on the packet always say a Rivet is better than a Clip. Some like them some don't. Opinions are below. Whatever you choose:

Note that both are called Master Links, one is a rivet type the other a clip type. Lots of people talk about master Links when they mean Master Clips as below.

Master Link type Opinions:

DID Chains

Model Link Type Max. Displacement * Comments
DID 520V O-Ring 400cc ** DID OE Equivalent
DID 520VM X-Ring 750cc Low Friction; Enduro/Off-Road Racing;
DID "Upgrade" from 520V
DID 520ERV3 X-Ring 750cc Racing version of the 520VM
with slightly more tensile strength;
Enduro/Off-Road Racing
750cc Ducati 520VL4 851/888 900SS/900SL 900 Monster only.
520MX ? 500cc NOT SUITABLE FOR F650

* The above maximum c.c. displacement is based on original manufacturers recommended chain size. Consult your owners manual.
** According to http://www.didchain.com/app.htm (no longer available) and http://www.accwhse.com/ZDID.HTM. Note DID's site does show the Chain is O.K. for up to 600cc engines for ATV's ONLY.

Tsubaki Chains

Regina Chains

Model Link Type Max. Displacement Comments
Regina 135 ORN6 O-Ring 650cc Regina Recommended for Classics and ST
Regina 135 ORS6 O-Ring 650cc Slightly higher tensile strength than ORN6
Regina 135 ZRH Z-Ring 650cc Specified as an upgrade for Classics and ST;
Regina Recommended for GS and Dakar
Regina 135 ZRD Z-Ring 900cc Slightly higher tensile strength than ZRH

EK Chains


Model Link Type Max Displacement Comments
EK 520SRX Quadra-X Ring 750cc / 90hp Value-Priced; available in colours
EK 520MVXZ Quadra-X Ring 750cc / 100hp Premium chain; available in colours;
Up to 160 links

Other Chain Options

Chain Details and Comparison

The following table shows the details of various appropriate chains. Please note not all appropriate chains are listed here - either because some details are not available, or it was too time consuming to fill the details in.

Model No. Pin
Weight Tensile
Index: Std.
Chain = 100
Inner Outer kgs/ lbs./
mm in mm mm mm 100 Links 100 Links kN lbs. Rivet
DID 520V 20.20 .795 10.16 2.00 2.00 1.52 3.36 30.4 6,830 O 2,350
DID 520VM 20.20 .795 10.22 2.00 2.00 1.54 3.40 35.8 8,050 X 3,220
DID 520ERV3 18.60 .732 10.22 2.00 2.00 1.50 3.30 38.5 8,660 X 3,100 -
Regina 135 ZRH 20.40 .803 10.23 2.00 2.00 1.64 3.60 34.8 7,822 Z ? ? ?
EK 520MVXZ (Not available at time)

About Sprockets

Sprocket Specifications

The stock configuration on all F650 chain driven bikes is a 47 tooth rear sprocket and a 16 tooth front sprocket. Steel sprockets will last far longer. For information on sprockets of other sizes, see the 15T and Other Sprockets FAQ. The BMW 16T front sprocket contains two rubber sides which act as a noise and vibration dampening system - aftermarket front sprockets will not have these rubber sides.

What about JUST Changing the Sprocket?

External/Internal SNAP-RINGS

by Flash #412, October '01

Classic/Pegaso Circlip observations

by Mtiberio (cugino pegaso)

I know some classics suffer this, but I was shocked as I pulled the front sprocket on my Pegaso yesterday to try a 15 tooth. this is what I found.

General Sprocket Comments

For opinions on Gearing Changes see the 15Tooth Sprocket FAQ. (Also contains other gearing Change Opinions).

Aluminium Sprockets

Kiernan Racing Direct Link
Sprocket Specialists

Sprocket Suppliers List

by Hombre sin Nombre, November '01

I asked the dealer if the sprockets were the same for both GS and Funduro. Guess what, they are! DHP #711

Care and Maintenance

Chain Lubrication - That Greasy Dirty Chain

by Steve #001. Opinions by Everybody, updated 8/22/99

Remember to lube the chain, especially after a long ride. Do this procedure immediately at the end of the ride. There are two basic schools of thought on chain care. One idea is to keep the chain under constant lube, as in a Scottoiler. Another is using lubricants like Chain Wax, PJ-1 Blue or Black label, or another marque's lubrication (Honda, Yamaha, etc).

