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Author Topic: Fitting gears  (Read 4699 times)

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Offline Punjanaman

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Fitting gears
« on: 01, January, 2013 - 17:00:31 »
Hi Everyone,
The chassis is almost complete...as i type the paint is drying on the chassis and all parts are cleaned, greased and ready to be bolted back on, with the exception of the rear drive wheel for which i have some feelers out.
I am a daily cycling commuter so i want to fit gears to my c5 so that i can pedal as much as possible,but i have not been able to find any threads on HOW to do this...there is mention of "an easy conversion" to Sturmey Archer 3 speed...my preference is for a derailleur but how does it fit on ???I notice the old single speed freewheel is screw on so is it a case of unscrewing and fitting an older type 5-6 speed freewheel ... what about issues with chain line and the tensioner ???
Basically anyone who has done it , can you give me some tips .

Offline C5 ENTHUSIAST + RESTORER

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Re: Fitting gears
« Reply #1 on: 01, January, 2013 - 21:25:19 »
H thereI have made up 3 three speed sturmey archer gear to C5s in the past and still have two left ...check out the photo .
regarding the derailleur I have not tried making one yet but there are some issues with the ground clearances ..Any way if you want any info about the 3 speed just ask (There is a 5 seed sturmey gear)


Offline Punjanaman

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Re: Fitting gears
« Reply #2 on: 02, January, 2013 - 10:14:59 »
Hi Chas, Thanks for the pic....how/where are are you connecting the second sprocket..are you welding it to the spoke flange??
I notice the chain line has now changed ..i presume you have moved the axle sprocket along the axle to accomdate the Sturmey Archer hub and hence the original "pedal " chain is untouched, is that correct ??
Is it any good???...Years of fiddling with bikes means iam VERY familiar with the 3 speed so iam aware it is direct drive, 1/3 below direct and 1/3 above direct drive..but how usable is this..i found on my very short initial ride before strip down that the c5's gearing was low and reducing it further seems unnessecary..
Any ideas

Offline KarlG

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Re: Fitting gears
« Reply #3 on: 02, January, 2013 - 15:07:46 »
Hi Punjanaman,

I tried to reply to your post yesterday but the IN kicked me out.

This subject has been covered a couple of times in the forum. Go the the start page and pump in 'derailleur' into the search box and see what it comes up with. I'm sure someone has done this but I'm not sure if it's been documented in the forum.

IMO fitting a derailleur will present you with quite a few problems.

1. As Chas replied, there could be a problem with ground clearance. On a normal bike the derailleur gear set is close to the wheel, on the C5 it would be located in the middle of the axle, if one wheel dips or you pass over an obstuction there is a chance of ripping off or bending the jockey unit

2. The original pedal sprocket is for a single speed chain and will not take a muti-speed one.

3. OK you can change the pedal sprocket, BUT the C5 pedal sprocket is heavily baiest towards the frame, if you fit a normal pedal sprocket you will end up fouling the body.

4. If you retain the original C5 sprocket then you will have to grind the teeth down to accept a smaller chain.

5. Mounting a derailleur set to the C5 will be a lot more difficult than mounting a hub.

I see no reason to think about the chain line, ain't no worry with the chain line on a derailleur set, it's changing all the time.  ;)
And why should you need a tensioner? The derailleur set is fitted with one, though a chain support might be an idea.

Quote
i found on my very short initial ride before strip down that the c5's gearing was low and reducing it further seems unnessecary.
I suggest you repeat this sentence very load when you're half way up a steep hill. I found the three speed not to be adequate for pedalling long distances without motor assistance, for this reason I'm going to fit a seven speed unit.

I had a Sachs three speeder on my C5. I removed the original sprocket from the hub and fixed a dished sprocket to the sprocket side of the hub case, then replaced the freewheeler sprocket. The fixed sprocket, being dished, allowed enough space for both chains. The hub was slightly offset to the right so the fixed sprocket was inline with the rear axle sprocket, the offset for the freewheel sprocket was so minimal that there was no worry about the chain line.

If you look closely at Chas's photo you will see very faint markings where the original sprocket was mounted on the axle.

Best regards and av phun.   KarlG.

Offline KarlG

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Re: Fitting gears
« Reply #4 on: 02, January, 2013 - 20:09:52 »
Hi Punjanaman,

I've just dug out my old photos of #1, I made this mod in 2006 as a test. I mounted the hub in an old bike frame, then welded a plate across the frame just forward of the hub to keep the spacing correct. I then cut off the rear section of the bike's frame,  clamped it onto the top of C5 frame, fitted the chain from hub to axle,  then welded it the correct position, when finished I removed the plate. Very crude, but strong enough for my tests. OK it was a bit higher than I wanted but there was no trouble with the chain touching the lower part of the frame.

