Anyone wish to compare gear ratios

[Old Timer]

Anyone wish to compare my gear ratios with different chainrings to compare with my results and where the crossover will come close(Flecc?)

6th gear 14T
5th gear 16T
4th gear 18T

Chainring 48 standard
" 52 now on bike
" 57 on route for delivery

IE: with a 57 ring fitted what gear would be similar to top gear when the 48 or 52 rings were fitted.

Better than a crossword

 

[Patrick]

48 tooth
6th - 3.43
5th - 3.00
4th - 2.67

52 tooth
6th - 3.71
5th - 3.25
4th - 2.89

57 tooth
6th - 4.08
5th - 3.56
4th - 3.17

So the top gear with the 52 tooth ring falls between 5th and 6th with the 57, and the top with the 48 falls between 4th and 5th with the 57.

Or to put it another way, the 52 adds about half a gear compared to the 48 and the 57 adds about a gear and a half compared to the 48.

 

[Mussels]

Try this workbook, if it doesn't work in older versions of Excel let me know and I'll amend it.

 

[Old Timer]

Try this workbook, if it doesn't work in older versions of Excel let me know and I'll amend it.

Thanks Mussels I`ll try that later

 

[Old Timer]

48 tooth
6th - 3.43
5th - 3.00
4th - 2.67

52 tooth
6th - 3.71
5th - 3.25
4th - 2.89

57 tooth
6th - 4.08
5th - 3.56
4th - 3.17

So the top gear with the 52 tooth ring falls between 5th and 6th with the 57, and the top with the 48 falls between 4th and 5th with the 57.

Or to put it another way, the 52 adds about half a gear compared to the 48 and the 57 adds about a gear and a half compared to the 48.

Patrick

This on my 36V Powertrek

That`s more or less what I thought. Top gear with the 48 was a touch low so using 5th with the 57 should be fine and just a bit higher as wanted. Leaving 6th gear as a down hill overdrive. Won`t get any assistance with the new top gear because it will be used above the 15mph limit. Having said that I noticed the other day when looking at my computer using the 52T ring I was still getting just a touch of assistance at around an indicated 18mph. Now that could be a slight mismatch between wheel size and computer ( there not rocket science) but it sure felt like more than 15mph.

Folder

I ran that with a 52T (up from 46T) the other day and it was far much more usuable but the chain was a bit short. So I have a 116 link chain on route + a 55T chainwheel. I don`t think the 55 will be too high for the folder but if it is it will give me a spare 55T that can be tried out on the Powertrek if the 57 doesn`t work out.

From what I`ve read and ridden I think that E bikes come out of the factory a bit too low geared, unless you are going up hill or against a wind your legs are spinning like a whisk

I`ve never been one for accepting the set up for Mr/Mrs average on anything and have found over the years that a bit of customisation has paid dividends and made many things far more user friendly.

Thanks for coming back

Dave

 

[Old Timer]

Here you are Dave, you can compare graphically by running down the right hand verticals:

View attachment 1190

The gear inches for a 26" wheel are:

For the 48 tooth: 67", 75", 86".

For the 52 tooth: 73", 82", 93".

For the 57 tooth: 80", 90", 102".
.

Thanks Flecc

BTW

Has anybody noticed that chains for E bikes need to be slightly longer than normal MTB`s

Most chains you see advertised are 116 links. My powertrek is 129 links as standard. Now fitting the 57T chainwheel I obviously will need a longer chain (up from 48-57) which means(if I`m correct) using two chains and joining them.

I`ve just fitted the 55T chainwheel to the folder(up from 46) and the original was 109 and I`ve fitted a standard 116 and it all works but is a touch tight on the granny gear ao I suppose a few more links are in order.

 

[flecc]

Anyone wish to compare my gear ratios with different chainrings to compare with my results and where the crossover will come close(Flecc?)

Here you are Dave, you can compare graphically by running down the right hand verticals:



The gear inches for a 26" wheel are:

For the 48 tooth: 67", 75", 86".

