Number crunching

We've been away on holiday for the week so no bike updates to report on.  Instead I've been crunching numbers.

mpg:

The second fill up showed that the bike returned 125mpg.  So, the 131mpg on the first fill up wasn't that far off.  However, the tank is going on to the reserve tap at about 3.5l, which is only ~90miles.  That's not far to go between fill ups when every minute counts.  I might have to look at modifying the tap to give more miles on main and leave myself with smaller reserve.  Or I could get really good at the mental arithmetic required to keep track of the miles completed on each tank...

Compression:

After the assembly of the top end I measured the compression, which came out at 120psi.  Now the rings and bore have bedded in it has increased to 140psi.  This is a good sign!

Average mph:

Thanks to an online matrix for the 2013 National Road Rally, courtesy of the Leicester Phoenix MCC, I've had a bit of practice at planning a route.  A Gold Award route needs to be between 500 and 540 miles according to the matrix (the actual distance may be a bit greater or less).  I pieced together a route of 505 miles, taking in 20 controls.

The rally is 20hrs long, less 2hrs of rest breaks (with particular restrictions on when those can be taken.).  Assuming that I take 5 minutes at each control and have 5 fill ups taking 5 minutes each, then I need to average 32mph.  If I allow for the matrix being 10% under on distance then this increases to 35mph.

Given that I'm struggling to hit 40mph on the flat then achieving an average of 35mph over this distance seems improbable.  Although the time I'm allowing at each control may be pessimistic.  I've not done the rally before so don't have a feel for how busy they get.

When Dad entered the rally he had to cover 600 miles, but had a genuine 24hrs of riding to achieve it.  He did stop for food and drink, but even taking 2hrs out for this the average speed he needed to achieve was just shy of 28mph.

What I need to do is a couple of long rides, to see what an achievable average speed is.  A job for one evening this week perhaps.  In advance of this I've had a look at some of the period articles on the bikes.  In John Thorpes book "The Book of the Honda", printed in 1964, he records an achieved average mph of 35mph for a C110 during Honda's successful attempt at winning the Maudes Trophy.  This arduous event involved seven days non-stop riding around the Goodwood race circuit.  That 35mph average should be optimistic for the road, as there were clearly no villages to slow down for riding around Goodwood!  It also managed between 124mpg and 140mpg.  So perhaps my mpg figures are about right.

He does say elsewhere in the book that the C110 can average 40mph on the road, but I can't see how that is achievable given the above.

Although I had initially set out to achieve a Gold Award, and would still like to, I will have a Plan B and a Plan C.  These will be to go for Silver (400 miles minimum) or Bronze (300 miles minimum) award instead.  I intend to plan out  my route with break points.  If I haven't hit particular controls by a certain time I will divert onto one of the shorter routes.

I've revised my goal to finishing the rally with an award, of whatever colour is possible!

One week in.

The C110 has been on the road for a week now, and so far things are going OK.  I double checked the points gap during the week and it was a bit tight, effectively retarding the ignition.  After resetting the gap the spread of torque was increased (slightly!) and the bike will sit at 40mph more comfortably on the flat.

I filled up mid-week, to get a feel for the fuel economy.  Up to that point it managed 130mpg, which I found a bit disappointing really.  However, the ignition was a bit retarded and the over flowing float chamber won't have helped.  I'll see what it is at the end of next week, I should have another 100 miles on it by then.

The chain has needed adjusting a few times, as has the headset, and I had a slightly unnerving discovery on getting home one day when I found that the swinging arm nut had gone AWOL.  Other than that there has been no maintenance necessary.

I've got used to the handling now, and am quite enjoying throwing it through the corners.  I'm missing the speed of my other bikes though!

Finally, I owe a thanks to Dan of Covent Garden Laminates who made up some really neat stickers to fit on the front number plate board. It makes for a nice bit of advertising space!  Thanks Dan.

Change(s) of plan.

So this weekend was the Spirit of the Sixties weekend and I was expecting to go on the back of Dad's A7 BSA as I didn't think the V5 for the C110 would arrive in time.  However, the V5 pitched up on Wednesday morning.  Some quick phone calls later the insurance was arranged and an MOT booked for Saturday morning.

The bike passed with flying colours on Saturday so, theoretically, it was possible to go to the Spirit of the Sixties on it on the Sunday.  We were both looking forward to the run, it's probably the best classic run of the year, but Dad and I eventually decided to prioritise getting some shakedown tests done on the C110 from home.  

