Bob's 920 Special 666

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Well, maybe not that special, but it definitely won't be standard. 666 because I bought the bike on 06/06/06. As I think I said, I have got nearly all the bits needed for the build, and am just starting out on their assembly.

These are the only pictures I have of the bike as I bought it - they are from the actual eBay ad and so won't be too hot. I didn't view the bike, as distance and work would not allow it and ended up paying £1750.00 - I thought the purchase price would be almost incidental anyway.

Bob's 920 Special 666


Bob's 920 Special 666


Bob's 920 Special 666


Yes, they are a bit fuzzy. Good enough, I hope, for you to see why I was attracted to this bike. Largely complete, some new parts, not rusty and not coated in layers of oil. In addition, I would be able to check it over carefully before I handed over my hard earned. In practice, It wasn't inspected at all, as I had to get back home ASAP in order to take my much better half, Carollyn, to the British Grand Prix and set up camp.

Anyway, what was done was done and it still looked ok as I loaded the bits into the van. Over the next few months I decided I wanted a 920 conversion and, from past experience, knew largely what needed to be upgraded or replaced. In order to enhance the build fund, I put all the bits I had been keeping up in the loft from my old Commando (I sold this on as a Norvil replica) together with the project bike parts and started selling the unwanted items on eBay. Amazingly, I have made more than the original purchase price from selling these components and still have a few more to go!

Looking at old receipts and ownership history, it looks as if three different owners have started on this project, beginning over 10 years ago. Most of the bits, as well as engine and gearbox numbers (but not matching), fit its appellation as a 1974 Mk11a. The registration document gives it an engine and frame number of 310575 - gearbox matched, engine didn't but not far away.

This is the frame as it arrived:

Bob's 920 Special 666


Frame was a bit chipped but sound, 'chromed' cradle, chromed and painted swinging arm, vernier isolastics and no idea what the shocks were. Not keen on too much chrome, so only the frame, isolastics and seat knobs retained from this lot. Replaced through eBay, but eventually bought a new Mk111 cradle - old one great for rebuilding gearbox though, so will keep!

I have just pushed the bike out of the garage, and this is where I am now:

Bob's 920 Special 666


The original yokes (trees) were also chromed, so eBay for top and a new bottom from Norvil, bars and instrument pods from my old bike. CNW brake kit, switches and light brackets - my daughter was working in Florida, exchange rate was good and she had plenty of friends visiting; worked out as a good deal. I sold the old switches for what seemed a fortune. Pushed the boat out for a Maxton fork conversion - the 'new' stanchions that came with the bike were rusty (!!!) so were replaced. Frame and other bits powdercoated by Triple-S.

Rims that came with the bike were original and fairly good, tyres were new but had stood for at least 10 years and so had to go. Decided to go for Excel 18" shouldered rims, with stainless spokes and Roadriders. Beautifully built by Central Wheel, who also do work for the National Motorcycle Museum.

Polishing done by me using the set-up you can just see in the background. Certainly not show finish, but good enough for a bike that is intended for use.

Bob's 920 Special 666


Note the nut of the superbly machined spindle and nut from British Bike Connection, NY (this one I got through my Brother-in-Law, who lives in Seal Beach and came home for Christmas 2007)

Bob's 920 Special 666


Maxton Twinshocks - in for a penny, in for a pound! CNW rear sprocket for 520 'O' ring chain (anything to get rid of that oiler), replacement brake plate - yes, the original was chromed. Brake lever to be powdercoated, or may go for stainless one that Les Emery is in the process of making now. He tells me that no more are being made by Andover Norton.

Bob's 920 Special 666


The Mk111 cradle and new centre stand - the one on the original bike was not included in the sale??? You may notice an extra hole in the cradle and evidence of reshaping. Of this, more later.

