Francis. The 1987 CB125 TDE (the other dust seal)

[ffoy]

Hi guys.

Quick backstory here. My then girlfriend's daughter went very quickly from being a non-rider to a Yamaha 600 rider. She was only 17 or something when she embarked on this. Think it was less than a year later she was on the 'big' Yamaha.

Anyway. To start off she bought a 125 locally. Being experienced with bikes (ie have had loads in bits for 30 years and never even sat CBT) I was asked to give it the once-over.

I didn't know anything about the bike but it seemed modern to me (ie wasn't behind a shed rusting to bits) and I had a quick spin on it. She (well her Mum) coughed up £600 for it which seemed quite high to me and that was it. Well not quite. It sat idle for months while she passed test and I had to revive it once she was road-legal as it wouldn't start.

It wasn't great cosmetically having had the typical budget re-spray: Non-standard colour with an attempt at decals. The engine also had some shiny black paint on it. Not very well done.

So while she had it the only repairs I recall doing were: re-welding frame at centre-stand pivot as she got caught out by stand flapping loose one horrible winter night; making a side-stand from Honda parts (CM185 iirc); replacing speedo cable; swapping clocks-pod after she'd had a bump.

Next incident was she had a big bump and bent the front forks so Francis, as she called him, was retired to the base of the local bikers' club that she and her fiance were members of. Despite their collective wealth and knowledge of bikes no-one managed to get Francis mobile again and he was shifted to my barn to be resurrected.

Not long after that her mother and I split up and some time later he was retrieved by the owner and her man in a hired van.

So the rebuild never really got off the ground but I always wondered what would happen with it.

Well fast-fwd a couple or three years and the young couple are now married and off to live in NZ (possibly) so had to have a major clear-out and donated Francis back to me, along with a pile of parts she'd bought to rebuild him.

I picked him up on an old trailer I have and hope to get him roadworthy and perhaps re-spray the 'tinware'

I've got loads of pics from various stages of the story above but prob best to start with the ones of the day I collected it.



   

Francis returns to my barn after owner gives up on him

[ffoy]

 

Just spent over half an hour writing up post about front forks and closed tab by mistake. no auto-save on this forum so everything lost. I'm not writing it again so pics will have to do




Francis's forks are definitely bent altho the pics doesn't really show it. rusty too



there were a pair of better forks included in the project-bundle









sticker on fork-bottoms show same number KC1 003 but castings show KC1 L & KC1 R



original fork-bottom on LHS looks like it doesn't have the sticker but it is there under hastily-applied silver paint



not sure this wadding found under cover is OEM. maybe put there to hide weeping seal for MOT...




when fork-cap is unscrewed it pops off due to spring tension but not enough to cause injury



damper assy at bottom of stanchion can be removed from top once the part at the bottom is taken off

[Piki]

Hello mate, could you take the measures from the front fork decals?
If you do it, I will send a pair free for you
Best Regards.

[SteveD CB500K0]

Autosave is a long overdue feature and is available in V2.1 which is in beta test at the moment.

I agree that it will be very useful, having had exactly this problem myself many times over the years.

Steve

[Johnwebley]

that looks like you have been working hard !!

 carry on !!!

 but at 3am

[ffoy]

Hello mate, could you take the measures from the front fork decals?
If you do it, I will send a pair free for you
Best Regards.

Yes no problem Piki. Or I could peel one off and send you it...

[ffoy]

Autosave is a long overdue feature and is available in V2.1 which is in beta test at the moment.

I agree that it will be very useful, having had exactly this problem myself many times over the years.

Steve

Hi SteveD. I use quite a few forums and the majority don't have it so I should have posted chunks as I went along then added to it but there are a few forums where you only have a really short edit-window and as I'm new to this one wasn't sure if that was the case. Anyway now a day has passed I see I can edit no problem so will add to the original post but yeah good tip is to post then add to it if writing a lot of stuff 

[ffoy]

that looks like you have been working hard !!

 carry on !!!

 but at 3am

Lol. Well it was about midnight I finished up. Had a day off and went to the barn in afternoon to address a few hundred overdue tasks. Got there to find the electricity had ran out and the top-up key was at home so 4 miles home and 4 back I eventually got started. Spent daylight putting up fascia-boards on the gable end to stop Swifts nesting there (they are due back any day now!) then inside to start on Francis. Had no plans to stay as long and when I left to go home the car was iced-up but I quite enjoyed my time there. I only had 2 t-shirts and 3 jackets on to keep warm     

[royhall]

If its going to be a long post, I write it in a word processor then copy and paste it into the forum. I can also use spell check that way as it doesn't work for me on the forum anymore. It used to but stopped working after Steve did an update ages ago. All I get is a blank pop up box.

