Fitting freewheels to splined freehub drivers

AussieJester said:

I would have thought for trials type riding having a freewheel on the back would be worse than fixed anywayz, wouldnt it be more 'motorcycle' like with a bit of resistance from the motor when you throttled off?
Im sure with fixed sprocket you wont have issues anywayz gwhy

KiM

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The freewheel do make it very difficult to ride in true trials style ( also the throttle resolution makes it hard as well , but Im working on that :wink: ), was planning to goto a fixed sprocket once the throttle thing has been resolved but looks like I have to sort out the freewheel thing out sooner rather than later

gwhy! said:

The freewheel do make it very difficult to ride in true trials style ( also the throttle resolution makes it hard as well , but Im working on that :wink: ), was planning to goto a fixed sprocket once the throttle thing has been resolved but looks like I have to sort out the freewheel thing out sooner rather than later

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I am thinking a dog clutch is what we need. Thud's tran would give us freewheeling and lockup, but it is overkill for folks that don't need two speeds. Maybe we could talk Thud into milling a couple of extra gears and shifting mechanical stuff that we could put in our own boxes.

Bubba

I was noticing the other day that my bike didn't roll any faster with motor off, it actually slowed down. Fixed gear has become very attractive for me after the last few rides. Sure it would be a bitch to pedal home if something broke, but keeping a tool kit would allow me to unbolt some drive or take a chain off and make it ridable as a broke moped.

I just got my SRAM DualDrive in the mail today Hopefully I am getting my Matt drive soon as well. Now i need to hook up with Luke to get the freewheels going. Life will be good shortly.

would you mind posting up some pics of the dual drive allround Drewjet? also where did you buy? after a LOT of ringing round the UK i ordered mine from prowheelbuilder (US).

D

johnrobholmes said:

I was noticing the other day that my bike didn't roll any faster with motor off, it actually slowed down. Fixed gear has become very attractive for me after the last few rides. Sure it would be a bitch to pedal home if something broke, but keeping a tool kit would allow me to unbolt some drive or take a chain off and make it ridable as a broke moped.

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I welded my broken freehub today just to see what it would be like and to be honest its not to bad as you say, you could just carry a small chain breaker should you need to peddle any great distance. Hopefully my die will arrive soon so I can try to tap a thread onto a freewheel hub to fit a screw on freewheel this then will also lock the motor driven sprocket securely but will be fixed. Thats the plan anyway

edit:
the problem i had with my freewheel hub was the teeth of the ratchet mech were rounded, if i took up the drive up slowly it would catch and the ratchet would be fine, I could have gotten round it by increasing the spring strength .. but i couldnt be bothered

gwhy,

For you, the less slack in your motor drive the better. You are asking a lot of even a freehub let alone a freewheel on top of that. The 2 together put a lot of slack in the drive system. I think for you the best would be a strong downhill or trials hub with a fixed sprocket driven by the motor and a splined freewheel for the pedals. That way your pedal chain doesn't move when your motor does. Your motor chain will move when you pedal, but you could put a oneway bearing, that has no slack, on the final drive of the motor reduction.

The more I hear about the issues with with the double freewheels, I am leaning towards one splined freewheel and a fixed sprocket for the motor. That will remove any excess slack in the motor drive train and make it less likely to eat it's self.

Clay

I got it on Ebay. I paid more than I should of but was still a good price. Seams to be in good shape and came with click box and cables and derailer. I'll post up pics later today.

flying monkey said:

The more I hear about the issues with with the double freewheels, I am leaning towards one splined freewheel and a fixed sprocket for the motor. That will remove any excess slack in the motor drive train and make it less likely to eat it's self.

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I am still of the opinion that a proper "cush" mounting of the larger sprockets will go a long way adding durability to these built for human power mechanical systems.

Gwhy's failure (& correct me if I am wrong) occured while abusing his drive train. (which is where all the fun is IMHO)
Trial's riding it G? for that you need to upgrade to a converted hub from a mini cycle. I am thinking a front (maybe rear)disc hub off a yamaha YZ85 or along that line.

In a normal "roll it on" & go down the road senario the shock loads are way more reasonable & a cheap freewheel would last a long time with proper maintainace.

If we are going into this with a racing mentality & max performance expectations, you can dis-regard any bicycle parts in the drive train in terms of "durability"

No one has ever had an ENO fail.

No one has ever had the splines/hub attachment fail.

Issues with low budget freewheels/freehubs being used in an extreme shock loading situation.

Cheapo freewheels/freehubs fail with no motor just from normal use with a strong guy on the pedals. Lol

Sounds like it was just a combo of gwhy's unique riding style and the quality of the freehub. I've got a friend who's a bike messenger puts tremendous stress on his drivetrain daily and has never had a freewheel or a freehub fail. He's 6'5", about 260 lbs. and rides a 48t/15t chainring/freewheel/cog combo on his flip-flop hub. In fact, in all these years he's only had a bent crank-arm.

:lol: Just for the record:

Yes I am using the drive train to extreme and fully expected it to fail sooner or later. It was a cheap freewheel hub this is true but I have always intended to lock the freewheel because I have had a more expensive freehub fail on me under normal 'trials' power and this is why I personally prefer the screw on freewheels they are cheaper than a really strong freehub and upto now 'I' have not had a 'trials' freewheel fail on me But that being said I know of people that have used WI and other 'good makes' of freewheels that have also failed but again so this is not unique to WI , I never have and never will be upto the standard of cycle trials that some of my mates are at that cause these types of failures in freewheels. But now putting a motor on these cycle components will really test them, Im not a skinflint or penny pincher and I would buy something off the shelf at a drop of a hat if I thought I would be upto the job. Most if not all failures on a cycle trials bike tend to be in the drive train ( chain/freewheels/peddles/cranks/BB ) . I think in the end I will have to go with a mini motorcycle hub for durability as Thud has already said. But Im hoping to dial in the electrical controls first before going down this route.

