FurryOnTheInside's first build: The Night Fur(r)y


Like the name? :cool: Night Furry hehehe! pronounced "Night Fury", after the dragon species from the movie How To Train Your Dragon. It's characteristics are lightning speed, deadly stealth, awesome firepower, and an appetite for fresh fish! :D

Anyway I actually wanted to start a build thread after the first engine start so it's a running bike first.. but never mind. :oops:

I mainly built this single speed Night Furry (motorised Specialized Sirrus 2012) because I thought this will be a faster way to get a running bike before summer ends. Far too late for that now but never mind. :oops:
I wanted to have two motorised bikes anyway. I'll always be riding solo if I don't build two bikes, haha. :rolleyes:

The Sirrus has been a touring bicycle work in progress for a while. I was fitting it with a more aerodynamic cargo system, trying to improve on the typical square shaped panniers and bar bag, to help with the headwinds I face on the coast. I wanted to have room for the things I need during the ride, and a modular system so I can just carry some of the bags when I only need certain items. I wanted plenty of room in the handlebar bag for my things. This is as far as I had got with that idea
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However I had stuck with the stem and bars that came with the bike, the straight fork, V brakes and the 32 spoke wheels.
I have been carrying more and more stuff on cycling trips. I wanted easier/better equipped camping, fishing and snorkeling but weight had become a problem already. Then the bulk became a problem, too.
Then I added a single wheel trailer for the bulk, and that increased the weight even more.
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All the water, food and stove fuel, clothing and personal comforts needed for the journey was growing exponentially as the weight slowed me. Trips to the nice places were taking too long and leaving me too saddle sore. :(
This bike needed an engine!

So this build is intended for long distance, up to 80 miles, but further than that when it has proved itself. :)
It needs to be pedallable if it isn't possible to fix on the road.

It has to carry shore fishing rods and rod rests along the top tube, which is why the rear rack is so high up.
I will try to carry all of my fishing equipment on the bike, so that I can camp in one place and make little trips out to the surrounding areas without always bringing the trailer with me. :)

So yeah that's basically what the bike is for and why it is this type of build on a so-called "hybrid" bicycle.

For the motorisation I have upgraded the wheels and the fork using the parts left over from the Dawes Galaxy Cross, and I have upgraded the brakes to hydraulics which I bought used on fleaBay.
I just got the front brake working without dragging on the caliper body (it wasn't meant to take a 220mm rotor!) by removing some material from the caliper body.
I also put better cranks/chainset on it, I have bigger chainrings again since I will be going faster.
Used different pedals too, because I want to keep the Shimano Saints for the D.G.C. mountain bike style build, but these are still awesome with their two sealed cartridge bearings per pedal and with replaceable steel pins.

I have tried to make it a stealthy bike by using the noise moderation techniques that are mentioned in the forum. I probably have some more work to do there.

I have been trying to build a reliable drivetrain too. I hope I have done a good job.

I have added a better head for cooling and reliability, and made a "head steady" to relieve the stress on the two lower engine mounts.
I have done some crank balancing work, done some port widening but no changes to port timing, retarded the ignition timing, improved the air filter and lengthened the intake.

I didn't want to use the rag joint sprocket mount but the top hat adapters are expensive to get shipped overseas. So I made my own double sprocket mount for standard mountain bike chainrings.

I got the single speed drivetrain set up without burning my bridges so I will test it like this, and then look into setting up the two speed system later.

I took the bike out once and couldn't get a spark. It has an upgraded spark plug wire, NGK boot and NGK iridium plug but I managed to break the thin wire coming out of the CDI. I'm 99% sure the problem is fixed now but I can't try out it due to a recent injury.

I had to fix a leak from around the fuel tank nipple when I found fuel actually dripping from it.

I have to fix some other faults I found during my first outing before I can get it out again anyway:

The plastic front fender keeps touching the tyre and dragging noisily (when will they invent lightweight plastic fenders that actually stay straight?)

The chain is never going to be quiet without a toothed tensioner pulley; but I needed to try out this "double" tensioner in readiness for my attempt at making a two speed shaftless shifter.

