Preload Adjusters for my NSR

Life Cars & Motorcycles
1

Just checking those preloaders on a few online forums. Some say they are OK but couldn’t find any outstanding reviews, some say they are a total waste of time and money…

How much do they go for RK, if they aren’t that expensive, I will give them a go. They supposedly changed my oil in my front shocks the first time I went to WuTian, but I didn’t notice any difference. Can they put in stiffer aftermarket springs, too??? Ha, are there springs in there, for some reason I thought they only worked on oil pressure… Any idea on price for heavy duty springs?

I got a new rear shock with the damper (slow raise thingy) a while back now and that made a big difference reducing the back end from jumping around, especially on Turn 1.

I have also seen another thing attached to the front end of some of the bikes out at TIS, kind of looks like the piston closing mechanism on doors to make them close slowly. My guess is that they are to reduce the front end from twitching left and right. I get a big wobble sometimes coming onto the main straight specially when I change gear on a rough patch while leaning through the corner. I also saw a lot of scooters get the same wobble last Sunday on race day. DIdn’t notice it on the bikes as much.

thanks

2

[quote=“TaipeiSean”]Just checking those preloaders on a few online forums. Some say they are OK but couldn’t find any outstanding reviews, some say they are a total waste of time and money…

How much do they go for RK, if they aren’t that expensive, I will give them a go. They supposedly changed my oil in my front shocks the first time I went to WuTian, but I didn’t notice any difference. Can they put in stiffer aftermarket springs, too??? Ha, are there springs in there, for some reason I thought they only worked on oil pressure… Any idea on price for heavy duty springs?

I got a new rear shock with the damper (slow raise thingy) a while back now and that made a big difference reducing the back end from jumping around, especially on Turn 1.

I have also seen another thing attached to the front end of some of the bikes out at TIS, kind of looks like the piston closing mechanism on doors to make them close slowly. My guess is that they are to reduce the front end from twitching left and right. I get a big wobble sometimes coming onto the main straight specially when I change gear on a rough patch while leaning through the corner. I also saw a lot of scooters get the same wobble last Sunday on race day. DIdn’t notice it on the bikes as much.

thanks[/quote]

Yeah the preloaders could be a waste of money, but I think they helped me a little. Beast619 used to bottom out his shocks until he went the cheap cheap route and put about 15 coins into each spring. I think I paid about $800nt for mine, but can’t remember. Next week, let’s see if you are bottoming out your shocks. I cam measure it for you with a zip tie. If you are then buy those dampers or put coins in there, but this is not guarenteed this will help. Yes our shocks have springs; I have personally rebuilt mine twice and have held the springs in my hand. I don’t know if you can buy stiffer springs, but I bet you can.

The other thing you are talking about is probably a steering damper. Personally for our NSR’s I think they are a waste of money because we don’t have enough power to produce high speed steering wobbles. People just add them for bling. I am pretty sure the stock 125 RS doesn’t even come with a steering damper and they have way more power than we have. (I could be wrong with the RS 125.) If you are getting the wobbles coming out of corners it isn’t the bike, it is probably you. You are probably holding on to the bike too tight. That’s what happened to me once (remember), when I crashed coming out of corner one. I was lucky and didn’t get hurt, but I got the wobbles because I was holding on way too tight. Now I have been very conscious about relaxing rather than becoming tense when riding. It has helped a lot.

Also I am wondering if you have ever adjusted your rear shock. If you haven’t then you probably should. You can tell a huge difference when you adjust it. Next time I can check it out for you. It just clicks left/right for soft/stiff.

If you want more power I think you definitely should buy a different carb. You can go really big, but I would start at a 29mm. That is what I run. Temple just got a 35mm (which I would like to run), but they are more unreliable. Also you can’t run a filter unless you custom make on. It is more of a pain in the ass, especially if this is your daily. A 29mm is what the stock NSR 150SP runs. It is reliable and you can still run your stock air filter. I just bought one for my friend. It cost about $2500 and that included the throttle cable. WuTian will have those in stock.

