D's RC Drive Kona DC1

[AussieJester]

Sure. What happened to stealth?

The noise of an 11t drive sprocket at 4,600 rpm or the 165t sprocket in the rear?

My recollection was of D worrying about a 90t sprocket being conspicuous - now he wants a 165t one

The mail is... due to snow and ICE in 'The Motherland' this will be his "winter bike" Deec figures he can do away with the rim and tire altogether and run a 165T sprocket on the rear will get him good traction on themz icey roads

KiM

p.s Miles stop trying to talk him out of it damit i have the custom one of a kind Recumpence drive almost in my grasp LoL

 

[Miles]

:lol:

 

[deecanio]

HELLLLPPP!!!

the figures you have Mitch are more or less identical to those that Gary told me so i think you are on the money.
Of course i've just realised a few things, firstly if i go with the dd sram 3 speed i wont need a delta/wye board which means im not sure i would need a 6 wire motor???
Secondly, can i still use a deraileur for tensioning if i have a sram hub? i think that the dd sram changes gear with a gizmo that fits on the end of the axel itself? someone please advise as i need to finalise my order with Matt ASAP!!!

only 3 wire 3220 rqd????

still able to fit my deraileur with sram 3 spd ???????


quick its not too late!!!!

D

p.s. don't worry Kim i think it's cert now

 

[deecanio]

shit i just thought of something else.


if i use the sram it will give me 3 spd on the motor as well as the pedals.

Miles - would you be able to calculate how that would pan out???

the motor would do................... 1st - 17.1 mph, 2nd - 23.1 mph, 3rd 31.5 with the sram.

so if im using a 16t for the rear, how best do i marry up the pedal gearing to the motor???
im not looking for an exact match but i certainly want a good amount of pedal input as an option? and also be able to input motor to assist me at my chosen rate, not true synergy but dialable?

i can use either 32t or 42t as my front chainring - what would be my pedal speeds with 16t/32or42t with the sram hub???? :?
why dont these questions reveal themselves when im not at work???


D

 

[blitzwagen]

D,

I wonder if you shouldn't just get the 6-wire anyway which costs nothing. Wiring the motor for delta or wye is just a matter connecting the wires in different configurations and you'll have the option of delta Y operation in the future.
I have another question for you - did you ever consider using the tppacks.com hub adapter which essentially gives you to freewheels at the back. I've ordered the adapter as well as a nexus 3-spd - we'll see how long it all lasts.

 

[Miles]

still able to fit my deraileur with sram 3 spd ???????

Yes.

 

[MitchJi]

Hi D,

so if im using a 16t for the rear, how best do i marry up the pedal gearing to the motor???
im not looking for an exact match but i certainly want a good amount of pedal input as an option? and also be able to input motor to assist me at my chosen rate, not true synergy but dialable?

i can use either 32t or 42t as my front chainring - what would be my pedal speeds with 16t/32or42t with the sram hub???? :?

D

You can play with all the possibilities using this calculator:
http://www.sheldonbrown.com/gears/internal.html

Using the pulldowns for (assuming you can pedal at 80 rpm):

Gear chart using MPH @ 80 RPM (Crank RPM)

For 26 inch (nominal) tire with 16 tooth sprocket

Results:
Chainring 32:
9.1 mph, 12.4 mph, 16.8 mph

Chainring 42:
11.9 mph, 16.2 mph, 22.1 mph

You might want to consider (its expensive) the Schlumpf Speed Drive for your crank:
http://www.sheldonbrown.com/harris/schlumpf.html

Switzerland's Schlumpf Innovations makes a nifty two-speed planetary gear system that fits into the bottom bracket of your bicycle. It allows the effect of a double chainwheel derailer system without derailing the chain.

Gear shifting is accomplished without hand controls or cables. There is a button on each side of the crank set designed to be operated by the rider's foot. Push on one side for the lower gear, push on the other side for the higher gear.

Speed Drive
Provides direct drive and increase of 1.65:1 (165%)

For example, if you use a 45 tooth chainring,
the high gear will be equivalent to a 74 tooth chainring!

The results for 32/52 are:
9.1 mph, 12.4 mph, 16.8 mph
14.7 mph, 20.1 mph, 27.4 mph

They also make a High Speed Drive but you probably want the Speed Drive.

High Speed Drive
Provides direct drive and increase of 2.5:1 (250%)

For example, if you use a 28 tooth chainring,
the high gear will be equivalent to a 70 tooth chainring!

I have another question for you - did you ever consider using the tppacks.com hub adapter which essentially gives you to freewheels at the back. I've ordered the adapter as well as a nexus 3-spd - we'll see how long it all lasts.

It gives you a FW for the wheel (built into the hub) and a FW for the pedal chain. Pedaling backdrives the chain to the motor. If you don't want your pedaling to backdrive the motor you need a 3rd FW at the motor or gb output.

The setup D is planning to use allows a 3rd FW at the rear hub. This is a much better solution for a Single Stage Reduction drive because with the 15:1 reduction using the ttpacks part pedaling without the motor would turn run the #219 drive chain over the 11t sprocket with a 32t chainring at a speed of 2 (32/16) x 15 (one stage reduction) x 80 (cadence) or 2400 rpm. This will require considerable pedal effort (and make a racket even with the motor off while pedaling). One other advantage of the 3 FW solution is that its easy to get greater reduction because its easy to use #219 chain between the drive and the rear hub.