As I said this was only for a test, the hub was fitted with a back-peddle brake which caused hellish problems. Often I couldn't back peddle when the peddles were in the wrong position to pull away resulting in me getting having to get out to push the C5 forward a bit.  :-[ :-[ :-[ So DON'T use a unit fitted with a back peddle brake.

I down loaded a photo from Chas who produced a similar assembly somewhat later, but I can't reproduce it here as I haven't asked for his permission. I had to smile when I saw his unit, it was a 3 three speed Sturmey Archer unit with a built in dynamo, and the dynamo was feeding the front and rear lights. But as always with Chas, a very nice piece of work. I'd allow him to install my seven speed unit if he'd do it for free. 8) 8) 8)



Please don't ask me why I wrote Sturmey Archer in the drawing when it was a Sachs, I must have been high sniffing my girl friend's parfume.  ::) ::) ::)

EDIT: Visable links removed.
« Last Edit: 03, January, 2013 - 22:48:54 by KarlG »

Offline C5 ENTHUSIAST + RESTORER

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Re: Fitting gears
« Reply #5 on: 02, January, 2013 - 20:42:51 »
Hi is this the one you mean. As you said it does light up the front/back light ..But it still has the original bulbs in the lenses that work of the battery ...I still have it in the loft ....Plus another C5 with a 3 speed Sturmey Archer gear fitted ...


Offline KarlG

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Re: Fitting gears
« Reply #6 on: 02, January, 2013 - 20:57:15 »
Hi Chas,

that's the one, I downloaded 3 but this was the best photo. As I said a very nice piece of work, puts my feeble effort to shame.  :(

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Re: Fitting gears
« Reply #7 on: 02, January, 2013 - 21:01:37 »
You maybe right but without you example I would have not have been able to make one myself .
So thanks for the idea even though its a bit late now .
Bye Chas

Offline Punjanaman

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Re: Fitting gears
« Reply #8 on: 03, January, 2013 - 15:40:30 »
Hmmmm, interesting reading and very inspiring....The problem with the chain size had not occured to me (the chain is too wide to accomodate a modern 6-7 speed).I suppose i could dig out an old (1960's -1970's)5 speed freewheel from my spares but i would still have the problem of groung clearance with the derailleur...not to mention that older gears are not indexed and have to be fettled into the correct gear.
Which brings it back to a multi speed hub...i guess it's time to scan e-bay for a cheap 3 speed hub,then see how that works with a view to fitting a 7 speed at a later date.

Offline rekooh99

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Re: Fitting gears
« Reply #9 on: 03, January, 2013 - 17:38:27 »
Chas,Karl where did you get the sprocket that is fixed to the hub? I have all the other bits and just need to find a friendly  welder

Offline Punjanaman

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Re: Fitting gears
« Reply #10 on: 03, January, 2013 - 18:07:26 »
Hi Rekooh,
If you go to ebay and search for sturmey archer 3 spped hubs there are plenty of sellers selling the sprockets..but you have to specify what chain you are using.Sturmey made these hubs for decades and whilst the internals are VIRTUALLY identical the size of chains changed 2-3 over the years..
On another note ...on an off-chance i visited the local council dump and bingo an old bike was being dumped with a '96 Sturmey 3 speed!

Offline KarlG

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Re: Fitting gears
« Reply #11 on: 03, January, 2013 - 19:25:16 »
Hi Rekooh,

I can't speak for Chas but after a lot of searching I found a dished sprocket, the one that I welded to the hub, from a very old Grandma's bike. I looked for a dished sprocket as I wasn't sure that a normal sprocket would give me enough clearance, maybe Chas has some info on this point.

One small point I had to grind the centre out of the fixed sprocket before it would fit.

You can install a 3, 5, 7, or 8 speed into a C5, I've no idea if a Rohlhoff 14 speed, or others,  would fit as they're beyond my price range.  :-\

You should also read about Phil's installation of a 7 speeder from this page on:
http://www.cypax.net/projects/c5/blog/page8?language=en#thispage

Cheers.  K.G.

Offline rekooh99

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Re: Fitting gears
« Reply #12 on: 04, January, 2013 - 13:28:19 »
Thanks lads dead helpful as usual thanks