I should have got around to shortening the idle screw on the carburetor, it does catch on my trouser leg as predicted. I'll get to that soon.
The >29" wide handlebars are going to take some getting used to. I hope the width proves useful when I actually load the bike up with some heavy cargo for a camping & fishing expedition.
My inverted gripshifter was confusing me on my first ride. I'll have to relearn which way to twist. At least I was pleasantly surprised with the front and rear gears' function having never tried this particular combination of components before (except when I tested indoors on the trainer).
I have a better rear derailleur on the way: 9 speed Shimano SLX (shadow) so I'll have to change that sometime soon, although the Acera I have is working.
Oh, and it still needs the new updated handlebar bag and side panniers.. And some good bright headlamps preferably with a bit of a bluish tint!
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I say go for it Furry. - - As for me, I started working on a front fender cut from a cheap stainless steel bowl, but it turned out to be too flimsy. So now I've started on one from a piece of flat stainless sheet, using my cheap English Wheel to shape it. Sadly though, to get enough curvature to match the wheel diameter, I'm going to need a metal shrinker, so I'm waiting for one to go on sale.

Thanks, Arty. I never tried to glue/fix together any complicated shapes from plastic before but I will have fun trying things out. :)

I have to say it wouldn't occur to me to use metal (particularly steel) for a fender. The strength just isn't needed.
Front fenders are the trickiest I reckon. They have to go low enough to stop the spray, and have to fit closely to not catch the wind too much.
The plastic one I got isn't great but it fits the wheel reasonably well.
With luck it will actually increase the speed and efficiency (comparatively to carrying the same cargo in awkward square panniers).
I don't mind at all if it looks a bit like a dragon's head at the same time. :)
Hehehe, makes sense to me!
There's only one rule in motorcycle fairing design: Don't make it look like a p*nis. :eek:
I've started wrapping tape around a layer of bubble wrap, around my fishing cushion and the rods & rests.
I had to put the black electrical tape eyes on it to avoid breaking the rule above. lol! :rolleyes:
This first layer of temporary support allows me to get an idea how to cut/glue/position the bits of plastic. :)
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Normally the way to avoid the penile problem is to fit two headlights like eyes. I have actually seen a motorcycle with a pair of headlights one above the other behind a lens that's a vertical line. What were they thinking? :rolleyes:

Don't worry, I'll add brow ridges and stuff to make the shape much more like a dragon face and less penissy. The thing pictured is just a layer of bubble wrap and tape as a temporary support structure. I'll build the fairing on the outside of that.
Actually I think I need this done sooner rather than later so I'll probably have to sew a temporary soft cover for the cushion and rods, rather than going straight for the hard shell, sculpted fairing with lights built in.

Only had my stitches removed yesterday so this is probably unwise lol, but here we are miles and miles from home lol. Only intended 5 miles each way but I reckon I have gone a bit further. :oops:

It's sunny today, storm Ophelia just passed so people are out walking dogs and cycling in the still pretty brisk wind. I kept stopping the engine while passing people. I have not got the idle working yet so it's very convenient using the clutch + released throttle to kill the engine.
It starts very easily and pulls okay. I don't mind a bit of pedalling to accelerate up to 15mph or so, then it produces enough power to accelerate away into the wind without any help. :)

I am having the loosening headset phenomenon like @Rusty_S85 was having. I have tightened it once and now at the cliff top sea view lunch stop I'm tightening it again. There's a bit of a tickle from vibes but nothing numbing. :)

It's a struggle to not to WFO all the time hehehe it's so fun and eats up the miles. :D

I did about a hundred yards on loose stones (beach car park) and it coped well but im glad it isnt all like that around here.
Here's a photo or two before my phone battery goes dead. :)

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Home now and having a coffee. :)
I am tired from all the pedalling when I was passing people or when there were more people ahead so I kept the engine off until I had passed everyone. There was quite a headwind on the outward leg of the trip! Not to mention there's a few patches of sand that has built up on the path, which I had to pick up my bike and carry it over.

