Recumbent Trike Questions

DIscuss anything relating to non-standard cycles and their equipment.
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squeaker
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Re: Recumbent Trike Questions

Postby squeaker » 9 Nov 2020, 9:18am

[XAP]Bob wrote:Hills are generally ok there is no minimum speed on a trike, meaning you can gear down as far as is needed.
Good reminder that many trike manufacturers do not equip their trikes with sufficiently low gearing for touring.
I was also reminded yesterday that tadpole trikes can suffer from rear wheel spin on steep tarmac hills covered with damp leaf debris :shock: I suspect that this would be less of problem with the shorter wheelbase of a 406 rear wheeled trike putting more weight onto the drive wheel.
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[XAP]Bob
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Re: Recumbent Trike Questions

Postby [XAP]Bob » 9 Nov 2020, 10:14am

I only had issues on my ICE sprint twice, once was the inside of a stupidly steep hairpin in the rain, the other was climbing a grit trail up an embankment.

Three wheel drive (push the tops of the front wheels) helps at that point.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

PDQ Mobile
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Re: Recumbent Trike Questions

Postby PDQ Mobile » 9 Nov 2020, 10:24am

I think the OP's concern for really narrow lanes is justified.
The ones round here are often bounded by quite high stone walls (and banks) making recumbents invisible at certain places.
A two wheeler can be leaned in (good hearing useful) but a trike really needs a high flag/pennant I think.
It is the single biggest reason I thought getting one a bad idea, as I rather fancied one.

A narrow road with verges is a rather different proposition I think, but the combination of trike, narrow twisting lanes, and high walls is problematic.
Years ago an accident - frontal collision between an MG Midget and a local driver (not me!) sort of demonstrates the point. Local drivers look for vehicle roofs!


(I was sorry to hear of the OP's problems too, by the way)

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[XAP]Bob
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Re: Recumbent Trike Questions

Postby [XAP]Bob » 9 Nov 2020, 3:21pm

If I was on such a road I would use a flagpole... streamers moving in the breeze are a pretty good visual clue that there is something there - I might even add an orange flashing light.

But it’s in many ways no worse than any other vehicle on such lanes, you can’t “become the wall”, but equally you can’t be expected to jump into the wall at the mere sound of an internal combustion engine.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
There are two kinds of people in this world: those can extrapolate from incomplete data.

Psamathe
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Re: Recumbent Trike Questions

Postby Psamathe » 9 Nov 2020, 3:25pm

[XAP]Bob wrote:....
But it’s in many ways no worse than any other vehicle on such lanes, you can’t “become the wall”, but equally you can’t be expected to jump into the wall at the mere sound of an internal combustion engine.

With my previous cycling on such lanes on many occasions I've heard a vehicle, slowed right down, etc. only to find no vehicle but a tractor in a neighbouring field.

Ian

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Tigerbiten
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Re: Recumbent Trike Questions

Postby Tigerbiten » 10 Nov 2020, 2:20pm

squeaker wrote:
[XAP]Bob wrote:Hills are generally ok there is no minimum speed on a trike, meaning you can gear down as far as is needed.
Good reminder that many trike manufacturers do not equip their trikes with sufficiently low gearing for touring.

I think it's more a case of bent trikes need a wider range than most derailleur can cope with.
Most standard derailleur/IHG setups default at around 5x.
That will give you a working range of around 20"-100".
Which I don't think is quite wide enough for a bent trike.

If you push the limits of a rear derailleur then it can cope with about 50t difference.
Do you split this roughly 50-50 in a triple or 33-66 in a double.
So something like a 24-36-48 triple and a 11-34 cassette or a 26-42 double and a 11-42 cassette would work to give you the range needed.
Even then you then need to right size wheel to give you the gear range you want.
20" back wheels make it easy to get silly low first gears but much over a 90" top is more tricky.
While 700C wheels are the other way around, it's hard to get a sub 20" first but a +120" top is almost standard.

This is where the non standard gear setups come in.
Like a Rohloff with a triple to give you a total of 18 unique gears.
Or a SA hub to give you 5 virtual chainring plus your cassette.
But as they're non standard, they cost more and will only be fitted if asked to.
But to learn that you need this type of non standard setup, you almost need to have ridden a bent trike a fair distance to find out exactly want you need.
It's a "Catch 22" .......... :cry:

I've pushed the limits on what easily possible with my twin chainrings on a Schlumpf HSD and a Rohloff.
It's an expensive setup but it does give me an 19X range ....... :shock:

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

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squeaker
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Re: Recumbent Trike Questions

Postby squeaker » 10 Nov 2020, 7:06pm

Tigerbiten wrote:
squeaker wrote:
[XAP]Bob wrote:Hills are generally ok there is no minimum speed on a trike, meaning you can gear down as far as is needed.
Good reminder that many trike manufacturers do not equip their trikes with sufficiently low gearing for touring.

I think it's more a case of bent trikes need a wider range than most derailleur can cope with...
Depends upon your needs, especially any requirement to pedal downhill ;) Personally I'm happy with a top gear that is one more than I can spin out on the flat, so with a 5.8:1 Hi/Lo spread (Trice T, above somewhere) I'm fine with a 15" bottom gear as a 'crawler' :D
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UpWrong
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Re: Recumbent Trike Questions

Postby UpWrong » 10 Nov 2020, 8:16pm

Psamathe wrote:
UpWrong wrote:If you say whereabouts you live then forum members are likely to offer you a chance to view/ride their trikes, at least within the constraints of boom adjustment......

I live South Norfolk. I have e-mailed the local CTC branch but only yesterday (so too soon to be expecting any reply).

