Single Seat Roketa GK-44 Suspension

[okda452]

Hello to all members. I am new to the mini buggy world. I have recently purchased a 2008 single seater Roketa GK-44 or as it is also known as a Coolster 6250. Took about 6 hours to assemble - I am really slow. Chinese manual really sucks, but still figured it out. Never saw it in the day light for about 5 days because of work schedule. I took it to a moto-x track with my sons and had a blast. The CN250cc has enough power, but after the 1st hour, two things came to mind. Suspension and suspension. My yellow bumble bee lands hard, takes bumps hard, and I am afraid if I play hard, I will be repairing it more than riding it.
Do any fellow members know if I replace the stock shocks with longer and better shocks, would this help the suspension? I have read other post about suspension for other types of karts, but does any one have experience with this type. Should I change the front of rear shocks first? Or if money allows, if I change all shock, will that make the suspension bearable? Once I adjust suspension, my plan is to up grade variator, clutch, CDI and rev limitator. I ordered the parts from Tom at Kidnme. Really nice doing business with him. I am also considering going to ebay and bidding on a Yamaha or Honda a-arms, spindles, hubs and breaks. If I get all the measurements correct, will this really help the suspension? But that is down the road. Thanks...

[ckau]

have you talked to Tom about your suspinsion? He would know whats your best options

[okda452]

I have talked to Tom a little about it and he has been very helpful. I was wondering if any one has done more than just shocks? If I put longer shocks on the rear of GK-44, making the swing arm more of an angle, would this affect engine performance?

[BuggyMaster]

Tom has a coolster and I had one as well. That particular machine would have been a home run if it weren't for the horrible suspension. The problem is the shocks don't have any rebound which makes for a very bouncy, and potentially dangerous, ride. Someone else on here replaced the shocks with blaster shocks. I would do all four shocks but if I had to choose which ones first, I think I would do the rears. Seems they bounce you out of control most. Coolster was a great machine though.

[SYCARMS]

The front suspension is terrible due to the short control arms. The rear shocks I have are for the Honda 350 Rancher. I went with these cause with the stock shocks on the rear I kept nailing the performance exhaust. The shocks are 1" longer than stock. TOM

[roysheepdog]

Originally Posted by okda452

I have talked to Tom a little about it and he has been very helpful. I was wondering if any one has done more than just shocks? If I put longer shocks on the rear of GK-44, making the swing arm more of an angle, would this affect engine performance?

dont go at to much of an angle becouse it may run out of gas when you go up hill.ive put air shocks on mine and have 22"of rear wheel travel buy it has to sit at about65%droop.havent tested yet dont have enought buggy to drive lol.i have seen it done on a buggy and it worked good.i used truck shocks@oriley 75$pair.you have to make shock mounts ,not hard but if you do that you can use almost any shock just check that the shock will hold the wait of the buggy.

[EJ Mac]

Don't know if anyone mentioned it or not but most of the stock shocks have a 5 position adjustment that may help until you are able to upgrade them. I'm not sure of how to adjust them, but will be finding out soon as I want to get our buggies set up until we have the funds to upgrade the shocks. BTW where are you located in OK?

[SYCARMS]

Unfortunately for one reason or another the challanger does not come with adjustable shocks. TOM

[okda452]

I am located in Perkins, OK. I do not see any adjustment on the stock shocks. But I will look again. Thanks...

[SYCARMS]

As stated in my last post they do not have adjustable shocks. TOM

[EJ Mac]

Originally Posted by okda452

I am located in Perkins, OK. I do not see any adjustment on the stock shocks. But I will look again. Thanks...

Cool I grew up in Cushing and my sister resides in Stillwater. There are a few riding areas around the Keystone lake area I'll be checking into when the weather warms up. Also as Tom stated there is no adjustment on your shocks, He has been in the game a long time and is very knowledgeable and a great trusted dealer. BTW Tom are the Eastside exhaust systems still available?

[SYCARMS]

I am working on finding the source. From what I have learned, Eastside Powersports which to my understanding is out of business had contracted someone here in the US to build them. The company who made them for Eastside is somewhere out west. I'm trying to find this company if still in business. If I find the source I will surely be stocking them since it is the finest exhaust to date for our motor. Will update when I find something. TOM

[BuggyMaster]

The whole shock thing on the coolster is just amazing to me. They put together one of the best looking buggies ever and then put the worst shocks ever on it. I gladly would have spent a little more money on ours for the sake of a good suspension.