For the 52 tooth: 73", 82", 93".

For the 57 tooth: 80", 90", 102".
.

 

[Old Timer]

Well, nipped down to Halfords and purchased two 116 link chains. Split them and fitted the correct length. The 57T chainwheel is now on the Powertrek but it`s dark and foggy so will test over the weekend. I didn`t use the supplied link joiners as I prefer to have the chain all in one.

The Folder now has the 55T chainwheel on and I will test that over the weekend.

Out of interest the new spiders were designed as doubles, I don`t have front changers on either bike but I fitted the 52 T chainrings on the inside of both bikes and I could flip them over by hand if ever needed.

 

[Old Timer]

1st ride today folder with 55T chainring. Superb A very comfortable leisurely ride on the flat in top gear. I think that part of the enjoyment is the upright seating position coupled with the lightness of the bike. Has turned the bike into something that most people would be quite happy with as there everyday ride.


Powertrek with 57T chainwheel, haven`t got that much time today as my son and the girls are on the way up for the day. I need to do one of my normal exercise routes with mixed terrain to be able to judge it properly. Down hill that top gear is superb but a bit high for leisurely flat cycling (remember I`m fairly unfit and an OAP now dropping down to 5th of 6 gears is now slightly higher than my original 5th gear was. I`m not quite sure that it isn`t just slightly overgeared now! I have the 52T bolted on besides the 57T so can stop and manually change the chain to compare.
I originally ordered the 55T for the Powertrek but somehow it got fiited on the folder so maybe that might be a better bet. It`s no secret that the Powertrek is not the lightest bike of the bunch so maybe in my state of fitness and the weight factor keeping the gearing down to the 52T might be a better compromise. I remember when I upped the Powertrek from 48-52 I was very pleased. But! if you don`t try then you don`t know what you might be missing, aye.

Some of you might be getting a bit fed up with my gear ramblings and I`m sorry but feel I need to share these things with the group for others to try

Dave

 

[Old Timer]

1st ride today folder with 55T chainring. Superb A very comfortable leisurely ride on the flat in top gear. I think that part of the enjoyment is the upright seating position coupled with the lightness of the bike. Has turned the bike into something that most people would be quite happy with as there everyday ride.


Powertrek with 57T chainwheel, haven`t got that much time today as my son and the girls are on the way up for the day. I need to do one of my normal exercise routes with mixed terrain to be able to judge it properly. Down hill that top gear is superb but a bit high for leisurely flat cycling (remember I`m fairly unfit and an OAP now dropping down to 5th of 6 gears is now slightly higher than my original 5th gear was. I`m not quite sure that it isn`t just slightly overgeared now! I have the 52T bolted on besides the 57T so can stop and manually change the chain to compare.
I originally ordered the 55T for the Powertrek but somehow it got fiited on the folder so maybe that might be a better bet. It`s no secret that the Powertrek is not the lightest bike of the bunch so maybe in my state of fitness and the weight factor keeping the gearing down to the 52T might be a better compromise. I remember when I upped the Powertrek from 48-52 I was very pleased. But! if you don`t try then you don`t know what you might be missing, aye.

Some of you might be getting a bit fed up with my gear ramblings and I`m sorry but feel I need to share these things with the group for others to try

Dave

Images of chainwheels. The last two images in this gallery
e-bike Photo Gallery by david chilvers at pbase.com

 

[Artstu]

The Folder now has the 55T chainwheel on and I will test that over the weekend.

I look forward to hearing how you get on, despite the hills around here I think I also need to gear-up my folder too. So I'll be on the look-out for a new chain-set.

 

[Old Timer]

I look forward to hearing how you get on, despite the hills around here I think I also need to gear-up my folder too. So I'll be on the look-out for a new chain-set.

I purchased one of these to start with and found the 52T wheel made a big difference and probably would have stuck with it if I wasn`t such a medlar
nice quality double road bike alloy chainset/crankset on eBay (end time 11-Feb-10 18:03:50 GMT)

It went straight on the existing BB spindle and cleared everything

Dave

 

[Artstu]

Thanks Dave, that's a good price. A shame a derailleur isn't a simple fit, what with the battery in the way, my chain has come off 3 times already.

