Radmission Gearing

[Spoonbender]

I just swapped the rear 16 tooth freewheel with an 18 tooth. Didn?t lose much top end, better torque starting out and on hills. Easy swap to do.

Is it easier to start out pedaling with no battery?

The 20 tooth I don?t even need battery power

[crorris]

@Spoonbender would you please post the part number or link for the 20 tooth that you put on? Thanks!

[Spoonbender]

@Spoonbender would you please post the part number or link for the 20 tooth that you put on? Thanks!

Amazon has lots, standard size. It?s very hilly where I live, this was a game changer!

[crorris]

Thanks!

[Spoonbender]

I just swapped the rear 16 tooth freewheel with an 18 tooth. Didn?t lose much top end, better torque starting out and on hills. Easy swap to do.

Is it easier to start out pedaling with no battery?

The 20 tooth I don?t even need battery power

I know, 20 tooth rules

[Karstan]

Feel free to contact me with any questions, I will try to help.

Hey mtatkow! I purchased a Radmission during the recent sale in the hopes of being able to do an upgrade like what you've done here. Your post here is the only one I can find of someone adding a rear derailleur! I was sure this would be a more common conversion as there seems to be plenty of room (as you've demonstrated).

I'm much more familiar with rear cassettes than freewheels and I'm having trouble figuring out what freewheel to purchase. My parts horde is embarrassingly large but only includes one freewheel and it's much too wide (a vintage Suntour Perfect 6 speed). I measure ~22mm to 25mm of space between the motor and the chainstay to squeeze in some gears. You mentioned that you thought you'd could potentially get a 5-speed in there but I haven't found any under 30mm (when I can even find measurements listed). Would you mind pointing me in the direction of which ones you think might work?

[DuaneL]

since Mtatkow has not been active since March 10, 2022 I doubt he will answer but I would love to know more on adding a derailleur and gears too

[DeeTee]

Hi There,

I'm new to the RadMission (I used to have a RadRover) community but also have interest in a simple 2 (Front) or 3 speed+(rear) solution. 

Love to hear if anyone else has accomplished this that's active.

 

[DuaneL]

Expensive as hell but one way to get a 3 speed front gearing is the Efneo Gtro gearbox which mounts in place of the crank but at 499$ its the same price I paid for my mission

[handlebar]

However,  your torque input to the pedals is fairly low given the 3.125:1 stock gearing, so the result is poor battery life.   

The old way to express gearing is in gear inches, where you multiply the sprocket ratio by the tire diameter. I believe the Radmission has 86 gear inches. My Radrunner has 76 gear inches, but my pedaling would have been pathetic even with a lower gear. The seat was so far forward that I couldn't put much power into the crank.

When Raleigh introduced the three-speed gearshift in 1902, second was 53 gear inches because that was standard for a one-speed. They soon changed sprockets for 50-67-89 gear inches. In other words, their gear for steepest climbing was almost the same as the cruising gear on other bikes. Their 60 degree frame allowed tall, widely spaced gearing. For every inch the saddle was raised to accommodate longer legs, it moved aft half an inch to accommodate longer femurs and give somebody with a taller spine half an inch longer to the bars.

To test seat position fore and aft, you raise it for full leg extension, then put the ball of your foot on a pedal that's forward and level ( 9 o'clock  for the left pedal ). As a rule of thumb, the seat is right if the forward end of the knee is plumb with the spindle. My straddle is 35", which according to one survey, is average for adult male cyclists. With the OEM post, my knee was 7" ahead of the spindle, as if the bike were designed for second-graders.

With a layback seatpost, the end of my knee was over the spindle at 9 o'clock, and my knee wasn't doubled over at top dead center. This increased torque in two ways. I could start my power stroke sooner, and my quads had a better mechanical advantage. I could steam up 4% grades like a locomotive, and pedaling felt good. I added the plywood support after I discovered that my cantilevered weight was gradually bending the post farther aft.

The stock Radmission isn't so bad. I can get the rule of thumb knee position by sliding the seat all the way back on the rails and letting my butt hang off the back. I chose the Radmission partly because of the strong rack, in case I needed a layback. I've ordered one. A plywood support requires only a hole for the post and notches for the rack. Locking the post down holds the support.

Still, I am interested in the possibility of gears...

[Hama]

I Would like to know too. Hopefully some one make a YouTube video

[boilerjad]

Have wrenched quite a few bikes and built a few, too. Thinking some combination of gearing for the Radmission would be possible. Feedback on putting a 3-speed freewheel with a derailleur with integral hangar bracket in the rear and a triple up front with an up pulling derailleur. Still working through my analysis. Parts considered attached. Asking for feedback.

[Tugboats]

Have wrenched quite a few bikes and built a few, too. Thinking some combination of gearing for the Radmission would be possible. Feedback on putting a 3-speed freewheel with a derailleur with integral hangar bracket in the rear and a triple up front with an up pulling derailleur. Still working through my analysis. Parts considered attached. Asking for feedback.

Reviving this old thread because this is a very small community. Boilerjad, did you end up trying this out? What was the outcome. I just picked up a used, like new Mission and I?m exploring my options. I?d like to be able to climb hills easier and be able to keep cranking on the downhills at higher speeds.

I?m thinking swapping the rear cog to a 15 and putting a 40/45/50 triple up front would be pretty slick if I could make it work.