CookeCityRider
Newbie
I have ridden my new Apex Mt for about 100 miles. I noticed right away that the grip heaters didn't seem to get near as warm as the ones on the MM700. The thumb heater wasn't extremely hot but it works better than the grip heaters.
From the information I have read, each grip heater measures about 2.5 ohms. The two heaters are wired in series for a total of 5 ohms. From what I have read the output voltage at normal riding RPM's and the 'high setting' is around 13 volts.
According to Ohms Law: E=IR where E is the voltage, I is the current and R is the resistance. Also, P=EI where is P is power(watts in DC). Doing the math, we find the current, I, to be 2.6 amps and the total power to be 33.8 watts with half (16.9 watts at each grip heater).
The obvious quick and easy solution would be to reconnect the grip heaters in parallel. Two identical resistors of 2.5 ohms in parallel would equate to only 1.25 ohms. The current, I, now would be 10.4 amps. The total power would be 135.2 watts or 67.6 watts for each grip heater.
CAUTION The are several concerns that come to mind right away, not the least of which is whether the magneto can produce that much power. Also, the wire size has to be large enough and the variable voltage regulator(which I assume is built into the ECU) has to be able to 'switch' or control 4 times the amount of current.
The other possible solution would be to find grips that have less resistance ( like 1.5 to 2.0 ohms). The only other variable in the equations is the voltage. Since I'm fairly sure the regulator is build into the ECU, there isn't much that can be done easily there.
For those few people that haven't fallen asleep and are still reading this, I'm NOT suggesting you change anything until Yamaha has a chance to figure this out which I'm sure they will do soon. I just thought it might help everyone to understand the different factors and issues involved in this issue.
Now I'm off to find my extra gloves and liners.....Zane
From the information I have read, each grip heater measures about 2.5 ohms. The two heaters are wired in series for a total of 5 ohms. From what I have read the output voltage at normal riding RPM's and the 'high setting' is around 13 volts.
According to Ohms Law: E=IR where E is the voltage, I is the current and R is the resistance. Also, P=EI where is P is power(watts in DC). Doing the math, we find the current, I, to be 2.6 amps and the total power to be 33.8 watts with half (16.9 watts at each grip heater).
The obvious quick and easy solution would be to reconnect the grip heaters in parallel. Two identical resistors of 2.5 ohms in parallel would equate to only 1.25 ohms. The current, I, now would be 10.4 amps. The total power would be 135.2 watts or 67.6 watts for each grip heater.
CAUTION The are several concerns that come to mind right away, not the least of which is whether the magneto can produce that much power. Also, the wire size has to be large enough and the variable voltage regulator(which I assume is built into the ECU) has to be able to 'switch' or control 4 times the amount of current.
The other possible solution would be to find grips that have less resistance ( like 1.5 to 2.0 ohms). The only other variable in the equations is the voltage. Since I'm fairly sure the regulator is build into the ECU, there isn't much that can be done easily there.
For those few people that haven't fallen asleep and are still reading this, I'm NOT suggesting you change anything until Yamaha has a chance to figure this out which I'm sure they will do soon. I just thought it might help everyone to understand the different factors and issues involved in this issue.
Now I'm off to find my extra gloves and liners.....Zane
orjan
Newbie
Another set of warmers in parallell should do it, but we dont know how much current we are allowed to take. Isnt there a fuse for them?
dirkdiggler
Suspended
Cook: excellent post
Can you find out how many Watts the RX-1 Puts out? That would help us come to manybe one these three comclutions.
a. if it's the wattage is the same on the RX-1 then the voltage being sent to the grips might be less on the Apex.
b. Or If it's the same on the RX-1 and the voltage is also the same then it's a design flaw on the Apex
c. If the RX-1 Grip actually puts out more Wattage you also have your answer.
Can you find out how many Watts the RX-1 Puts out? That would help us come to manybe one these three comclutions.
a. if it's the wattage is the same on the RX-1 then the voltage being sent to the grips might be less on the Apex.
b. Or If it's the same on the RX-1 and the voltage is also the same then it's a design flaw on the Apex
c. If the RX-1 Grip actually puts out more Wattage you also have your answer.
RTX Meirda
TY 4 Stroke Master
I would like to keep my current grips....they seem like they are supper sticky for a surface with little texture.
leaddog
Expert
Can you (or someone) measure the heater resistance on another sled. I won't be able to access my sleds until Saturday. It would be helpful in determining if it's a problem with the grips, or the sled. :|
srxtwins
Expert
the grip resistance for 4 different sleds is posted in another string about poor grip heat.
Tork
TY 4 Stroke God
Zane, outstanding post.
Possible fix is wire them in parallel with resistors, go for an amp draw of 5-6 amps.
The watts are way too low in series like that , somebody in engineering should have cought that
Possible fix is wire them in parallel with resistors, go for an amp draw of 5-6 amps.
The watts are way too low in series like that , somebody in engineering should have cought that
dirkdiggler
Suspended
Grip resistance test
shop ambient temp of 50f
98 srx grip 3.3 ohms left grip
03 rx-1 grip 1.9 ohms left grip
05 rx-1 grip 1.9 ohms left grip
06 apex gt grip 2.5 ohms left grip
hope this helps you guys figure this out
shop ambient temp of 50f
98 srx grip 3.3 ohms left grip
03 rx-1 grip 1.9 ohms left grip
05 rx-1 grip 1.9 ohms left grip
06 apex gt grip 2.5 ohms left grip
hope this helps you guys figure this out
leaddog
Expert
Thank you
CookeCityRider
Newbie
Yes, srxtwins posted the following left grip resistance in an earlier post: 98 SRX-3.3 ohms, 03 & 05 RX1-1.9 ohms.