[SteveD CB500K0]

The edit window is 15 minutes so better to post and then edit if you get anywhere near that.



Sent from my iPhone using Tapatalk

[ffoy]

I've still got the 'modify' button on my post from March 7th. Need to change an of to an off actually

[ffoy]

Ok. Now I'll try and flesh-out the post I made the other night....

So the forks are clearly bent on the bike but Hannah (previous owner, looks terrible referring to her as 'she' in every other line  ) bought a good used pair a while ago and these were included in the bundle I trailered away. Still to get the keys and V5 actually 

Even tho the 'new' forks are pretty good they do have rust specks on the stanchions so should really be sent away for hard-chroming. This costs around £200, once you've factored-in P&P both ways. Now the first thing I really want to do here is get the machine up & running so putting on straight forks is a good starting-point but that means they need to come back off again later if they are to be re-chromed. I could perhaps send the original stanchions away to be done but I'm not sure if they can be straightened by the company doing the chroming, or if they can even be straightened at all. However a glimpse at John Webley's RD125 thread showed something about forks getting straightened so I'll need to have a better look at that.
 
What ever the case I decided to remove and strip-down the originals....   

This was pretty straightforward compared to when I tackled the forks on my 1976 RD250C. Main difference is that although the arrangement for securing the damper to the fork-bottom looks the same from outside it's not.

Both have a recessed Allen-headed (6mm) screw under the leg. On the RD250 when you turn this the damper assy spins round inside the leg so you need to knock-up a tool to hold the invisible part still. On the CB I just used the long leg of an Allen key as I didn't have a long bit for my ratchet. The screw is pretty tight so I put the key in vice and turned the leg.

Moving back up the leg you can prise out the rubber 'cover' that sits in the alloy outer- tube. I was surprised to find wadding under this.

Anyway once the damper assy is no longer fixed to the fork tube you can pull it out and then tackle the actual fork seal.

There are all sorts of views on this online. One guy on YouTube actually jacked the seal out by filling the leg with oil and leaving the stanchion in. He nearly wrecked his shed in the process but it's an entertaining video.

Some say using the stanchion like a slide-hammer will pull the seal out but I don't see how this would work on the CB as the stanchion and damper just pull out together.

To get the damper out the stanchion you remove the top-cap from the stanchion revealing the spring and once that's out the way the damper will slide out too but you need to take off the little alloy piece at bottom. This will fall off anyway unless you put the screw back in for safe-keeping.


   

[Green1]

My favourite tool for removing fork seals is a large flat bladed screwdriver with a piece of rubber hose over the shaft and then just work your way round levering it out.

[ffoy]

Hi Green1.

Yes that method is great if they aren't stubborn but if they don't come out relatively easily it's wise to back off and try something else as you can soon end up cracking the thin-walled lip of the alloy fork-leg around the seal.

Quite by chance I found a good tool to lever them out which didn't bear on the leg at all. The front of the tool hooked under the casing of the seal and the heel of it rested on the opposite side of the seal. Worked well for me on my RD250C but didn't have any luck with it the other night on the CB.

The problem seems to be that the underside of the seal-casing is curved (like a bearing race) and the tool isn't getting any purchase.

So today I'm going to try heat to expand the alloy then pop the seal out. I read somewhere that a heat gun or boiling water can be sufficient to do this.


leg of my home-made clutch-holding tool turned out to be ideal for popping out fork seals on RD250C


seal-casing is flat underneath so tool gets a grip once rubber is cut away

[Chris400F]

I couldn't get the seals out when replacing them on my 400/4.
Someone on here suggested a heat gun and it worked a treat for me, they came out easily then.