Other riders feel that cleaning with WD-40 (or equivalent) after each ride is the answer. NEVER clean the chain with a solvent. Solvents destroy lubricants. Solvents get beyond the O or X rings and chains die quickly without lubrication. This is the Voice of Experience speaking!

Another easy way to clean the chain is to use PJ-1 Spray and Wash (see picture). It cuts the grime easily and using rag can to clean the sprockets, covers, and housings on your chain drive can make it even easier. Just rinse off those areas with water while your washing your F650. Once you've cleaned the chain, be sure to relube it with your preference for lubrication.

And while your down there lubing that chain, don't forget those chain rollers (upper and lower). However those are not true chain rollers since they do not run on bearings. Keep them lubed and free rolling otherwise that chain will eat through them rapidly. Look at the picture on the right for example of well-worn rollers. If you have a lowering kit, be sure to check the rollers since your suspension is in a different position.

So what is the Best Chain Lube to use?

by Kristian #562, 25/11/01

Like OIL, everyone has an opinion on The Best Chain Lube. So here are some of those opinions along with a few observations

Chain Lube Opinions

Inspecting Your Chain and Sprockets

More detailed descriptions can be found below on how to check the chain and sprockets conditions. However the following is a summary with pictures of how and where you need to check your chain and sprocket condition.

Inspection 1: Chain Tension

On the sidearm of your bike, or in the manual you will find a sticker indicating how much tension should be in your chain. This will depend on the bike you have. Grab a ruler or mark a piece of cardboard with the "range" specified for your bike. Hold that against the swingarm so you have a fixed point. Now simply push your chain upwards and make sure the distance it moves is within specifications.

Inspection 2: Pulling Chain Off Rear Sprocket

Try pulling the sprocket toward the rear of the bike. You should see less than half a tooth. (Note: This picture was taken on an Aprilia Falco. On the F650 the sprocket is on the other side). This picture shows a chain that is still okay.

This picture shows a worn chain / sprockets. Notice how the chain can be lifted more than half a tooth off the sprocket? Also notice the chain does not appear to have been lubed very often. In this case the chain and/or sprockets need to be replaced. You can find an interesting chain wear calculations on this website.

Inspection 3: Stiff Chain Links

Slowly rotate the rear wheel and closely watch the chain as you go around. Watch out for stiff links - these will show up as kinks in the chain. Stiff links will increase the wear on the sprockets.

Inspection 4: Uneven Chain Stretching

Grab a ruler again, and count off ten or so links on the chain. Measure that distance and note it down. Now rotate the chain around and measure another section of ten links, and repeat until you have four or so "samples" of the chain. If the distance varies too much between these measurements, you have uneven stretching of the chain.

Inspection 5: Sprocket Condition

Finally have a look at the sprockets. This sprocket on the left is a new BMW 16T sprocket. You can see the teeth are symetrical around the whole sprocket.

This is another new sprocket, a 15T sprocket. Again all the teeth are symetrical.

This is a worn BMW 16T sprocket. You can see hooked teeth. When you draw two lines relative to the sides of the teeth, you can see clearly the wear pattern on the sprocket. It is debatable if this sprocket was worn enough to replace.

This is a slightly worn 15T sprocket. Again you can see the hooked teeth and again the lines show the wear pattern on the sprocket. Note: This sprocket was installed around the wrong way! The flush side of the sprocket should be facing the engine. If the sprocket had been installed correctly the teeth would have worn in the opposite side more.

Checking the Condition of Chain and Sprockets

by Steve Johnson #1

The stock chain for the F650 is a continuous loop 520 o-ring with 110 links. The stock chain has no master link for easy removal. The 520 denotes the width; the 110 denotes the length, and "o-ring" means that tiny o-rings seal the inner workings of each link from outside moisture and grit while keeping in a lubricant. All this is important to know when removing, replacing, cleaning, lubricating, and adjusting the chain. F650 owners should take care to monitor the chain and sprockets. The chain connects engine power to the rear wheel and tremendous force is exerted on sprockets and chain. Sprockets and chain wear, and the rider should make frequent checks on the condition of these items. Exaggerated chain wear is dangerous.