Assuming the same 13 volts, each grip of the RX-1 would have approx. 22 watts. But the 98 SRX would only have 12.8 watts?!.
If I remember correctly, it wasn't until the 2K model that Yamaha started using a variable voltage regulator to control the grip heater. Previously, they used a dual resistance grip heater with a low & high selector switch which might explain the different in the 98 SRX.
If someone could accurately measure the voltage at varies RPM's of the Apex and 03-05 RX1 at each grip, then we could know if it was related to that or the grip resistance and/or handlebar design. I won't be able to check it on the Apex until this weekend and I don't have access to a RX1.
Of course, we could just let Yamaha figure it out but what fun is that?!..
...Zane
Assuming the same 13 volts, each grip of the RX-1 would have approx. 22 watts. But the 98 SRX would only have 12.8 watts?!.
If I remember correctly, it wasn't until the 2K model that Yamaha started using a variable voltage regulator to control the grip heater. Previously, they used a dual resistance grip heater with a low & high selector switch which might explain the different in the 98 SRX.
If someone could accurately measure the voltage at varies RPM's of the Apex and 03-05 RX1 at each grip, then we could know if it was related to that or the grip resistance and/or handlebar design. I won't be able to check it on the Apex until this weekend and I don't have access to a RX1.
Of course, we could just let Yamaha figure it out but what fun is that?!..
...Zane
Rewiring the grips will work as I did it to my 02 Viper as those grips were not near as hot as my 00 SXR. BUT, I DID damage the voltage regulator. So with that in mind I am going to wait for yamaha to come up with a FIX! ===SRXSRULE===
Tork
TY 4 Stroke God
Zane, this is from that 7 page thread, dont know if you saw it
this info needs to be double checked though
snowbelt
Extreme
Joined: 15 Mar 2005
Posts: 78
Location: Cicero,NY
Posted: Mon Nov 28, 2005 7:53 pm Post subject:
--------------------------------------------------------------------------------
FWIW,
I tested the wire coming from the ECU going to the grips. At 2000rpm's and the grips on high, the voltage was 6.5. At 4000rpm's it was 13volts. Whats it mean? I dunno, but sounds like they have adequate power being supplied to them. Could just be a case of the heated grip being to small/weak.
_________________
They can't repossess the memories!
06 APEX GT
this info needs to be double checked though
snowbelt
Extreme
Joined: 15 Mar 2005
Posts: 78
Location: Cicero,NY
Posted: Mon Nov 28, 2005 7:53 pm Post subject:
--------------------------------------------------------------------------------
FWIW,
I tested the wire coming from the ECU going to the grips. At 2000rpm's and the grips on high, the voltage was 6.5. At 4000rpm's it was 13volts. Whats it mean? I dunno, but sounds like they have adequate power being supplied to them. Could just be a case of the heated grip being to small/weak.
_________________
They can't repossess the memories!
06 APEX GT
Tork
TY 4 Stroke God
SRXSRULE said:
Could not agree more, just tossing out ideas, nobody should do anything other than compile info.
CookeCityRider
Newbie
Thanks for the kind words, Tork. I have quietly read and use alot of valuable information on this site, so I figure it's my turn to give some back.
I had thought about the same thing as you suggested about adding another resistor(s) is series with the parallel grip heaters. In fact, I had already done the calculations with adding a 1.0 ohm resistor and ended up with 5.8 amps of total load. I'm not sure if that is too much or not for the ECU. The wattage at each grip would then be 20.7 watts. I'm not sure if that would make enough difference or not.
Also, there would be 33.6 watts disappated by the 1.0 ohm extra resistor. A guy could mount it inside the handlebar and use it to heat it up from the inside...j/k... Zane
I had thought about the same thing as you suggested about adding another resistor(s) is series with the parallel grip heaters. In fact, I had already done the calculations with adding a 1.0 ohm resistor and ended up with 5.8 amps of total load. I'm not sure if that is too much or not for the ECU. The wattage at each grip would then be 20.7 watts. I'm not sure if that would make enough difference or not.
Also, there would be 33.6 watts disappated by the 1.0 ohm extra resistor. A guy could mount it inside the handlebar and use it to heat it up from the inside...j/k...
ZaneCookeCityRider
Newbie
Tork, no I didn't see the early post about the voltage. It sounds about right to me, however.
The question I would have is does the voltage ever rise about the 13 volts at a higher RPM? If someone has a track jack and could check at higher RPM, then we would know if the 13 volts is as high as it gets. I'm thinking it probably is since that is the normal system voltage. I agree with snowbelt extreme, I'm thinking that the grips are just too high of resistance(small/weak).
The easiest fix might be to replace the grips with less resistance ones of the same type and texture. Once again, just as Tork as mention, this is only to give everyone a chance to understand what might be going on with the weak grip heaters. At this point, I'm going to wait to see what Yamaha comes up with...Zane
The question I would have is does the voltage ever rise about the 13 volts at a higher RPM? If someone has a track jack and could check at higher RPM, then we would know if the 13 volts is as high as it gets. I'm thinking it probably is since that is the normal system voltage. I agree with snowbelt extreme, I'm thinking that the grips are just too high of resistance(small/weak).
The easiest fix might be to replace the grips with less resistance ones of the same type and texture. Once again, just as Tork as mention, this is only to give everyone a chance to understand what might be going on with the weak grip heaters. At this point, I'm going to wait to see what Yamaha comes up with...Zane
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