Author Topic: What gear range have you got?  (Read 1544 times)

What gear range have you got?
« on: October 06, 2019, 03:19:29 pm »
My think about messing with bikes period has started and I’m think (again) of getting a custom made chainring. With only A 20” drive wheel, more normal sized chainrings leave one a little short at the top end. My current setup tops out at about 98”.

So, what gear range have you got on your ‘bent. How high and low do you go in ‘normal’ use.

And a bonus question. Is anyone using oval rings?
Sorting my life out, one shed at a time.

Re: What gear range have you got?
« Reply #1 on: October 06, 2019, 04:13:14 pm »
My trike has a Sram 3 speed hub Dual drive fitted and has a nine speed cassette. Plus there's a 30,40,50 triple chainset up front giving a total of 81 gears.

Lowest ratio is 11.2 inches and highest is 114 inches. When using the lowest ratio, I'm barely moving and if on a two wheeled recumbent would be unable to balance.

I mainly leave the hub gear in the central position giving direct drive.

Cruising ratio on the flat, I'm usually somewhere in the 60's for gear inches.
I don't want to grow old gracefully. I want to grow old disgracefully.

Re: What gear range have you got?
« Reply #2 on: October 06, 2019, 04:26:52 pm »
You beat me to it! I'm looking at gearing for an upcoming build and have been spending a lot of time on Sheldon Brown's gear calculator thing.

There are now some ridiculous MTB cassettes out there now which may help. 10 speed with 11-46 range is now easy to get hold of which might mean less overlap and fewer chain rings. Obviously the downside of these is that the gear to gear steps can be quite large.

My upwrong commuter is 700c and ranges 28-119"

I'm currently toying with the idea of 20" wheels, something like 75-44 chain rings and an 11-42 cassette which gives a range of 19-125" in steps of between 6-10". The other thing I'm toying with is a Capreo rear wheel with a 9t sprocket which would allow slightly smaller chainrings for a decent top gear.

Looking for a PDQ frame to restart my recumbent collection!

Rebuilding a PDQ frame to restart my recumbent collection!

Re: What gear range have you got?
« Reply #3 on: October 06, 2019, 04:28:50 pm »


My trike has a Sram 3 speed hub Dual drive fitted and has a nine speed cassette.

@Blade, what size drive wheel are you running?

Looking for a PDQ frame to restart my recumbent collection!

Rebuilding a PDQ frame to restart my recumbent collection!

Re: What gear range have you got?
« Reply #4 on: October 06, 2019, 04:30:53 pm »
I've got a bog standard 3x9 on mine (specced out for touring so deliberately tried to use common components as far as possible). Counting them it looks like about 50-26t on the front and 11-33t on the back? 26" rear wheel so presumably makes for a slightly spinnier range than the same on an upright.

At the low end I definitely run out of balance before I run out of gears. Long climbs of 10% or less are no problem (I enjoyed chugging past the walking Rapha gang on Ditchling for this year's London-Brighton - especially those who'd whizzed past me at the start of the climb), steeper than that and it gets a bit dicey (but bear in mind I'm very overweight).

At the high end I occasionally wish for another gear (particularly unladen) but I'm sure if I had one I'd use it inappropriately. Top gear is a comfortable cruising speed on the flat which is what I want really - I ride distance rather than speed. If I were doing time trials or racing then I'd want faster gears, which I guess would have to mean a less standard size or indeed something custom, unless someone's selling recumbents with full size drive wheels.

Re: What gear range have you got?
« Reply #5 on: October 06, 2019, 04:34:20 pm »
2 or 3 wheels ??

The easiest way to get a big range on a 20" wheel is to add an SA CS-RF3 hub to the mix.
This will give you the equivalent of 5 chainrings, 3 standard plus an overdrive & granny ring.
Using a standard 53-39-30 road triple with a 11-28 9 speed which gives you a 15"-120" range.
Plus it gives you the ability to drop a range after an emergency stop.

I use a 55-38 double on a Schlumpf HSD and a 21 sprocket on a Rohloff hub which gives me a total range of 9.4" - 179.4" on my bent trike.
My normal range is around 20"-120", the rest are use as an overdrive and granny range.

I cannot use oval rings on a HSD due to the overdrive mode spinning the chainring faster than the crank.

Luck ......... :D

Edit:- The Dual Drive is no longer made, the SA CS-RF3 hub is the direct replacement.

Re: What gear range have you got?
« Reply #6 on: October 06, 2019, 04:43:14 pm »


My trike has a Sram 3 speed hub Dual drive fitted and has a nine speed cassette.

