Part 3: Getting a bit carried away now...

What began as an exercise to replace my manky wheels 'on the cheap' and get the Tranny back on the road so I can sell the Pan, is turning into a customising exercise.

Already won and paid-for are the rear caliper-and-bracket (£20) and an engine sprocket with 14 teeth as I think I mentioned yesterday. (However at the time I thought the original had 16 teeth. Having removed the cover I now see it only has 15T so I've ordered a 14T item (£13.79). That gives me a final ratio of 1:3.07 instead of 1:3.13. Not too much in it so I won't worry).

Also decided to buy the speedo drive (£15) as I don't think the original Tranny unit is a very good fit in the CBR wheel. I'll work out which way round works best and mount the wheel accordingly -It could mean I don't have to change the tyre round at all. Let's see...

I pulled the luggage rack and mount off the back of the bike and I think it looks quite good so I'll probably leave it like that, especially if I go ahead and (wait for this.....) fit a stainless under-seat exhaust unit. Currently watching one on the 'bay! It'll mean a bit of modding of the rear mudguard/number plate mount and some heat insulation between the can and the seat pan but it will look so-o-o-o-o much better than the crappy standard unit. With being off the same-sized engine I shouldn't have to worry too much about the mixture either. Just cutting-and-shutting it to fit! Realistically I can't really afford the exhaust though, it's supposed to be in 'VV Good' condition so it'll be outside my budget. It's just a bit of a pipe dream (geddit?).

I still don't quite understand why the back wheel looks offset in the frame when it's central in the swinging arm (gauged by equi-distances from tyre-walls to the arms). Surely the sub-frame can't be bent? (The only time it's been on its side was outside the house when a neighbour reversed into it and knocked it over - that was the off-side it went down on so I wouldn't expect this offset to be caused by that particular altercation.)

My biggest bugbear at the moment, though, is the front end. Bottom line is that the old calipers won't work on the bigger disks.

This means that I need to get hold of a pair of CBR600 calipers and mounts and try to make them fit my forks. Currently negotiating with a guy on the 'bay re a full set of full front hydraulics off an '87/'88 bike but these are likely to be the single biggest investment if I can get them - £60 - and that will be a bargain. Fingers crossed.

The other issue which I should have spotted earlier, is that the TransAlp front axle is a 17mm diameter whereas the CBR wheel uses a 20mm. It seems the easiest way to remedy this mismatch is to knock out the CBR bearings and replace them with smaller internal-diameter items. The actual spec for these is 42x17x12 mm. And wouldn't you know, it's not a 'standard' size - there are a lot of fellas changing wheels on their Hondas and Suzukis and coming up against this exact same problem! Actually there have been one or two early Hondas that used this spec bearing - the CR250 Elsinore for one, according to a search, so I should be OK to get a pair without totally breaking the bank or having to machine down a new axle! (Not completely discounted yet...) Anyway, I've put out feelers, let's see what turns up!

That's this evening's brain dump. The weekend's coming and I'll have more time to look and think about how I'm going to achieve my goal. Good thing is the girls are away again on Saturday so I won't be disturbed! It's like being 23 again. Apart from all the aches and debts, obviously.

Part 2: Should I be worried?

Well, after Sunday's euphoria of having a pair of lovely bright red wheels sitting 'comfortably' in between my forks, this evening I took a more objective look at the situation.

The first thing to occur was that I wasn't going to be able to customise the existing rear brake carrier to fit the new wheel/disk as the keying mechanism which locates in the swing-arm and acts as a torque stay, wouldn't allow the 17.5mm lateral movement I need to centralise the wheel in the fork. Which ever way I look at it, I'm going to have to go 'Old School' and employ a torque-arm layout (as originally fitted to the CBR600 F1 whose wheels I'm using). The prerequisite for this will be a caliper and carrier from a CBR600 RR3 (should fit with luck) which I'm bidding on currently, (mainly 'cos I can't find a F1 unit to bid on!) plus a home-brewed bracket, for a torque rod, which I'll need to MIG weld onto the arm. Well at least we're into a bit of interesting engineering now!

All that said. I took a picture of the back of the bike and with the wheel more or less centred in the swing arm fork, it all looks off centre with the rest of the bike! Methinks I need to take its clothes off and check for straightness....

