Beta Suspension

[billyt]

On the topic of Beta suspension, I have a new Evo 300 2012 model. The front fork adjustment seems easy enough with a clicker on the right leg and a hex cap on the left. It looks like the method of adjusting the compression is to simply turn the red hex cap with an allen key which causes the red insert to screw up or down inside the cap of the fork leg. Removal of the tube cap reveals that the hex cap does indeed appear to be threaded inside the cap however...I have tried to turn the hex with an allen key and it is TIGHT to the extent that I doubt the soft ally will stand any more force without something going snap. Has anyone encountered this problem yet or do I just need to eat some spinach and look out a length of pipe for the end of my allen key before I give it another go?

There is no compression adjustment only pre-load to the spring. The other adjustment is for rebound.

[motomofo1]

BillyT, are you still in the North Texas area? I welcome you to try my new bike, and compare it to several others in the area.

Edited January 24, 2012 by Motomofo1

[billyt]

BillyT, are you still in the North Texas area? I welcome you to try my new bike, and compare it to several others in the area.

Hi

Several other 2012 Beta's"? Have you modified yours? I am not the one complaining about the Beta's suspension. I like the Beta's suspension.

Maybe you should read all of the posts on this topic to get the gist.

Cheers.

[motomofo1]

I've read it all. Sounds like several folks need to worry less about their suspension. If anything, all it needs is minor adjustments to suit each individual... Unless the rider is above the target weight of which the bike sprung for, of course.

Edited January 24, 2012 by Motomofo1

[billyt]

RP

I totally agree.

Tweak with oil viscosity and the Beta's suspension is great. Spend more time practicing.

Cheers

[liviob]

On the topic of Beta suspension, I have a new Evo 300 2012 model. The front fork adjustment seems easy enough with a clicker on the right leg and a hex cap on the left. It looks like the method of adjusting the compression is to simply turn the red hex cap with an allen key which causes the red insert to screw up or down inside the cap of the fork leg. Removal of the tube cap reveals that the hex cap does indeed appear to be threaded inside the cap however...I have tried to turn the hex with an allen key and it is TIGHT to the extent that I doubt the soft ally will stand any more force without something going snap. Has anyone encountered this problem yet or do I just need to eat some spinach and look out a length of pipe for the end of my allen key before I give it another go?

I think your fork cap was assembled incorectly at the factory. Either the Oring is binding or the red adjuster piece was installed cross threaded. Dont force it. It should turn with little resistance. Since your bike is new take the bike back to the dealer for a warrenty replacement.

Edited January 24, 2012 by Liviob

[liviob]

I tried this link and its working again.

http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid

Copy and paste it to your word editer before it dissapears again.

This chart is a valuable tool to help decide which oil to use to get the desired feel in your suspension. When you look at this chart you will notice that all 5wt oils are not the same Cst. I think the stock oil is either Bardall 5wt or Belray 5wt. Both are at 19-19.5 Cst. If you want faster suspension you must first get your ride height set properly so the spring preload setting gives you 1 1/2"- 2" ride sag. If you cannot get this ride height with 10mm of preload or less you will need firmer springs. After getting the ride sag set and you still want a faster suspension try adjusting the rebound screws to a faster setting even if you have to turn them to the fully open position. If you still cannot get the feel your looking for then try a thinner oil. Use fork oil in the fork and shock oil in the shock.

I weigh 250lbs. and ride middle intermediate level. I have a .71 spring in the fork with 2.5 turns of preload adjuster to get the desired ride height. "The stock 09 spring was .61 and even if i turned the preload adjuster fully in the bike felt too soft". I currently am using Silkoline pro rsf 2.5wt. in both forks which is 13.5 Cst. set to factory oil height. I have also changed the spring and oil in the rear damper. Because my weight 250lbs. is so far out of the design envelope changing both springs is necessary to keep the front and rear of the bike in balance. I currently have the 8.0 Beta spring mounted on the damper. I have eight turns of preload dialed into it which equals 8mm of preload. and i am using Belray HVI 10 wt. oil in the damper which is 33.5 Cst. Here is a link with info to open the shock.

http://www.trialscentral.com/forums/topic/33584-suspension-setup/page__pid__254486#entry254486

I have ridden the 2012 beta 300 and am certain Beta has again installed firmer springs in this new model. Their not as firm as mine but their firmer than previous models. Thats why theres more energy for rebound pop with the 2012 bike. With the spring rates and oil viscositys that i am using i am certain that a 170Lb. rider could comfortably ride this setup if they backed off the spring preload to get the desired ride height for their weight.