@Blade, what size drive wheel are you running?

Looking for a PDQ frame to restart my recumbent collection!
My trike has 20 inch wheels.
I don't want to grow old gracefully. I want to grow old disgracefully.

Kim

  • Timelord
Re: What gear range have you got?
« Reply #7 on: October 06, 2019, 10:31:59 pm »
I'm tired and don't entirely trust my maths, but:

1.4-9.3 (17.6"-113") on the Streetmachine.  I'll live in the middle ring for normal un-loaded riding.  Big ring for fast descents and to get a half-step ratio for the flatlands.  Granny ring only normally needed when loaded.

1.4-9.3 (17.1"-113") on the Baron.  Big ring gets a lot of use.  Granny ring only really there as a bailout gear to keep the cadence up on steep climbs.  Have a race wheel that sacrifices some bottom end for closer ratios.

1.3-9.4 (16.1"-113") on barakta's ICE trike (in electric mode).  I never use the granny ring with the motor.  Don't think barakta does much, either.  Big ring could be a bit bigger, but MTB crankset.

1.3-8.6 (15.6"-102.4") on barakta's ICE trike (in non-electric mode).  Top end is lacking for fast descents, but about right for barakta.  Bottom end lower than is reasonable on a bike.

Careful, Kim. Your sarcasm's showing...

Re: What gear range have you got?
« Reply #8 on: October 07, 2019, 07:25:44 am »
22"-114" a Rohloff 14 speed hub single chain ring up front, 26" driven wheel. Nazca Fuego.
If you don’t make time for exercise now, sooner or later you’ll need to make time for ill health.

Re: What gear range have you got?
« Reply #9 on: October 07, 2019, 07:52:50 am »
I'm currently toying with the idea of 20" wheels, something like 75-44 chainrings and an 11-42 cassette which gives a range of 19-125" in steps of between 6-10". The other thing I'm toying with is a Capreo rear wheel with a 9t sprocket which would allow slightly smaller chainrings for a decent top gear.
I looked into this when I upgraded my trike.

That probably won't work.
I ran a 22-36-48 triple and a 9-32 Capreo hub 20" rear wheel (12.5"-100") on my first bent trike and maxed the range of both derailleurs out.

Max range of a rear derailleur is just under 50 teeth and the front is around 26 teeth.
42-11 is 31 teeth.
That leaves only around 20 teeth maximum for the range at the front.
You cannot fit a non standard longer rear derailleur for a greater total range because it will hit the ground with a 20" wheel.
You can mod a front derailleur for a greater range, but you'd still be limited by the back.

The Capreo hub is only a 9 speed and the smallest 4 sprockets are fixed, that only gives you 5 sprockets to work with.

With a Rohloff on a 20" wheel, you'd need a 13 sprocket and a 38-56 double for a 15"-118" range.
A 13 sprocket and a 38-50-65 triple is just doable for a 15"-137" range.

Luck .........  ;D

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: What gear range have you got?
« Reply #10 on: October 07, 2019, 10:57:48 am »
Current Cruzbike is a 52-39-30 triple and 10sp 12-32 on the back.  That was able to get me up 14% with a light touring load and not wobble over sideways. Would have been more comfortable with a 30/34 lowest gear. Normal cross-chain rules apply on this one, as it's front end is pretty much a rotated DF back end.

M5 had 50/34 up front and 11sp 11-40 MTB casette on the back. All 22 gears usable. 

Both with 700c wheels and 28mm Conti GP 4 Seasons
“Procrastination is the thief of time, collar him.” –Charles Dickens

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: What gear range have you got?
« Reply #11 on: October 07, 2019, 01:55:32 pm »
Gears to recumbentistas are like the inverse of altitude to pilots: too low can be an embarrassment but too high is fatal.  To your knees.

Cosimo the Stealth Baron (26") has 12-25 9-speed and 53-39 double, but has never ventured onto a real road.  Top gear only ever got used on the hill that led onto the back straight at Eastway.

Speedmachine (26") has 11-32 9-speed and, IIRC, 48-36-20 triple (TA Zephyr chainset).

Trice XXL (20") has 11-32 9-speed and 52-38(?)-24 triple (Campag road triple with titchy inner ring that crept of of a box in the Sheds).