Thanks
Ian

Nobody has yet mentioned D-Tek HPVs in Little Thetford, Near Ely, Cambs. They're an ICE dealer and also the largest "pre-owned" dealer of recumbents in the UK. If you want to try an ICE Adventure and an HPV Scorpion back to back then they are probably your best chance. Worth a ring and having a discussion about your requirements.

Psamathe
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Re: Recumbent Trike Questions

Postby Psamathe » 10 Nov 2020, 8:49pm

UpWrong wrote:
Psamathe wrote:
UpWrong wrote:If you say whereabouts you live then forum members are likely to offer you a chance to view/ride their trikes, at least within the constraints of boom adjustment......

I live South Norfolk. I have e-mailed the local CTC branch but only yesterday (so too soon to be expecting any reply).

Thanks
Ian

Nobody has yet mentioned D-Tek HPVs in Little Thetford, Near Ely, Cambs. They're an ICE dealer and also the largest "pre-owned" dealer of recumbents in the UK. If you want to try an ICE Adventure and an HPV Scorpion back to back then they are probably your best chance. Worth a ring and having a discussion about your requirements.

A few years ago I was considering a recumbent bike (2 wheels) and had a chat with him (very helpful) but a back issue prevented me progressing it. I'll give him a call tomorrow.

Thanks
Ian

belgiangoth
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Re: Recumbent Trike Questions

Postby belgiangoth » 14 Nov 2020, 2:58pm

Could you add a schlumpf speed drive to you BB, to have 2x3x9 gears?

You could also try on the bhpc forum to see whether there is someone local who would let you have a go on their bike.
(I didn't realise there were hill in Norfolk)
If I had a baby elephant, it would point out that there is no evidence for planing. Then it would eat all my bananas.

Psamathe
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Re: Recumbent Trike Questions

Postby Psamathe » 14 Nov 2020, 3:04pm

belgiangoth wrote:Could you add a schlumpf speed drive to you BB, to have 2x3x9 gears?

You could also try on the bhpc forum to see whether there is someone local who would let you have a go on their bike.
(I didn't realise there were hill in Norfolk)

I'd be very unsure about fitting one as (I believe) it requires you mill out a taper (45'ish °) each side of the bottom bracket. So to install you have to modify the frame in a non-undoable way that could make returning to a traditional BB impossible? Maybe I'm out of date or misunderstood the installation?

Ian

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squeaker
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Re: Recumbent Trike Questions

Postby squeaker » 14 Nov 2020, 4:05pm

Psamathe wrote:I'd be very unsure about fitting one as (I believe) it requires you mill out a taper (45'ish °) each side of the bottom bracket. So to install you have to modify the frame in a non-undoable way that could make returning to a traditional BB impossible? Maybe I'm out of date or misunderstood the installation?

There's a version with a torque arm that doesn't need BB mods. (You can just see the torque-arm on mine, behind the right side crank.)
HTH.
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UpWrong
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Re: Recumbent Trike Questions

Postby UpWrong » 14 Nov 2020, 4:31pm

I was intrigued enough to work out the best range using only derailleurs and keeping within RD capacity. There are 9-speed Shimano long cage RDs with 47T capacity. Assuming a smallest rear sprocket of 11T and a smallest front ring of 22T then you can split the 47T as 25T rear and 22T front by using an 11-36 cassette (by Sunrace) and a standard 22-32-44 triple at the front. If you have a trike with a 26" rear wheel you then get a gear range of 655% from 15.2" to 99.5".

I would find the cassette a bit gappy. A 10-speed 11-36 would reduce the gaps but I can't find any 10 speed (or 11-speed) RDs with 47T capacity. They seem to have a rating of 45T. Odd.

Psamathe
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Re: Recumbent Trike Questions

Postby Psamathe » 14 Nov 2020, 4:40pm

UpWrong wrote:I was intrigued enough to work out the best range using only derailleurs and keeping within RD capacity. There are 9-speed Shimano long cage RDs with 47T capacity. Assuming a smallest rear sprocket of 11T and a smallest front ring of 22T then you can split the 47T as 25T rear and 22T front by using an 11-36 cassette (by Sunrace) and a standard 22-32-44 triple at the front. If you have a trike with a 26" rear wheel you then get a gear range of 655% from 15.2" to 99.5".

I would find the cassette a bit gappy. A 10-speed 11-36 would reduce the gaps but I can't find any 10 speed (or 11-speed) RDs with 47T capacity. They seem to have a rating of 45T. Odd.

(I have no expertise on this but) how "tight" are the teeth specs? On my 2-wheels I changed everything for a 4703 Tiagra triple which Shimano spec'd max 11-32T (or 12-28T) rear cassette using a triple on the front. But I wanted lower and LBS thought about it and reckoned a 11-34T cassette should be OK so we went for it and it works fine apparently no "chain droop". Seems Shimano were being a bit "cautious".

Also, does the longer chain and turning wheels, etc. allow you more leeway on a recumbent?

Also, how does using long cage RDs go with 26" rear (ground clearance)

Ian

UpWrong
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Re: Recumbent Trike Questions

Postby UpWrong » 14 Nov 2020, 4:51pm

It used to be the case that shimano were a bit conservative when listing RD capacity. Often 2 more teeth could be handled. I'm not so sure with the newer designs.

It's no different on a bent, however some RDs cope with chain wrap on the RD (excess chain dangles safely) and some don't (excess chain fouls the top jockey). Running chain tubes on the chain stay run can help control excess chain.

Thus I have an 11-32 cassette with a 28-39-53 triple on a 43T capacity SRAM X9 derailleur. The excess chain dangles and is controlled by the chain tube next to the RD.