BMI's DB12R
07-30-2008, 10:19 PM
#5206
Tech Fanatic
I'd recommend you ditch the IRS micro shock and either pick up the Hot Bodies Cyclone 12 (recommended!) or the CRC micro shock. I used to have 5 different IRS shocks pre-built and I would swap them out after every one or two runs. The Hot Bodies shock has a really strong/thick shock shaft, not to mention a bladder.
I've rebuilt many shocks for people and find the following things give the best action, and longest life, to an IRS/CRC shock. I get 10 to 15 runs from a rebuild, by which time it's lost some oil due to too many sudden stops against the corner markers!!
Change the foam compensator regularly - every two rebuilds is my experience. The foam rots in the oil, goes hard, and makes it difficult to get a good result. This is the biggest factor in getting a good, even shock action that improves the handling of the car. IRS sell these at $4 for 10.
Change the O Ring every three or four rebuilds. Once the O-Ring has expanded to the same diameter as the shock body, or if it dumps oil after a couple of collisions with a barrier, time for a new O-Ring. IRS sells these at $6 for 10.
Always rebuild the shock with Associated Green Slime - a smear on both sides of the O-Ring - to give the best seal and shock action.
Don't use the rubber o-ring to hold the batteries in, use tape. The O ring allows the cells to jump up in a crash, and the only thing holding them in then is the shock - it takes a very hard blow and bends the shaft.
The action of a properly serviced and built IRS shock is superior to the HB shock, so there is no need spend money on one. $20 for foams, O-Rings and Green Slime for a season's racing is all it takes! HTH
07-31-2008, 12:25 AM
#5207
I was curious as to why people are bending shock shafts.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
07-31-2008, 03:04 AM
#5208
I haven't had to change my volume compensator foam yet but I do let it soak in oil for awhile before installing it. I think this helps to let the oil penetrate better into it.
Shock shafts get bent from the battery in heavy accidents. There is an 0-ring holding it in place and in a heavy accident that is not enough to prevent the battery from hitting the shock. However in the majority of accidents it works fine. If you want to be more sure about it use strapping tape to hold the battery in. There is slots provided for the tape. I've bent shock shafts in my CRC and my Darkside cars...so it's something that just happens.
Shock shafts get bent from the battery in heavy accidents. There is an 0-ring holding it in place and in a heavy accident that is not enough to prevent the battery from hitting the shock. However in the majority of accidents it works fine. If you want to be more sure about it use strapping tape to hold the battery in. There is slots provided for the tape. I've bent shock shafts in my CRC and my Darkside cars...so it's something that just happens.
07-31-2008, 02:39 PM
#5209
I was curious as to why people are bending shock shafts.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
07-31-2008, 04:18 PM
#5210
I run 19t or stock and I cannot ever remember bending a shock shaft, but I allways tape in my batts also. I'm thinking this is more of a problem if your running mod, or it could be that I'm just too slow
.
07-31-2008, 04:21 PM
#5211
Ok, Im really new to 1/12th scale. (Like it so far) Trouble is I have been super busy lately and have not been able to do all the reading I need to in order to learn about what some of the set-up tricks are. So, I thought I would just post a few basic questions (which Im sure are here about 3k times) and hope someone in the know will take the time to answer them. 
1) What's the typical effect of changing the height of the front shock mount ball-stud (On power & Off power)?
2) What's the effect of changing the weight of the fluid in the damper tubes?
3) Which body is best for running stock on asphalt?
4) What's the main impact of going to lighter (thinner) flex plates?
5) Which caster blocks do most people use for asphalt?
Thanks in advance!
1) What's the typical effect of changing the height of the front shock mount ball-stud (On power & Off power)?
2) What's the effect of changing the weight of the fluid in the damper tubes?
3) Which body is best for running stock on asphalt?
4) What's the main impact of going to lighter (thinner) flex plates?
5) Which caster blocks do most people use for asphalt?
Thanks in advance!
This will cover most of your questions
http://richardchang.com/hobby.php?topic=112setup
07-31-2008, 09:16 PM
#5216
hey guys i just got my DB12R and i LOVE it. it is my first 12th scale to own. I ran it at the local asphalt track last weekend and im going to go run some carpet oval with it saturday. Keep up the good work.
08-01-2008, 03:07 AM
#5219
I've noticed this in 1/12th no matter what the car and have narrowed it down to 2 causes I can see. First off is one of the front springs have collapsed more then the other. In those cases you end up with more droop on one side then the other if you look closely. The other is one lower pivot ball has more play then the other in the lower front suspension. Because stock springs make contact with the ball and not the arm then if one side is more loose then the other you will have a lower side.
08-01-2008, 07:13 AM
#5220
I was curious as to why people are bending shock shafts.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
I asked about durability because the car looks like it's built just a little bit better than most other cars. More specifically, the rear flex plate design. The link cars just look like they'd be more prone to having the rear ouf of alignment with a small wack on the side.
And "specifically" the rear flex plate design makes the DB12R MORE resistant to "alignment changes" when hitting stuff than any other 1/12 car I've driven. Jason is the Ron Popeil of chassis manufacturers...just set it and forget it--go racin'.
Armed with Rich Chang's wonder-sheet you don't NEED any other cheat sheets. You've got it all right there in your hand.
I've noticed this in 1/12th no matter what the car and have narrowed it down to 2 causes I can see. First off is one of the front springs have collapsed more then the other. In those cases you end up with more droop on one side then the other if you look closely. The other is one lower pivot ball has more play then the other in the lower front suspension. Because stock springs make contact with the ball and not the arm then if one side is more loose then the other you will have a lower side.
Another thing to check if you're using the BMI front height adjusters would be to make sure the chamfered side is down toward the chassis. Myself--I'd pay another $1 a set if they were chamfered on both sides so I had one less thing to think about when changing them. I can't tell you how many times I can't remember if I made sure of this when changing spacers and have to pull 'em all apart again and look. I invariably have, but I have to check.