I am sharing most of this info with you to use as a reference. You may find after some experimenting that only minor changes are necessary to find a setup that works for you.

Edited January 24, 2012 by Liviob

[hamilton]

Thanks for that. There certainly seems to be some problem with it. I will seek some help from the supplier.

[bigbird2]

Beta Evo Suspension

Over the past year, I have been experimenting with the suspension on my 2009 Beta Evo 300 4t with the objective of making it suitable for a 200 pound 69 year OLD guy (me) to use it as a trail bike. This has included significantly stiffer springs on both ends and loaded sag set to about 2" on both ends PLUS a number of other MAJOR changes described in a separate post about my FrankenBeta :>) In the course of this experimentation, I believe that I have learned some things about the way the OEM suspension works and how to tune it, that may be helpful to others. Some of this information is contradictory to things said in earlier posts in this thread. I would welcome comments or corrections on what I am posting below.

The left fork, with the spring and the ride height (or preload) adjuster is the old fashioned "damper rod" design. However, the passages for the oil are so huge that is provides almost no damping in either direction even if you use thicker oil. The exception to this is the anti-bottoming cone at the bottom of the damper rod. This device does nothing (no damping) until you are about 5" into the 7" of available travel. At this point it DRAMATICALLY increases the damping to minimize/eliminate the chance of actually mechanically bottoming the forks. Before I understood how this left fork worked I tried going to thicker oil in hopes of getting more compression damping. This did almost nothing for compression (or rebound) damping in the first 5" of travel. However, it made the damping in the last 2" of travel so firm that it effectively limited the fork travel to 5" or a little over. NOT good! Although I'm still experimenting, I suspect that, even with oil of the nominal OEM thickness oil I have gone back to, this anti-bottoming cone is overly restrictive and is effectively limiting travel by ramping up too much at the bottom of the stroke. The next thing I will try here is thinner oil. The other option would be to modify the shape of the cones so that the increased damping comes in more gradually through the last 2" of travel. In OEM configuration, it seems to be almost a step function from no damping to very firm damping which tends to make it unlikely to ever get into the last 1" of travel. Note that the right fork, discussed below, also has a short anti-bottoming cone which would supplement the damping in the last 1/2" of travel, thus providing some progressive increase in damping at the end of the stroke.

The right fork has a modern adjustable cartridge for rebound control. It also has a very short anti-bottoming cone that is effective in about the last 1/2" of travel. The adjuster on this fork has a wide range of firmness even with standard thickness oil, however with thicker oil the maximum damping is substantially increased. Surprisingly, the use of thicker oil also has a very significant effect on compression damping. Thus, it is possible to increase the oil thickness to achieve the desired compression damping and then use the adjuster to dial in the desired rebound damping. I haven't really taken time to try to figure out whether the significant effect of thicker oil on the compression damping is from (a) the oil flowing up through the cartridge or from ( the oil flowing past the outside of the cartridge between the cartridge and the fork tube.

I have done nothing to the rear shock except to max out the rebound damping adjuster to control the rebound of the substantially stiffer rear spring that I have install. This seems to work well.

