Performer JC-70 / TW Bents Power/Idler Sprocket - Hoorah !!

[hoarder]

I recently swapped out my Performer JC-70 Trike's 700c rear wheel for a newly built 26" replacement (made up with components from various sources).
The idea had been to increase the clearance between tyre and mudguard to reduce risk of mud and debris collecting whilst riding country roads around here.
The pleasure and pride that comes from riding on a wheel that you laced-up yourself was short-lived; generally, I stop for only three things - horses, cake....... and loud grating noises. It was the latter that had prevented any rides since the beginning of the month.

The cause - fracture of the lateral wing of power idler (yep, the delrin cracked on one side of the casing). Rubber O-ring - no trace !!
The solution - mail order from Performer, Taiwan. Christine at Performer promised an improved replacement (CNC Al), and it would be a straight swap.
Having returned from holidaying in Norfolk last night, I find the part has arrived, and I'm ready to reassemble the drivetrain.

I've written up the dimensions below - once I find a way of posting photos, I'll add a link. But for those who have older TW Bents / Performer trikes or recumbents of similar design, there is now an option of a toothed-sprocket replacement for the power-side idler wheel, and in replacing it, so will end the need to replace the central rubber O-ring on the original (which does wear out).

Photos now uploaded

http://s991.photobucket.com/user/jonjonbell/library/Performer%20JC70%20chain%20wheel%20idler%20sprocket

Performer Power Sprocket - Part number: PL-09
14-toothed CNC Al idler, bearing included
Direct replacement for broken delrin original (non-toothed, rubber O-ring version), as dimensions near identical, and fits directly on to Performer's 12mm stub axle mount underneath the seat.

Outer diameter - 64.5mm
Inner diameter (to base of tooth) - 44.5mm

Outer width - 12.1mm
Inner width (channel for chain) - approx. 9mm

Bearing inner diameter - 12mm
Bearing outer diameter - 24mm
Bearing thickness - 6mm

USD 28 + USD 6 shipping to UK (it arrived within 7 days of ordering).

For details of availability, email Christine - christine ampersat performer.com.tw


The item may also be an alternative to other toothed sprockets - it may be possible to replace the bearing with one of different ID, but same OD, to suit other 'bents' mounting points.

[OldBloke]

Hoarder,

Does the chain run on the rollers on the sprocket teeth or does the side plates of the chain run on the metal at each side of the sprocket?

I ask because on the idler on my Trike-F the chain is noisy going through it because it is running on the side plates of the chain and the sprocket simply acts as a guide. I'm sure it would be much quieter if it was the chain rollers on the teeth of the sprocket that was taking the pressure.

I hope what I'm asking makes sense.

Thanks

OB

[[XAP]Bob]

Annoyingly 2mm wider than skateboard bearings.

[hoarder]

Hoarder,

Does the chain run on the rollers on the sprocket teeth or does the side plates of the chain run on the metal at each side of the sprocket?


OB

Makes perfect sense. As the newly-cleaned chain is still in its Ice Cream Pot patiently waiting for assembly time, it was easy to check. Unfortunately, it does look as if the the sprocket teeth do not raise the chain sidepieces above the bottom of the "channel" - so I reckon mine will be as yours, OB.

What a disappointment. Well, sort of. It's better than having no working trike. But I was hoping for a bearing-ed sprocket that would run as quietly/reliably/truly as it could, but I fear I may be accompanying OB's Trike F idler noise.

I too had looked at 10mm bearing-ed skate wheels, and a number of YouTube videos harnessing power drills, cutting implements and old urethane wheels to create a channel for the chain. But even in these cases the chain is running on its side plates, rather than correctly (IIRC) on its pins. And as XAP mentioned, these are frequently 10mm, not 12 - as needed by TW Bent/Performer.

SO - I'll be expecting some added noise when I run this new sprocket - if so, I'll now go back to one of my other options, to source a 3/32 sprocket 14 or 15t that could be mounted on a bearing with an ID of 12mm. Presumably OB, if I find one, you'll be interested too ?

[[XAP]Bob]

ICE idlers run on skateboard bearings, custom idler though, jusy uding easoly available bearings

[hercule]

ICE idlers run on skateboard bearings, custom idler though, jusy uding easoly available bearings

Think you've had enough of that beer now, Bob!

Re Performer idler - could you shave off enough (probably doesn't need to be much) of the bit the side plates are resting on to let the rollers engage with the teeth? Surely that's what the designer originally intended, otherwise there wouldn't be much point in the sprocket.

