Full Suspension Street Ebike Gearing?

[ElectricJustin2020]

Let's say You purchase the Giant Trance E+ 1 Pro because you love the feel of full suspension and you like to hop curbs and cut through trails on my commute but you will never take it in the Mountains and you mostly ride on hilly pavement in the suburbs and you want a better gear ratio that allows you to pedal a slower cadence at high speed and have your most used gears in the middle of your cassette, Would you remove the 3 biggest cogs and slide on 3 higher gear cogs or would you try to find a larger narrow wide chainring or would you just put on a standard larger chainring because the Trance E+ 1 Pro has a shadow+ derailleur???? And if you make this change to your electric bike Do you need to re-tune the engine?? I don't know if you can answer this crazy question but I'm sure you know someone that can. Thanks!

 

[Browneye]

Subscribed.
Curious how an eMTB might get re-geared.

AFAIK, you can't fit a cassette gear smaller than 10 or 11 for physical limitations. So your higher gearing needs to come from the other end - the crank.
I would be interested to learn how to fit a larger chain gear on the crank. Seems like that would do the trick in your application. And I'm curious about this on the off chance I replace my Explore for an actual MTB.

 

[Admin]

Hi @ElectricJustin2020, that's a good question. My impression is that ebike mid-drive motors are not tuned to specific gear ratios... except for possibly the Specialized models that go out of their way to communicate that their Brose motors are "trail tuned" for Specialized. Even in that case, I think the motor can handle different sized chainrings and cassette ranges. Depending on the rear hub spacing and freewheel hub, you could probably get a wide range of gears like 11-46t or even 10-50t from SRAM Eagle and the new Shimano hardware. @Browneye is correct that you really can't go smaller than 10 or 11 tooth on rear sprockets because of axle size constraints. This is in fact why companies moved away from freewheels (where the freewheel was built into the cassette and forced 14 tooth as the smallest sprocket.

Long story short, depending on how proprietary the bottom bracket and spindle are, you could either get a different sized chainring or swap out the cassette for a wider range. There are many ways to achieve what you're expressing, and I think the most affordable would be the start with the chainring size... the most effective is going to be cassette upgrade (because you'll get a wider range of gears to use for low and high speed), but the price will go way up if you also need to replace the derailleur. I made a video about freewheel vs. cassette that touches on some of the topics in this conversation... and it seems like you already understand some of this, but hopefully this helps others who might stumble upon this question

 

[ElectricJustin2020]

Hi @ElectricJustin2020, that's a good question. My impression is that ebike mid-drive motors are not tuned to specific gear ratios... except for possibly the Specialized models that go out of their way to communicate that their Brose motors are "trail tuned" for Specialized. Even in that case, I think the motor can handle different sized chainrings and cassette ranges. Depending on the rear hub spacing and freewheel hub, you could probably get a wide range of gears like 11-46t or even 10-50t from SRAM Eagle and the new Shimano hardware. @Browneye is correct that you really can't go smaller than 10 or 11 tooth on rear sprockets because of axle size constraints. This is in fact why companies moved away from freewheels (where the freewheel was built into the cassette and forced 14 tooth as the smallest sprocket.

Long story short, depending on how proprietary the bottom bracket and spindle are, you could either get a different sized chainring or swap out the cassette for a wider range. There are many ways to achieve what you're expressing, and I think the most affordable would be the start with the chainring size... the most effective is going to be cassette upgrade (because you'll get a wider range of gears to use for low and high speed), but the price will go way up if you also need to replace the derailleur. I made a video about freewheel vs. cassette that touches on some of the topics in this conversation... and it seems like you already understand some of this, but hopefully this helps others who might stumble upon this question

Thanks, I ordered a 46t chainring about an hour ago and I'm fairly certain that will give me exactly what I need. I've been building single speed and fixed gear bikes for years so engines and gears are bit foreign to me but I do understand the Basics. I really appreciate the information, feel more confident now