Chainring upgrade how many teeth

[Old Timer]

My E bike has 48 teeth on front ring, I want to raise the gearing slightly. How much difference would a 53 tooth ring give me? and how do you measure your chain width/pitch?

thanks

 

[Memran]

Gear ratios in their simplest form are just pretty easy to work out, but to answer your specific question we also need to know the size of the rear as well. (And depending how far you want to go with this, your wheel size too.)

Without those bits of extra info I can tell you this much:

The change in ratio from 48t to 53t is 53/48=1.10416666666667 (lets just call this 1.1)

So for the same pedal cadence with a 53t ring you will be going 1.1 times the speed you would with a 48t.
For the same speed you will pedal at 0.9 of your original cadence (rounded slightly from 0.905660377..)
This is irrespective of rear sprocket and wheel size.

Hope that helps

 

[Old Timer]

Gear ratios in their simplest form are just pretty easy to work out, but to answer your specific question we also need to know the size of the rear as well. (And depending how far you want to go with this, your wheel size too.)

Without those bits of extra info I can tell you this much:

The change in ratio from 48t to 53t is 53/48=1.10416666666667 (lets just call this 1.1)

So for the same pedal cadence with a 53t ring you will be going 1.1 times the speed you would with a 48t.
For the same speed you will pedal at 0.9 of your original cadence (rounded slightly from 0.905660377..)
This is irrespective of rear sprocket and wheel size.

Hope that helps

Yeh! that does help and Thank You.

That tells me enough to base a purchase on. If I was turning the chainring 10x every 10 secs I will now (approx) be turning it 9 times in 10 secs at the same road speed?

Cheers

Dave

 

[Mussels]

I worked out the chainring I needed by noticing the gears I didn't use. Work out the lowest gear that you need and calculate it's ratio using the teeth count (x = chainring / lowest used rear cog), then use x with the lowest gear you have (new chainring = x * lowest available cog).
That way you will still have the lowest gear you need but no more.

 

[Blew it]

My E bike has 48 teeth on front ring, I want to raise the gearing slightly. How much difference would a 53 tooth ring give me? and how do you measure your chain width/pitch?

thanks

Chain width = 3/32"
Pitch = 1/2"

 

[flecc]

Up to 8 speed derailleur chain width is 3/32". measured across the rollers between the side plates.

Hub gear bikes are mostly 1/8" chain width measured the same way, but occasionally have derailleur width chain and sprockets.

There are also special narrow 9 and 10 speed derailleur chains.

Chain pitch is always 1/2" on bikes.
.

 

[Old Timer]

Thanks lads

I`m just wondering just how much difference I will feel from 48-52??(in top gear) and is it really worth all the agro??

Anyone

 

[Mussels]

Thanks lads

I`m just wondering just how much difference I will feel from 48-52??(in top gear) and is it really worth all the agro??

Anyone

We need to know what rear cogs you have, if you don't know we may be able to work it out from the bike specs.
If you aren't going too fast to pedal then it's not worth doing anything, remember it's difficult to ride many hub motored ebikes faster than the motors maximum speed.

 

[flecc]

Thanks lads

I`m just wondering just how much difference I will feel from 48-52??(in top gear) and is it really worth all the agro??

Anyone

Not much difference since it will only lift your gear by 8%.

To be really noticeable you'd need around 15% increase, a 56 tooth would gve a 17% increase, but chainrings of that large size are often quite expensive.

The 48 to 52 is probably not worth bothering with since it's easy to train oneself to a slightly higher cadence which is healthier anyway.
.

 

[Old Timer]

Not much difference since it will only lift your gear by 8%.

To be really noticeable you'd need around 15% increase, a 56 tooth would gve a 17% increase, but chainrings of that large size are often quite expensive.

The 48 to 52 is probably not worth bothering with since it's easy to train oneself to a slightly higher cadence which is healthier anyway.
.

I did wonder

 

[Old Timer]

We need to know what rear cogs you have, if you don't know we may be able to work it out from the bike specs.
If you aren't going too fast to pedal then it's not worth doing anything, remember it's difficult to ride many hub motored ebikes faster than the motors maximum speed.

