Bike tuning questions

I ride a Hartford VR200XK and almost every other one I see on the streets (not so many after all) are heavily modified with brembo brakes, upside-down forks and tuned engines (looks like by easy-to-purchase tuning kits) and the lot.
Now aside from the brakes (which I am considering to get) I wonder what the fuss is all about. I mean, whats the advantage of having the bikes engine tuned to 250 or bigger cc - what about the gears? Can they take the extra force? What about a different exhaust system? How much would I get out of it?
Don’t get me wrong, I play by the rules and I am more than happy with my bike and its performance. As I said, aside from better brakes (any input on that issue is welcome) I would not want to modify the engine, but what is that all about? How much more in hp and torque would I really get out of it?

Have a nice day alltogether

ok, i was hoping for a little more input but never mind; i’ll figure it out.

Hang in Stefan - there are some pretty good motorheads on here, and a variety of opinions regarding your bike.

They’ll chime in anytime… :whistle:

“I play by the rules and I am more than happy with my bike and its performance”

Which is why I didn’t reply to you.


ok, let me rephrase:
if i want to tune, pipes and cylinder head and valves and the whole lot, what do i need to know first and what will i gain performance-wise?

I am assuming this is for off-road use only since riding a modded bike on public roads is probably illegal.

The more engine mods. you do, the less reliable the bike may be. Also, you might spend a fair bit of money for only modest performance increases.

IF I were to mod such a bike for off-road use, I’d probably just change the pipe, the carb jets and maybe the air filter. That would give a noticeable performance increase though of course fuel economy would drop. These changes need to be done together, as they are interelated. There are some bikes on which you can just change one of these three elements and still get a performance increase but, in general, best results are obtained by making sure all three are “tuned” together.

I don’t think I’d bother with any increase in cylinder capacity. I think that would decrease reliability and wouldn’t make that much of a difference in performance.

Braided steel brake cables are very worthwhile.

Aftermarket suspension parts are also worth looking into.

All for offroad use of course.

suspension and brakes should always be the first you do… you’d be surprised how much difference it can make when you’re gunning it in the mountains…

as for power… add nitrous :sunglasses: this month’s ‘cool biker’ has two 125cc scooters with nitrous… then you too can quote “No, make it two, two of the big ones. And Harry - I need it by tonight.” Seriously, the amount of power you will get out of that bike is not going to be considerable, and you’re much better off buying a REAL bike if you want power. I have ridden race-built scooters (both 50cc and 125cc) before and I still was falling asleep even at full throttle… and I only ride a Hornet 250 normally…

PS. i asked a cop once about the shock i had installed at the back on my scooter… he said it was fine and they are more concerned about power making mods

so its just for show and a better sound… thought so. thanks for the input.
actually i have the streetgoing version, with 17" tires. its reasonably quick and strong for an engine that size and old design. but since we mostly ride it 2-up a little bit more power (read ‘torque’) would be welcome. but not at all costs. i once saw a bike like mine with a different cylinder head, actually having 4 valves and 2 sparkplugs. weired i thought. but maybe more effective given the same bore and stroke.

i’ve done the suspension almost immediately after i got the bike, it was way too soft, both front and rear. got a very reliable mechanic who helped me out.
changing to other brakes i consider for quite a while already. maybe its best time now to do it since the stock pads need to be replaced anyway and the oil probably too. so, nissin, brembo or what other brand? i think 2 calipers in the front are enough for a bike of this size and weight, but what about disc size? and do petal-shaped disc make a difference?

again, any idea welcome. don’t want to spend a fortune though and all the changes together should not exceed the value of the bike itself…

have a nice day

as people have already said if you’re after power / torque increases you’ll have to do quite a lot to get not very much improvement… at least exhaust, carb, filter… I’d be amazed if that got you even 5% improvement on that engine…

if brakes are your priority going with Brembo is a safe, top of the range bet… Nissin is owned by Honda and used OEM on the vast majority of Honda bikes and is fine, but focus less on aftermarket… AIRC the Hartford has only a single front disc, so I assume you mean two piston, single caliper front no?.. petal discs are 90% fashion / 10% function, they claim to offer greater leading edge surface area to cool the discs and some more extreme designs used on dirt bikes claim to prevent the pad surfaces and calipers from getting choked up with mud… anyway I don’t think there’s any real need to go to the expense of upgrading to double discs at the front, in fact I don’t think there’s any need to upgrade to Brembo or anything else… you’d spend probably 50% - 60% of the cost of a new bike to put in a single Brembo disc, caliper, lever/master cylinder…