I've never felt the need for Monster Gears on an unfaired road-going machine.  If you're spinning out then sit back, relax and enjoy the view.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Kim

  • Timelord
Re: What gear range have you got?
« Reply #12 on: October 07, 2019, 02:09:23 pm »
Cosimo the Stealth Baron (26") has 12-25 9-speed and 53-39 double, but has never ventured onto a real road.  Top gear only ever got used on the hill that led onto the back straight at Eastway.

It's shocking how different my use of gears on the track is compared to even flat roads.  Nevertheless, as a mere human who rides like a GURL without the aid of fairings, a 50T chainring is perfectly sufficient.


Quote
I've never felt the need for Monster Gears on an unfaired road-going machine.  If you're spinning out then sit back, relax and enjoy the view.

The only reason the big ring on my Streetmachine is as big as it is is because with the right combination of shifts it gives half-step ratios that come in handy on the odd occasion I venture into the flatlands.  My R17 descending career never really recovered from that front wheel blowout I had a couple of years ago, and I've generally found that once you're past about 35mph it's more useful to shuffle down in the seat and tuck your legs and elbows in than it is to flap around turning the pedals.  (Also, while it's true that aerodynamics trumps linear power gains at high speed, aerodynamics is itself trumped by TEH FEAR, which probably goes up with the natural logarithm of how much it's going to hurt, or something.)
Careful, Kim. Your sarcasm's showing...

Re: What gear range have you got?
« Reply #13 on: October 07, 2019, 04:35:57 pm »
When I finally got some proper cycling glasses my peak (downhill) speed went up by 20kph. (Well, glasses plus the fact I was trying to make the last train).

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: What gear range have you got?
« Reply #14 on: October 07, 2019, 05:29:25 pm »
I managed perfectly well Audaxing in Essex/Suffolk on saturday using just the middle ring, apart from one downhill-Give Way-90deg lft to uphill section where I dropped into teh granny ring to save my knees. could have probably brutalised my way up, but CBA for an audax.

Could have used the big ring in parts, but no real point, I was just relaxing. Still came home second only 5-10 mins behing the guy who left the halfway control ahead of me, both of us having hit the control ahead of time.
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: What gear range have you got?
« Reply #15 on: October 07, 2019, 07:05:44 pm »


That probably won't work.
I ran a 22-36-48 triple and a 9-32 Capreo hub 20" rear wheel (12.5"-100") on my first bent trike and maxed the range of both derailleurs out.

Max range of a rear derailleur is just under 50 teeth and the front is around 26 teeth.
42-11 is 31 teeth.
That leaves only around 20 teeth maximum for the range at the front.
You cannot fit a non standard longer rear derailleur for a greater total range because it will hit the ground with a 20" wheel.

I'd neglected to consider the mech dangle factor! Thank you.

Given your experience it sounds like I might be needing to look at an 11-32 with sensible sized chain rings and an education in either chilling out or high cadence . I guess as a start point, standard chainsets should be relatively cheap to get going and I can then faff with chain ring sizes later.

Looking for a PDQ frame to restart my recumbent collection!

Rebuilding a PDQ frame to restart my recumbent collection!

Re: What gear range have you got?
« Reply #16 on: October 07, 2019, 10:52:16 pm »
Given your experience it sounds like I might be needing to look at an 11-32 with sensible sized chain rings and an education in either chilling out or high cadence . I guess as a start point, standard chainsets should be relatively cheap to get going and I can then faff with chain ring sizes later.
Do the maths......

chainring / sprocket x wheel = gear, gear x sprocket / wheel = chainring, chainring / gear x wheel = sprocket.
If 100" top gear, 20" first gear, 11t small sprocket and a 40-406 wheel is ~18.5"-19" diameter.
Then 100 x 11 / 18.75 = ~58 teeth for large chainring.
You should just be able to get away with a 12t drop per chainring.
So a 34/46/58 triple to start with.
And 34 / 20 x 18.75 = ~32 teeth for large sprocket.
Total tooth difference for the chain is 45 teeth.
You'll be pushing the limits of both derailleurs so no guarantees.
But it's probably doable for a 20"-100" range .......  :thumbsup:

Going 36/48/58 and 11-34 is probably better idea.
The 36/48/58 and a 9-32 Capreo hub lifts top gear to ~120".
But you can fine tune it from here.

Luck ........... :D

Socks

  • FFCT rally, France 2012
Re: What gear range have you got?
« Reply #17 on: October 08, 2019, 12:45:38 pm »
Interesting too see how low some of the gear ratios go even on a two wheel recumbent.  My most used bent (Velomotion, a Bachetta style stick bike) has 12 - 32 cassette with 30, 40, 52 chainrings.  With a 650b rear wheel that's a gear range of 24" to 122".

