Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Electrically assisted bikes, trikes, etc. that are legal in the UK
PAB855
Posts: 396
Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

Problem solved.

9 speed removed and replaced with 7 speed Shimano Megarange.

PERFECT.. With having a motor there isn't the same need for 9 speeds.

At long last. Thanks for all the helpful suggestions.

Cheers
hercule
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Joined: 5 Feb 2011, 5:18pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by hercule »

Out of curiosity, does your hub have a freewheel or a freehub?
PAB855
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Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

It's a freewheel, because I've just checked the 9 speed which was removed and it is a freewheel. Why do you ask?
Maybe you can help me with a question about the replacement Megarange 7 speed.. I would like to change the smallest sprocket because it is currently giving too low a top gear. Can this be done easily?

Cheers
PAB855
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Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

It's ok Hercule, I can't change it, 14t is the smallest on the Shimano Megarange.
PAB855
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Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

I'm wondering if it's possible to change the front triple because by my calculations, to achieve a top gear as before with 11t rear, 44t t front and 20inch wheel, gave a top gear of only 80inches,
Now that the Shimano Megarange is installed, with a 14t , it would need a 56t chainring to achieve an 80inch top gear.

Currently the front is 44,32,22. It's a 4 point fixing 104mm BCD. Coded7075/T6.

I can't see it being possible to change it to something like 56,36,46, but that's the kind of numbers that are needed for an 80inch top gear. It's currently only 63inches.

It's getting a bit messy and it's unfortunate, but the trike is going beautifully and my wife says she can accept it if necessary.

Any practical suggestions?

Cheers
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squeaker
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Joined: 12 Jan 2007, 11:43pm
Location: Sussex

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by squeaker »

Sunrace do a 13-28 7spd which would be a step in the right direction - assuming it fits... Or a 13-34 Megarange if you really need the 34T.
Otherwise I suspect you would need to change the whole chainset to get significantly higher front tooth counts - sounds like you have an MTB set on there at the mo, so might also need a different front mech etc.. :?
BTW: "Coded7075/T6" refers to the Aluminium spec (material and heat treatment): the 4-arm 104PCD is the bit that restricts you to 46T max....
"42"
PAB855
Posts: 396
Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

Thanks Squeeker, it's all useful information. I have emailed the cycle mechanic, these forum entries all help me to understand what's going on before I speak to him again.

Cheers
hercule
Posts: 1156
Joined: 5 Feb 2011, 5:18pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by hercule »

hercule wrote:Out of curiosity, does your hub have a freewheel or a freehub?


Just asking because swapping a freewheel seems an easy job but I think all Shimano freehubs from 7 speed upwards are the same width... happy to be corrected! I do have a mix of 7 and 9 speed bikes in my fleet and the cassettes can be switched from one to the other...

Increasing the big ring would be the easiest way to get bigger gears... it sounds like you might have the ICE/Lasco 152mm crankset, I have it on my Fuego. I do sometimes feel that the big ring could be a bit bigger, but with that chainset I think you are limited to 50T max.

https://www.sjscycles.co.uk/104-bcd-4-arm/?teeth=50

If you have got short cranks fitted, SJS do a nice Thorn branded chainset that goes all the way down to 125mm and with a 74/110mm ring spacing you can get some good quality rings from the likes of Spa, Stronglight and TA. I have a 145mm one on my Trice QNT. Some day I’ll get round to upgrading the Lasco chainset on the Fuego with the same with more useful ring choices.

https://www.sjscycles.co.uk/cranks-cran ... rand=thorn

Please ignore if I am jumping to conclusions! :D
PAB855
Posts: 396
Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

There's an 11,28 freewheel cassette by Shimano, would that solve the problem or is there a width issue?

Hercule, thanks, just trying to get my head round these possibilities.
See my previous entry for the chainrings spec, 140mm 4point fixing.. A larger chainrings would bring up a problem for my wife if the chain was higher than it is above the boom. She currently slides her foot over the bottle bosses on the boom and just clears the chain tubing.

I'm currently waiting for the mechanics answers!!!!

Cheers
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squeaker
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Location: Sussex

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by squeaker »

What size is the rear tyre - going from, say, a 30-406 to 50-406 would get you another 5GI for small cost...
"42"
PAB855
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Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

I've had a half hour chat with the mechanic and for just now at least we are leaving things as they are.

The trike is running beautifully. It has taken 4years of trying different pedal powered machines over many many miles and this one is doing 99percent of what we would like and life's too short for trying too hard to find the last 1percent.

Thanks all.
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[XAP]Bob
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Joined: 26 Sep 2008, 4:12pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by [XAP]Bob »

PAB855 wrote:You say overlap, Bob. Does it not fit with the end faces against each other?

Cheers



Mine is a sidewinder and does overlap...
Which is fine, it means that positioning it is easy.

As an aside...
I also have a free hub rather than a freewheel (don't like the screw on freewheels for maintenance or strength, and I have a selection of cassettes to hand) on my motor, took a little bit of finding, but worth it IMHO.
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.
PAB855
Posts: 396
Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

Things have moved on and I'm having another think about this gearing problem.

Taking on board the foregoing suggestions, it would appear that I can get close to my target of a 80inches top gear if I use a 50 tooth chainwheel and a Sunrace 7 speed Megarange which has an 13tooth top gear. This combination on a 20in wheel gives 77inches.

To achieve this both front and rear gearing would need a shakeup . The rear hopefully is simply to swoop the Shimano Megarange for the Sunrace.
The front might be tricky because the cranks are only 155mm long.

I'm due to speak to my local ICE retailer soon and would like to be prepared.

Please, usual suspects, can you back up my thinking?

By the way Squeeker I could get a higher gear with a bigger tyre OD, but currently the tyres are 50-406 and the mudguards clearance is only a couple of miĺlimetres. What is a 5GI ? Pardon my ignorance.

Cheers
hercule
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Joined: 5 Feb 2011, 5:18pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by hercule »

Should be quite possible to fit a 50T ring to your chainset (though ICE may not be the cheapest source). The length of the cranks is immaterial, it’s the dimensions of the spider onto which the rings are bolted, and how many arms (usually 4 or 5) that counts. Because of leverage etc, short crank arms are usually paired with smaller chainrings and vice versa but not inevitably.

The Lasco chain set that ICE uses for their short crank option has a 104mm bolt circle if I remember right and four fixing arms so the chainring linked to at SJS above should work.

Chainsets with a bigger bolt circle diameter tend to have larger maximum ring sizes so if you wanted bigger gears and short cranks the Thorn chain set above would give you a bigger choice - but obviously this would be a more expensive option.

I tend to decide on a maximum and minimum gear and juggle figures on a gear calculator (eg Sheldon Brown’s) to see what components I will need. With electric assist you don’t need such low gears as without - on my Kettwiesel I hardly use the small ring at all even on quite steep climbs. Of course when the battery’s flat and you have to haul it all up yourself, it’s a different story... :-)
PAB855
Posts: 396
Joined: 26 Apr 2014, 3:07pm

Re: Rear wheel tight fit. Panda motor +9 speed. ICE recumbent

Post by PAB855 »

Thanks Hercule, not least for reminding me of the legendary Sheldon Brown who for some reason had gone off my radar! I used to refer to him frequently.

I am again astonished at his wealth of knowledge and the masses of useful detail on his sight. I can now put the sliderule away, he's done it all for me.

Cheers
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