Bob
 
That is really starting to take shape, looks great. I have the Maxton forks and they are excellent, some of my bike budget for this year is for Maxton shocks and possibly rims from Central Wheels. They have just done the wheels on my Triton and they look great, but i'm still unsure what rim sizes to go for on the Commando, the old, stay 19 inch all round, go 18R and 19F, go 18 all round, is running through my head.

Hope you enjoy the rest of the build and I look forward to further photos
 
Bob,
Excellent looking bike & it will be worth all the effort when you finally
get on the road.
I hope you have as much fun as all the rest of us on this forum with our
Commando's.

Hursty.
 
Hi Shaggy, thanks. I have just looked at your photos and you seem to have a very good looking and well sorted machine. Maybe I will get to see it in the metal one day? Ultimately, I am also aiming for an Interstate - I have the tank, panels and seat - but will go with a Roadster to start. I want to get the bike on the road for this Summer and will worry about tarting it up later.

I also took for ever deciding what size wheels. There is so much conflicting opinion that I came to the conclusion, that with a sensible tyre choice and well set-up machine it did not really matter. I preferred the look of 18" wheels and went for 100/90's on WM2 rims on the front and 110/90 on WM3 at the rear. I'm a real short arse, so they may get me half an inch closer to the ground. Only time will tell if the turn-in is noticeably slower with this arrangement - I can't believe that it will be significant.
 
Wow, nice! I like the suspension bits quite well. That front floater is pretty nifty, too.
 
Maxton Conversion

The Commando is shaping up nicely!
You mention that you have some Maxton work done on the forks. Does that convert the damping into an adjustable setup by fitting modern Yamaha internals or do they modify the standard kit to make it work better? Interested in improving the front on my own 750.
 
Maxton

Hi Bob,

Good move with the Maxton suspension, they did both my Seeleys and my featherbed, also our Rob Norths......makes a big difference! Not cheap, but money well spent!
 
Maxton

Hi
following on from Johns comment: good but not cheap.
Can you give me a guide price?
Also did you phone them or use the website. I logged on & gave my bike spec & details but have not had a reply yet.
Thanks Chris
 
Hi Chris,

the last set I got done were about £450, they come with adjustable rebound damping through an allen screw accessible through the top fork nut, so easy to get at!
 
man that bike looks bitchin!! i would love to hear more about that maxton suspension upgrade, i've never head of this before???
 
You mention that you have some Maxton work done on the forks. Does that convert the damping into an adjustable setup by fitting modern Yamaha internals or do they modify the standard kit to make it work better?

They throw away the original internals and put in their own.

following on from Johns comment: good but not cheap.
Can you give me a guide price?
Also did you phone them or use the website. I logged on & gave my bike spec & details but have not had a reply yet.

The forks cost £410.00, including new seal holders and plus VAT, the Twinshocks were £360.00. They replied to my enquiry very quickly, but I later took my stuff in as I was working in that area. From what I could see, most of their work was posted in, so I should try again. Be warned, they are not quick, but I did get mine done 'off season', so order books were full.

Bob
 
Ok, so that was the state of play with the cycle parts. I have also been working on the gearbox and engine. First the gearbox:

Bob's 920 Special 666


All cogs replaced - the teeth were ok on the sleeve gear and so I started by retaining that pair, belatedly I noticed that the splines were so badly indented that I decided to replace that as well. I discovered later that the sleeve gear I had was from the pre-Commando era, so probably a good job it was junked. Fitted the wizzo 'special racing' layshaft bearing from Hemmings, new main, quadrant, kickstart shaft, ratchet plate, pawl carrier and all the normal stuff. Lay and mainshaft seemed ok, so I kept these - I can always replace them next winter if the box ends up being sloppy (I have to admit to being a fair weather rider these days).

