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Messages - Thoppa

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1
Citycom 300 / Re: citycom panel problem
« on: December 12, 2020, 10:44:54 PM »
I guess it is the Hall-effect sensor switch - it either cannot trip itself enough times per second to get to the frequency of switches needed to exceed 60kmh, or it can, and the cable has a problem sending the pulsed signal, as you guessed.

But why. Is it not picking up the ferrous bolts correctly? Is it corroded inside? Is the cable coming out of the speed senor corroded?

The cable has a double rubber protection but tiny amounts of water can get inside and will collect at the base of the cable - its lowest point - where the cable comes down from the frame then bends back up again to the wheel speed sensor mount near the brake caliper. This copper cable can corrode making a poor connection. This bad connection creates an intermittent issue and/or increased resistance, either of which would prevent the cable transmitting the pulsed signal accurately/correctly.

So, if you have the tools, you could remove the rubber protections around the cable near its lowest bend and see if there is a problem with corroded copper.


2
Citycom 300 / Re: citycom panel problem
« on: December 03, 2020, 03:19:07 AM »
Hi,

Welcome to the world's least active forum.

It sounds like the needle is sticking in position - jammed - needles can get stuck or come loose over time, to the point where the stepper motor that drives them is not powerful enough to overcome it. I got a sticking needle on another machine - I had to remove and disassemble the display to find out that was the problem. I adjusted the needle position out from the dial using a fork as a lever. The other problem could be that something has come loose and is jamming the needle. Has the display been sitting in the sun for long periods? Has it had an impact of any kind? How old is the machine?

Normally, when you turn the ignition on, the needles do a full sweep to their maximum position and then return. It sounds like yours are only turning to 20kmh and then not returning? Then they move to 60kmh and stick there when the front wheel rotates - do they go back to 20kmh when the wheel stops turning? Is the movement between 20 and 60 somewhat normal?

3
General Discussion / Re: What is the latest news from SYM?
« on: November 28, 2020, 08:14:00 PM »
Hi,

Gogoro are great - the battery swap stations in Taipei work so well. I'd get an electric scoot if they had that here in HK. We have hardly any electric two-wheelers because the govt makes it obstructively difficult to get them registered. There's one company that has just managed to break through the red tape - hopefully more will follow.

The other place for news is SYM's own site (but I guess you checked that already) - they signed a deal with GFX in Thailand recently. And they have been working on e-scooters for over a year now - two models - but they aren't great.
The e-scoot
http://www.sym-global.com/news-events-page85
News
http://www.sym-global.com/news-events

4
General Discussion / Re: What is the latest news from SYM?
« on: November 28, 2020, 03:08:51 AM »
I live in Hong Kong and have relatives in Taiwan. Because of the way HK is going, we might leave and one option is Taiwan, so I pay attention to Taiwan news. There was some about Sanyang 三阳 (SYM) being very popular in S America but it isn't the kind of news of a deal or anything like that which could send shares suddenly higher.
https://twmt.vi.taiwantrade.com/news/taiwan-s-sym-scooters-highly-popular-in-el-salvador-embassy-39366.html#
Focus Taiwan is my main source of English news:
Gogoro
https://focustaiwan.tw/sci-tech/202011280006
Kymco
https://focustaiwan.tw/business/202011260018


5
General Discussion / Re: Bike died
« on: November 15, 2020, 07:05:07 AM »
I think it is usually called an engine stop - is it rhs or lhs on the sym? but it also is effectively an engine won't start too right? Plus, the engine won't start unless a brake light switch works so if they both go at once.,,,

6
General Discussion / Re: Bike died
« on: November 13, 2020, 05:51:41 PM »
How do you know the underseat security switch actually works? I would test this and the other "kill" switches such as those on the sidestand and right hand switchgear.

7
Citycom 300 / Re: Bike died
« on: November 13, 2020, 05:48:42 PM »
The better version of this post, with answers, is here https://symforum.com/index.php?topic=14537.0

8
Currently running Pirelli Angel.

The site I linked to does have some issues - he talks about hard static unpolished surfaces and equates them to soft dynamic polished ones, which is misleading, so his brick on steel analogy is inadequate.

