Jeremy McCreary
Well-Known Member
- Region
- USA
- City
- Carlsbad, CA
Curious, what's the rule of thumb here?
Pretty much done fiddling with the gearing on my current bike, but that would be handy to know for next time.
Which way would you go?
- Thread starter Nvreloader
- Start date
Pretty much done fiddling with the gearing on my current bike, but that would be handy to know for next time.
If just changing chainring, the chain goes halfway around the chainring so you halve the difference in teeth, err on the side of longer just in case....
If swapping the biggest gear on the cassette, you can get fancy by adjusting chain length to get ideal derailieur angle - then stuff it up and add an extra couple of links next time
Jeremy McCreary
Well-Known Member
- Region
- USA
- City
- Carlsbad, CA
Thanks! Of course, no good deed goes unpunished...If just changing chainring, the chain goes halfway around the chainring so you halve the difference in teeth, err on the side of longer just in case....
If swapping the biggest gear on the cassette, you can get fancy by adjusting chain length to get ideal derailieur angle - then stuff it up and add an extra couple of links next time
Speaking of ideal derailleur angle, I've seen recommendations for the derailleur arm at 5 o'clock as viewed from the drive side. Do you agree with that? With the chain on which rear cog? How much leeway?
I think on the largest cassette cog when the B screw is set so you're not quite clashing gears . But I've never known if that's with suspension extended of compressed.
Nvreloader
Well-Known Member
- Region
- USA
Thanks Guys
Questions,
Since I don't ever use the 11/13T gears,
can they be taken off and then I can add higher tooth gears on the slow side,
making 9 gears total?
Can I add more than 9 gears to the rear cassette group,
like 10/11 total gears to the cassette?
Tia,
Don
Questions,
Since I don't ever use the 11/13T gears,
can they be taken off and then I can add higher tooth gears on the slow side,
making 9 gears total?
Can I add more than 9 gears to the rear cassette group,
like 10/11 total gears to the cassette?
Tia,
Don
PCeBiker
Well-Known Member
- Region
- Canada
If you change out your front chain ring with a 30t or 32t, your 11t gear would then become equivalent to the 15t gear and you would start using it as your high speed gear.
It's probably best to change out your front chain ring first, and see if that works for you.
It may very well be enough.
If not, you could do the next step, and change out some sprockets on your freewheel/cassette.
That step is a lot more involved and expensive and you may need a new derailleur.
Changing your chain ring is a much simpler chore that you could do yourself for a lot less money.
Changing sprockets on the freewheel/cassette is a lot more involved and special tools are needed.
PCeBiker
Well-Known Member
- Region
- Canada
You can't really just add gears. You would need to replace the entire cluster/freewheel/cassette.
If there is more gears on the cluster, each gear has to be thinner, and your derailleur and shifter would have to be replaced to match the new cluster.
Your e-bike is a heavy duty 100 pound hunting ebike. The thinner gears on a 10 or 11 speed cluster are a lot more delicate, and probably wouldn't be as reliable. They're just not as strong.
Or you can spend silly $ fitting a wide range 9 speed cassette and discover the gaps between gears are too wide for you.
As an example, if your bike has a shimano hg hub you could try a 12-50 ( nb aus $ so don't have a heart attack https://www.mtbdirect.com.au/products/box-three-prime-ebike-9-speed-cassette?variant=40685459898413 ) That'll allow you to keep the chainring and almost achieve the slow speed you want BUT most budget derailleurs will struggle with that cassette so you can add more silly $ for the rest of the set up . This is their "cheap" option https://www.mtbdirect.com.au/products/box-two-prime-9-speed-x-wide-groupset?variant=40684436127789.
They make a non ebike rated option at 3x that price....... So start by replacing your chainring and only look at wide range cassettes if you have to!
As an example, if your bike has a shimano hg hub you could try a 12-50 ( nb aus $ so don't have a heart attack https://www.mtbdirect.com.au/products/box-three-prime-ebike-9-speed-cassette?variant=40685459898413 ) That'll allow you to keep the chainring and almost achieve the slow speed you want BUT most budget derailleurs will struggle with that cassette so you can add more silly $ for the rest of the set up . This is their "cheap" option https://www.mtbdirect.com.au/products/box-two-prime-9-speed-x-wide-groupset?variant=40684436127789.