I might try smaller chainrings, I rarely use top gears and a lower one would help on steep hills if I can maintain enough speed to balance.

Kim

  • Timelord
Re: What gear range have you got?
« Reply #18 on: October 08, 2019, 12:50:01 pm »
Interesting too see how low some of the gear ratios go even on a two wheel recumbent.

As usual, nobody's talking about crank length.  Spinning helps you balance a two-wheeler.  Shorter cranks make spinning easier.  Shorter cranks raise the gain ratio, so require lower gearing to compensate.

My 17.6" gear feels like a 20" gear would with 170mm cranks.
Careful, Kim. Your sarcasm's showing...

Mr Larrington

  • A bit ov a lyv wyr by slof standirds
  • Custard Wallah
    • Mr Larrington's Automatic Diary
Re: What gear range have you got?
« Reply #19 on: October 08, 2019, 01:18:43 pm »
Remember that if you take care to avoid trying to use silly small-small or large-large combinations you can exceed the manufacturers' stated derailleur capacity by a fair chunk.  Get it wrong, mind, and you and your chain tool will spend a long time at the roadside, swearing.
External Transparent Wall Inspection Operative & Mayor of Mortagne-au-Perche
Satisfying the Bloodlust of the Masses in Peacetime

Kim

  • Timelord
Re: What gear range have you got?
« Reply #20 on: October 08, 2019, 01:26:30 pm »
Remember that if you take care to avoid trying to use silly small-small or large-large combinations you can exceed the manufacturers' stated derailleur capacity by a fair chunk.  Get it wrong, mind, and you and your chain tool will spend a long time at the roadside, swearing.

Depending on the chain run, the chain going completely slack in small:small may not be a problem.  On an ICE trike, for example, the weight of the chain in its tube acts as a tensioner, and everything still works as long as you don't backpedal too much.  (This is occasionally useful, because small:small raises the dreailleur of a small-rear-wheeled cycle out of the recently-mown grass, while maintaining an appropriate gear for off-road riding.)

I always set things up so that large:large works well enough that it doesn't jam.  You are going to crash-downshift to the big sprocket at some point without remembering what chainring you're in due to traffic shenanigans, and it's best to be able to recover from that with nothing worse than a bit of derailleur-fu.
Careful, Kim. Your sarcasm's showing...

Re: What gear range have you got?
« Reply #21 on: October 08, 2019, 01:54:47 pm »
I wouldn't mind try shorter cranks.
But Schlumpf only make 170mm Kick plates for their drives.
So I'm stuck at that length.

As for silly high gears, I like them because they match with my riding style.
My natural cadence is around the 70-80 rpm range and if I go over 90 rpm then my efficiency takes a big hit.
I also don't like to freewheel downhill if I can avoid it.
So having a 179" top gear means I can have "fun" pedalling slowly downhill at 40 mph ......   :P
At that type of speed I'm not putting a lot of energy into turning the pedals.
It's more about shifting any lactic acid out of the leg muscles while keeping them warm.

YMMV ........  ;D

Arellcat

  • Velonautte
Re: What gear range have you got?
« Reply #22 on: October 08, 2019, 09:29:55 pm »
I'm running:

1.7–8.3 (22.7"–111.6") in my Quest velo with 170mm cranks.  Top gear is 52-12 (from my impossible-to-buy Shimano 12-34 cassette), and isn't high enough.  Riding the mean streets into and out of Edinburgh, I use almost every single ratio at one time or another.

1.6–8.7 (22.4"–120.0") with my Lightning P-38 and 175mm cranks.  Same cassette as my Quest; the small and middle chainrings get a lot of use, the big ring not so much.

Re: What gear range have you got?
« Reply #23 on: October 12, 2019, 12:08:16 pm »
I run a SA-8sp, XRK-8, with 26" wheels. A 33T chainring and 25T sprocket. The SA 8-sp is probably better suited to small wheels, but this setup gives me 33" to 106". I spin out top around 35mph, and spin out 7th at about 24mph. Also nice is that 1st is 1:1, so max torque when climbing has let chance of damaging anything. Getting on for 4000 miles, no servicing, no adjustments, same chain.
Cruzbike V2k

Re: What gear range have you got?
« Reply #24 on: October 12, 2019, 09:26:12 pm »
If anyone needs chainrings bigger than normal and has difficulty finding them this might be useful. I believe they supply a few racers.
https://www.dutchbikebits.com/recumbent-velomobile-parts/alligt-chainrings