Sprockets and chains show wear in obvious ways. The driving sprocket (countershaft sprocket) is the smaller of the two. A protective cover just above the rider's right footpeg is easily removed with an Allen wrench. The teeth on a new countershaft sprocket are upright. Think of each tooth of the sprocket as an isosceles triangle, equal on each side. Teeth on a worn sprocket will appear leaning to one side; the constant force of pulling on the chain at 6000 rpm and rapid accelerations does this.

The rear sprocket is a driven sprocket, meaning that the chain tugs against the teeth . The countershaft sprocket is a drive sprocket, meaning that it tugs against the chain. The material used to make rear sprockets is not as hard as that of the countershaft sprockets and wear is usually more obvious. Thinking of the teeth as triangles, look for wear on one side of each tooth. Note this wear in the picture.

A chain that is very worn is obvious. With the bike on the centrestand, rotate the rear wheel and watch to see if the chain alternately tightens and loosens. Look also for "kinks" in the chain. If you have adjusted the chain, test it for wear by grabbing the chain at the very rear of the rear sprocket. Tug at the chain. A new chain stays against the sprocket; a worn chain, though properly adjusted, can be pulled away from the sprocket far enough to see the "valley" between the sprocket teeth. The greater the wear, the more the chain can be pulled away from the sprocket. If the screwdriver in the bike's tool kit can be pushed into this space between chain and "valley" an immediate chain replacement is called for. An alternate way to test for a worn chain is to remove the chain, stretch it out on a flat surface, and attempt to bring the ends toward each other to make a semi-circle. A new chain stays nearly straight; a worn chain will make an arc of 120 degrees or more. Note the wear of the chain as shown in the picture.

A badly worn chain is a danger. If a chain "pops" as the bike is ridden, it means that the chain and sprocket no longer match and the chain is being forced to jump a tooth. Do not ride the bike under these conditions.

Although I do not do so, some riders suggest replacing both sprockets when replacing the chain.

NOTE: as of this date, 3-17-2003, I have nearly 29,000 miles on my chain - more than that on the sprockets. I expect that 35,000 is possible with the chain-lubricating system that I have devised. The chain is the best DID has to offer.

Chain Primer

by Shank, October '01

This is how I see the chain mess:

More on Chain Slack Measurement

In measuring chain slack, is the correct method to:

  1. Measure the distance from the bottom-most point of travel of the bottom of the chain to the top-most travel of the top of the chain or
  2. Pick a point on the chain - top, bottom or middle - and measure the distance from its lowest point of travel to its highest point of travel?

By travel I mean pressing the chain down and up, at the appropriate point on the chain, as in the repair manual and FAQ. Formerly shaft-driven minds want to know.

Dirt behind the Front sprocket cover

I got some dirt stuck up behind the front sprocket cover. I assume just taking it off to clean everything out is the easiest thing to do. Does the Touratech front sprocket cover alleviate this? It looks like it would help, but does it make a noticeable difference (like 60 bucks worth?) or should I just stick to taking the original off for cleaning? I cleaned and lubed the chain yesterday but when I spin the wheel backwards you can hear sand grinding under the sprocket cover...that can't be good. Runaway #1259

Chain and Sprocket Life

Refer also Survey Section for early chain feedback

An article that might prove interesting (although industrial rather than motorcycle chains). Chains for Drives and Conveyors - Lube 'Em to last. Marty #436

Misc Chain and Sprocket Stuff

Chain Tools

Removing the Countershaft Nut

by Colorado Bob

If you obtain a wrench like the one in the picture, insert the 6mm key into the alternator, let it push against the brake pedal so nothing moves when removing the nut.

Switch it to the other side of the brake pedal to install the nut to the proper torque. This is a very easy one person method.

I also use the tool shown from the BMW tool kit to keep the foot peg out of the way when removing the Sprocket cover. You still have to put a foot on the brake pedal, but again, it only takes one person who doesn't have to become a contortionist to perform this function. Just hold the peg up, and insert the round end of this tool into the hinge underneath.