[nif40]

BigBird2,

Without coming off as a complete jerk, I am afraid you may not get the answers you are looking for in this forum. I went through the exact process you have just described except I took the spring completely out of the left fork when I did my testing. I tested the following (2.5wt, 5wt, 10wt). My results matched your results, which were if you put thicker weight oil in the left fork leg on a 2009 beta evo, this will not increase compression damping. After (3) different oil types with no change in compression dampening, I put some 20W-50 Castrol motor oil in and there was virtually no effect. My first thought was that I had something wrong with my front forks from the factory, but later confirmed that other Beta owners had the same issue as my bike.

I think the key is in what you said: “However, the passages for the oil are so huge that it provides almost no damping in either direction even if you use thicker oil.”

I have a good riding buddy that is considered our local master motorcycle mechanic (he has gone to all of the schools for suspension work). He took a look at my beta forks and basically concur with what you said. The oil passage holes are too large and need to be welded up and re-drilled. He commented that it is somewhat of a guess for the first few tries before you can get the correct orifice size dialed in.

As a side note:

Don’t be surprised if several guy’s chime into this conversation and tell you that you don’t now what you are talking about. Others will comment that you haven’t spent enough time riding. Heck, I had one guy tell me I didn’t have any business riding motorcycles. At 69, I suspect you have been riding long enough to know what you are talking about.

I really like the Beta’s design, ergonomics, motor, styling, handling, but with back to back testing of other bikes can truly say that the Achilles heal of the Beta is the suspension. I suppose there are commercial reasons for why Beta doesn’t just swallow their pride and put some better forks (Marzocchi) on their bikes and the rear would hurt to be tweaked as well. I am not going to argue which is better, but if you have any “feel” and all, I would suggest riding some of the other brands and come back and tell me how the two compare in the suspension department.

BTW, if I ever get my forks welded and drilled I will let you know how it goes.

Good luck.

[copemech]

BigBird2,

Without coming off as a complete jerk, I am afraid you may not get the answers you are looking for in this forum. I went through the exact process you have just described except I took the spring completely out of the left fork when I did my testing. I tested the following (2.5wt, 5wt, 10wt). My results matched your results, which were if you put thicker weight oil in the left fork leg on a 2009 beta evo, this will not increase compression damping. After (3) different oil types with no change in compression dampening, I put some 20W-50 Castrol motor oil in and there was virtually no effect. My first thought was that I had something wrong with my front forks from the factory, but later confirmed that other Beta owners had the same issue as my bike.

I think the key is in what you said: “However, the passages for the oil are so huge that it provides almost no damping in either direction even if you use thicker oil.”

I have a good riding buddy that is considered our local master motorcycle mechanic (he has gone to all of the schools for suspension work). He took a look at my beta forks and basically concur with what you said. The oil passage holes are too large and need to be welded up and re-drilled. He commented that it is somewhat of a guess for the first few tries before you can get the correct orifice size dialed in.

As a side note:

Don’t be surprised if several guy’s chime into this conversation and tell you that you don’t now what you are talking about. Others will comment that you haven’t spent enough time riding. Heck, I had one guy tell me I didn’t have any business riding motorcycles. At 69, I suspect you have been riding long enough to know what you are talking about.

I really like the Beta’s design, ergonomics, motor, styling, handling, but with back to back testing of other bikes can truly say that the Achilles heal of the Beta is the suspension. I suppose there are commercial reasons for why Beta doesn’t just swallow their pride and put some better forks (Marzocchi) on their bikes and the rear would hurt to be tweaked as well. I am not going to argue which is better, but if you have any “feel” and all, I would suggest riding some of the other brands and come back and tell me how the two compare in the suspension department.

BTW, if I ever get my forks welded and drilled I will let you know how it goes.

Good luck.

I do not think you are a complete jerk. I do not have a Beta to experiment with, yet my Sherco Paioli's are similar.

I do not think there is much if any compression damping, nor are the really designed to. Seems one still must pass oil through these large holes upon compression, and them being large, viscosity change in the range mentioned would make little difference in regular movement. Where the difference would come to play would be in the upper shock range of "sharp edge" impact reaction, or the point to where sharp edge impacts start to literally HURT the riders arms and hands because one cannot push fluid through those holes that quickly. You get a pressure spike!

