# R4F gear ratio's for gear sets 1 & 2 **URL:** \ **Category:** GEM Forum\ **Created:** [June 20, 2021, 2:57pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705 "2021-06-20T14:57:48Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 20, 2021, 2:57pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/1 "2021-06-20T14:57:48Z")
i emailed Jim @ R4F, for the gear ratio’s for the 2016 to present GEM car speed kit 1 35 - 38 mph, and the speed kit 2 38 - 42 mph. he say’s the gear ratio’s are for speed kit 1 19:1, and speed kit 2 is 25:1 (aprox) does this sound Kosher ? ---
**Author:** ![AssyRequired](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/assyrequired/32/7621_2.png) [@AssyRequired](https://community.electricforum.com/u/AssyRequired)\ **Post date:** [June 20, 2021, 4:17pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/2 "2021-06-20T16:17:34Z")
I think you might have the ratios swapped? ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [June 20, 2021, 4:23pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/3 "2021-06-20T16:23:29Z")
> [@schinia](#): > > does this sound Kosher ? No it does not… ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 20, 2021, 5:19pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/4 "2021-06-20T17:19:00Z")
do you really think it’s right even if (they were) swapped ? and i don’t have them swapped, thats the way he gave them. i don’t know what the stock gear ratio is, GEM hasn’t answered yet. sometimes they answer w/a question. ---
**Author:** ![AssyRequired](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/assyrequired/32/7621_2.png) [@AssyRequired](https://community.electricforum.com/u/AssyRequired)\ **Post date:** [June 20, 2021, 5:39pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/5 "2021-06-20T17:39:47Z")
First, I am not very familiar with late model stuff (use my opinion very lightly) That being said, just doing the math- Guessing a tire height at 23 and a ratio of 25:1, a motor needs to be turning 14k rpm to hit target speed of 38 max. I know those AC motors like to sing, but that’s a pretty high note!!! Realizing the ratio was swapped, I use the same rpm for example: Changing to a 19:1 ratio, that same 14k will get you to 50mph. (So the faster set is the lower numbered ratio) Knocking that down to target speed of 42 the RPM will be about 11,500. Still crazy high. Either talk to someone else or clarify what that number was that he was quoting. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [June 20, 2021, 8:04pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/6 "2021-06-20T20:04:27Z")
> [@schinia](#): > > stock gear ratio 17:1 12:1 and 8:1 are what’s available. From memory. 10:1 from Rodney’s quiet kit. ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [June 20, 2021, 9:48pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/7 "2021-06-20T21:48:59Z")
Assuming 6000 RPM and 24 diameter tires. TRIM 17to 1 = 25 MPH TRIM 12.3 to 1 = 34/35 MPH TRIM 9.3 TO 1 = 44/45 MPH Not recommended. No acceleration. No range. SCHAFER/RODNEY 10.35 TO 1 39/40 MPH quieter, no other modifications required. Can build SHAFER/RODNEY IN 10.35 For Stock carts and flat terrain. 12.44 For Hilly terrain and modified applications. Mike Newhouse and Gabrial Debre have 10.35s Mike helped in development of the unit. Gabrial has not installed his yet. Come to me for your TRIM 12.3 upgrades. Have completed 20. ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 21, 2021, 4:32pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/8 "2021-06-21T16:32:42Z")
thank you for your input/reply. Jim from R4F answered me about the gear ratio’s he gave me. he said to ignore the quoted ratio’s, just to order the gear set for desired speed. he said gear set 2 is not for hilly (areas) then i told him that i ordered the 6.5kW motor option (for pulling and for hills) and he said it would work for both gear sets. i also upgraded from the standard wheel/tire which is 155/80/r13 to the 165/ ?/r14. i am trying to find the aspect ratio for that tire from GEM cause they don’t give it ! that would give me the tire height. thanks Rodney ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [June 21, 2021, 6:03pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/9 "2021-06-21T18:03:34Z")
He didn’t tell you that your range on a 48 volt cart with the 9.3 is going to suck. You will need to up grade to one of Daves 24 cell lithium setups. ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 21, 2021, 7:11pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/10 "2021-06-21T19:11:50Z")
no, he’s like GEM, don’t offer any info. 9.3 ratio is the gear set 1? i also ordered the distance gel, says to get 30 to 55 miles. gem has lithium batts 8.9kW for $9K, and 12.4kW for $11.8K. i’m pushing $23K right now. my wife isn’t going to let me go any further. how much range do you think i will get ? ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 21, 2021, 9:36pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/11 "2021-06-21T21:36:08Z")
got an answer from GEM Company. tire size is 165/70/r14. MY2020 & MY2021 gear ratio is 17:05:1 also they said “was not possible to change” i asked them to explain why ? ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [June 21, 2021, 9:51pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/12 "2021-06-21T21:51:59Z")
Hmm I average (1) 12.3 upgrades per month. Note: when you change something your warranty goes out the window. Rodney ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 21, 2021, 10:50pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/13 "2021-06-21T22:50:22Z")
actually that wouldn’t bother me. there are a lot of people who want a 35MPH. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [June 22, 2021, 12:01am UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/14 "2021-06-22T00:01:06Z")
Go with @Old_Houseboater . I would not trust someone who keeps the tech info to themselves. It shows “for profit” motive only. Rodney works like me. Help first, then make enough money to keep helping others. (And support a gem addiction) ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 24, 2021, 3:02pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/15 "2021-06-24T15:02:32Z")
Jordan said, because thats the ONLY gearset for 20-21. (from GEM anyway) ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 25, 2021, 12:31pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/16 "2021-06-25T12:31:59Z")
Jordan, also said that it’s the only choice (because it’s the entire gear case) whatever that means ?? ---
**Author:** ![bundcur](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@bundcur](https://community.electricforum.com/u/bundcur)\ **Post date:** [June 26, 2021, 1:56am UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/17 "2021-06-26T01:56:13Z")
8/1 gears, 23.5” tires, 9000rpm motor=71mph. Here is a link to the spicer gear ratio calculator. > **[Spicer Transmission Ratio RPM Calculator](https://spicerparts.com/calculators/transmission-ratio-rpm-calculator)** > > Use the Spicer Transmission Ratio RPM Calculator to determine your engine’s RPM based on the transmission gear ratio, tire height, MPH, and ring and pinion gear ratio. ---
**Author:** ![schinia](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/schinia/32/8694_2.png) [@schinia](https://community.electricforum.com/u/schinia)\ **Post date:** [June 26, 2021, 12:34pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/18 "2021-06-26T12:34:23Z")
(1) where did you get 8.1 ? (2) the tires are 23.1 (3) where did you get 9000 rpm ? getting info from Jordan is like pulling teeth, and getting a gear ratio from R4F ditto. ---
**Author:** ![bundcur](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@bundcur](https://community.electricforum.com/u/bundcur)\ **Post date:** [June 26, 2021, 5:48pm UTC](https://community.electricforum.com/t/r4f-gear-ratios-for-gear-sets-1-2/21705/19 "2021-06-26T17:48:38Z")
That is the rpm my motor is set to. A d&d or RFF motor will never turn that high of rpm. There are standard ger box ratios gems have. The other is height of your tire. Do your research and trust @Old_Houseboater and @Inwo. Their advice and guidance will save you in the long run because the road to hells basement is a long and costly one. Unfortunately I figured that out the costly way.