Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Thoppa

Pages: 1 [2] 3 4 ... 8

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

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.

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

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 battery’s more important jobs is to handle the massive charge punched out by the alternator at high revs. Without it, you can fry your electrics."

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. 


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.


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.

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 :-)

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

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 :-)

Here’s 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. It’s in order of expense, highest to lowest.

1. Fuel: on my regular commute I get 32km/l. That’s  $1,235 for 24,000kms. It’s 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 I’ll never sell it so it’s a total loss from purchase. As a result, depreciation loss per year keeps decreasing the longer the machine is in constant use and it’s had 5 years of this so far. The Ninja cost $5,000 and I’ve had it 10 years, and it’s still worth something, so they’re 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 it’s 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 I’ve 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. It’s 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.

Citycom 300 / Re: Citycom 300 front fork seals
« on: January 14, 2020, 05:54:33 PM »
I finally got time to replace the seals so here's a brief how to. It's quite similar to cheap motorcycle forks.

The main difference with cheap motorcycle forks is that the fork tops don’t unscrew like a motorbike – there’s a rubber cap that pulls off to reveal a white plastic insert that is fixed and doesn’t seem to have any way of removing. So there's no access at the top of the fork leg. The only way to disassemble is to undo the 8mm hex bolt in centre of the bottom of the lower fork leg.

Another difference is a circlip on the top of the stanchion above the steering clamp. This stops the forks from sliding out when unclamped. It’s not too difficult to unclip using a thumbnail. There's also a diameter change in the stanchion top that stops the fork stanchion from being pushed through the clamp beyond the design limit.

Another difference is the springs can’t easily be replaced because they are part of an assembled unit with the upper stanchion. When the hex bolt at the bottom of the lower for leg is undone (just like a motorcycle), the whole stanchion/spring/damper rod assembly slides out of the lower fork leg so the two are very easy to take apart, allowing easy access to the fork seal. The hex bolt is the 8mm and needs a few whacks with a hammer or impact driver to make it loose from the damper rod – that’s the same as a motorbike.

After replacing the seal and reassembling the lower fork leg with the stanchion assembly, fork oil has to be poured in slowly through the hole at the bottom of the fork leg where the 8mm hex bolt fits. You can't fill it from the top of the stanchion because of that white plastic plug at the top of that assembly. After filling, insert and tighten the 8mm bolt and it's done.

I used 120ml of ATF in each leg, and because there was really no damping before, it now feels heavily damped.

Citycom 300 / Re: Short Sport Screen for Citycom
« on: November 19, 2019, 07:32:21 PM »

You didn't post any photos/link to photos .

I don't know of anyone selling screens other than Givi and they tend to be bigger?

Have a look through this thread - it's the most exhaustive for all things Citycom.

General Discussion / Clutch pad thickness - how thick when new?
« on: November 13, 2019, 07:34:21 PM »

Does anyone know how thick clutch pads are when they are new for the SYM 250/300 models?

I have a Citycom 300 and the service manual says the wear limit for the pad "lining" is 3mm, and the pads measure 3.5mm thick after 62,000kms. If I know how thick they are when new, I can work out how much longer they should last.

The manual p.143 also says the thickness of the clutch "weight" is between 6mm and 3mm. Does it mean the weight is the lining? Anyone confirm the pads are 6mm thick when new? If so, it's 25,000kms per mm of wear for my commute, so another 12,500 or so left before I need new "clutch weights/lining".

I just changed the belt - lasted 40,000kms - so if I can avoid taking that section apart again for a while, that'd be great.

There were no other problems when I did the job yesterday - lots of black dust of course, and some minor wear on surfaces, but nothing problematic with clutch, variator, etc. The new belt has dropped the revs by about 10-15% for a given speed and the machine seems to be a little smoother, with noticeably less mechanical noise at idle. After 40k, the retired belt was 22.7mm wide, with the service limit being 22.5mm, and it was also showing some lateral cracking in the grooves.

Thanks for any help on the pad thickness :-)

Citycom 300 / Re: maximum engine mileage
« on: November 08, 2019, 07:43:58 PM »
My CC has turned 62,000kms - new spark plug and engine and gearbox oil changes. Belt is barely okay so I'll change it during the Christmas holidays.

I paid a little more attention to oil levels these last 3,000kms and it seemed okay. At the oil change, 1.0L came out and 1.2L went in. I'll park her in the same spot, let her cool down, and take a pic of the oil dipstick over the next 3,000kms to make a more accurate assessment of the oil loss.

The LCD display is slowly worsening - I guess it is the polariser screen cos this looks a lot like what happens to old Gameboys. It's still readable during the day but it's impossible at night with the backlight washing out most of the display.

But still she takes me to work and back every day without issues so I wonder how much life she still has left.

I'm tempted to get a Joymax Z when the LED headlight version is released - it was on show in Tokyo last week.

Citycom 300 / Re: ecu
« on: September 16, 2019, 07:17:20 AM »
Hello to Georgia,

Have a look on this thread?

Citycom 300 / Re: maximum engine mileage
« on: September 07, 2019, 02:30:03 AM »
I just did an oil change at 58,821 and a lot less oil came out than usual. About 700 to 800ml came out I'd say, and it's usually over 1 litre. It took the usual 1.3L fill so it's not trapped - must have burned in the engine I guess, which means the engine is now showing signs of wear.

The LCD dash clock has faded too - the fuel gauge and ODO are still fine - just the central part of the LCD display is failing.

The next service is more major - will need a new spark plug, belt, both oils and maybe more, so I'll keep an eye on the oil level before then too. I wish it had a sight glass :-(

Citycom 300 / Re: Blowing Ignition Fuses
« on: September 07, 2019, 02:22:49 AM »
Mate, you did great fault finding and I'm pleased you got it fixed  :-) Thanks for sharing.

Comparing all the Sym models, the seat height is largely due to the 16" wheels, and you get more luggage space with smaller rims too. Hope she finds one she likes and you don't mind working on :-)

Thanks... and sorry, but it became necessary to lock down the blog so it's dead now - no access to anyone. There's not much more there anyway - just my waffly opinions on stuff - nothing actually useful.

BTW, she's just about 56,000kms and the rear brake light switch is playing up again. It seems the dealer fitted a crappy pattern part and ripped me off. It's a stupid cost cutting move so typical here - there's a China phrase "chabuduo" which means good enough, in other words, it works, but not for long.

Makes me wish I lived in Taiwan. 

Pages: 1 [2] 3 4 ... 8