Sylvie’s New Groove – Part 1 – CBF250 Chain Tensioner And Sprocket Replacement

I got a parcel last week, far earlier than expected.

Inside the outer bag was a tough bag.

Inside the tough bag were the new chain and sprockets I had ordered from the UK only a few days earlier!

I checked the spare rear wheel I had for Sylvie and found the tyre was more worn than the one I was thinking of swapping it with!

I gathered every tool and spare part I though I would need and got ready to remove the chain, rear wheel and right chain tensioner. From the left, spanners in 24mm, 17mm, 14mm and 12mm sizes, a spare chain tensioner, small socket wrench with an extension bar, 10mm and 8mm sockets, small and medium standard screwdrivers, new Ognibene o-ring chain, new AFAM front and rear sprockets in standard sizes for the CBF250, WD 40, Inox, lithium grease, my new chain tool and Vernier calipers.

I started by loosening the rear axle nut.

The 24mm spanner was used on the axle nut.

The 17mm spanner was used to hold the bolt end of the axle.

After slacking off the axle nut, I unlocked the steering and straightened the handlebar.

I then put Sylvie in neutral and raised her onto the centre stand.

Next I used the 14mm and 12mm spanners to loosen the chain tensioners.

I turned the rear wheel until the master link was visible and prised off the clip with the medium screwdriver.

I took the faceplate off and pulled the link out from the back.

I gave the old chain a cursory clean to inspect the overall damage.

After cleaning off the worst of the grime, the chain seemed to be in relatively good condition apart from the obvious wear near the ends where the broken master link had been.

I cleaned the outside of the front chain cover with Inox lanolin spray as it is kinder to plastic than WD 40

Next I removed the cover with the 8mm socket and extension bar.

I put the cover aside with its bolts and the mounting bracket under it.

I put Sylvie back into first gear and cleaned up the front sprocket and the outside of the transmission with more Inox spray.

I switched over to the 10mm socket.

I then removed the front sprocket mounting bolts and rotated the retaining plate to to get it past the splines on the drive shaft.

After removing the sprocket I cleaned up the rest of engine casing outside the transmission.

The old front sprocket had a fair amount of wear.

I unwrapped the new sprocket for a comparison before fitting it.

Fitting was of course a reverse of the removal process.

While replacing the mounting bolts, I realised I’d forgotten an important tool when laying out all the tools before starting.

This was of course the small torque wrench.

I set the torque to the specifications from the manual and tightened the bolts.

I set about removing the rear wheel.

With everything loosened, I realised I had forgotten to remove the nut for the rear brake lever. The right chain tensioner had some badly stripped thread too.

I screwed the nut back onto the connecting rod for the brake pedal so I wouldn’t lose the spring.

I removed the rear brake assembly from the wheel and inspected the shoes for wear before placing the wheel on a soft rag with the sprocket facing up.

I realised at this point that i had forgotten another important tool – A large socket wrench, extension bar and 17mm socket.

I loosened and removed the nuts in a star pattern, then removed the rear sprocket.

The wear on the rear sprocket wasn’t as bad.

As with the front sprocket, I unwrapped the new rear sprocket for a direct comparison before fitting it.

I removed the right chain tensioner from the swingarm.

Here it is with its replacement below.

I decided to clean up the rear brake lever connecting rod while the wheel was off.

While I was at it, I cleaned up the right side of the swingarm.

Much better!

Here’s a closer look at that stripped thread. Pretty nasty!

The replacement part ready to grease.

I coated the replacement with a good layer of lithium grease on both sides.

It slid in easily and held itself in place quite nicely.

By this stage it was getting close to dinner time, so I sped things up a bit.
Returning to the rear wheel, I realised I had forgotten yet another tool – my large torque wrench!

I fitted the sprocket, then set the torque wrench to the specified torque and fastened the nuts in the same star pattern I’d loosened them in.

I quickly cleaned up the rear axle bolt.

I cleaned the left side of the swingarm, reassembled the rear wheel and moved it into place.

I cleaned and re-greased the left chain adjuster and slid it back in.

I greased up the rear axle bolt liberally.

I realised I’d almost forgotten to reconnect the rear brake lever rod.

After sorting out the rear brake, I pushed the axle bolt through.

Finally, I replaced the bracket for the wear indicator and moved the bike under cover again.

At this point I called it a night and went to buy something for dinner.

I got the chain fitted the next day, but I will cover that in next week’s post!.


Filling In The Cracks – Work On Khaleesi Nears The End

This week, I finished up most of the work on Khaleesi.

I started by cleaning up the shed and sorting the pile of old parts from Khaleesi

I found my J B Weld and mixed up a small amount.