My wireless speedo doesn't work when the engine is running. It was worth a try I suppose. So it only recorded my distance and top speed when I was pedalling only. Of course I still pedalled lots with the engine.
I did get up to a good speed once or twice into the headwind but mostly only used WOT for a few seconds at a time. It splutters a little bit, but clears up and is very smooth when it's pulling me up steep hills. :D
That's with both WOT and with up to 3/4 throttle. I think that means the carb is set correctly for break in.. just a little bit rich. o_O

I lost power on the way home. Suddenly at about halfway home. I am fairly sure it was because I had used up all the fuel. :oops:
I didn't fully fill the tank since the leak. I just poured in the amount of fuel that I had drained into a bottle when I discovered the leak, so I probably went out with only about half a litre of fuel, thinking that I would only be going 4 or 5 miles each way. :rolleyes:

Apart from the headset loosening up, I didn't have any problems. The gears need adjusting of course, like any new gear cables always do. There's a bit of oil getting on the rear rim but not a lot.
The intake is noisier than the exhaust. The stealth exhaust system (muffler wrapped + 83cm silicone hose exhaust extension) works well, I think.
I would like to make some sort of a shroud around the front of the air filter just to cut down on the high frequency (more raspy) sounds from the intake.
Over all, the noise level is very low. Surprisingly stealthy.

I'm very happy with my bikey. :D

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I've just done some gear calculations since my wireless speedo won't work when the engine is running.

With my 700c wheels and 32mm (1.25") tyres and 42t rear sprocket, BikeCalc says that I am going 19.1mph per 1000RPM of the drive sprocket (4100RPM of the crank).
I can only really read the first two digits on the tachometer while riding, so my approximate speed can be calculated from the tach as:

(RPM/1000=k e.g. 41** = 4.1k)

k÷410 (x 1.91) = mph , or
k÷214.66 = mph

4.1k = 19.1mph
4.5k = 21 mph
5k = 23.3 mph
5.5k = 25.6 mph
6k = 28 mph
6.5k = 30.2 mph
7k = 32.6 mph

I definitely saw over 5.7k (= 26.55 mph) on the tachometer into a brisk headwind during my first test ride but I stopped looking at the tach at that speed lol!
I think I let off the throttle around/before 6k, since I am supposed to be just breaking in the engine, seating the rings.

I'll have to get a wired speedo or see if I have an old one that will still work, then I can get a more accurate figure. :)

I noticed that the chart included with my speedo is a bit optimistic about wheel circumferences. It appears that they didn't imagine that the tyre will be squashed down by bike and rider weight and will be around 10% less deep in use. :rolleyes:
I have been setting the speedo for my actual real life "rollout" and not the unweighted circumference.
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I have only received one of the cheapo basic frame bags from China, so far. It is about the right shape and size for what I need but the Velcro was on the wrong sides for what I wanted to do with it, which is why it was behind the saddle during my first test ride.
Today I cut the Velcro off one side and moved it to the other, and added a new bit, and a couple of buckles to the Velcro straps on the seat tube, to give the Velcro a 2:1 leverage so it secures better. I have cut some pieces of card, to be replaced with plastic later, to stiffen the sides and give the bag a bit better shape.

The bag will be used for carrying as many 4-7.5oz lead weights ("sinkers" in US) as I can stuff inside.
The best position on the bike for carrying such heavy items is low as possible and in front of the bottom bracket, but as this isn't practical I will carry them within the front triangle as close to the bottom bracket as possible.
I think this also (unimportantly) adds to the looks and the aerodynamic shape of the bike too. :)

Since I'm not able to go on any fishing trips just yet (still healing) I am using the bag, just for now, to carry a spare inner tube and a pair of rubberised gloves. :)

(Sorry for the poor lighting, it's a stormy day here today)

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Got the second frame bag today and moved the Velcro straps around a bit, and added a cool micro quick release buckle on some doubled flat elastic to hold the top corner up to the saddle clamp. :)

Now I just need to paint over the white lettering with some black acrylic paint.