Rough ride?

[Madfoxx]

I just got a 2007 Road Star trike with a Champion kit and was wondering about the rough ride in back. I have the EZ steer kit. The rear seems to only have 2 inches of travel and jars the heck out of my back over the bumps. If I'm braking hard on a bumpy road the back tires skip and chirp. Is there some way I can make it ride better? Or am I stuck with it? I should add that the shocks are on the softest settings and the tires are at 25 psi.

 

[Nana]

Try dropping the tire pressure down to about 18-20 for a start and see if that makes it better. I actually keep mine at about 17, but my kit installer says he keeps his own no higher than 20 psi for the best ride.

 

[ThirdWheel]

What shocks do you have on the back?

 

[Gorilla]

See if someone makes a softer shock for your bike, if they used the same shock on the conversion as was on the stock bike. Nana's suggestion might also be all you need. If the tires have to much air for the weight there will be no give in the side walls and transfers to much for the shock to handle.

 

[Baz]

If your shocks are on the softest setting meaning spring preload I presume , then I suspect you are using too much of the shocks available travel in static sag leaving next to no travel for the shock to be effective when compression & rebound dampening are called upon to do their job of soaking up the bumps & keeping the tyre pressed onto the road surface.

The spring is there in the main to set the ride height. The front would only use approx 1/3rd of the available fork travel in static mode. The rear should only compress 10 / 20mm in static mode. It is very important that static sag is correctly set to get the best out of your suspension from both a safety & ride quality point of view. If you cant correctly set the above parameters then a change to a firmer or softer spring may need to be fitted to your shocks. Believe me the difference in handling & ride comfort between a correctly set up Bike or Trike & one that isn't is like chalk & cheese.

I repeat, the spring has very little to do with ride comfort but every thing to do with where the vehicle sits relative to the stroke of the shocks. :yes:

 

[john95632]

Nice bike.

What type of trunk you have on it? and also your seat. Anyway you can send me some pictures of the trunk and it's mount?

I'm running 20 psi in my rear tires right now and not bad of a ride. Thinking of changing my shock spring to see if I can get it smoother.

John

 

[Baz]

Nice bike.

What type of trunk you have on it? and also your seat. Anyway you can send me some pictures of the trunk and it's mount?

I'm running 20 psi in my rear tires right now and not bad of a ride. Thinking of changing my shock spring to see if I can get it smoother.

John

John read the above posting. Baz

 

[Madfoxx]

If your shocks are on the softest setting meaning spring preload I presume , then I suspect you are using too much of the shocks available travel in static sag leaving next to no travel for the shock to be effective when compression & rebound dampening are called upon to do their job of soaking up the bumps & keeping the tyre pressed onto the road surface.

The spring is there in the main to set the ride height. The front would only use approx 1/3rd of the available fork travel in static mode. The rear should only compress 10 / 20mm in static mode. It is very important that static sag is correctly set to get the best out of your suspension from both a safety & ride quality point of view. If you cant correctly set the above parameters then a change to a firmer or softer spring may need to be fitted to your shocks. Believe me the difference in handling & ride comfort between a correctly set up Bike or Trike & one that isn't is like chalk & cheese.

I repeat, the spring has very little to do with ride comfort but every thing to do with where the vehicle sits relative to the stroke of the shocks. :yes:

Good info, Here is what I noticed. When I lift the trike's back end off the ground the static sag is about 1 inch measured at the tire to body. Now this kit uses the stock shock with two shocks mounted to the axle. when I lift it up the stock shock linkage does not move very much and there seems to be plenty of travel left on the shocks when I weight it down. I don't want to adjust the spring preload any tighter so I will try to find softer springs. Thanks

 

[Madfoxx]

Nice bike.

What type of trunk you have on it? and also your seat. Anyway you can send me some pictures of the trunk and it's mount?

I'm running 20 psi in my rear tires right now and not bad of a ride. Thinking of changing my shock spring to see if I can get it smoother.

John

The trunk I bought on ebay, easy to find but made in China, not the best. I would rather use an HD trunk. The mounts were another thing, I modified a set of ROADKROME brand mounts and extended them to make them taller. The part # is 16-12071. They are made in Canada and mount on the Star sissy bar brackets. The seat is a Mustang with the riders backrest. Also I changed the front drive pulley to a Baron 31 tooth to lower the gearing.

 

[Madfoxx]

John, I looked at your conversion photos and noticed your axle is made all out of aluminum, mine is all steel, it's got to weigh a lot more. Maybe that's another reason it rides stiff.

 

[Baz]

John, I looked at your conversion photos and noticed your axle is made all out of aluminum, mine is all steel, it's got to weigh a lot more. Maybe that's another reason it rides stiff.