Now the thicker the oil the greater the spike, because one can only push soo much oil through the holes in a given amout of time, like trying to pound a column of oil through a hole with a hammer! The oil will not compress, so this will create high pressure that will prevent the fork from giving in prematurely its length of travel upon repeated rapid hits, yet any fluid will still hydrospike. (bellyflop in the pool) Water will hurt you! Now try that at 20ft!

This is a limitation of an orface rod fork design, and also why it is not used in rebound on the newer forks, which is more critical for us trials riders. Finding a happy rate for your weight and such is still an option, yet is limited in range. If I am not going fast and not hitting things hard and at a high rate, the standard oil is fine, thinner may give you a bit more shock relief, but you will never push it through those holes any faster than it can go.

[carl ekblom]

BigBird2 wrote:

"The left fork, with the spring and the ride height (or preload) adjuster is the old fashioned "damper rod" design. However, the passages for the oil are so huge that is provides almost no damping in either direction even if you use thicker oil. The exception to this is the anti-bottoming cone at the bottom of the damper rod. This device does nothing (no damping) until you are about 5" into the 7" of available travel. At this point it DRAMATICALLY increases the damping to minimize/eliminate the chance of actually mechanically bottoming the forks. Before I understood how this left fork worked I tried going to thicker oil in hopes of getting more compression damping. This did almost nothing for compression (or rebound) damping in the first 5" of travel. However, it made the damping in the last 2" of travel so firm that it effectively limited the fork travel to 5" or a little over. "

I agree in every respect.

Consider that you will only have about 3"-4" of compression travel when standing on the footrests and half of them goes into a rock hard hydraulic damping, What is even worse is that the oil will cavitate when the fork is trying to rebound from the compressed rock hard position causing very strange behaviour of the fork. I think the design of the anti bottoming cone is a major drawback of the fork. Using thicker oil will only make things even worse. Use as thin oil as possible to avoid the worst.

I have just started to modify the cone making it shorter and thinner to improve things. Will report later after more testing.

Carl

[spenser]

BigBird2,

I really like the Beta’s design, ergonomics, motor, styling, handling, but with back to back testing of other bikes can truly say that the Achilles heal of the Beta is the suspension. I suppose there are commercial reasons for why Beta doesn’t just swallow their pride and put some better forks (Marzocchi) on their bikes and the rear would hurt to be tweaked as well. I am not going to argue which is better, but if you have any “feel” and all, I would suggest riding some of the other brands and come back and tell me how the two compare in the suspension department.

This topic has been informative for many of us in trials land, but I would like to just mention one thing. The Marzocchi fork is not a "better fork", it is only different; many people prefer the Showa/Paioli/Ceriani/Tech etc over the Marzocchi. As well it is worth noting that the Marzocchi feels different on the Gas Gas than it does on a Scorpa or an Ossa.

Thanks to all that have contributed.

Spencer

[stonezone]

I just added the stiffer front spring along with new seals and oil and my eve came alive. I'm a little light for the rating on the spring (says 220 and I'm about 210 with gear at the most) but since i ride it like a mountain bike the thing is wicked...highly recommended. As for dampening/rebound, i'm happy with where it's at now so whatever.

I have a rear spring to put in as well, I'll report back once that's done.

[spenser]

BigBird2,

I suppose there are commercial reasons for why Beta doesn’t just swallow their pride and put some better forks (Marzocchi) on their bikes and the rear would hurt to be tweaked as well. I am not going to argue which is better, but if you have any “feel” and all, I would suggest riding some of the other brands and come back and tell me how the two compare in the suspension department.

BTW, if I ever get my forks welded and drilled I will let you know how it goes.

Good luck.

Looks like Gas Gas swallowed their pride and changed to the Tech fork for their top of the line Raga. Makes me wonder about Dougie Lampkin's influence in the bikes; Beta changed to a new linked suspension when Dougie came on board, now Gas Gas is changing to a suspension that feels closer to the Beta and new Sherco....just thinking out loud.