Another quick easy thing to make more power is by disconnecting your RC computer. I didn’t like it at first, but now I love it. This takes 3 sec at the track and I can show you how to do it. It also takes 3 sec to plug it back in. This will allow you to make power until about 12,000 RPM’s. But you will have no power below 7,000RPM’s. None of the racers are using their RC valves, so I suggest trying this too.

Oh yeah and take off that rear stand…:wink:

3

When I rode your bike, it felt really loose on the front, thats probably why you have some trouble with the wobbles. A steering dampener would help that issue somewhat, but only from the human aspect side of things, the bike itself wolnt have any greater ability to overcome bumps and provide more stability. You are better off not wasting money on a dampener since the bike is so light and easy to handle anyways, I always thought it’d be more of a harm than help since it cuts off your sensitivity from feeling what the bike is really doing. Best to go with either of the two options suggested so far. As far as power is concerned, lightening your bike and turning off the RC valve are both good ideas. It’ll make the bike less enjoyable for everyday use though. When I ride on the road now, the powerband is too dangerous to use all the time, and my gearing is also set up for high rev power, so its definately counterproductive for normal use. I’m considering switching it over to a full purpose race bike since i rarely use it outside going to the track and back anymore. You can also gain more power by running without and air filter. It may be slightly risky, but the setup I have has worked perfectly well so far. The biggest power gains i’ve noticed so far however, have been after an engine rebuild and modification. BTW sean, my old carb and cable are still sitting at wutian. You can borrow them for the time being.

4

Thanks Temple, What size is the old carb? I appreciate the offer of using your old carb, like I have your old exhaust, but maybe best if I get my own. What size do I have on now (assuming it is stock) and what size is your old one. I can’t take my bike out to WuTian until September, I am flat out all day M - F for this month at work, so spare time. Maybe I can ask them to put your old one on and see how it goes and then get myself a new one. For sure my bike is going better with your old exhaust on, but as you know it is slightly damaged, how much do you think that is holding me back…

How difficult is it to remove the airfilter and put it back on. Maybe I can do that on track days. Like RK said it is a quick thing to disconnect and reconnect the RC valve, maybe I can do that on track days, too.

And with the front end being loose like you said, is that normal? should I get WuTian to look at it. I am sure it’s not about to fall off though…

5

My old one was a 28. I had a noticable gain back when I upgraded that and the throttle cable from stock. The damage to the exhaust is minor, and I doubt you could feel any change if it was in perfect shape. A better exhaust would give you more gain, but its not cost effective for you at this point. Removing the air filter requires replacing it with custom fitted cardboard housing in order to keep debris from entering into your carb and destroying your engine, so it’s not something you’d want to do on the spot. I was saying your front end felt loose compared to mine, its probably mechanically fine, but it never hurts to check up on things. During the last race one of our scooters lost a critical bolt and looked like the entire rear wheel assembly was about to fall off. He had to pull in and lost more than a minutes time mid race :frowning: As you also may know, almost all the racers have dedicated race bikes without plates that they transport to the track. With the exception of me and some big bikes, I don’t know of anyone else who does this. Once you get something high performing and on equal footing with the competition its really counterproductive to waste it’s life riding around on the street, and like I said earlier the tuning will probably be ill suited. Having a daily driver/race bike is pretty much unheard of. You really need to pick up a scooter and start dedicating your NSR more for track use if you want to get serious. Its been a hard letting go of process for me as well, but im finally starting to come to terms with the fact that if you try to have both worlds, it wolnt be that great for either. I’ve also fully realized that racing around on the streets is excessively dangerous and puts your fate into the random hands of others. Still, I’d love to have another bike since I’ve been missing my country road riding alot lately.