These quora answers are much better https://www.quora.com/Why-do-tyres-with-larger-contact-surfaces-provide-more-grip-when-frictional-force-has-nothing-to-do-with-surface-area

I also read this research which says, "As inflation pressure increases, contact area decreases whilst wet grip increases." It sounds counter-intuitive but might explain why the smaller contact area of the front tire seems to have more grip in the wet than the wider rear.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjOmfnPuvrsAhUbM94KHXE0CggQFjABegQIAxAC&url=https%3A%2F%2Fpure.ulster.ac.uk%2Ffiles%2F11388459%2FMeasuring_grip_and_the_contact_patch_9780784413005.278.pdf&usg=AOvVaw1I_kxP_XjPL700tW7ljZtM

9
Hi,

I've noticed my Citycom scooter is more prone to a rear loss of grip than the front. In fact, the front feels so unloaded it never feels anywhere near losing grip, but I can get the back to move around with some deliberately aggressive control. I wonder if this is true for scooters generally? It certainly feels quite different to a motorcycle in this regard.

I know it isn't the tyres - front and rear match so they have the same grip, and pressures are correct, both warmed up, running on the same surface (of course). It is, of course, harder to get the Pirelli Angel to slide compared to Maxxis but that's the coefficient of friction, nothing else. There's a discussion of why contact patch is largely irrelevant and it is weight that offers traction on this page https://www.stevemunden.com/friction.html

My Citycom seems typical for a scooter with a strong rear weight bias - 77kg front 107kg rear is roughly 40/60 distribution. So the rear should have more grip, yet it feels the opposite, with the front being more secure. Maybe it's the huge sprung weight of the engine assembly at the rear that has an effect?

Has anyone else had this experience? Is it a thing?

I've been riding for 30+ years - learned to do stoppies and get my knee down on sports 600s, wheelie and slide on a supermoto, so I find it hard to believe I'm imagining it.

The CC is my first scooter - just hit 70,000kms, 66,000 of which are my use, and she's still running well, although not as well as 40,000 ago. Top speed is much lower and fuel consumption is higher.

10
Citycom 300 / Re: Citycom 300i - electrical issue / not starting
« on: August 23, 2020, 05:17:09 PM »
Hi,

Sorry to hear about your problem.

I think the electrician has found the cause and it's likely you have fried the electrical system. So that will mean replacing everything that could not handle the surges such as the the bubs, ECU, maybe the speed display unit.

Scooters run at mid to high revs a lot of the time so the alternator is producing close to its maximum output, and if a large stabilising load like the battery is removed then reconnected, this could cause the alternators output voltage to rise before dropping down again. This seems to be what you experienced.

"Can you run a modern motorcycle without a battery, and the answer is most definitely, no. One of the batterys more important jobs is to handle the massive charge punched out by the alternator at high revs. Without it, you can fry your electrics."
https://firstcheckpoint.com/will-a-motorcycle-run-without-a-battery/

11
General Discussion / Re: Clutch pad thickness - how thick when new?
« on: May 02, 2020, 11:18:26 PM »
Update - it seems I measured the thickness incorrectly - I measured the outer top of the pad to the metal of the shoe/weight which is the the thickness of the material above the surface of the shoe - that was 3.5mm. However, the shoe has a 2mm recess which is only visible on one side of the weight, which I didn't notice before. This means the pad thickness is actually 5.5mm, not 3.5mm as I said before.
Here's a pic that shows the recess, although it looks much smaller here than it measures.


I found this out because I bought a replacement clutch assembly on Taobao and noticed the pad thickness of the new one, 6mm, wasn't significantly different to the original. So in fact, it didn't need replacing and probably won't for another 60,000kms of my mostly highway commuting - good for 100,000kms + of mixed highway/city riding.

About the replacement - I saw on expensive Ebay ads that the clutch from the Yamaha Majesty YP250 was the same as the Citycom 300, RV250, etc. I then hunted for a YP250 clutch on Taobao and found a China pattern part assembly for US$35 - that's the complete assembly including the outer drum. I figured it would be crap (and the metal is crude) but I only wanted the pads, and I can't get them easily otherwise, and if I ended up throwing most of it away and keeping the pads it would still be the cheapest option. Long story short, that's what happened - I ended up throwing it all away except the pads/weights, springs, and circlips.