Bob's 920 Special 666


A bit of a contrast between the new and the old, but not as bad as it looks. I would have probably gone a different route with the box had I realised straight off all that was amiss - poor working practises on my part! Lah de dah. Once I removed the bearings and wearing my new specs, I spotted a hairline crack in the classic spot, so a new shell was the only solution. I went for the beefed-up version from RGM. In order to fit it, I had to grind out the opening of my new cradle and also took some alloy off the fixing bosses. When I ordered the new case, I asked them if any mods would be necessary. They chose not to reply, so I assumed no - a pity as I went ahead and fitted the cradle and had to do the mods in situ.

Bob's 920 Special 666


Bob's 920 Special 666


You can just see the witness marks of my grinding. This new shell is definitely bulkier than the original and, apart from having to accommodate its slightly larger dimensions, all went together without any real problems. I have trial fitted the outer cover, gear selection is ok and I am just waiting for a screw for the clutch actuating mechanism to be able to close it up and fit it.

However, the fun started when I looked at the crankcases.............
 
The gearbox is now finished and loosely fitted - I have mislaid the top spacer and still need to tighten up the sprocket nut. However, it seems to change ok so fingers crossed.

Bob's 920 Special 666


I have also included a shot of the Maney outrigger in situ for anyone interested. It needed a small amount of metal to be trimmed off in order to clear the centre stand.

Bob's 920 Special 666


The photos also show that I need to polish off all the dust from grinding the gearbox cradle and that I still have to remove the powder coat from around the engine mount points! I can now return to the engine - this is where I have really had to pay for not being able to inspect my purchase carefully.

At first glance, the crank looked fine apart from needing a regrind - if only! Magnafluxing showed that it was starting to crack and it had also been balanced to suit a vertically mounted engine - the reason for the second set of holes in the primary chaincase now became clear (even to me). My plan was to have the lightweight crank cheeks from Steve Maney, but now I needed a new crank and so I thought sod it and had the whole thing. No way was I going to look at a used crank and there seemed to be lots of advantages to be gained from all the weight lost, if you see what I mean. Then it went from bad to just as bad. Upon opening the crankcases, a disaster lay before me:

There must have been 20 good sized chips out of the mating faces and even more dents, rows of weld inside the left case and further damage where the camshaft bushes had been driven out with God knows what - maybe the only tools a PO had was a hammer and chisel? Some of the nuts I've removed certainly look that way. The only good news was that, with a totally honest description and full photographs, it made around £200.00 on eBay. The crankshaft went into the scrap bin for obvious reasons. Again, if I was buying, I didn't want to use S/H cases and, working on the principle of paying a bit more for something better, I opted for Maney cases to partner his crank - and there was my entire initial budget gone. My first intention had been to get a working machine as quickly as possible and then improve it bit by bit. I gave up on that and decided to take longer but make the bike as good mechanically as I could - at least in terms of the parts that were hard to get at. So here is the bottom end:

Bob's 920 Special 666


Bob's 920 Special 666


Bob's 920 Special 666


I don't know if this helps Grandpaul, but here are some of the 920 bits as they were collected from Norvil.

Bob's 920 Special 666


Bob's 920 Special 666


And the camshaft I am using.

Bob's 920 Special 666


Cheers, Bob
 
Thanks for the great progress photos! I've heard when boring the barrels for the 920 liners it is not uncommon to poke through the casting so the liners become visible between the fins. Did you encounter this?
 
That's of no help to me DIRECTLY, as the 880 jugs I got from KD were prepped and ready.

All of that high end Maney stuff, and it's got plain cam bushings instead of rollers?

What cam is that? I like the look of it. Heck, all new stuff looks nice to me.

Wow; nice stuff just the same, but too spendy for me.
 
Grandpaul,

I'm curious about your comment of no camshaft roller bearing in the Maney cases. Who uses roller bearings for a camshaft? I've never had a camshaft bushing failure in any engine I've owned. I'm not denigrating your comment, just curious. I've been looking at those Maney bits for some time now. Unfortunately, Maney's numbers are bigger than the numbers in my piggy bank. They sure are beautiful though.
 
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