6

stacking coins will reduce your available travel, but it does boost your preload (washers work too but coins are, funnily enough, often cheaper) and that alone can reduce bottoming out. stiffer fork oil works a charm in some cases: you can add five ml of heavy gear oil to your current fork oil if you want, for a cheap fix, and add the same amount in increasing steps until you get what you want. treat each fork the same way if they are both rebound and compression dampers in each fork, or just treat the compression fork if they are separate functions… or the rebound if that’s your problem.

7

It was mentioned that the oil was replaced in your forks, and it appears that your bike is looser on the front end than Temple’s bike. Then there’s the concerns with the wobbling…

I would bet any money that the guys who replaced your oil screwed up twice…

1-They probably used gear oil as opposed to fork oil as 100% of mechanics do in Taiwan.

2- They most likely A- did not put enough oil in your forks which makes them soft/loose and B-they did not put an equal amount of oil in each fork which causes wobbling.

What you need to do is clean them forks out, get yourself some real fork oil and refill them yourself, or at least supervise the mechanic who will do it for you. Find out the specs for how much oil the forks need when stock, and add 25% more oil to them and use a large syringe to make sure that you have exactly the same amount of oil in each fork. This should solve the loose front end for sure, and providing that your front wheel doesn’t need to be balanced, it will also solve the wobbling problem.

No need to tighten the springs with coins, IMO. More oil will do a much better job at providing a more sturdy feel to your front end. It will be less bouncy and will perform much better on the track. And as mentioned by urodacus, you will not lose in terms of travel as you would by adding coins.

Other advice you have received are dead on the money.

BTW, you can change the jets inside your carb if you disable the rc valve and that would work well, too, but a bigger carb is likely to provide more improvements than just replacing the jets.

[quote]
How difficult is it to remove the air filter and put it back on. [/quote]Not difficult at all. One bolt to remove the gas tank and one connector to disconnect the fuel gauge, two bolts to remove the air filter located below the gas tank. It takes about three minutes to remove the air filter on a NSR.

marboulette

8

Thanks for all the tips.
The same mechanics that work on Temple’s bike also work on mine. Everything else they have done on the bike has been fine and made it go faster. Nobody is perfect. I guess I will need to give clearer instructions to them in Chinese about having a proper going over of my front end. I know shit about this as well as most things about my bike. Last time I really worked on a bike was back when I was a teenager and had a YZ80G. Totally out of touch now, but still enjoy a tinker now and then.

Temple, you mention your old carb is a 28mm, what would mine be now then? RK mentions the 29mm. 1mm difference. hmmm what do I go for? NT$2500 isn’t a great deal. Maybe you could show me the cardboard housing. Actually I used to do something similar to my old V8 with the Holley carb I had on it when drag racing it.

Here is another dumb question… What air pressure should we have. I have the Bridgestone BT39 on the front and a Dunlop GP on the back. As I was having the rear slide a bit last Saturday, I checked them today and I only had 20psi (or whatever) in them both. They were cold, when checked. I feel it should be more but I couldn’t find the air pressure shown anywhere on the side of the tyres.

9

Not exactly sure what the stock size was. The 28 was a noticable step up. They’ve been setting me at 25psi on the rear, around 22 on the front. Also sean I think you’re still running the stock rear rim. Upgrading to the 3.5 inch gives you alot more grip and alows you choose better tires. I’m pretty sure all the racers have this as well. BTW my mechanic told me that tire prices are going up next month for all tires. If you need a new one soon, I’d get one now.

10

Temple is running a 25mm carb, and it is hard to find a filter for it. Plus yes running no filter on your carb maybe gives you a little bit more power, but it is dangerous too. I run the 29mm carb, basically the same as the 28mm. I used to run an aftermarket filter, but for some reason it seemed like my NSR didn’t like it. I put my stock filter back on (which is not easy to take on and off really fast). It is easy to take off, but putting that stupid giant filter back one sucks. Just buy or use temple’s carb. $2500 for a new carb and a accelerator cable isn’t pricy at all. (Your accelerator cable isn’t stock either, you have to get a Daytona, or maybe a Taiwanese company makes one too.) You should use Temple’s old one because it is all ready and setup.