I filled the cracks in the bottom of the engine casing and put a thin layer around the bottom to keep the cracks from spreading further

I checked the charger and found that the connector was connected to a circuit that had  some sort of overload that didn’t work with my charger, so I took the side cover off and attached the trickle charger’s clips directly to the battery.

Finally I tightened the front sprocket nut to the specified torque and replaced the front chain guard.

I didn’t have any suitable oil to top up the lost oil, so I’ve let Khaleesi’s owner know and he’ll top it up.

The two remaining tasks are to to tighten the gear shift lever bolt and loosen the chain a little and she’ll be picked up next weekend.

That’s all for this week – hopefully I’ll have some time to work on my own bikes again in time for next week’s update!

Progress On Khaleesi’s Front Sprocket At Last!

This week, I got Khaleesi’s old chain from her owner so I could temporarily fit it and hopefully get the front sprocket off.

I lined up the chain on the rear sprocket so I could temporarily fit a spare 520 master link.

I fitted a clip-style master link without the clip just to hold the chain in place but forgot to take photos of that step. After a lot of swearing while putting most of my weight on the rear brake while trying to use a breaker bar on the opposite side of the bike, I decided to  liberally apply WD40, set my large torque wrench to the specified torque setting and give it one last try. To my surprise, it worked!

With the nut finally loosened, I removed the chain again.

The nut was next, followed by the retaining washer and the sprocker itself.

I put the parts aside until I was ready to fit the new sprocket.

With the sprocket removed, I set about fitting the replacement external shifter cover.

I then replaced the clutch lever.

Comparing the old sprocket with the new one, there was a world of difference in terms of tooth wear. Also noticeable is the difference in size, as the new sprocket is one tooth smaller.

I fitted the new sprocket and finally added the small plate on the bottom left of it .

I still need to check under the engine and make sure the crack doesn’t appear likely to be causing any other issues before filling it with some J B Weld.

After that I’ll need to remove the rear wheel, fit the new sprocket to it (or the original wheel if the chain doesn’t have enough clearance form the tyre), put the new chain on torque the front sprocket nut completely.

I’l also connect a charger to the battery and top up the oil if I have any suitable oil before she goes back to her owner.

That’s all for this week, hopefully I’ll have most of this finished and can focus on my own bikes again after next week!

Khaleesi’s Sprocket Refuses To Budge And Sylvie Gets A New Footpeg

This week, I attempted to get Khaleesi’s front sprocket off with an old o-ring chain between the sprockets. I couldn’t fit the chain fully, as it was a little shorter than the length needed.

I had discussed my suspicion that the o-ring chain wasn’t likely to fit with Khaleesi’s owner and we’d decided against opening the sealed bag for the replacement chain in case it turned out the rear tyre was too wide. This turned out to be a wise choice, as there was absolutely no clearance between the old o-ring chain and the tyre.

I had no luck whatsoever with getting the front sprocket off, even with the old chain on the sprockets and the rear brake applied as hard as I could manage. As I don’t own an impact wrench and I’m not sure about the extent of the damage indicated by the cracked outer side of the bolt hole for the left side engine cover I discovered last week, I’ve advised her owner that he’s better off taking her to a qualified motorcycle mechanic.

Sylvie’s rear footpeg was looking a bit bare, so I had been looking forward to receiving the replacement parts for it.

The parts arrived, so I unpacked them ready to fit on the footpeg.

I didn’t realise when I ordered them that I’d  missed the plate at the end closest to the bike. The pillion pegs don’t get much use at the moment anyway, so I’ll order one with my next parts order for her.

With the new rubber cover fitted, the footpeg should at least stay in the folded position a little better!

That’s all I had time for this week. It’s my baby daughter’s first birthday next week, so I may not have free time for bike work. If that turns out to be the case, I’ll see if I can write a post about the work I did on my compressor recently that I’d intended to cover in a bonus post I forgot to write.



Swapping A Footpeg And Work On Khaleesi Continues

Since the replacement parts for Sylvie’s footpeg hadn’t arrived and I needed to keep riding Sylvie, I checked the pillion footpeg on the same side and found the parts were all the same. I decided to swap them over, so off they came!

I fitted the parts to the front footpeg and folded the rear one up and out of the way again. I’ll fit the new parts to the pillion peg when they arrive.

Khaleesi’s owner brought over the spare parts I’d been waiting for, so I unpacked the rag from the external shift mechanism and inspected the area where the replacement cover needs to go.

At first glance, everything looked ok.

I compared the old parts with their replacements.

On closer inspection, it looked like there was some minor damage to the engine casing I hadn’t previously noticed, but not enough for concern at this stage. I’ll make sure I let the owner know and re-check the bottom of the engine for evidence of oil leaks.

I started fitting the parts. I had put the new gasket in place before I realised that I needed to remove the front sprocket before the replacement cover place will go on.