Right, top gear 6th is 14 and 5th is 16

I never use the very large granny gear (if I had to use that then I`d probably get off, find a pub and have a few pints
Ideally what I was hoping was that a 52 tooth chainwheel would give me the equivalent of my 48-14 but in my 5th gear then being a 52-16 (thats the combo that I tend to ride a lot) that would then give me a slightly higher 6th gear to be used as and when if I wanted or for downward slopes when I want to pedal and would then leave me 4,3 and 2 for hills and then even the granny gear if needed that would not be quite as low as is now.

Does that all make sense?

 

[Old Timer]

Forgot to mention 26"wheels

Dave

 

[Old Timer]

Not sure if this is right

26" wheels 170mm crank arm

48-14 6.7
48-16 5.8

52-14 7.2
52-16 6.3

Where the lower number is a lower gear ratio which means (if I`m right) that even the 5th gear is slightly higher with the 52 chainring than the 6th gear was with the 48 chainring

 

[flecc]

Not sure if this is right

26" wheels 170mm crank arm

48-14 6.7
48-16 5.8

52-14 7.2
52-16 6.3

Where the lower number is a lower gear ratio which means (if I`m right) that even the 5th gear is slightly higher with the 52 chainring than the 6th gear was with the 48 chainring

That last bit is wrong. To judge the comparison easily, just divide the rear sprocket into the chainwheel:

48/14 = 3.43

52/16 = 3.25

The higher the divided figure, the higher the gear, so the 52/16 is a 5% lower gear than the 48/14. Your highest gear with the 52 chainring will be:

52/14 = 3.71

that 3.71 being only 8% higher than the 3.43 of the 48/14 gives you.
.

 

[Old Timer]

That last bit is wrong. To judge the comparison easily, just divide the rear sprocket into the chainwheel:

48/14 = 3.43

52/16 = 3.25

The higher the divided figure, the higher the gear, so the 52/16 is a 5% lower gear than the 48/14. Your highest gear with the 52 chainring will be:

52/14 = 3.71

that 3.71 being only 8% higher than the 3.43 of the 48/14 gives you.
.

Thanks Tony

So, I might be caught between the devil and the deep blue sea then!

with the chain wheel change the 5th gear would be a touch lower than my present 6th gear (meaning I wouldn`t like to be pedaling faster as my commonly used gear) and my new 6th gear might just be outside the power band for comfort and still not really high enough to really gain much benefit.

Perhaps there is more thought gone into the ratios than I appreciate. To make any decent difference would probably need a rear gear block change with at least a 12 as high gear?

Dave

 

[Mussels]

Perhaps there is more thought gone into the ratios than I appreciate. To make any decent difference would probably need a rear gear block change with at least a 12 as high gear?

Dave

That's not easy to do as Shimano Freewheels only go down to 14 on the highest gear, there were some 13 tooth ones around but that was a while ago. I fitted a Sun Tour freewheel as they do come with a 13 tooth top gear but the cog spacing doesn't work well with Shimano kit so I had to change back.

I'm assuming it's a freewheel, if you have a cassette then there is much more choice.

 

[flecc]

If it's a rear wheel motor, it's got a freewheel, which as Mussels says are only around with 14 tooth minimum now.

You can fit larger chainrings though, here's the 60 tooth monster on my rear motor bike:

.

 

[Old Timer]

If it's a rear wheel motor, it's got a freewheel, which as Mussels says are only around with 14 tooth minimum now.

You can fit larger chainrings though, here's the 60 tooth monster on my rear motor bike:

.

Ooooh!!! that`s a bigun any bigger and you`d have problems with speed ramps

 

[flecc]

Ooooh!!! that`s a bigun any bigger and you`d have problems with speed ramps

I can take it up steps without problems, only the chain touches the step a little behind the chainring.

The main thing I have to watch out for is crossing grass on this 20" wheel bike, found out when I crossed a grass verge and cut the council's long grass for them. The derailleur rear mechanism didn't work too well clogged with cuttings.
.

 

[jkirkebo]

That's not easy to do as Shimano Freewheels only go down to 14 on the highest gear, there were some 13 tooth ones around but that was a while ago. I fitted a Sun Tour freewheel as they do come with a 13 tooth top gear but the cog spacing doesn't work well with Shimano kit so I had to change back.

I'm assuming it's a freewheel, if you have a cassette then there is much more choice.

ebikes.ca sell 9-speed freewheels that are 11-32 tooth.