Chain-Related Surging

by Muriel #582

About 3 weeks ago I asked for things to check to cure by 97 F650's hesitating (opposite of surging?) and got some great replies - use dry gas, use carb cleaner, clean air filter, put in in-line gas filter. It didn't seem like any of those suggestions helped - at least much.

That is because the hesitation was my first "early warning symptom" that my chain had a problem. Today I had a new DID VM X-ring chain and sprockets put on (along with a new back tire), and . . . no more hesitation :-) I appreciate all the input I got, but know I know to add one more thing to the list: have you checked your chain?

A chain with stretched and frozen (or freezing) links definitely causes those symptoms. When it happened to me I called it hesitating - the bike was holding back rather than surging forward. Immediate cure as soon as I got new chain and sprockets.

As a relative newbie and non-wrench, I wasn't all that familiar with chain symptoms other than check the adjustment (I wax it frequently) which I had been doing, but evidently not often enough. Now I know. See the Chain Replacement FAQ.

Chain Adjuster (Screws)

THIS BIT! (This is the one on the Classic. The GS seems to have more problems than the Classic)

Q: Am I the only one with this problem? I have talked to several other owners as well as 4-5 different BMW dealers, but no one has come across this before... I have had 3 (THREE!) chain adjusters (those little aluminum pieces at the end of the swingarm) snap off in under 2 months! The first two times it was on the right hand side (same side as sprockets) and buckled the swingarm in the process. 1st time - 200 kilometres after an Authorized BMW dealer installed new chain/sprockets/tires. This was the right hand side one that broke. Riding on dirt roads. 2nd time - 5 days after the first one was replaced it broke again, leaving me stranded in the Australian outback. I had to hobble along for 400 km to nearest bike shop. Now BMW did not have any more spares (3 week wait) so they authorized a new one to be manufactured by the local bike shop. This was the right hand side one again. 3rd time - When I got to Perth (closest dealer from where it happened 2nd time) I had a full service done (20,000km service) and new tires fitted. 9 days later, once again on a dirt road in the middle of nowhere, the left adjuster broke, leaving me with 1,200km of horrible dirt roads to get to BMW dealer (or any bike dealer for that matter!). This time it was the left had side one (opposite the chain/sprocket). This time BMW in Adelaide machined up a new part for me (BMW still did not have the part in stock!) The bike shop that fixed it the 2nd time thought the chain may have been too tight, but every time it has happened just after a BMW service! I had not touched or adjusted the chain since. I now have too wait until I get back to Sydney for BMW Sydney to see if they will warranty a new swingarm b/c of the damage caused... Anybody else have any problems? Please help! I carry a fair bit of luggage, but am still well under the max recommended weight by BMW. (Johan Rodskog - In Australia, heading for Asia)

Q. I stopped for breakfast this morning and before getting back on the bike I looked at my chain. To my surprise I noticed that the end cap on the swing arm had come loose and was jammed. It appeared that the end cap had rubbed against the sprocket and had badly bent the screw. It appeared that the end cap could have gotten jammed against a bolt on the sprocket and caused some real damage. The screw doesn't do anything except help align the rear axle when adjusting the chain tension. It has been my experience that the end cap is just hand tightened because if you try to do more then you may effect the axle position. Is this correct. This has been one of my frustrations in adjusting the chain tension. There are a lot of variable to get right with only two hands and four bolts to tighten is has been trying. What am I doing wrong? How do you tighten the end cap so that the tension bolt doesn't get loose after torquing the axle? (davemishalof)

Slide Rail Screws

by Kristian #562

So you've stripped the Screw to the Slide Rail//Swingarm Protector! (this is the upper one). Silly you. You probably thought you'd tighten them up when you replaced the Chain didn't you?

Well you'll be (sort of) happy to know it's happened to a few people, either those screws (Lower Screw) are too soft or the swing arm metal is.

So what to do? Well it's easy. Go down to the hardware store and buy a new one, that looks like this. New one.

But how do I get the old one out, it just keeps turning and turning.? Use a screwdriver underneath the head of the old screw and while prising it up, undo the screw. It should eventually "bite" and you can screw it out normally the rest of the way.

Chain Links