This turned out to be somewhat more difficult than I’d expected as the engine turns over when I tried to unscrew the mounting nut, so I took a break for the evening and will consult the manual before giving it another go.

I will be fitting a new chain and sprockets on Khaleesi too – hopefully I’ll have an update on that next week!

If my replacement footpeg parts and bearing kit for Sylvie arrive next week, I may have a few busy weeks ahead…

Organising The Pegboard And Starting On Khaleesi

This week, I continued organising the shed so I could get to my spanners and made another timelapse video in the process.

Here’s the shed from outside before I started.

A better view of the organised pegboard.

I found a few stray tools that don’t belong on the pegboard – some JIS screwdrivers that belong in the toolbox and a cheap set of spanners I don’t use on vehicles due to poor quality.

This was the mess on the floor in front of the bikes.

I had left a space for this spanner on the pegboard, as I knew it was somewhere nearby!

Much better!

Sockets in the box of bolts? This is what I end up doing when it starts raining unexpectedly!

This bolt had escaped the box altogether!

Another socket out of place.

With the wayward sockets out of the bolt box I finally was able to close it again.

The stray socket was reunited with is siblings.

More random bits and pieces on the floor.

The bolt box was relocated to the bench without losing the rest of its contents and the side-cutters and sockets left on top of it until they find a more permanent place.

The inside of the shed was slightly more easy to get to again at last!

I even looked a little less cluttered from outside compared to when I started!

With the shed more organised, I started looking more closely at the damage on Khaleesi.

The plates below the front sprocket came off first.

First was a single JIS screw that needed my large JIS driver to remove.

The other mounting bolts were 8mm.

Once the plates were removed, I disconnected the Neutral switch lead connector and the 8mm mounting bolts.

With the bolts removed, the larger part of the cover came straight off.

The part that had broken off was held on by a 10mm nut.

The nut wasn’t all that was holding it in place though. The oil seal around the selector shaft was badly bent out of shape and unusable.

With the oil seal out, it still wouldn’t move!

Some gentle persuasion with a ball peen hammer and a small pry bar soon took care of that.

I don’t own a MIG or TIG welder and I’m not very skilled with my arc/inverter stick welder yet. I also don’t have any aluminium arc welding rods, so I didn’t attempt to weld these aluminium alloy parts back together!

Fortunately, it didn’t look like there was any internal damage other than to the gasket.

I put all the parts and tools aside on a clean scrap of cardboard in front of the bike lift so they are out of the way until the new cover goes on.

Finally, I covered up the remainder of the external shift mechanism with a shop rag.

I’m waiting on a replacement cover, sprocket and chain from Khaleesi’s owner before I can finish work on her, so that’s all for this week.

I’ll continue sorting the bike shed next week. Hopefully some of the parts for Sylvie I’m waiting on will arrive too!

A Chain And Sprockets For Sylvie

I got another parcel last week.


The new chain and sprockets arrived, with a catalogue from the seller’s company.

After checking my chain breaking tool, I realised it had seen better days.

The 520 pitch pin was burred and bent from the last chain I riveted and the spring I’d replaced the original with hadn’t fared well.

I de-burred the pin with my rotary tool.

After checking the pin was straight, I found a new spring.

I reassembled the chain breaker and prepared to remove the chain.


After locating the master link, I discovered that the old chain had a clip link, so the chain breaker wasn’t needed to remove it!

After removing the clip, I found I couldn’t pry the link out.

Moving the chain to a different position and WD-40 didn’t help.

So it was off with the wheel and there was room to move the chain a bit more freely.

A bit of brute force and the master link was finally freed up!

The old sprocket was next to go.

The new sprocket went onto the wheel.

Back on went the wheel.


With the rear wheel back on, the front sprocket cover was next to come off.

The front sprocket had definitely seen better days.

The new sprocket wasn’t going on the spindle without a good clean first!

Once the oil residue was cleaned off, the new sprocket went on.

I got a shot of the new chain with the old for contrast, then fitted the new chain.

The rivet link was easier to fit with the ends of the chain on the sprocket.

The o-rings were lined up and the outer plate put in place.

Then came the process of riveting the new chain. First up, I moved the master link to the bottom of the chain loop and pressed the plates together with the chain tool’s pressure plate.

I ended up switching between several different configurations to get the master link riveted.

FInally I managed to get a decent rivet on the chain without over-flattening the ends of the pins.

I cleaned up the rust and oil from the front chain cover.

The mounting bracket got a good clean too.

The cover went back on and I cleaned up the outside.

Here’s the new chain with the tension adjusted and rear wheel tightened .

Sylvie’s list got an update – I’ll revisit this in the next post.

My stepdaughter had been helping me clean up, so I got her to stand still long enough for a couple of quick post-cleanup shots. Note the oily hands!

I got a lot done this week, so will cover more in the next update.