LocostUSA.com

What is my options when I cant use a electric reverse.

these are not locost, but high cost.
- quaife https://www.quaife.co.uk/
- elite http://eliteracingtransmissions.com/cat ... -sub-menu/



Or built one of a:
- FWD differensial (will need a locking mecanisme)
- boat gear. (not a inline option, but could work in a differensial)
- automatic transmission.
- strip down a small lightweigh transmission.

pros and cons?

I have installed an electric reverse but have yet to use/test it. The other options aren't very good.

Stripping down a transmission will require added weight and a larger center tunnel.

Reverse gearboxes suck from what I have read. They leak, make lots of noise, and break. Lots of Westfield guys remove theirs for electric reverse or no reverse.

I'm not sure what you mean by adding in a differential.

Also, there are some not so obvious issues with using transmissions. The input shaft must be full supported and remain removable. The best way to do that is with a pilot hub in the output shaft of the bike engine/trans. Another issue is the torque capacity of the trans is probably not adequate for first gear ratio and primary reduction ratio multiplied by the torque at the crank.

Machining and heat treat can be very expensive. A well designed reverse box for $1500 is a good value but nothing beats the cost effectiveness of starter based electric reverse.

I suppose a diff could be driven through the spiders for reverse but they would wear rapidly if not used only for reverse operations. I really have not though out how to do it though.

Considering all the other work to sort out, I probably would not bother with reverse unless it was required. It can be added later.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

If I could lock the housing to one end of the shaft it will flow the shaft turning. If I then discontect the shaft/housing and then lock the housing rotation then I will have a reverse gear. I dont need much torque in reverse, so the diff gears could be small and light.

Spinning a diff housing, side gears, and spiders at driveshaft rpm can be dangerous and it would be difficult to know how much torque you may be applying in reverse with a twitch of the throttle or if the tires slip then grab.

If you replace your side gears and spiders with a planetary (such as from an automatic trans) and slider with shift fork, it would be much more efficient way with just the shaft turning in drive. Another is to have two pinions on the rear axle diff facing opposite directions with a slider to switch between them.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

To elaborate further, the planetary will have a much greater torque capacity due to greater tooth engagement. Four to five pinion/planet gears are not unusual.

The input shaft has the sun gear, pinions/planets, and ring gear in constant mesh that protrudes beyond the sun and splined the same as the output shaft with a relief for the output shaft pilot bearing to maintain alignment but free to rotate independently.

The slider matches the shafts but the od has dog teeth that engage the ring gear that necks down to about the size of the sun gear od and is splined to match the slider.

If you want not to have the gear set turning in drive, float the sun on the input shaft with caged needle bearings and have dog teeth on the sun to engage a second slider, linked to the output slider through two forks with a common rail or you can have two levers.

Automatics don't have all that so you are looking at a lot of custom machining and hardening.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12