So did it fit? well, yes and no.

The outer drum doesn't fit because although the shaft is the same diameter, it has larger and fewer teeth than the Citycom's shaft which has smaller and more teeth.

The rest of the clutch assembly fits (SYM part number 22300-HMB-000) BUT it needs an extra washer on the engine side - a very specific washer size and thickness so the back side is spaced outwards and doesn't interfere with a lump in the engine unit housing. I'm guessing the Yamaha doesn't have that lump. With just the right size spacer/washer, it fits on both inner and outer bearings, but only half of the outer bearing makes contact with the shaft. Without the washer, it fits exactly on both bearings, but fouls the housing. I only had one suitable washer - a standard part - a custom made spacer might be better, or just using the original drive plates would do it because they have a little spacer/riser designed into the shape. Maybe it was not that the Yamaha part was wrong, but the China pattern part was missing the riser and had located the outer bearing 3mm too far along the shaft.

It's shame this site doesn't host pics - one pic of the riser would show very clearly what to look for. Here's an online pic of what I'm talking about but it doesn't clearly show the rise at the centre.

It seems it's possible to make it fit with some more involved modification so I tried to disassemble it to see if/what could be done to create a perfect fit. I used two large c-clamps as spring compressors and tried to undo the large (46mm) nut holding the assembly together. I failed. That nut has been put on so firmly I could not shift it either with torque or shock.

So, because I couldn't get a perfect fit, and there's no way to modify it, I just cut out the three shafts holding the weights, and removed them, the springs, etc and threw the rest in the bin. One day, I will try to get the SYM clutch assembly apart to replace the pads but it doesn't need doing anytime soon. 

12
Hi,

It's quiet here too - well, at least for Hong Kong - even under the virus, it's still busier than say, Canberra, is on a crazy day. We get 50 million tourists a year - no exaggeration - hundreds of thousands every day from China - but that's now a few hundred a day. I actually like this aspect, but still can't wait for the virus to go away. What a catastrophe.

I doubt I'll ever get to test my LiFePo4 battery in cold weather - rarely less than 10 degC here and never below freezing even on a mountain top. The battery is rated to -20C - a "Power Start Super Natto" - but I doubt it does what it claims though, like all China stuff. They do a version with a Bluetooth kill switch for security/anti-theft which seems like a good idea that is bound to go wrong. But the 2 batteries I have so far have been excellent - I was surprised how it actually seems to make the scooter more lively. I had not expected that.

https://item.taobao.com/item.htm?spm=a312a.7700824.w4004-18617185565.3.335c7be8SNLebl&id=13314463089



13
Hi,

I haven't had any trouble with bulbs, although I did replace the original headlight unit with some relays so I could use LEDs.

The Wuhan pneumonia virus has meant the CC has been parked outside, rarely used for 2.5 months now as I work from home. I charged up the battery once during this time but it seems that was not enough and the CC refused to start on a journey home from the supermarket. I left plenty of time between starting attempts so I know it wasn't "flooded" and I thought it must either be the battery or stale fuel.

I got the bus home, took the battery out of the Ninja ( they are identical types - except the Ninja has a LiFePo4 lithium iron phosphate battery ) and went back to the CC to first try a replacement battery - started instantly. So, not stale fuel but an underused battery.

I charged and tested the battery - it charges up fine and hits 12.6V fifteen minutes after the charger is turned off. It should be 12.8V to be a-okay, so it is a little old after five years.

A new LiFePo4 battery is $45 here so that adds US$9 to the annual cost.


14
Citycom 300 / Re: Citycom 300 running costs in Hong Kong over 5 years.
« on: February 28, 2020, 03:26:16 AM »
Thank you - it's a great machine and that's why I can do a five year review. And the CC is why I'm a scooter convert too :-)

15
Citycom 300 / Citycom 300 running costs in Hong Kong over 5 years.
« on: February 08, 2020, 09:11:04 PM »
Hi,

I thought I'd share this with y'all since I think my CC is one of the best ways to commute and I'm willing to argue that with any takers :-)

Heres a record of the averaged running costs over 24,000kms (2 years for me), in US$. I've done over 64,000 in 5 years so far, and although the LCD display is almost dead (burned out in the middle, like an old Gameboy), the rest of the scoot is fine. I bought the CC with 4,000kms on the clock, 4 years old, for $3,000. As you can see, the biggest costs are fuel, depreciation, and paying the man. Its in order of expense, highest to lowest.

