Topic: von Wanderlust's CB550F rebuild

[von_Wanderlust]

Hello again. Haven't been on here in a while. It's amazing how easily you can get sidetracked in real life.

A few years ago I purchased an engine and a frame (separately) and started collecting bits and pieces to make up a CB550. Through some luck I acquired almost another 2 bikes in pieces for free, one being a 500 plus another 550. Started work on a CB550, had a problem on the forks (lost a crush washer), so pulled the engine down while trying to find one, and got stuck there when I saw the case was slightly damaged under the stator cover, having one of the 3 mounting holes damaged. The plan was to get an in-law to fill in the case with some welding, but it never happened and the whole project dropped off the radar.

Due to space constraints at my Personal Storage Facility (read: Mum's House), I've had to relocate this stuff to my new place. A bike in pieces takes up much more room than one assembled, so funnily enough I re-started the rebuild out of necessity, but now that I have I have restarted I can see that I have been bitten by the bug again. I'd forgotten how addictive this (and the forum) is.

Good news, I have a lot of parts to get things underway. I'd forgotten just much I put aside getting ready for the rebuild: gasket sets, wheel and steering bearings, carb rebuild kits, HondaMan ignition, Dyna coils, NOS CB750 pistons for a Gentlemans Express engine build, and the list goes on. I think I'll hold off on the 590cc build for the time being, because I am worried that if I get stuck on something tricky I'll put it to the side again and it will never end up finished. So the goal is to get 1 x machine running quickly out of the parts that I have. This will free up a large chunk of room in the shed.

[von_Wanderlust]

Done this weekend:

1) New All Balls wheel bearings in front wheel. There was an extra seal in there, much larger than the wheel bearings, looks like it matches the seal for the speedo drive - is that serviceable? Does the center just press out?

2) Modded speedo drive plate for dual disc conversion. Already have drilled discs that I prepped up years ago.


Goals for this week:
1) Get crush washer for forks from a hydraulic place and assemble forks.
2) Get longer bolts for dual disc conversion. I bought some years ago and they are the right length, but the thread is longer on them. I'd rather have the non-threaded section extend right through to support the 2nd disc, even if it means cutting off any excess thread on a longer bolt.

[FunJimmy]

Welcome back. We've missed you.

You've objectives sound good.
Get it assembled and running first, then you can hone in on mods.
Don't forget.....a picture says a 1000 words.

[von_Wanderlust]

Thanks for the warm welcome back FunJimmy.

Good news, I unexpectedly gained some free time today. Bad news is that it was because my shift was cancelled. Made the most of it anyway.

Picked up some class 8.8 bolts (your grade 5) for the discs, had to order longer ones to get the thread to stop just at the second disc. Cut them down to 110mm. Had a problem with clearance, the speedo drive was hitting the nyloc nuts. Swapped back to the standard nuts, still hitting.  Then realised I had the bolts around the wrong way. Swapped them over (and back to nyloc) and there is now 1mm clearance all round.

I am concerned about the clearance of the cable against the center of the disc, unfortunately in my many boxes of things I can't find a speedo cable to check right now. Does this look normal for a dual disk conversion? I am hoping that the cable end itself is slightly smaller than the entry point into the speedo drive, so will just clear?

I take on board the comment re pics.    Here is also a pic of the completed wheel. The disc pattern is a trade-off between weight reduction and surface area. I also went with this design as I am sure I saw some pics from the 70s of bikes with this pattern (rather than the curved patterns), and I am trying to improve it but keep it period correct. Just because I like old stuff.


Ps, it's funny that you welcomed me back as I came across your name again on the weekend when going through the site. I've had to go through my boxes and do some research on each part to to rediscover what my plans were. Do you still have VM26s as your carbs? I have a set of those stored away as well for the 'future' engine.    Can't believe I went to all this trouble and let it get swept aside.

[von_Wanderlust]

So, in answer to my question above on whether you can service a speedo drive, yes you can.

Dislocated the seal with a screw driver.
Lots of grease to clean out.
Once you can see the mechanism, there is a spring clip holding the gear in place. Pain in the arse to get out, need 3 hands really, but you can get it out by spreading it apart with a couple of screwdrivers and then somehow pulling it back to towards you.
Behind that is a washer, then the gear itself.
Between the gear and the housing were two shims.

Gave it all a good wipe down. Couldn't get the worm drive out, there is a grub screw I removed from the side, but the cap is pressed in pretty tightly and I starting to leave nicks in the alloy so decided to leave it. You can get it pretty clean anyway.
Gave the shims a light coat of grease and replaced them. Gave everything a good coating of grease, into the threads of the gear and the worm drive (you can hold grease against it and spin the output shaft to get all of the drive), replaced the clip into position, replaced the seal, and packed some more grease around the seal.

Here's a pic of internals, think of it as an exploded diagram (ignoring the seal of course which is at the top of the pic and goes in very last).

[FunJimmy]

Ps, it's funny that you welcomed me back as I came across your name again on the weekend when going through the site. I've had to go through my boxes and do some research on each part to to rediscover what my plans were. Do you still have VM26s as your carbs? I have a set of those stored away as well for the 'future' engine.    Can't believe I went to all this trouble and let it get swept aside.

Sometimes life gets in the way of the fun stuff. The important thing is....you're back and enjoying the build. As for carbs.....I never got yo using the Mikuni VM26 carbs. I went the CR26 route but they're supposed to be really good on the 550's. Check in on Bwaller's race bike thread.

The speedo drive looks right. You might want to install a wire cable guide to keep the speedo cable from rubbing though.

