Is the rear wheel on your motorized bicycle strong enough

[bairdco]

Re: Is the rear wheel on your MB strong enough

SB, i just noticed you asked about lacing. my older Worksman wheels off my 24" have a 4 cross pattern. sportscarpat said the ones he got were a three cross. the wheels i got weren't laced up, so i dunno for sure what they use.

i laced mine with a 4 cross pattern. the more the spokes cross, the stronger the wheel.

 

[KCvale]

Re: Is the rear wheel on your MB strong enough

...Later on we think about how fast can we stop and how well can we see where we're going.

I got my first taste of real night driving in total darkness last friday night now that summer is leaving and it gets dark earlier. Even with two battery powered headlights I couldn't see squat and it was the first time I was truly frightened riding.

Thanks reb1 for the lights link.
Hard to believe a simple light costs more than our motors though.

 

[KCvale]

Re: Is the rear wheel on your MB strong enough

[br]At the time there was still much debate as to whether or not an internally geared hub would stand the abuses of a shift kit...
As it turns out "reports of their imminent demise were greatly exaggerated" lol, I've not had even the slightest problem at all with either of them

This has to be the coolest pic of a Jackshaft I have ever seen.

Nice pic BA ;-}

 

[BarelyAWake]

Re: Is the rear wheel on your MB strong enough

Thanks lol - it's a mid-build pic tho, it's changed a lil since then


I threw it together and in my excitement I neglected to notice a coupla things before I took that pic;

AND the cable mount is out of line with the chainstay but I was psyched to have my wheels on it heh

 

[Chalo]

Re: Is the rear wheel on your MB strong enough

{re: drum brake hubs} my only minor complaints would be wishing for a touch more stopping power (fast, but very heavy bike)

Traditional drums like Sturmey Archer can take thousands of miles to fully break in. So give them some time. They are also very sensitive to the cable throw and mechanical advantage of their levers. I have found that old fashioned full length motocross-style levers such as those used on 1980s mountain bikes offer the best combination of force and cable pull for drum brakes.

and just one more gear to use as an "overdrive" as I regeared for improved acceleration (again, heavy bike lol) by using a 10t & 48t combo on the SBP shiftkit. As they don't seem to have a 4sp hub w/drum brake, I've included the link for the 8sp instead (untested to my knowledge) & the dyno drum front hub w/larger brake.

The Sachs/SRAM P5 Cargo hub may be the best choice to serve your goals. It is specifically designed to accommodate heavy loads and high torques, for use with tandems and load haulers. It has five speeds distributed over a 225% overall range (versus 177% for a Sturmey Archer 3 speed). SRAM has abandoned the US market for internally geared hubs, but you can still find their products at European retailers.

Naaf achter, SRAM Spectro P5 Cargo, trommelrem - Fietspunt

Chalo

 

[silverbear]

Re: Is the rear wheel on your MB strong enough

Ah, a heavy duty Sachs five speed; just what the doctor ordered. There's a nitch market for someone to import for us. How about you, Chalo? What kind of cost are we talking about?
SB

 

[BarelyAWake]

Re: Is the rear wheel on your MB strong enough

Thanks for the info Chalo, TBH the Sturmey 3sp I considered an experiment at the time & was considering the NuVinci... but couldn't get around the lack of an internal brake (disk or rim brakes "inappropriate" for that bike, band brake reported as "ineffective"). The Sachs/SRAM P5 Cargo hub looks to be an excellent alternative if it can be found for US purchase... but as my Sturmey has proved so faithful despite my abuses I'm now reluctant to replace it heh, but I'll keep the Sachs in mind for other builds or if/when the Sturmey decides to hate me

Traditional drums like Sturmey Archer can take thousands of miles to fully break in. So give them some time.

I've just broken 4000 miles on that build w/o a noticeable change in stopping power for good or ill, it's possible I've acclimated to any increase in stopping power - but even if that's the case it's still slightly insufficient... tho obviously it's (drum brake's) durability & longevity are impressive.

They are also very sensitive to the cable throw and mechanical advantage of their levers.

This is something I've wondered about but haven't bothered to experiment with - as again I've made some small compromises for aesthetics on that bike I've used the dual pull brake lever with some mixed feelings... I suspect as it's 2 in 1 I'm halving the "squeeze power" as I'm using one hand to apply both brakes - but as it does actually stop well enough I'm comfortable with it's safety & despite the fact I very much prefer independent brake control with any two wheel vehicle... with that build I don't think I'll be runnin' three levers.

Gaw... I'm such a fashon slave lolz

I have found that old fashioned full length motocross-style levers such as those used on 1980s mountain bikes offer the best combination of force and cable pull for drum brakes.