If I were you I’d get a good quality S/S braided brake line (imported are usually better, try HEL, Galfer or similar), and some nice new EBC or similar sintered brake pads and leave your disc and lever/master cylinder/reservoir as is… take off the stock caliper, strip it, then clean it immaculately, use care and a nylon brush, not steel, around the pistons, do the same with the lever/master cyclinder/reservoir, if any seals show signs or wear and/or swelling, replace them, check the often quite soft alloy lever for signs of wearing down where it actuates the master cylinder, if worn, replace… then reassemble, install new pads and brake line (use new crush washers), fill with nice fresh DOT5 (assuming it doesn’t eat your caliper piston boots, or master cylinder diaphram, it shouldn’t but if in doubt DOT4 is fine) bleed the system over and over until all bubbles are removed and it’s perfect and then try it for a while… Also, if you’re going to do all this you may as well put some fresh, stickier rubber on it too since this will give a marked improvement in both braking and handling, a good local brand is Maxxis who make street tires in 17" sizes although largely for export, otherwise Bridgestone is the best value for money road rubber in Taiwan… If you still want more stopping power, time to talk to your flexible friend Mr.Visa…

thanks for that, exactly the info i needed. of course i meant 1 disc and 2 pistons on the front wheel…
the maxxis rubber came stock with the bike and i can’t complain about. when we go up the mountains (like 2-3 weeks ago to wuling farm) i can go to quite some angle without fear.
guess now that’s so much raining i will have plenty of time to work on the brakes. think will do together with the mechanic i found (posted under

one last question: i’d like to have a bit better windprotection so i looked at different websites with models of attachable windshields. no jokes, i don’t want to make a goldwing out of it, i just think a bit more would be better for a 184cm guy. the models on the websites where 200$ at least and thats just ridiculous. where could i get that here for a bike like that? does anybody know?

If your tires are the OEM ones that came on the bike, chances are Maxxis have much better / stickier aftermarket ones available… Also be aware that ChengHsin are the makers of the Maxxis brand tires, but generally Maxxis branded tires are better than their ChengHsin equivalent… Also, I can’t speak for your bike, but the Hartford supermoto I briefly owned came with OEM tires that were probably manufactured in the 60’s… even if your current tires are still okay, I’d take a look at new rubber, tires alone can make a drastic improvement to your bike…

MRA make shields for every bike imaginable… but in Taiwan finding MRA screens that will work on a “dirt bike” like yours will be almost impossible and anything you do find will be NT$5000 or more guaranteed…

It’s a bit ghetto, but if I were you I’d buy a sheet of good acrylic / plexi-glass / perspex… cut it to the appropriate size and shape, (you can work this material surprisingly easily, it’s even possible to get a good pro-looking effect by bending nice neat lines/curves using a vice with a couple of pieces of flat wood) then look around at the B&Q or a better hardware store for a decent mounting solution to attach to whatever seems solid near your instrument cluster… Alternatively you could go to a scooter shop, buy one of the purpose made NT$300 windshields for use on scooters and cannibalize/re-engineer it…

you’d probably be aiming for something similar to this I guess…


MRA make shields for every bike imaginable… but in Taiwan finding MRA screens that will work on a “dirt bike” like yours will be almost impossible and anything you do find will be NT$5000 or more guaranteed…

It’s a bit ghetto, but if I were you I’d buy a sheet of good acrylic / plexi-glass / perspex…[/quote]

The coffee stall at the University I pretend to teach at had an article on Japanese Biker Gangs (“Bosozoku”, apparently) in one of its glossy “Cosmo for Men” magazines (GQ, FM, that kinda crap). Along with the kamikaze clobber, retro riding boots and baseball bats there were some pics of mini-chopper-styled bikes with small windscreens. These looked (to me) very much like they’d been adapted from the sort of curved full face perspex screen people wear when using an angle grinder or a strimmer. The headlight poked out of where the top of your head would be, with some sort of flexible (rubberised?) cowl filling the gaps.