They make a non ebike rated option at 3x that price....... So start by replacing your chainring and only look at wide range cassettes if you have to!
10 sp groupsets were a sweet spot for reliability / reasonable range with the gaps being OK . For most people, 11-48 covers most of their requirements, the gaps between gears aren't excessive and you can get a really nice feeling shift with something like this . https://www.mtbdirect.com.au/produc...ge-group-set-for-ebike?variant=41554873974829 There is an argument that the closer gears between shifts improves reliability - I have a 14 year old mtb with original 10 sp chain and cassette!! ( the shifter is wearing out) .
Going way off thread now.....11 +12 sp start sacrificing longevity , especially with their thinner chains. But a nicely set up 12 sp is a joy to use........the thinner chains seem to flick between gears much easier, and the gaps are closer. I'm conflicted every time I replace a cassette - there's an XT 11 sp groupset sitting on my shelf that was going to replace my 12 sp as a weight / reliability improvement. But even an xt 11 sp feels soggy compared to my sram 12 sp with garbaruk cassette.....it has this magical click and shift without me even noticing.....and I can always find the perfect gear....but I chew through chains at an alarming rate! To add to my confusion, I'm in need of a new rear wheel and high quality hg mtb wheels are getting harder to find . I vowed to never return to sram freehubs because of the crazy cost of sram cassettes , but I might not have a choice!
Jeremy McCreary
Well-Known Member
- Region
- USA
- City
- Carlsbad, CA
Agree. That was my Plan A, and I still think it was the place to start. Given the OP's willingness to sacrifice more top-end than I was, might even be enough.
In my case, it soon became clear that the chainring (maybe 34-36t?) required to get a low-enough bottom gear with the stock 11-34t 9-speed cassette would also sacrifice way too much top gear. That's when the cassette went to an 11-42t 10-speed. Ah, just right — and so far, so good!
Nvreloader
Well-Known Member
- Region
- USA
Thanks Guys
I thought that you could build a cassette in the range that you needed/wanted
via just replacing each gear as long as they were in the proper order/spacing etc.
I did not know that these cassettes were a sealed unit and could not be dismantled and then assembled in the configuration you wanted/needed.
I guess I should start looking for a cassette in the steps I need or want,
so far I haven't found much SRAM stuff for this OEM setup,
Sram X-5 9 speeds, DNP 11T-34T with KMC Chain
Can a 10 sp cassette work on a 9 sp hub, with the proper adjustment?
Tia,
Don
I thought that you could build a cassette in the range that you needed/wanted
via just replacing each gear as long as they were in the proper order/spacing etc.
I did not know that these cassettes were a sealed unit and could not be dismantled and then assembled in the configuration you wanted/needed.
I guess I should start looking for a cassette in the steps I need or want,
so far I haven't found much SRAM stuff for this OEM setup,
Sram X-5 9 speeds, DNP 11T-34T with KMC Chain
Can a 10 sp cassette work on a 9 sp hub, with the proper adjustment?
Tia,
Don
PCeBiker
Well-Known Member
- Region
- Canada
I know that at least some cassettes can be at least partially disassembled to replace a cog or two.
A lot of people wear out their high speed 11t cog and some cassettes allow for it to be replaced.
It's not just the cassette. The derailleur has to match the cassette.
If you go from say, an 11T-34T to 11T-42T cassette, the derailleur has a lot more chain and slack to deal with and your original derailleur may not work?
As far as I know, all cassettes are the same height, and have the same distance from highest gear to the lowest.
I have an 8 speed cassette and my shifter has 8 equally spaced shifts from top gear to low gear.
A 12 speed cassette would have 12 equally spaced shifts from top gear to low gear, but it would travel less distance with each increment.
8,9,10,11, and 12 speeds all have different cog spacing, cog thickness, chain thickness, matching derailleur thickness, and shifter increments. And everything needs to be matched.
I don't know if Jeremy needed to replace his shifter, chain, and derailleur to go from a 9 speed cassette to a 10, or if adding a single gear still allowed everything else to work?