I'm not saying that the ttpacks part isn't a good solution. But the triple FW's at the hub ameliorates some of the shortcomings of Single Stage Reduction with a High RPM Motor.

 

[AussieJester]

p.s. don't worry Kim i think it's cert now

WoooHooooo

shit i just thought of something else.

UT Oh...

Why only 31mph Deec? you getting nancified in your old age mate?!?! 50mph Deec
50mph is what you should be aiming at

Yes

Thats it Miles, nice simple answers buddy stick to the plan....
its almost mine... LOL

KiM

 

[deecanio]

hi All,

well funny you should say 50mph mate

the plan is:

3220 6t 6 wire (for delta wye switching later which could well see 50mph)
etard monster sprocket
sram DD hub

im mulling over the schlumpf speed crank also,as per Mitch's suggestion

if my 3220 is connected to an sram DD via etards monster it will mean that i have three motor gears, negating an immediate need for a delta/wye board - using the shlumpf might help with not running out of pedal legs as if i run a 4245t single upfront the shlumpf can make that 70/74t without having a monster sprocket on the front - i need to see what sheldons calc gives me top pedal speed for a 72-16? taking into account the sram gearing also to see if its worthwhile.

before giving this a shot does anyone have any real world experience of the shlumpf??
fitting one means a slight mod on the bottom bracket (chamfer) as far as i can tell and the crank is not cheap, so any feedback on that would be great.

Also whilst looking at the sram DD i come accross 2 types - the white one posted here on the forum from prowheelbuilder.com and also a silver one which seems to be the later model, can anyone clear that up for me??
i'm happy to go with the white one (more expensive) as long as i get disk compatability and a decent shifter which must mount on the left side of the bars - maybe one for Gary as there seems to be two types of changer too :? - in an ideal scenario i would like trigger shift but as long as it fits on the left no biggy, soon as i know which one to get i'll be getting it and lacing it up ready for the ENO arrival.

i've bought and sent to Luke a sickbikeparts eno and a 16t for broaching (thx Luke/Thud) and Thud is also looking into the 219 sprocket issue as per the other thread, we're trying to get a 219 mod so it can slip straight onto the astro shaft.

So im on the build now gathering all the parts i need for the 2010 model, but before i invest another wheelbarrow of money can anyone shout if they see floors or better ways to do this?? looking in your direction Miles


cheers,


D

 

[Miles]

D,

The Dual-Drive trigger shifter, for the internal gears, mounts on the left-hand side.

 

[Miles]

http://www.ukbikestore.co.uk/product/97/h2999/sram-dual-drive-3-speed-trigger-shifter-front.html

 

[deecanio]

excellent thanks Miles, do you think these figures look ok for some synergy?

i've had a quick play with the calc for myself and it throws up the following for a cadence of 60 (trying to be realistic) using a 75t front (schlump in high) and a 16t rear:

0.73 (Low) 1.0 1.36 (High)
15.9 21.8 29.6


amazing calculator.

am i right in thinking that if i can manage 60 cadence with schlumpf in "high" and i will be able to match the motor very nicely?
im aware that the motor may accelerate a lot quicker than im able to but if i dial it in at a reasonable pace i should match it gear for gear through the sram?


D

 

[deecanio]

wow, beautiful Miles

ok so one of those and which dd hub? the white or the silver?

D

 

[Miles]

I don't know anything about a white version.... Have you got a link for it?

 

[deecanio]

http://www.prowheelbuilder.com/product.php?prod_id=332

unless it is siver ? but it looks different from the other one - looking for a link now.

ah here:

http://www.fisheroutdoor.co.uk/product.asp?part_no=H2136D

D

 

[Miles]

http://www.prowheelbuilder.com/product.php?prod_id=332

unless it is silver ?

As that's the only choice in the color drop-down list.......... :wink:

 

[deecanio]

aha!!!

any difference between the two non colour wise then ?
whats the "guard" type thing on the "white" one ???? :lol:
damn gotta go to work, let me know Miles and then i'll order one - oh, any thoughts on the schlumpf calcs?

thanks,

D

 

[cargo]

.

 

[Miles]

D,

It's just a spoke protector.

As long as you get the disc brake version - I don't think there are any other differences (apart from spoke count, of course).

 

[deecanio]

WOOHOO.

thanks Miles.

i will shop around for the best deal and get one ordered asap.
Being my most trusted source, what did you think about employing the schlumpf Miles?

D

 

[Miles]

A 54t chainring alone, would get you to 35 mph.... How fast do you want to go?????

 

[deecanio]

not that fast but the need to keep up with the motor pushes me in the schlumpf direction.
getting a 54t normally means employing a a road tripple upfront, im trying to stick with single in order to have as many options as possible for chainlines.
by using the shlumpf i thought it would enable me to keep up that much better, as if i had a 42/75 double upfront ?
im all for not buying the shlumpf but can i do a 54t in a single ring? i already have a 52t but on a triple - also whats the cadence for doing 35mph ??



D

 

[Miles]

Cadence would be 100 rpm

I'm sure you can get 54t single.

Sure, the Schlumpf would do the job - it adds weight and takes away efficiency, though.....

 

[deecanio]

thats fast, i start to puff above 60
ok what i'll do is go for the single ring and see how it pans out, actually check that, what i'll do is use my existing road triple and test out at 52 as it wont cost me a bean to try, maybe i can even lose the two inner rings and us that as my single, see this is why i ask for your thoughts before i waste money
Thanks Miles,

D

 

[Miles]

60! What a wussy