I think these masks are fairly cheap in the UK (and probably in Japan, or maybe they get somebody to knick them from a shipyard.) Of course in Taiwan I routinely see people arc-welding without ANY form of eye protection (!) from the (almost inevitable?) UV damage, so protection from merely possible splinter damage perhaps isn’t a consideration here.

If its of any interest I’ll try and locate the article, and maybe scan a picture or two.

The Hartford dealer down here is in a crappy old shop outside of town fairly close to our factory. One day I stopped in there and he was in the process of doing an extreme mod to the existing 200cc motor. I didn’t have time to check out the head or take a close look, but he did mention the total cost of the hopup was over 70k.

If you want, I’ll drop in and ask him some more details about what he’s done on Thursday.

Sounds sketchy I know, but if this white-haired old fart is doing it down in our hillbilly land, there must be more and better available in Taipei. Suspension and brakes is all good, but after doing the trip with you I know that more power is mainly what you’re after.

How fast do you normally ride around town? Maybe playing around with different sprockets as a cheap alternative, providing of course you are willing to give up your 80kph easy cruising.

I’ll put this question to Redwagon as he’ll have the answer…What other heads will bolt up to this motor?

thanks, but i think a 70+K engine job is a bit rich for a bike like this. for that money i could ask someone to weld my V2desmo that i have under my bed into the frame.
we have a saying in germany that says: ‘Keep the church in the village’ - read: ‘don’t do overboard with your ambitions’. my bike is red but will never be a ducati after all.
when i bought the bike over a year ago in a Nangang shop i saw hefty modded bikes there, but didn’t think much of it that time. my trusty mechanic discouraged me on that matter, too. he mentioned something in the line with ‘isn’t worth it…’. think i have to agree with him. and then i saw this other webpage whith pics of bikes where the authorities compare your bike to when you wanna sell it - and do all the re-building all over again… too much hazzle.
what i have in mind are rather minor changes as for the looks, practicality and safety. i was wondering in general about all that engine tuning, because virtually all other bikes of this kind i see are engine-modified. and as for the speed: the top-speed of the bike is somewhere in the range of 90-95kmph - not much but enough for where i go. certainly i wouldn’t mind to tackle the region beyond 100kmph but the engine is already screaming like crazy and sometimes im afraid it will pop any minute. better brakes have the higher priority to me. the engine runs well so modifications there i will keep in mind for some other time.

what about all the other readers in here with a hartford supermoto: what did you do to it? i can hardly believe i’m the only one with these questions. but then again, i don’t see too many of them on the streets. at least not in taipei. and if so, its the dirtbike version with 21" wheels. so, c’mon; tell us about your modifications here.

enjoy the day. it finally stopped raining so there s a good chance you’ll find me on some twisty mountain roads…

btw: someone, i think it was ratlung, mentioned he never did yangminshan on a bike. i know some very nice roads and corners there for a daytrip. shall we get something organized?

just found a nice article about windshields, especially for BMW.
check it out under

have a nice day.

ok, let’s not call it ‘bike tuning’ questions, let’s say: bike upgradiing.

i’m still quite interested in other guys stories what they have done to the bikes to increase safety, looks and/or performance, especially for the hardfort vr.
i found a windshield for less than 5K (with shipping) at - think it will fit and suit for the purpose. hasn’t arrived yet though, but if anyone is interested about whats better now (then) i’ll give an update.

another question: in case i’m willing to sell the bike one day, do i really have to reinstall the parts of the day i bought it? i mean, remove the brushguard, put back in the crappy soft stock rear suspension and all the lot? and then bring it to the authorities where the buyer and i do the handover of the papers? please, somebody, fill me in. i’d appreciate that.

have a nice day

In the US, one would probabaly go down to wrecking yard and get a bigger engine. Then, rebuild it and slip it in the chassis. Probabaly something like a 600 cc thumper donated from a Honda XR would do the trick.

I know that engine swapping cannot be done with cars, is it possible with motorcycles?


ryan wrote:

good question. should be possible but in scooter-land quite difficult to come by, i reckon. and it will be a heap of junk anyway. wouldn’t trust it. but aside from that, any engine should fit in that big frame, question is only if the frame can take the extra weight and vibration… makes me think that it’s not such a great idea after all.
but good point though. has anyone done that? was it worth it? (think i will dust off the desmo-twin under the bed, just in case :happybiker: )

keep posting.

As far as I know, it can’t be done, legally that is.