The main observation from the first ride out was that the C110 is slow!  It wasn't really possible to gauge it's performance on the flat as the weather was so windy (pretty much constant 25mph westerly with up to 40mph gusts).  I think it'll be able to hold 40mph on the flat though, based on how it ran today. What the weather, and the local hills, did show up was the penalty you pay for having so little torque.  The slightest headwind or uphill meant dropping to 3rd (max of 35mph) or 2nd (max of slightly over 25mph).  Quick gearchanges were a must in order to maintain momentum.  

We had a quick stop at Sharpness docks, to make sure that nothing important had vibrated off, which gave an opportunity to take a snap of the C110 with Dad's BSA.  Dad's had his BSA since 1962 so had it when he entered the National Rally on 'his' C110.  Therefore it seemed appropriate to take a picture of the two bikes together.  There's quite a difference in size!

The need to conserve momentum on the C110 brought back memories of riding my old Yamaha FS1E as a 16 year old. Cornering becomes an exercise in wide sweeping lines and avoiding touching the brakes.  A lot of fun on the lanes, until you have to knock it back a gear for the next slight up hill!  I was surprised by how well the C110 handled, very quick steering but pretty accurate and stable, and the limited suspension worked smoothly too. The brakes are pretty useless though.  It does have new shoes fitted so hopefully they'll improve over the week as I use the bike for commuting to work.

The first ride out showed up a slightly slipping clutch and, more importantly, a sticking carb float.  The latter resulted in fuel pouring over the top of the engine, a slightly risky situation.  Stripping the carb down showed that the cause of the sticking float was that the new float chamber gasket I had made was slightly too large. It was just catching the edge of the float preventing it returning and closing off the fuel supply.  A bit of time with a Stanley knife soon sorted it out and all was fine on the second ride out.  It wouldn't have been feasible to fix that if we'd been on the Spirit of the Sixties, which vindicated our decision. 

When I took on this endeavour my main concern was getting the bike running reliably enough to complete the 524 miles on the rally.  After today's limited mileage my two concerns are whether I can maintain a high enough average speed (more on this in a later post) and if my back will take it.  I hadn't realised what a hunched up riding position the size of the bike demanded.  I broke my back a few years ago and it can be a bit uncomfortable at times.  After doing a mere 40 miles today I was in a fair bit of discomfort.  I'm hoping that commuting on it each day will allow me to adapt to the riding position.  Otherwise I'll be needing a lot of painkillers come the rally itself!

All-in-all it was a fairly successful weekend and I'm now well set up for starting to rack up some miles on it.

There are still a few things that need to be sorted:

1) A better way of fitting the seat (it fell off at one point!)
2) Perhaps some improvements to the electrics, a more modern rectifier and maybe the addition of a regulator
3) A method of holding the route map during the National Rally
4) A method of illuminating the route map during the dark hours of the National Rally
5) Sourcing a steering lock
6) A decent throttle grip

All together!

This week has been spent putting the final touches to the bike, fitting the mudguard, engine cases and chain case.  It's now all together and ready for the MOT.  The only thing stopping it from being on the road is waiting for the V5 to come through from the DVLA.  As it had been stood for so long the V5 had been lost, and the bike was no longer on their system.  Thanks to David Casper at the NACC for processing the forms for me to reclaim the numberplate.  This is a great service that the club offers up and they are a sociable lot with plenty of knowledgeable members.

I've had one technical problem this week; the pattern fuel tap stopped working.  Upon further investigation it appears that the plastic components in it had swollen, preventing any flow.  I've fitted the original Honda fuel tap instead but I have a concern that this tap will have a similar problem.  This will be down to the ethanol that gets added to fuel these days, it's a constant challenge with older bikes to find components that are resistant to modern fuels.  It's caused me no end of grief with my '67 BSA as well.

Unfortunately the lack of a numberplate will mean that I can't take the bike on the Spirit of the Sixties run next weekend.  With the BSA in bits I'll be consigned to riding pillion on Dad's '57 BSA A7.  Perhaps if I promise him a beer in the evening he'll let me have a go up front too.

There are only 8 or so weeks left until the National Road Rally now, so getting on the road and racking up some miles is becoming a lot more important.  I can't wait to see how it runs on the open road!

It was such a lovely day here I took the bike into the back garden to get some photos to mark the end of the evenings in the garage (for now at least).  I'm very pleased with the outcome, it's quite a fine looking  machine.  I've come to quite like these little bikes whilst working on this one, whether that fondness persists after sitting on one for 524 miles in one go remains to be seen!