[SYCARMS]

I totally agree, they have larger diameter and thicker tubing, water tight plugs thru out but the worst shocks. The main problem is the short a-frames in the front. The 2004 Blade single which I have, had the short a-frames. I think it was 2006 they increased by only 2-3" the length and this made a big differance in both the ride and stability, so I had installed the longer ones on mine. I started to do the same on the Challanger but realized I was changing the whole geometry, so I put things on hold until I have more time to think things thru and do it right. TOM

[okda452]

I am thinking about modifying the front suspension by putting stock Honda trx 450 a arms with stock trx 450 shocks. I know that I will have to modify the steering as well. I know this will give the front a wider stance and better suspension. Any thoughts?

[SYCARMS]

It will only make a good buggy better if done correctly. As stated in previous post I started to convert mine to longer arms than realised I have to move the mounting brackets for the arms as well as shock brackets. So I put it on hold since it will take some planning to reengineer. TOM

[booda72]

does any one knoow what i can do shock wise for the helix for an upgrade

[roysheepdog]

Originally Posted by okda452

I am thinking about modifying the front suspension by putting stock Honda trx 450 a arms with stock trx 450 shocks. I know that I will have to modify the steering as well. I know this will give the front a wider stance and better suspension. Any thoughts?

http://www.racingaspirations.com/?p=286
http://www.rctek.com/technical/handl...principle.html
the racingaspiration will help you know were to put every thing and the ackerman will help get the steering to turn write.not to hard but do your research first and you will have good luck.

[roysheepdog]

Originally Posted by booda72

does any one knoow what i can do shock wise for the helix for an upgrade

see how long the shocks are and get the weight of the front and back of your buggy.if you dont get a atv around the weight of your buggy the shocks wont hold it up.an atv a little heaver may be best becouse the buggys wheel base is longer.find some atv or sled shocks that are a match.i have read that sled shocks are better than atv shocks.

[booda72]

thanks

[okda452]

Thanks Roysheepdog. Both of the sites you posted are great. I understand the second site: http://www.rctek.com/technical/handl...principle.html. I am still trying to under stand the 1st site - which numbers go where. I will tell you when I install the shocks on the rear and hopefully I will have checked and measured twice and cut once...thanks again

[roysheepdog]

if you can buld a mount with more than one hole on the a arm for the shock so you can move it.this will let you fine tune the ride hight and how soft or hard it is.if your shock has 4" of travel and you mount it at the wheel you will get around 4" of wheel travel.if you mount the same shock in the center of the a-arm you will get around 8",get the idea.but when put it in the center the shock has to be stiffer to hold the buggy up.make a mount with 4 or 5 holes for the shock to fit in the a-arm and youll have it made.
for the best angle mount the shock at 90*to the a-arm at full bump.that will let the shock work with less effort.the futher from 90* the harder the shock has to work.
you may not be able to get 90* if not get as close as you can.

[roysheepdog]

Originally Posted by okda452

Thanks Roysheepdog. Both of the sites you posted are great. I understand the second site: http://www.rctek.com/technical/handl...principle.html. I am still trying to under stand the 1st site - which numbers go where. I will tell you when I install the shocks on the rear and hopefully I will have checked and measured twice and cut once...thanks again

on the first one get the measurments from the a-arms you will use top and bottom convert to mm.then build it on the site it will even tell you how much travel you will have.play with it and get the camber right and get it how you want it and it will tell you were to put every thing.
.

[okda452]

I bid on and won 2008 TRX450 a- arms for my buggy. When they arrive, I will start tearing the front end down on the GK-44 and try the calculations before I permanently weld on the mounting brackets. thanks

[BuggyMaster]

Very cool. Can't wait to see how it comes out.

[okda452]

Still working on the suspension. I did receive the performance variator and clutch upgrade from Tom at Kidnme. Kit also included CDI, performance plug wire, air filter, and bigger jet. All parts made really well. Video Tom posted on his web site really made change over very very easy. Thanks for the Videos Tom. All went well until I started it. I didn't size the new outside variator plate to old plate - dummy me. New plate about 1/2 inch bigger and made a racket rubbing against case when when started. Shut buggy done - saw the problems and put old front plate on - no problems. Issue was not Tom's doing, I like the bigger plate, but it just will not fit on GK-44. Anyway, I have a question about shock mounting. When completely replacing location of shock, do you compress the shock any when you install it or install it full extended?
Oh, forgot to mention one thing. On the GK-44 single seat buggy, when I was going through some pretty mean bumps, and my head was going side to side (with helmet on), I could not stop hitting both sides of the roll cage. I'm 5'8" and I was really surprised the roll cage was too close with my helmet on. A two hour fix. Took the roll cage off, cut it in six places, leaving at least 4 inches on both ends to insert 14" of 1" 5/8 tubing over existing tubing. Drilled the thick wall tubing first and then placed new tubing over existing tubing. Used grade eight bolts. This procedure extending the roll cage about 6 inches and no more head knocking. If any one tries this the tubing is smooth on the outside, but you have to grind the inside seem. I am waiting to receive my elka shocks, before I start cutting shock mounts and suspension. Regardless of my modifications, I really enjoy this buggy? I know that I go on and on, but one last question - maybe for Tom. I like the quick response of the upgrade parts, but I want the buggy to grab a lot sooner. Do I need smaller gram roller? When I read some of the other posts, people have mention 9 grams. Too small - please advise. Thanks.......

