Sir Real Ed

I've noticed this one in addition to the CSP: https://shop.betausa.com/p/evo-billet-aluminum-gas-cap So obviously, Beta is well aware of the problem. Any specific reason you went with CSP? I see two different pictures for the CSP. Which one do you have? Did you notice any adverse effects on the handling/wheelie-ability of the bike??

I've read that the cap swells with time. But a bike that is less than a few days old, that has the cross threading problem, before any fuel is put in the bike, tells me that it is definitely a thread geometry problem. Changing the cap to a blunt start thread fixes the cross threading problem immediately. A blunt start thread is a common solution to a thread geometry problem. It is very common in the nuclear and aerospace industries. I don't expect it to fix the swelling problem, as that is a material problem. My Sherco had the swelling problem, but it had rounded threads. So five minutes with a 1/16" diameter drill and some 220 grit sand paper was an easy fix. I'll probably go the bling route with an aluminum cap eventually, but with the holidays and the weather, the post office is running about 10 days late with a lot of mail right now. I expect someone to reply that going to an aluminum cap will add weight and ruin the balance/handling the bike. We trials riders are an anal bunch.........?

It is extremely easy to cross thread the gas cap on my 2019 Beta during installation. A friend said the same is true with his 2018. I have read that older Betas had aluminum caps rather than plastic like the 2018-2019 Betas. Any cross threading situation can be cured by changing one or both threads to blunt start threads. The attached picture shows the modified gas cap. Modifying the female thread in the gas tank would require careful flushing of the gas tank afterwards so I opted to only modify the gas cap male. I used an exact knife to remove about two full threads from the gas cap which creates a male pilot to properly align the gas cap. I then used a Dremel tool with a small end mill like cutter to clean up the removed threaded area to a diameter smaller than the female thread minor diameter. The O-ring was removed before modifying the threads. A picture is worth a thousand words:

Good question. I have not checked to see if my bike does or not. It might only be an improvement on a vintage bike.

Everything you say makes sense. I was taught that proper trials technique is for the rider to ALWAYS cover the clutch and front brake lever with their index fingers and use ONLY their index fingers to operate both. I have never noticed numbness in either hand while riding trials. Every non-trials bike (6-8) I have ever done this to, resulted in significantly less (70-80%) numbness in my right hand. Could be the placebo effect, but since I am forgetful as hell, I doubt it. Cheap mod to tinker with. As they say, your mileage may vary.

I originally posted this on another forum as a time tested method to reduce numbness in your right hand, and someone tried it and replied that it was a great way to increase throttle precision. So why not post it in a trials forum? If your right hand gets more numb than your left, it is probably due to excess clearance between the throttle tube ID and your handle bar OD. I have measured a couple bikes with handle bar diameter = 0.870" and throttle tube ID = 0.910, or 0.04" of diametrical clearance. Get some UHMW bearing tape (McMaster.com, pn 76445A722, 0.005" thick) and in 3 equally spaced places, wrap your handle bar with a couple loops of tape. One wrap increases handle bar diameter/reduces clearance by 0.010". Wrap an extra turn more than you think you need. Slip the throttle tube over the tape, it should have virtually no clearance, but still turn freely enough to not bind so that the throttle return spring does not allow the throttle to stay open. If it is too tight unwind 1/2 to 1 turn at a time until you get little or no clearance, but no binding. Re-assemble your throttle and test that the throttle returns by itself before riding. give it a shot.

I've had 3 Sherco over 15 years. 2001, 2005, and 2011. Only the 2011 had the minor problem of the water pump shaft leaking. One of the two seals was installed backwards at the factory. Some claimed the vacuum pumps on the 2011 and never bikes can be a problem. Of the 5 or 6 riders I know with those bikes, none have had any problems. Initial inspection leads me to believe the Beta is a higher quality machine. I just bought a new Beta. Why? I have no cartilage in my right hip, and the Beta has a left side kickstarter. How is that for a personal rationalization/reason! ? As I told a buddy "Even if the Beta is only 70% as good as the Sherco, the left side kickstarter makes it 30% better than the Sherco!" ?

Very interesting. I tried to send you a PM, but the response was you can not receive PM's for some reason. send your email address to me at jebeehler@comcast.net and I'll send you my address. thanks.

mcman56, do you remember the ID, OD, and thickness of the spacer you made?

Thanks Lineaway. Just got my 250 Beta, so I don't have any options on stock gearing, but I like your line of thinking.

Great thread! Thanks to Dan and all who contribute. I'm going to take a look at my 2011 Sherco plates. Regarding spacers, without knowing any relevant dimensions, my first thought was shim washers from McMaster-Carr. Precision made, and cheap. McMaster.com. Best search function on any website I have seen https://www.mcmaster.com/#shim-washers/=1ef9nb8 Example: 6mm ID x 12mm OD x 1mm THK stainless steel shim, Part number 98089A377, Quantity 25 for $11.00