In your case, being as you never use your 11T and 13T gears, a simple swapping of your chain ring may very well be all that you need to do, at least as your first step.
If you're convinced that a new chain ring isn't enough, then it's probably best to replace your chain ring, chain, cassette, derailleur, and shifter, all as a complete set to make sure everything is matched.
It's a big rabbit hole.
Get ready to jump in with lots of cash in hand.
Another thing to keep in mind is whether or not you have cadence sensing or torque sensing on your ebike.
My ebike has cadence sensing, speed based PAS modes.
My PAS mode 1 was set at about 25 kph. It didn't matter what my cadence was, the damn bike wouldn't go slow.
And when I started to pedal, the stupid bike would go to full power to get me up to 25 kph.
I didn't like it at all, so I installed a KT controller and display.
I can now use my "Throttle Gears" to go as slow as 3 kph using less than 50 Watts if I want, or I can crank it up to 1200 Watts to climb 45° hills in the dirt.
I now have complete control of my power and speed.
Are you sure your bike has an sram cassette ? Nb SRAM use a different freehub ( the bit that attaches the cassette to the wheel ) - so don't go buying an sram cassette if your bike has the traditional shimano ( hg) freehub !
Jeremy McCreary
Well-Known Member
- Region
- USA
- City
- Carlsbad, CA
Cassette, derailleur, chain, and shifter were all changed to go from 9-speed to 10-speed. All were significant upgrades from stock. Kept the existing like-new chainring on that go-round. Don't recall the cost, but it was less than I expected. Maybe $300 parts and labor?
Didn't do all that just to get an extra gear. The stock derailleur and chain had to go anyway (long story). Just took the opportunity. Very glad I did.
PCeBiker
Well-Known Member
- Region
- Canada
I found a couple pictures of the two cassettes,..
And a picture of the special tools needed to remove the cassette.
You can cheap out on the chain whip and get a Chinese knock-off but don't cheap out on the cassette removal wrench or socket, and get a proper Park Tool. And make sure that you get the right tool. The tools come with different spline counts, spline reach, and spline depth (thickness).
You may be able to remove all the sprockets from the cassette without removing the cassette hub from the wheel hub, and replace all the sprockets with the 9 speeds that you want, but keep in mind that you can only go so big on the low gear before you're derailleur can't deal with it.
PCeBiker
Well-Known Member
- Region
- Canada
From what I think I remember, some cassettes allow you to replace 1 or 2 sprockets on either end of the cassette, with the sprockets in the middle being fused/welded together.
That allows you to pick the lowest gear tooth count (34T-52T) of your choice, and replace the highest gear (11T) which tends to wear out.
That can give you a super low gear for slow speeds and steep climbs.
Your cassette will look something like this, with a huge jump from first to second gear.
You'd need to know if your derailleur can cope with it and if it will even fit on your wheel and ebike.
Nvreloader
Well-Known Member
- Region
- USA
Thanks Guys
I have an email into Bikeonit to find the spec's and what I have on this bike,
type of derailleur long or short etc.
I can't believe some of these prices for parts, almost outa of price range,
for this retired Old Phart.
But I'll start with the chain ring first.
I have an email into Bikeonit to find the spec's and what I have on this bike,
type of derailleur long or short etc.
I can't believe some of these prices for parts, almost outa of price range,
for this retired Old Phart.
But I'll start with the chain ring first.
PCeBiker
Well-Known Member
- Region
- Canada
It's like switching from 4H to 4L on a 4WD vehicle.
Way easier than rebuilding your transmission with different gears.
Nvreloader
Well-Known Member
- Region
- USA
So far,
for this 130mm BCD, 5 Bolt On chain ring, 38/39T is the smallest I have found,
this would give me approximately 6 mph @ 60 rpm cadence,
with the 34T rear gear, which is close to my normal pedaling range.
To go smaller, I would have to change to 110MM BCD to go smaller
than 38/39T for the chain ring.
for this 130mm BCD, 5 Bolt On chain ring, 38/39T is the smallest I have found,
this would give me approximately 6 mph @ 60 rpm cadence,
with the 34T rear gear, which is close to my normal pedaling range.
To go smaller, I would have to change to 110MM BCD to go smaller
than 38/39T for the chain ring.