[SOHC4 Cafe Racer Fan]

So, in answer to my question above on whether you can service a speedo drive, yes you can.

Dislocated the seal with a screw driver.
Lots of grease to clean out.
Once you can see the mechanism, there is a spring clip holding the gear in place. Pain in the arse to get out, need 3 hands really, but you can get it out by spreading it apart with a couple of screwdrivers and then somehow pulling it back to towards you.
Behind that is a washer, then the gear itself.
Between the gear and the housing were two shims.

Gave it all a good wipe down. Couldn't get the worm drive out, there is a grub screw I removed from the side, but the cap is pressed in pretty tightly and I starting to leave nicks in the alloy so decided to leave it. You can get it pretty clean anyway.
Gave the shims a light coat of grease and replaced them. Gave everything a good coating of grease, into the threads of the gear and the worm drive (you can hold grease against it and spin the output shaft to get all of the drive), replaced the clip into position, replaced the seal, and packed some more grease around the seal.

Here's a pic of internals, think of it as an exploded diagram (ignoring the seal of course which is at the top of the pic and goes in very last).

A LOT of grease is right.  Thanks for the exploded view (completely disassembled).  I never got it completely broken down.  I just cleaned out all of the old grease and relubed it.

[Ewan 500K1]

I am concerned about the clearance of the cable against the center of the disc, unfortunately in my many boxes of things I can't find a speedo cable to check right now. Does this look normal for a dual disk conversion? I am hoping that the cable end itself is slightly smaller than the entry point into the speedo drive, so will just clear?

[von_Wanderlust]

Thanks Ewan, that's exactly what I was hoping, the cable itself is much smaller than the housing.

Today: Decided to do the steering bearings, so that when I rebuild the fork legs this weekend they have a nice home to go to. The steering was quite notchy, and as I suspected there were indentations for every bearing position around the bottom race. Whoever rode it last must have had fun. I took a picture, quite noticeable in the flesh, but multiple reflections ruined it.

I have a tapered bearing set from All Balls to go in there. Used a dremel to cut the bottom inner race most of the way and then a chisel to loosen it as per Hondaman's book. All the old races are out, gave the adjusting nut a good clean, which was surprisingly quite hard to do as the grease was so old it had a wax-like consistency. Used some metho (methylated spirits) to get it all off, as well as clean the other parts (stem, seal, washers etc). Reassemble tomorrow.

[von_Wanderlust]

Went to re-assemble then realised that I hadn't put the races plus steering stem in the freezer. Then tried again but didn't have a piece of pipe, and so on and so forth. Anyway, it's installed now.

Notes: After choosing the correct height washer for the bottom bearing set, I used the spare washer in conjuction with the pipe to install the bottom bearings, a nice fit to avoid any damage to the bearings themselves.

I used all-thread to install the races, a trick I've seen in the local bike shop. (Cycle shop - although they have a proper engineered piece). To be honest it was fairly easy, by the time I found some correct diameter pipe the races had been in the freezer for 3 days. The only difficulty I had was that I didn't realise that the bottom race is recessed into the stem tube by a large amount, so it was a quick rush to grab the steering stem and bottom bearing to push it in. I'll still use the all-thread again in the future, it's easy to keep the races lined up nice and straight, and you can give it a good crank to make sure that the the top race is in nice and firm. Actually, I could have done the same with the bottom race plus the bottom bearings if I hadn't already installed the bearings onto the stem.

[von_Wanderlust]

These caps were in my bag of bits, I machined them out years ago in preparation for rebuilding the forks. Being very proud of them (I'm not a machinist / fitter and turner so kindly humour me), so it was a bit of a disappoinment to realise they were way too long - the handlebar is almost directly above it.

Went back to local tyre store, found some caps with a shorter stem, and also machined the cap another 2mm in (4mm all up - as much room as available) to get it to fit. Fits with 1mm to spare on the left, hits on the right - the bar has been in the wars at some point and has a slight bend in it. So have the legs set a little below where they should be and will need to get another bar as I go along.

[von_Wanderlust]

The forks are rebuilt, nothing too special there. The usual pain getting the bottom bolt unstuck - used a tapered wooden rod plus the fingers from a rubber glove to get into the opening of the daper rod and hold it tight, still took a while. I've lost the seals on the fork caps so will have to add that to a future order, must have taken them off years ago when maching the caps. Just need to fill with fork oil once have the seals.

Fitted the front wheel, looking forward to being able to move the bike around the shed (currently sitting on a milk crate). Went to fit up a rear wheel, have two different types. Is one a 500/550 and the other a 750? Would like to use the "other" if it is a 750 wheel as it is in better nick, and I read that they have less chance of rusting out? It is minus a complete axle and spacers, although I have found some bits in one of the attached pics. Can anyone help me identify these wheels and axles, tried to search last night but while I could find lots of internal pics I couldn't find a post that has different model CB wheels next to each other.

Cheers,

[von_Wanderlust]

It's OK, I wasn't thinking straight, was trying to find a post/thread with these wheels side by side, but worked it out by opening two different threads at once to see the difference.  Will use the 500 wheel, all the bits are there, but most importantly, I remembered that I already have the bearings for it. 

Was hoping to do some work on Sunday, got a few house things done in the morning, but the weather was so nice that I pulled out the hammock in the afternoon, grabbed a bear and a book and fell asleep after a few pages. Great weather here considering we are only 1 week out from winter. Warmest May on record. Still, part of the work in the morning was making room in the shed so that's helped the project anyway.


I have a Gl1000 master cylinder here, salvageable?