 

[Old Timer]

Thanks Dave, that's a good price. A shame a derailleur isn't a simple fit, what with the battery in the way, my chain has come off 3 times already.

Not sure what you mean that the battery is in the way. Do you mean that is what is causing the chain to come off?

I had a better ride on the folder with the 55T and there is no doubt about it, it is definitely a much better road bike with that chainring. the small wheels combined with the lower gears still leave plenty of assistance when required.

Going on from that. I had a good ride on my powertrek today with the 57T chainring on. I wasn`t convinced Luckily as I had mentioned) I had combined my 52T chainring on the spider so I did my route all over again with that ring engaged and I really do think that(at my level of fitness) the 52T is a better bet. I`ts not just a matter of gearing, you have to bring into the equation where the pedal assist leaves off with regards to road speed. Yes, a higher gear can see you flying down hill and on the flat at times but you forgo the enjoyable assistance because you start to travel beyond the approx 15mph where the pedelec falls away. So I think at this time the 52T is the best compromise on the Powertrek.
The folder is a different story because it it is so low geared to start with and that might take the 57t, we will see.

And now to repair a rear puncture on the Powertrek caused no doubt by the crud on the back lanes around here where I like to ride that the tractors bring on and it is flint country.

I`m considering either, pump in slime, ready made slime filled tubes or the slime re-inforcing band that goes inside the tyre and sits on top of the tube(that I`m told is a PIYA to fit)

Any suggestions?

 

[Artstu]

Not sure what you mean that the battery is in the way. Do you mean that is what is causing the chain to come off?

No I mean for fitting a front derailluer which would also help to stop the chain coming off.

 

[Mussels]

No I mean for fitting a front derailluer which would also help to stop the chain coming off.

I've found the same problem and looked at various ways of fitting one, nothing was workable. I bought a special bit of kit for downhill MTB racing to stop the chain coming off but that doesn't quite fit with the battery in place.

 

[Artstu]

The original chain set on the bike does have plastic guards either side, but the outer one has enough room to let the chain slip between the chain-wheel and guard, the first couple of times it happened I thought the rear cluster had lost drive because the chain spins silently round on the plastic guard.

I'll be on the look-out for a chain-set with guards either side given the frequency the chain seems to comes off.

 

[flecc]

I've found the same problem and looked at various ways of fitting one, nothing was workable. I bought a special bit of kit for downhill MTB racing to stop the chain coming off but that doesn't quite fit with the battery in place.

All the centre battery e-bikes seem to have this front mechanism fitting problem, there's been much previous head scratching by eZee owners about this same issue in an effort to get two chainrings. Wisper's new 806 folders have cracked it with twin chainrings and changer though.

Shimano make a bottom bracket mounting plate with arm that can carry a changer, but I think it only fits certain BB types and it's not an easy item to find.
.

 

[Old Timer]

To be honest I think you only really need one chainring on the folder.

I`ve been playing around with the folder and chainwheels as you know, yesterday my son, his wife and both daughters were tearing around on the folder, apart from me now have ridden maybe twenty or so miles on it and not once has the chain come off (you are worrying me now)

there has got to be something either out of alignment or adjustment surely??

 

[flecc]

Some of the things that can cause chains to come off the chainwheel:

1) A sticking freewheel action. When pedalling is stopped, the continuing spin of the wheel can drag the freewheel around and snake the chain forward towards the chainwheel.

2) The plastic guard disc that some Shimano cassettes have at the rear to protect the spokes against the chain jumping in sometimes has the same effect if binding.

3) A slightly buckled or warped chainring.

4) A slack rotation tensioning spring in the rear mechanism can cause the chain to thrash up and down and jump off when pedalling stops or slackens.

5) Binding jockey wheels in the rear mechanism can have the same effect.

6) Seized chainlinks giving stiff link joins can try to run the chain straight on and cause jumping.
.