However I still don't know if the RR carrier uses an integral detent for torque control; If so, I will need to mill and drill it to suit the revised application. Let's see if I win it first, then I can take it from there!

Re the rear sprocket, I've just won a CBR600 R item for 525 chain that should fit the bill - I hope - so that should be here before the weekend. Add £7.74 to the running total...

A new split-link which I still need to order, will see the drive train restored in principle. However I still need to replace the engine sprocket. Given the smaller rear sprocket (43T as opposed to 47T), I need to compensate for it by reducing the number of gearbox teeth from a 16T from 15T. This will give a final ratio of 1:2.87 as opposed to the original of 1:2.93, so there should be negligible difference in acceleration and general performance.

The cush drive rubbers were here today but I wasn't in to take delivery so they'll be redelivered tomorrow and left in the side alley!

I haven't given a lot of thought to the front end yet. I really want to keep the new disks - they look so good - so I need to think seriously about how to modify the caliper carriers to compensate for the extra diameter of the rotors. As I mentioned yesterday, I did have a couple of ideas but I need to pull a caliper off the bike and see how much metal I've got to play with. Maybe tomorrow if I can get away from work sharp enough, I'll do that.

I was having a think about the speedo gearbox on the front axle and wondering if I really need to bother about a pukka CBR600 F1 item. The disadvantages of not doing so are that (a) the speedo will read slightly high, which isn't an issue - I never use the speedo anyway ;o) and (b) the mileometer will register a higher mileage than it's actually doing. That isn't a showstopper for me, given the fairly low commuting mileage I do each week.

(Just looking at ebay, there's a correct speedo gearbox available for £21... I've tagged it but I'm inclined to wait until I'm on the road before spending out on this little luxury! And it occurred to me, is the 600 gearbox actually different from my TransAlp unit or do the respective clocks compensate for the wheel size? Dilemma!)

Well, this was only ever going to be a little update so I'll leave it for now and see what the rest of the week brings. In the meantime though, I'll add a couple of pics of the splits in the original rear wheel rim...

(I know, the wheels are filthy - I ride my bikes rather than polish them but I guess that's not much of an excuse!)

If by chance anyone's reading this and has successfully completed such a project, please shout up - helpful advice is always welcome!

Part 1: How do you make omelettes? Oh yeah, break some eggs...

I took my T-registered TransAlp off the road last September when I realised that it wouldn't pass the MOT without spending some money on it.

At the previous MOT my friend Peter (Chessington Motorcycles) warned me to keep an eye on the aluminium rims as I tended to let them get a bit....well, manky. It wasn't until giving the bike a once-over during the summer holidays that I realised why I should be wary.

If you own a TransAlp or perhaps an Africa Twin (I saw a horrendous example of this problem on the front wheel of such a bike...) you may be aware that there seems to be a fundamental problem with the wheels insomuch as the spokes tend to corrode quite readily, as do the rims. The latter however, corrode from the inside and you don't see the results until you change a tyre or worse, actually see splits appearing near the centre-line of the rim. Time to act and quickly!

Now, searches on forums suggest that if you can't get hold of a decent second-hand wheel from ebay (and believe me, I've kept my eye open for months!) then the only option is to get a new rim laced onto your old hub, preferably using new spokes too. If you include having the hub cleaned up and powder-coated too (because they rot as well) you are probably looking at about £220 per wheel. In my case I also needed a pair of tyres so I was looking at potentially £600 to get the bike roadworthy again. I just ain't got that sort of money.

Necessity being the mother of invention (and in too many cases the instigator of catastrophes!) I started looking around to see what other wheels I could use in place of the spoked items. I actually did this a long time ago for my aged Z750 Twin, when I fitted a pair of Lester alloys which I purchased from Graham Little Motorcycles in Sunderland. That would have been about 1983 then! (And the wheels were designed for that bike so all the running gear was transferrable).

Back to the forums and I read somewhere that with a bit of ingenuity the wheels from a CBR600 just might fit, with a bit of help...... Well, enough said!