Changing your rear wheel put for the 3.5 is a big project. I did everything myself and it cost be about $13,000nt. (Wheel, paint, custom rear sprocket, bearings, tires, etc.)

I run 29psi cold at the track. I find if I go any lower than I feel like lose traction. Remember like Temple said the more you do to your bike more unreliable it becomes for daily use. Even driving my NSR to the track without the RC is a pain in the ass. So just remember that.

11

beware that some carbs really really like to have an airbox fitted to the front end, whether or not the air is actually filtered, and some don’t. experiment. using velocity stacks (tapered tubes of a particular length that help with resonating air input at particular preferred revs, which might be handy with a 2 stroke) with simple mesh screens rather than an airbox will also sometimes help air get into the engine. always always use at least a screen over the carb intake, please, as getting a small pebble into the engine at high revs is not fun. but then my experience is more with big 4 strokes rather than small 2 strokes. if you have an airbox, point the intake at the front of the bike (maybe through the fairing around the headlight slot) so it gets high pressure cool air, rather than suck air over the hot engine case or over the exhaust in a low pressure zone…

12

Is there a wider rim from another bike that swaps straight over or with minimal adjustments required? I got a wider than stock tyre put on, (against the friendly advice), the Dunlop GP. It actually was a fraction too wide for the frame and was slightly rubbing , but that thin line that was sticking out aroud the edge of the tyre has now been worn away. Though it may not be ideal as some suggested, it has still definately made a big difference over the stock size in handling, as well as looking more like a motorcycle instead of a bicycle from behind.

Just wondering if I had a wider rim am I going to have the same inititial rubbing problem?

What about for the front wheel?

Man this hobby does kind of add up. Would kind of like to keep my bike for everday use, but would like to get it going quicker for sure, but I have definatley got the bug to try and race, too. I don’t care how far down the field I get, but all that may change after a few races.

13

Ain’t this the truth, happened to me with my NSR two years ago, but it wasn’t a pebble it turned out to be a small piece of metal and it ate the crap out my cylinder.

TpeSean…no there isn’t an easy swap for a rear wheel. You can buy the 2.5’ FZR wheel, which might be a little cheaper, but it still requires some custom work, so you might as well do the 3.5". As for the front, if you have noticed not many NSR riders change the front tire, because there is not need to go wider. If you want to go lighter than I would recommend the RS 125 front wheel. It is a little wider and way lighter, but also not cheap.

Look at my NSR, really I am the closest you can get to a race bike that is still capible of riding on the street (if I connect my RC valve again). I have a lot more power than you do, and here is why. First I run the Thai cylinder and piston which creates higher compression and is a lot stronger than the stock Taiwanese. (These are really hard to come by, but there are other companies that make cylinders and pistons for our NSR’s that are just as good, WuTian would have these in stock, probably around $7-10,000nt). Also I have the 29mm carb, which you really need to do. Besides my RPM rear suspension and my front aftermarket sprocket, my bike is mainly stock. I am still running stock front suspension and brakes (except for the brake line and master cylinder.) One main reason us NSR guys buy that rear wheel set up is so we can buy a Bridgestone BT002 which is basically a slick on the sides. The stock NSR wheel is a 18", and that is just a bizarre size so there are shit for different tire selection in that size. Running that tire helped dramatically for gaining time. Just running a wider tire in the rear really doesn’t not necessarily help things, it is more about the tire it self. With this setup I am turning consistent 62/63 second lap times. Pretty damn good. And I consider myself a decent rider.

Before you get carried away, I would recommend just putting on Temples old carb (and for sure use the air filter), and disconnect your RC valve. Also play with you rear suspension and tire pressure. You can easily gain a second from this.