- This topic has 9 replies, 4 voices, and was last updated 8 years, 5 months ago by Robert Finlayson.
October 25, 2014 at 2:34 pm #35946
Hi all, new to this forum and been karting about a year. I purchased a used Birel RY-30 S4 and a set of snipers. My tires are wearing badly on the inside edge, I have just checked things out with the Snipers for the first time. Here are some photos:
So the Snipers show I have about 10mm of negative camber with the kart on the stand. This is my main concern as I’ve read that recommended is +/- 2mm. But the bushings in the photos don’t appear to be the same as the stock photos for a RY-30 S4 (the ones in the stock photos have a bunch of holes). Also, the bushings appear to be perfectly concentric so I don’t know how to adjust the camber.
Do you guys recognize these bushings? Is there any way to adjust the camber with them? Am I correct in assuming the 10mm of negative camber is a major cause of the inner tire wear?
October 25, 2014 at 9:08 pm #35959
Show me another picture of the front of the kart, or rear to front, I wanna see what it looks like with the front tires on, I wanna eye ball it, so please make sure I can see the whole side of the tire walls.
I also wanna see another picture of your snipes mounted on the spindle, please. I’m just trying to help you. We’ll take care of it for sure. But I need your help.
October 25, 2014 at 10:18 pm #35964
I’m going to bed now, but honestly I think you may not be setting the snipes correctly, there’s no way you’re getting 10mm of neg camber. I would look like a major negative camber on an Indy Car, set up for a tight course, in fact it would be hard to ignore or pretend it isn’t there, as you can see the tire leaning inward on the top.
If the front tires look straight up, and you don’t have a problem with broken or worn out spindle bearings at the steering yoke, then your problem is most likely to be too much negative Toe.
How many sessions did you use those tires?
Do you flip them? We usually flip them after 1 race day, then use them for the next can race, after that they’re pretty much done (good for a couple of hard sessions of hard practice ) and ready for the trash.
Sorry about all the questions, but I need to know.
How old is the chassis? Where the tires new, and became this way immediately after 1st, 2nd or 3rd practice session? Or after a few days of practice?
October 27, 2014 at 1:42 pm #36044Steen CarstensenParticipant
October 27, 2014 at 6:26 pm #36061
The tires were used for 2 race days (about 60 laps total) and 2 practice days (prob another 60 laps total). I should probably have shown a photo of the tires after 1 race day instead of with them that old, but that’s what I had. When I get back home I can put up a new photo since I bought a new set of fronts at the race and they are 1 race old now.
I did manage to get the toe adjusted. It was set at about 1-1.5mm of toe in, so I adjusted the toe to 1.5mm toe out. After I made the adjustment to the toe, I checked the camber again and now it is reading -4mm on the right side and -2mm on the left for a total of -6mm. In the photo I provided it looks like the Snipers are on the tapered part of the spindle, but they are not. I checked again with the snipers moved further out on the spindle, the readings were the same.
I did determine that the Pills that I have are Birel part # 10.9747.00. They have 0 offset so if I want to adjust the camber I will have to purchase either the .5 degree or 1.5 degree offset pill.
Thanks for the advice so far, please feel free to make any other recommendations for a Birel RY-30 (2012) in the 4 stroke clone class.
October 27, 2014 at 9:12 pm #36086
Your set up seems to be pretty good, those tires did what they had to do and designed for.
2 race days, and 2 practice days is a lot, they lasted pretty good I should say. Lol. I can only use a new set of tires for a pipe race, then save them and use them at my next race, which it’s a CAN race ( a bit slower ), but some guys buy tires each race.
If you’re in a budget then buy a new set for one race, then flip them over for the next race, and just use whatever is left for practice till they’re done. All tires do develop most of tire wear on the inside ( both front and rear) that’s why you have to flip them over, so that you get more rubber on the inside again.
Is this a sprint track with a lot of tight corners, and a few fast sweepers?
And the most important question:
How did the kart behave, and how did you do in the race? Any fun at all? What place did you finish?
October 27, 2014 at 9:51 pm #36087
Thanks for the follow-up. I heard several guys say the same thing about flipping the tires. To be honest I have had a heck of a time so far removing the tires from the rims. I have just been having the supplier at the track mount new tires. I need to learn the best method for taking them off because whatever I’m doing isn’t working. I have MG Yellows on Birel mag wheels. I have a bead breaker but trying to roll the tire off the rim by hand seems to be just about impossible. I’m sure it’s my technique.
Our track (google “JRP speedway tulsa”) has 1 long left sweeper and 1 left banked NASCAR-style turn on the north end. Everything else is low speed technical turns.
I had a blast. They run all of the 4 stroke guys together and there are a wide range of engine classes within the race so the scoring is weird – “stock” clone, modified clone, LO206. I’m running mid-pack lap times with the “stock” clone (1 of 2 guys out of 12) and I knocked .4 s off my PR so I was pleased. Especially since I think there are still a few things that can be done setup-wise.
I could use about 200 more laps around the track and then I think I’ll be getting there. I’m hooked.
October 27, 2014 at 11:39 pm #36091
I googled your track, and checked out some youtube videos on it. Looks pretty fun
You’re gonna need a new tire machine, trust me it will make it a lot easier, it will get the job done in 5 to 10 minutes.
You can install new tires in less than 5, and you can remove old ones and install new ones in about 10.
Look for a TDC tire machine, you’ll love it, best $250 bucks you’ll ever spend. and could be attached to your towing hitch.
October 28, 2014 at 8:27 am #36124
Thanks for the link. That looks like a very useful tool, I will probably get one.
Thanks for all of the advice, I’m really enjoying all of the helpful people in this sport.
October 30, 2014 at 11:35 am #36237Robert FinlaysonParticipant
I would suggest that you contact the person who sold you that chassis because the Birel RY30-S4 chassis is supposed to come with the zero pill that you have on the bottom, and the .5 adjustable pill on the top. As you have already found out, Birel makes the adjustable pills in .5 and 1.5 offsets and you can combine them to get various degrees of caster. The pills that you have are both zero pills and you can’t get any adjustment of caster or camber with them. The person who sold you the kart kept the adjustable pill so he could put it on the bottom of his kart would be my best guess.
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