Thud said:

I am still of the opinion that a proper "cush" mounting of the larger sprockets will go a long way adding durability to these built for human power mechanical systems.

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I don't disagree that cush in the drive system for most of us is a great idea. The way that is achieved and how much there is would be the issue. For gwhy, no cush would be best as he wants to trials ride and wants response immediately without shock loading anything.

For the rest of us, drive train lifespan would be increased if we could have a little cush with out shock loading anything. If there was none, we would probably see a lot of broken chains, sprockets and mounts, and bent shafts. The problem with freewheels and free hubs, is they have prawls that catch and create a shock load. If the hub and freewheel are not both engaged when power is applied, then a quick application of power will shock load the system as the the prawls engage. With a freewheel and free hub you get double the shock load or the chance for two shock loads.

So to get that cush, it could be a rubber mounted sprocket, or maybe there could be enough in the tire as it will flex as it gets grip with the ground. I think after ridding my bike with only a free hub, that driving the free hub direct with the motor will be the best option if you don't want to pedal alone with the least drag possible. The double freewheel is great for those that want to be able to pedal like a pedal bike and motor when they want to motor. It all depends on what you want to do with your bike. gwhy, may want instant power with with no cush, but may break other parts of the drive train.

Well, that was more than I've said in a long time. I guess I'm saying, think about what you want from your bike and build to suit. There isn't one solution for all. But come up with a cushined sprocket mount would be the cats pajamas (good for those that didn't get that).

Clay

D,

Here are the pics

Thanks for posting Drewjet, looks like quite a tidy example, i did see one on ebay myself but couldn't bring myself to click the buy it now
what are you doing for shifter and cable? did it come complete?


D

It came with the shifter and cable, and the clickbox as seen in the pics. The problem with the shifter is it is a dual shifter in one. It has shifters for both the 3 and 7 speeds so is kinda useless. My thoughts are that I am going to use a left side 3 speed shifter from a front derailer. Hoefully the spacing will be right.

i maybe wouldnt risk damaging the sram with a shifter that might line up the internal gears correctly,
http://www.ukbikestore.co.uk/product/97/h2999/sram-dual-drive-3-speed-trigger-shifter-front.html
not cheap, but then the hubs arent to replace either?

D

Best deals I've found are:

http://aebike.com/page.cfm?PageID=30&action=details&sku=HU2597
265 with disc brake

or

http://www.jensonusa.com/store/product/HU407C05-Sram+Dual+Drive+Hub+06.aspx
285 with disc brake

both cases, shifter, cables, clickbox all sold separately.

My LBS actually has one of these, already built into a wheel (from customers that wanted to upgrade to a derailleur system) for 500$

Much cheaper online, but how much for the other parts? + 30$ shipping? + 120$ rims+spokes+tire+labour building into a wheel?

Starts to look more reasonable. But I still say these hubs are too much. There's got to be a cheaper way. I'd much rather buy an entire bike with the dualdrive on it, but I haven't seen any yet at a reasonable price.

Katou

Check out the Schwinn DSX.
http://www.pushandpedal.com/Product...chwinn_Sierra_DSX_Comfort_Bike_(XS/S)_S5434Z/

Thats actually not a bad idea. For an extra $70, you get an entire bike, the clickbox and cable shifting system for the Sram-DD, and the hub is already laced to a 26" rim with 14G stainless spokes.

I notice the front has rim brakes, but the suspension fork has the disc caliper mounts already from the factory. That would be nice for all bikes, no need for a new fork just to add a front disc.

My Die and die stock Eventually turned up , and after a bit of head scratching I set about trying to cut threads onto a splined freehub , I carried out a surface hardness test on the freehub and decided to just lightly grind the hard surface off ( it really wasnt worth stripping the freehub down and heat treating ). The main problem was getting the die to bite and keeping the die straight at the start of the process. I used a BB threaded cup and bolted this to the end of the hub with the axle, this then gave me a thread for the die to follow and push against it worked a treat. I only wanted enough thread to be able to screw a free wheel onto the end of the hub, It would be possible to thread the whole freehub this way but it was hard work and very time consuming but Im happy

Anybody know of another source of the flanged Eno free wheel other than Sikebikeparts? They appear to be out at their website, probably the ES rush! I am sure I saw a slotted and flangrd version on a build here somewhere but it did not pop up on the search. Any direction truly appreciated.

Gerard

comradegerry said:

Anybody know of another source of the flanged Eno free wheel other than Sikebikeparts? They appear to be out at their website.
Gerard

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Expect to start shipping again 3/8/10

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You can just use the 22T version. The radial cutout slots are the same BCD as the 5 holes on the 'Sickbikeparts' exclusive unit, although if your going to make a custom sprocket adapter disc, this convienience doesn't really matter...

Thank you for the info, I can wait a few days for the availability of the flanged variety.
If the offer of Live For Physics is still open when they are available I will be only too happy to Paypal Thud $20 per free wheel and send a self addressed box with postage for the return of the broached freewheels.
This is still one of the most interesting threads from a colaberative point of view, I am truly impressed by the effort and skills on this forum.

Gerard