I don't have easy access to a friendly bike breaker, nor do I have a friend with said Honda so I couldn't draw similarities between the two bikes. I was able to make a few basic comparisons between brake disks (different), sprockets (different again), caliper mounts (you can guess where this is going...) etc. but I had little else to go on. Accordingly then, I bit the bullet and in true 'Del Boy' tradition ('Who dares, wins') decided to go for it.

Ebay has always served me well and so it did last week when I spotted a nice pair of red cast wheels with good tyres 150 miles away in Wisbech, Cambridgeshire, collect only. No disks on the front wheel though.

Hang on, there's a different front wheel (VFR400 NC24) with the same disks (I hope!) and a good tyre up for grabs up in Barnsley (they'll post). I bid and won it in 48hours. Total cost there, £16.05 plus £14.95 postage.

I also bid on the red pair in Wisbech, won them then collected them on Saturday. Cost of petrol about £50 and 5 1/2 hours driving. Cost of wheels, £30. Unfortunately some of the cush rubbers were missing so another trip to ebay last night and there's a full set on their way to me for £18.50

So now I have a pair of wheels with disks, good tyres, sprocket..... but will they fit?

Well yesterday was a beautiful day and once I'd done my chores (3 loads of washing, cleaned the guinea pigs, tidied up etc) I did a few measurements of the bits I had now accrued and took the bull by the horns.....

Rear wheel first! Out with the old; swing the caliper out the way. In with the new... I have to say I was pleasantly surprised - it all fitted in quite nicely! Obviously not properly, but I'll get to the finer points later! Finger-tight the nut on the axle and stand back to admire! Like it!

Front wheel now! Jack up the bike under the sump (protected with a piece of wood obviously), pull off the calipers, yank out the axle and throw the old wheel away. Slip the new wheel in, slide the axle back in and admire once again, Very Super Motard!

The immediate improvement in the look of the bike would surely justify the challenges I yet faced? Those challenges I list below;

Rear:

• Disk is smaller than original so caliper doesn't 'cover' the braking surface properly. (About 70%). Can I turn down one of the front disks to suit? Certainly it will be impossible to do anything with the caliper/mount.
  
• The wrong-pitch sprocket is fitted - I need a 525 to match the chain and gearbox sprocket. Currently bidding on a 43-tooth one from guess-where. May need to get a smaller engine sprocket to compensate if I win that one - it certainly will need a replacement anyway, the original is showing signs of hooking so the small one will be 3 times worse!
• Spacers needed on both sides to centre disk on caliper mount. Not an issue, just need to work out exact lengths.
• Sprocket/hub may need shimming a few mm to align with gearbox but difficult to determine until wheel spacers installed. Again, not a big problem at all.
• Cush rubbers missing from hub (ordered).
• Chainguard fouling on inside against tyre so needs 'reworking'.
• Suspension linkage is manky and needs cleaning/lubing.

Front:

• Wheel needs spacers to centre disks between forks. Again, easy.
• Ideally needs correct speedo drive hub as wheel is much smaller than original so speedo will read about 10% fast. The one I was given was broken but hey, no sweat.
• Tyre needs removing and flipping round as the speedo drive is on opposite side of the new wheel and I don't want the speedo going backwards... No great sweat.
• Disks bigger than originals by 20mm so calipers won't go near mounts. Hmmm. Possibly the biggest challenge of all. I have one or two ideas...
• Fork brace inside mudguard is fouling tyre so needs reshaping and new holes drilled.
• Brake hoses may need to have new fork-leg support brackets re-angled.
• Forks are manky so need cleaning up to do the wheels justice!

Now, that little lot might put some people off but it's not that bad. (Surely...?) Obviously safety is paramount here - spacers are easy enough to turn down and changing the sprocket is a doddle but the brakes are another matter. I don't quite know how I'm going to accomplish this - Front and Rear propose two different problems - but I bet it involves using my milling machine and lathes at school where I'm workshop technician. Dead handy, having them at my disposal ;o)

The important thing to me is that for £129.50 outlay I've got a complete 'new' set of wheels and boots on the bike. and with a few hours work and perhaps another £20 or so, it could be MOT-able. And to top that, I think it looks great!

Anyway, More next weekend once I've had a chance to reappraise the situation!