No that is not the reason as the axle assy is unspring weight ie weight that is not supported by the springs. Baz

 

[Baz]

Good info, Here is what I noticed. When I lift the trike's back end off the ground the static sag is about 1 inch measured at the tire to body. Now this kit uses the stock shock with two shocks mounted to the axle. when I lift it up the stock shock linkage does not move very much and there seems to be plenty of travel left on the shocks when I weight it down. I don't want to adjust the spring preload any tighter so I will try to find softer springs. Thanks

When you lift the rear you need to lift from a point higher than the axle to fully unload the suspension & measure from some point on the body to say the wheel centre. Now carefully sit it down to load the suspension & measure again using the same points, the difference is static sag. Forget the unsprung weight but the extra weight such as bodywork & fittings etc would have the sprung weight greater than the bike itself . Therefore it is going to sit lower in the shocks stroke. Therefore it needs more preload to raise it up or a spring with a higher rating. A softer spring will only exacerbate the problem. This assumes of course the shocks & springs fitted to the bike were close to being in the ball park to start with. OK !!! :yes:

 

[Madfoxx]

When you lift the rear you need to lift from a point higher than the axle to fully unload the suspension & measure from some point on the body to say the wheel centre. Now carefully sit it down to load the suspension & measure again using the same points, the difference is static sag. Forget the unsprung weight but the extra weight such as bodywork & fittings etc would have the sprung weight greater than the bike itself . Therefore it is going to sit lower in the shocks stroke. Therefore it needs more preload to raise it up or a spring with a higher rating. A softer spring will only exacerbate the problem. This assumes of course the shocks & springs fitted to the bike were close to being in the ball park to start with. OK !!! :yes:

Ok, I got it now! I jacked it up high enough to get under it and looked at the stock shock and I could see the bump stop on it had been hitting. so I cranked up the two Champion shocks three notches and that did the trick. The springs on those two shocks are pretty weak and don't hold the trike up in the stroke so new springs would be in order, if only I knew what rate they are. As far as I can tell there is no adjustment on the stock shock. It rides much better now.

 

[Baz]

Ok, I got it now! I jacked it up high enough to get under it and looked at the stock shock and I could see the bump stop on it had been hitting. so I cranked up the two Champion shocks three notches and that did the trick. The springs on those two shocks are pretty weak and don't hold the trike up in the stroke so new springs would be in order, if only I knew what rate they are. As far as I can tell there is no adjustment on the stock shock. It rides much better now.

Well done, Any good shock / suspension or spring specialist for that matter should be able to check the springs to rate them for you and specify alternatives. Having said that I tried 3 springs to get mine right . It is well worth the effort as the rewards are huge.
Again well done :yes: I think you are onto it now. Baz.

 

[Madfoxx]

Well done, Any good shock / suspension or spring specialist for that matter should be able to check the springs to rate them for you and specify alternatives. Having said that I tried 3 springs to get mine right . It is well worth the effort as the rewards are huge.
Again well done :yes: I think you are onto it now. Baz.

Where did you get the springs Baz?

 

[John Luciano]

Wow great work BUT if fell like i just to a course in quantum Physic. <LOL>

 

[ThirdWheel]

Speaking of coil over shocks, I busted the air assist shocks on mine and replaced them with a set of Progressive shocks. It has never ridden any better. Fortunately they are not bad to get to in order to adjust if I ride two up, which is rare.

 

[Baz]

Where did you get the springs Baz?

Because we use Ohlins gear on our race & road bikes springs are freely available. Not sure what brand of shock you are using but any good suspension specialist ( preferably motor cycle ) should be able to help. Most standard shocks supplied as standard equipment on most motorcycles are very basic & border on being barely able to carry out their intended function. Over here were the road surfaces are probably bumpier with tighter & more corners maybe than you are used to, setting up the suspension correctly to suit the conditions pays big dividends in handling, ride quality & of course safety. I dont see why the above approach wouldn't apply any where else in the world.
I'm not trying to lecture you but I believe it is an important & not very well understood point that the manufacturers would prefer that we remain ignorant about.
Anyhow I've enjoyed the discussion. Right next subject ??? Baz.

 

[spiritdream]

Wow great work BUT if fell like i just to a course in quantum Physic. <LOL>

That makes 2 of us - and I barely passed Algebra many (many, many) years ago! .

 

[1550vt]

On mine...it's a pass-off between handling vs. comfort. I think 17-18 pounds of tire pressure is way too low. If it's too stiff to ride at anything below 20-pounds...listen to these other folks concerning the shock/suspension. I did a self-install of my kit and the manufacturer recommend 18 psi. At 18 psi, mine will roll so badly in curves that it is un-drivable. I cannot run below 25-or-so psi and keep it drivable in the sharp curves. I normally run 27 psi with the wife and all her baggage.