Fitting the hydraulic disc brake

Fitting the hub was fairly self-explanatory, and the one problem I did have (front wheel not being central in the forks) I posted about previously, and I rectified it by straightening out some wear on one of the fork links. It is worth noting however that these hubs (mine's a SPAQ/Sterling jobby) don't require a nut between the link and the large plate on the right hand side. The hubs don't come with them, but at a recent parts fair I saw some of these hubs with nuts fitted - I guess the stall owner thought they were missing and fitted them!

Here's a pic of the assembly in place:



To connect it all I discarded the rather bulky rubber hose that came with the unit and bought a new slimmer Goodridge braided stainless steel one from http://www.busters-accessories.co.uk/. This is what I got:

Buildaline Adaptor Banjo 90deg 3/8 Jic Male 5.99 1 5.99
Buildaline Adaptor Banjo 45deg 3/8 Jic Male 5.99 1 5.99
S/B Buildaline Hose 1100mm Clear

The 90 degree banjo enabled me to avoid having any exposed hose at the top of the bike. I simply used a round file to create a hole in the top if the headset for the banjo and the small front brake wire to feed through. Here's the end result, a lot neater than any others I've seen:



And here's an internal shot, showing how it all worked out:

Here you can also just see a replacement white earth wire that I fitted from the headlight to the mounting point of the throttle guide. This provides a more reliable earth than the headlight rim as is standard. The loom comes in on the right on my bike, as I simply couldn't find the room on the left!

Get your motor running

I may not be able to ride out on the highway yet, but getting my motor running is a major milestone and somewhat of a relief. I've jumped the backlog of blog posts about cabling, wiring and plumbing in the brakes to report that the beast is alive.

I expected a whole heap of electrical or fuel/air niggles to resolve, but there were no such problems. Instead there was a mechanical problem that was entirely my fault. When I first tried to start it the resistance on the kick pedal felt wrong, and further inspection revealed that the flywheel was actually contacting something behind. I removed the flywheel and uncovered two potentially disastrous problems. Firstly, I used a spring washer on the stator bolts, and the top one that holds the cable support was slightly too prominent and had come into contact with the rear of the flywheel. Needless to say I replaced the washer with a wavy one. Secondly, and rather embarrassingly, there was a wavy washer lodged between two magnets on the flywheel:



I've no ideas where it came from, and I'm finding it hard to believe the washer was there when I fitted the flywheel as I would have checked it. Perhaps it was sitting loose in the mag housing or around the stator and got picked up after I fitted it?

Anyway, here's the video taken by my wife on a mobile phone in the late evening so it's a bit dull. It isn't the first start, as she'd have been standing there for over an hour; It's the second. I'm also pleased to report the noise didn't wake the baby.

Front wheel not central?

My new outboard disc hub wasn't sitting central in my forks, it was about 9mm off. I don't have a photo because I was too annoyed to take one.

I couldn't work out why this might be, and a bit of googling only led me to one theory that I had a bent fork link. I can't possibly imagine a scenario where a fork link might get bent. If your fork link was exposed, in situ, to enough force to bend it then other things would bend or break first, surely?

With this in mind I dismantled it again and found the culprit. In the photo below you can see uneven wear on the face around the edge of the bush. The face has worn to the rear of the link (the top in this photo), but not at the front. This causes the link to sit at an angle when fitted to the forks.

The fix is simple. I filed the rest of the face in line with the wear so that the face was perpendicular to the bush/bolt that holds it in place. Then to compensate for the loss of width I doubled-up with another cup on this side, as not very clearly shown in this photo. You could also use a large penny washer under the cup.

While I'm on the topic of fitting the front hub, an important part of fitting your front hub assembly is using the right axle washers. They ensure that the hub sits exactly where its supposed to be but are more importantly a critical safety feature which will hold your wheel in place even if your main nut becomes a bit loose.

It's all back together now, and I'm pleased to say it sits perfectly in the middle!

More painting

Here's the rear hub in primer. I stripped it by hand with paint stripper so the finish isn't perfect under scrutiny.