[SYCARMS]

The GK-44 is a CN250 which usually come stock with 18gr rollers. The 9gr rollers would be for the GY6. What gram rollers are you currently running. As far as the shocks go, with the wheels off the ground the shocks should fit without compressing. By installing compressed with wheels off the ground mainly the front you would be putting pressure on the ball joints causing failure down the road. TOM

[okda452]

Thanks for the info on the shocks. The rollers that came with new variator kit are 23 grams. If I go to the stock 18 grams would that improve faster take off at lower rpm....thanks

[SYCARMS]

The variator is your transmission the clutch is like the torque converter. When you lighten the rollers you raise the shift point of the transmissiom, like manually shifting your car. The heavier the clutch springs are the higher the rpm will be for clutch engagement. The torque spring controls the rate of the driven pulley on the clutch. So in a nutshell the rollers control the rate at which the variator pulley will open,eg. lighter rollers will need more RPM to squeese the variator pulley causing belt to rise, whereas the heavier the torque spring the more rpm it will take to open the clutch pulley for belt to drop down. The heavier the clutch springs are the more rpm it will take to engage the clutch just like reving an engine than popping the clutch. The lighter the rollers the more low end torque you will have like for climbing but you will suffer at top end. The trick is to have the correct combination of rollers, clutch and torque spring for your satisfaction of the type of driving performance you are looking for. It is best to mod the cvt system after your mods, since mods change the power curve of the engine your cvt will need changing to be in sync with the engine. TOM

[okda452]

Tom, thanks for the information. I took my buggy to the river bottom Sunday afternoon and had a blast. Low end torque is great - high speed in lacking in sand. Have not taken buggy on trails yet, but it climbed every hill at the river - some about 10 feet tall - but had to get a run at some of them first. Buggy does donuts in sand very well. Performance at top end seems like I need to rejet carb a little. Even though bottom end is great, like you said, balance between the two is necessary. I will reject carb. On water soaked sand, ran fast enough for me until suspension is modified, but in loose sand seemed like she would not top out as on the wet stuff. I received my shock tabs Saturday, still waiting on Elke triple rate shocks. Once I start the modifications on the suspension, I will post some pictures. Again thanks.....

[SYCARMS]

You have to realise that driving on dry sand is like driving with the brakes half on. Just try to remember how much more you will exert yourself walking on dry sand versus wet sand, its the same for the buggy. It takes more HP ro run sand. TOM

[okda452]

Been away for a while. Have been driving my buggy till I broke suspension. I have not modified suspension yet, but now that I broke it, time to work on it and UPGRADE IT. I have decided CN250 engine is not big enough either. I have purchased a 08 Honda trx700xx engine that I am going to put on it. 700xx does have reverse and I think that reverse is necessary.

Upgrades for my Roketa GK44 also know as Coolster 6250, as follows:

1. Bottom and top Honda 450r a-arms, brakes, calipers, rotors, and hubs; this also means new rims for front;
2. Elka shocks - off of a 450r Honda triple rate for front, 16 3/4";
3. Fox shocks for rear off a a Polaris, 18 1/2";
4. cable foot clutch - this means moving brake over to make room for foot clutch;
5. removing cn250 engine and transmission - probably be for sale once removed;
6. cutting off swing arm where cn250 engine was mounted, but keeping rear axle;
7. welding, welding and welding. Strengthen frame, extending rear of fixed frame to accept Honda 700xx engine;
8. attaching swing arm (duel mount) for rear axle so that Fox shocks can be attached;
9. modification of steering column;

Once I do these modification, I will have the frame sand blasted and powder coated, and then the build, with wiring.

I will probably start tearing the GK-44 down this week. I will post plenty of pictures, to include mistakes.

Hope it works as good as it sound. I will let you know.

[BuggyMaster]

How did you break it?

[okda452]

When riding the trails I drove over a hill, well let's say it was really a cliff with a 4' fall into a creek bed. Tried to back off the hill, but gravity took over. Trashed the right a-arm, tore the shock mount off, and jarred my eye teeth. After riding dirt bikes for years and now my cart, a good thing to remember (which I forgot for about a minute) is to know what is on the other side of the hill that your climbing. Anyway, suspension upgrade is necessary now.

[rightnwrong]

For me, Tom is the most genius person when talking about the suspension.