Recumbent questions

Location
EDINBURGH
GrasB said:
Really?

32/13 = 2.46
I was thinking with the standard 16 tooth. Using the set up you suggest would not give any advantage over a standard rear sprocket with say a 39/53 double up front, all you would gain would be two very high top gears that would be more or less unusable.
 

GrasB

Veteran
Location
Nr Cambridge
I was more thinking about with a 451c or 507c wheel. Also considering how easily I got up to 55mph on a 7% descent I would have thought a 150" gear would have come in useful my self.
 
Location
EDINBURGH
GrasB said:
I was more thinking about with a 451c or 507c wheel. Also considering how easily I got up to 55mph on a 7% descent I would have thought a 150" gear would have come in useful my self.
The trike pictured has a 26" rear wheel, with a 507 your top would be 142" with a 451 it would be 126".
 

mark barker

New Member
Location
Swindon, Wilts
nigelb said:
Hi Fiona

How do the gear sets stack up?

Do people really have 30-40 gears on recumbents?

Nige
My recumbents have 24 gears, and normally thats enough, although I do often wish there was a wider range of ratios, but a lot of the problem is my bad riding style!:becool:

There is a recumbent trike on ebay that boasts 81 gears! I've not seen one in the flesh, but would love to give it a go (although I think many of the ratios will be repeated in various combinations)
http://cgi.ebay.co.uk/Mantis-Foldin...d=ViewItem&pt=UK_Bikes_GL&hash=item4a99eadc18
 
Location
EDINBURGH
mark barker said:
My recumbents have 24 gears, and normally thats enough, although I do often wish there was a wider range of ratios, but a lot of the problem is my bad riding style!:ohmy:

There is a recumbent trike on ebay that boasts 81 gears! I've not seen one in the flesh, but would love to give it a go (although I think many of the ratios will be repeated in various combinations)
http://cgi.ebay.co.uk/Mantis-Foldin...d=ViewItem&pt=UK_Bikes_GL&hash=item4a99eadc18
20-25 unique gears with that set up some too low to use anyway, to be fair a good 18-20 gear set up with good ratio spacing is great, even with a Rohloff and a double chainset you get a lot of crossover but you do get a nice low and high range with that set up. With our 27 speed set ups we find that people at some point stop using the granny ring up front.
 

Auntie Helen

Ich bin Powerfrau!
Yeah, I've pretty much entirely stopped using my granny ring on my 27 gear setup (mine goes from 15" to 110"), although saying that I did use it for the first time in ages a couple of days ago at the tail end of a long ride when my legs were tired and I suddenly faced some hills. I also use the granny when towing the trailer full of shopping up a reasonably steep hill near me.

Next Trice, which I plan to buy for myself next spring, will have a Rohloff/Alfine/Nexus and a triple at the front. I've never got on with derailleurs at the back and am hoping the hub gear will suit me rather better.
 

GrasB

Veteran
Location
Nr Cambridge
Catrike UK said:
The trike pictured has a 26" rear wheel, with a 507 your top would be 142" with a 451 it would be 126".
150" comes from a 26x1.375" wheel & that's 45mph @ 100rpm allowing most riders to drive the pedals at around 60mph (IME the average rider can't put out meaningful power above the 135rpm marker).

Catrike UK said:
20-25 unique gears with that set up some too low to use anyway, to be fair a good 18-20 gear set up with good ratio spacing is great, even with a Rohloff and a double chainset you get a lot of crossover but you do get a nice low and high range with that set up. With our 27 speed set ups we find that people at some point stop using the granny ring up front.
Though there's overlap with a normal double there's no duplication of gears, in fact if you use 39/54 (instead of 39/53) where there's overlap the other chainring is almost exactly 1/2 a gear out, this gives you circa 7% gearing steps (with double shifting) right where you're going to be doing almost all of your riding. So you effectively have 28 gears, not even a 3+10 delivers that many discrete gears!
 
Location
EDINBURGH
GrasB said:
150" comes from a 26x1.375" wheel & that's 45mph @ 100rpm allowing most riders to drive the pedals at around 60mph (IME the average rider can't put out meaningful power above the 135rpm marker).


Though there's overlap with a normal double there's no duplication of gears, in fact if you use 39/54 (instead of 39/53) where there's overlap the other chainring is almost exactly 1/2 a gear out, this gives you circa 7% gearing steps (with double shifting) right where you're going to be doing almost all of your riding. So you effectively have 28 gears, not even a 3+10 delivers that many discrete gears!
On a 39/54 with a 13 tooth cog on the Rohloff and a 26" rear wheel your gear inches in each gear would be 21,24,27,29,31,33,35,37,40,43,45,48,51,55,58,62,66,71,75,81,85,92,97,104,110,118,135,153

Many of those are close enough to forget about especially if you have to double shift to get to them.
 

betty swollocks

large member
I have a two-wheeled short wheelbase Challenge 'Hurricane'. I have a double 65/53 on the front and a 9-speed 11-28 on the back. Gets me up pretty much anything, unless I'm exceptionally loaded.
On machines such as mine, slow speed ie hillclimbing stability can be a bit of a challenge (small c this time), but is mastered with practice.
Cadence is relevant to a person I believe - some people are naturally 'pushers' and others 'spinners' and I do not think and it's also been my experience that a fast cadence is no more relevant to 'bent riding than it is to riding an ordinary bike.
 

GrasB

Veteran
Location
Nr Cambridge
Catrike UK said:
On a 39/54 with a 13 tooth cog on the Rohloff and a 26" rear wheel your gear inches in each gear would be 21,24,27,29,31,33,35,37,40,43,45,48,51,55,58,62,66,71,75,81,85,92,97,104,110,118,135,153

Many of those are close enough to forget about especially if you have to double shift to get to them.
I look at this slightly differently.

My ideal cadence is between 115 & 135rpm, in that 20rpm band is when I make the most power. Now the 13.5% gear spacing works well when accelerating, as it places my cadence well in my powerband but with a good amount of powerband left.

However when dealing with cruising it would be easy to find I'm swapping between 2 gears as the undulations take me either over the top, fatigue sets in quickly, or off the bottom of my powerband, further speed will drop off easily. With the ability to have gears around 7% apart it's easy to find a gear where I'm moving about all in the powerband, even if I'm climbng up a 6% slope at around 10.5mph.
 

CopperBrompton

Bicycle: a means of transport between cake-stops
Location
London
Cadence is a very personal thing, and it seems we each have our preferred range.

My natural cadence is relatively slow, and I like blasting down the hills, so a high top-end gear is important to me. I upgraded to the 9-34 rear cassette, with front rings of 30/42/52, giving me 17-112 inches. :-)
 
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