I suspect you're right and I've a dual-pull brake lever from a four-wheeler with a significantly longer lever and it's construction is much stouter, I've been meaning to swap it out... but that and a couple few other things have been put off for the winter rebuild *shrug* It was supposed to be only a "road test" when I first rode it this past spring, even the paint job was incomplete (just a base coat & no detailing)... yea... obviously it went well enough plans changed

 

[silverbear]

Re: Is the rear wheel on your MB strong enough

We need for someone to import that Sachs 5 speed hub. Someone perhaps who speaks German? Crazy Horse? Somebody with relatives over there? How could I find out how much that costs and how to get it? I'm picturing that on my Worksman cruiser build with the PK-80 engine and SBP's improved shift kit. Oh boy, what a bike that would be.
SB

 

[silverbear]

Re: Is the rear wheel on your MB strong enough

I got the following message from Harriscycle.net, the USA outlet for the Sachs hubs... I don't know anything about how much one would cost, but thought first to see if they were even available. Apparently they are.

"Hi,

The drum brake version is currently out of stock. The distributor should have more in another few weeks. But we don't know exactly when.

Yes, we could help you on a larger purchase. Is this hub holding up for motorbicycle use? I would have thought the torque would damage it.



Tom Deakins@Harris

Harris Cyclery
1353 Washington St.
W. Newton, MA 02465"

 

[reb1]

Re: Is the rear wheel on your MB strong enough

silverbear: These lights are designed for the 3watt 6volt setup. The inoled will also run off of a 12volt battery. Yes they are expensive but will allow you to see the road.

 

[Chalo]

Re: Is the rear wheel on your MB strong enough

Is this hub holding up for motorbicycle use? I would have thought the torque would damage it.

My impression is that it isn't gross torque that allows engines to harm bicycle components, but vibration. Electric motors put out more maximum torque than gassers as a rule, and good old pedal power can apply the most force of all (think standing up and jamming on the pedals from a standstill). I'd expect internal combustion power in the less than 5hp range to contribute to loosening parts, lubrication breakdown, and overall wear and tear, but not any brute force type failures.

I have busted a 7-speed hub by downshifting under heavy load, and one of my Seattle buddies broke one which was used in conjunction with a Stokemonkey through-the-gears electric assist. Both were repairable. But these were both hubs with modest weight limits that were not designed for heavy duty, like the P5 Cargo.

When I last saw the P5 Cargo for sale, it cost less than $200 complete with shifter and associated hardware. It looks like you can still get one for around $200 even including shipping from Germany. I found this item on the Endless-Sphere forums:

Re: Internal Gear Hubs (with source for 5 speed cargo hub)

Postby drewjet » Fri Sep 25, 2009 10:49 am
I found a supply for the 5 Speed Cargo Dear Andrew,

yes we are able to serve you with Sram Cargo hubs. The price is net 84,00 each plus freight of about €55,00. Cable length from 150mm up to 185mm are available. If you are interested in, we will send you bill for payment in advance. Delivery takes about 8 days.

Best regards, i.A. Christine Hilf

Traub Fahrzeugtechnik GmbH
Licher Str. 25
35516 Münzenberg
Tel.: 06004-930550
Fax: 06004-1709
Traub Fahrzeugtechnik, Innovative Fahrzeuge für Sport und Transport, Falträder, Lastenfahrräder

I hope this proves to be of help to someone.

Chalo

 

[reb1]

Re: Is the rear wheel on your MB strong enough

The sachs 3 speed and the 5 speed cargo have hardened internal gears instead of powdered metal. The Rohloff 14 also has hardened steel gears. These internal geared hubs would probably hold up better. I agree that standing on the pedals would create more start up torque than the motor. If you purchase one of these hubs please post all the details.

 

[silverbear]

Re: Is the rear wheel on your MB strong enough

It won't be me buying one any time soon and I'll do lots of research first, compare prices, etc. Barely has had good luck so far with his Sturmey Archer and realistically for the way I ride, a three speed would be adequate. If the Sachs 5 speed wasn't too much more expensive I'd go that way. Any more gears than that I would never use. And it has to have a drum or disc brake as a coaster brake won't work with the SBP shift kit. I'm still holding out hope for Ferball's three stacked sprocket shifter in which case I wouldn't need internal gears or the SBP shift kit. But at some point I will have something to give my Worksman gear options.
SB

 

[Goat Herder]

Re: Is the rear wheel on your MB strong enough

I hear you Silverbear it sure would be sweet if any of these hubs were able to be reversed and run as left side drive..