The end result with the top coat of Silver / Metallic Grey looks great and matches the silver ScootRS rims really well. I used the same silver for the forks too.



It was also time to spray the top side of the frame and new cross member before I start doing the cables. A perfect match nor finish isn't required here as I'm going to be covering it in Waxoyl before finally fitting the legshields. Remember this ain't no show bike, this is going to be used!



Rather uninspiringly, the best (and it is rather good) match I could find was simply.....Beige.

New fork springs

I wasn't happy with the seemingly different performance of the old fork springs, so with the forks still in place on the scoot I dropped out the old ones and treated them to new uprated springs and rods as seen below.



These compliment the new link bolts, cups, bushes and buffers already fitted:



With the hub and the dampers in place, this is how its looking:

Taking shape

The engine looks great prior to refit with all its new shiny bits:





and now it was time to hang it back on the frame, along with the rebuilt forks complete with new bushes, buffers, cups and bolts...



The front hub is not bolted in yet, and it's interesting to see that the bike leaned to the left at the front (or the wheel to the right) as though the left spring was compressing more easily than the right spring. I'm going to investigate this a little further as I may have to replace the springs and rods with new ones to ensure I have a fork that's behaving properly.

ScootRS tubeless rims

Tubeless rims reduce (or do they eliminate?) the risk of a blow-out. A compelling reason, so I bought some from ScootRS in Vietnam. They arrived in good time and well packaged, although I got stung for an extra ten quid by Fedex for some kind of unpaid customs taxes.

The rims are nicely made, and if you read about them on the web you'll learn that they're popular, but are difficult for the tyre-fitter. This proved true for mine, and they didn't escape fully unscathed. If you're a perfectionist or you've bought some chrome ones you probably won't be happy, as you either won't want to or won't be able to touch up the near-inevitable marks.

Regardless of this, I think they're great, and with Schwalbe Weathermans on they look great too:





These 100/90 tyres are 10mm wider than the crappy old Indian tyres, and the differences in width, shape and footprint are neatly demonstrated below by my son Bill, who gets excited about literally anything with wheels and so a stack of wheels was a dream come true.



And in a state of my own excitement I couldn't resist offering up my hydraulic disc and hub unit. More on that in a future post...

Rattle-can spraying

This is no show-vehicle, so I've opted to use an aerosol for the few parts that need it. I stripped the forks with Nitromors paint stripper and a wire brush. A few coats of high-build primer followed the next day by a sand and then a few coats of Silver/Metallic Grey did the job:



And the new cross member looks a lot better after just one coat of primer:

A professional weld

I think I found the best way to find a good welder, short of personal recommendations. I chucked the Lammy in the back of the car and drove round the corner to the nearest backstreet car workshop and asked them. They sent me round the corner to another workshop, and a guy called Gary. It was 9am, and he said he'd have it finished by 2pm and it would cost only fifteen quid.

I'm pleased to report he did an excellent job:






and he did my damper mounts at the same time:



Now I can start rebuilding!

Welding on the new cross member

Removing the old cross member revealed a little more about the history of the frame. A crack can just be seen just beyond the end of one of the repair welds, and this shows that the frame suffered a collapse at some point which necessitated a full circumferential weld and strengthening plates to the upper and lower sides. You can see the crack arrowed in this image:



I bought a new cross member and borrowed a MIG welder to enable me to fit it in exactly the right place prior to taking it to the local welder who can do a better job finishing it than I.

To place it properly I used a scaffolder's spirit level (they are magnetic) placed on the engine mount to get the frame perfectly vertical. The lens of the camera makes everything look a bit skew here. It isn't - the engine mount is perpendicular to the frame:



I had to modify the cross member to cater for the existing stengthening plate and welds:



After careful measurement and multiple checks here it is welded on by the front edge only:



Then I ran a final panel placement mock-up to check that everything fitted. You can see here everything fits straight and as expected:





Now I just need to take it to a professional to finish it off for me.