1. Fuel: on my regular commute I get 32km/l. Thats  $1,235 for 24,000kms. Its mostly highway at 100km/h plus some lane sharing through jams and a little city riding. Compared to my Kawasaki Ninja 650R, this is a saving of about $600.

2. Depreciation = $1,200, 2 yrs the machine cost $3,000 and I assume Ill never sell it so its a total loss from purchase. As a result, depreciation loss per year keeps decreasing the longer the machine is in constant use and its had 5 years of this so far. The Ninja cost $5,000 and Ive had it 10 years, and its still worth something, so theyre about the same. The CC would be impossible to sell here - the old age and the relatively high seat means no-one would buy it. It's fairly obvious that the more often you buy/sell vehicles, the higher this cost is, and it can easily be the most expensive.

3. The man - government mandated costs insurance ($200 for 2 years), and road tax ($325 in 2 years) = $525 in 2 years / 24,000kms. Again, the insurance is 30% cheaper than the Ninja.

4. Tires $120 Maxxis lasted 18,000kms, would cost $100 to replace, but typically scooter tires cost around $200-$300 for 24,000kms it seems? For me, the actual cost of Seyoun NJK is US$60 for 12,000. Compare to my Kawasaki Ninja, which is $250 for 8,000kms, the Ninja is over 6x the price of the CC.

5. Belt $50 replaced at 21,870kms when the revs started rising a little not fully worn $80 for the SYM part: Mitsuboshi is $55 on Amazon. The second belt had worn to 23.1mm at 49,460km. The service limit is 22.5mm. I replaced it after 40,000kms of use (62k on the ODO) when it was 22.8mm and looking a little cracked between the grooves. Say $50 for 24,000kms.

6. Oil changes every 3,000kms and gear oil every 6,000kms is 11 litres of 10W40 engine oil and half a litre of gear oil (Castrol GL-5 85W-140) for 24,000kms = $45

7. Air filter switched to K&N = $150 for the filter, cleaner and oil = a lifetime, so its hard to say, but call it $40 for 24,000kms.

8. Transmission clutch, variator, rollers, etc. still working fine at 62,000km. Clutch pads at 5.5mm wear limit is 3mm so clutch life is 120,000kms or so. Again, hard to say, but call it $40 in 24,000kms.

9. Brake pads the front and rear use the same pads and Ive used 6 sets in 60,000km the originals, 1 pair of EBC sintered ($20), another EBC organic ($10) in the front and some very cheap unbranded pads in the rear ($2.50). Brake fluid was replaced at 30,000kms for $15. Overall that is $20 in 24,000kms. The rear brake is so powerful, every pad I've tried has made little difference. The same can't be said for the front, where only the EBC are good enough, and the SFA264HH sintered pads make it a decent brake.

10. Spark plug Iridium CR8EIX or CR9EIX (tuned) every 30,000kms or so is $10

And that's it for running costs.

For repairs, I needed new fork seals and ATF fluid ($50), a new main stand bump rubber ($10), a new left brake light switch (a standard part used widely on a huge number of machines, $5), and some rear axle nuts and thread lock ($10). I might say I need a new display but not yet. It's bad but the ODO and fuel level are still readable. The clock can barely be made out, which means it's useless on the go when I need it.

The total running costs are $3,285, and it means $0.137 per km or $9.58 for my 70km commute. In Hong Kong, it means about HK$1.07 per km, or HK$75 a day, which is about 35% more expensive than the cheapest public transport but it's less than half the time, and is so much more enjoyable and convenient. Its also about $600 a year cheaper than the Ninja, mostly because of lower tire, fuel and insurance costs. 🙂

I've got my eye on an X-Max 300 and a MT-09 as replacements/upgrades, but as long as the CC and Ninja keep doing what they do, I am holding off on the new machines.

Well done SYM - you made a mighty fine scooter.

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