DIY - a Sturmey Archer 3/32" sprocket would be a good basis, file off the three teeth that engage with the hub driver, find a bearing to fit with the right ID and OD, fabricate some side plates out of plastic with a holesaw (small ones at first to give the outer plates clearance, or just use some big penny washers drilled out as spacers). Just an idea...

[[XAP]Bob]

touch screen keyboard with right wrist in a double splint. too much like hard work to go back and correct typos

[hercule]

You have my sympathies! Must admit I find touchscreen keyboards hard going with the use of both hands.

[hoarder]

Looking at the new idler in front of me now: quick measurement shows there's barely 2mm thickness for the base of the chain channel, so there's no possibility to remove more metal either side of the sprocket teeth.

As for fettling one with a Sturmey Archer sprocket - I'm on that track already, but starting using a Dicta fixie sprocket, 3/32, 14T. No need with that to file off the three internal prongs, but I will still need a route to mount onto a centralised bearing with ID of 12mm. Plastic discs for either side of assembly from two blu-ray coasters (BluRay discs appear to be thicker and more resilient than DVD or CDs).

Another route forward idea - came from this website:

http://imajeenyus.com/mechanical/20110913_bicycle_sprockets/index.shtml

....just need to learn to weld and all the other stuff

[Neilo]

I use these on my home built tadpole.

http://www.ebay.co.uk/itm/151056115009?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Not that expensive and a reasonably quiet. 10 or 12mm spindle, and various diameters available. Popular with home builders.

Neil

[hoarder]

Update:

I've been out for a ride this morning with the new idler in place. The noise of chain on the metal wheel wasn't as noticeable as I feared - but it can be heard.

I had attempted to compare how noisy the new aluminium and the old delrin(albeit broken-sided) idlers were yesterday evening, but the first problem that presented was incorrect gear shifting with the new wheel (and newer 11-34T megarange cassette) in place. Despite a good while spent checking H/L screws, barrel adjusters and even the "b" screw, the shifting was poor, and noisy. Only by replacing the cassette with the original did I achieve an improvement.

OK, so checking the fit of the chain on the large front ring (which never gets a lot of use !!) made me suspicious that I'd experienced one of the symptoms of chain wear. Mixed feelings about that - annoyance that I'd missed something so important, but also one of achievement in having used the trike so often I'd actually worn something out !! I had a quick check on its mileage since new (2009) - about 4-5000. I'm sure I read that trikes' chains last longer than ordinary bikes, so it may be that I need to up my cleaning regime ?

The second problem that prevented direct comparison of noise from idler was when putting all the clean components back together, I gave a liberal coating of Muc-Off spray PTFE lube to the chain. I hadn't appreciated that the solvents in this lubricant may well affect the "O" ring that straddles the middle of the channel on the Delrin idler. The result was that within several rotations of the crank the "O" ring had a consistency that could only be described as "sweaty licorice", and hence failed to stay located under the centre of the chain.

The rides tomorrow and Tuesday may give me chance to try again - I have a spare "O"ring, and by then the volatile substances in the spray are likely to have evaporated.

I'm reserving judgement on the new Al idler sprocket - time will tell. But does anyone else have "O"ring banded Delrin idlers, or is it just peculiar to the older Performers ?

[hercule]

IIRC, the underseat idler on my Trice has two O-rings that are in contact with the sideplates, on the power side of the chain run. The idlers on the Kettwiesel have O-rings in the middle, on the return side.

I think Sheldon Brown says somewhere that you should put off lubricating a new chain as long as possible as added lubricant washes out the factory grease and also attracts the dirt and grit. However chain lubrication is a subject of religious fervour and I don't want to start a riot.

[hoarder]

An update - as a temporary measure to reduce the noise from the new Al idler, I've done the last 100 miles with two rubber "O" rings on either side of the central "sprocket".

As OB noted, this newer Performer power idler looks as if the chain runs on its sideplates on the channels either side of the central sprocket teeth, and the consequence is an off-putting "jangle" when pedalling even gently. My thought was that a rubber "O"ring in each channel would cushion the sideplates, and reduce the noise.

I'll try to link to a picture of the idler, removed from the trike this evening, 100-miles later. What I see is that both rings have accommodated the sideplates within a self-created groove on the external circumference of each rubber ring. I'm not sure how long these will last, but I can say that for the whole time they've been on I've not noticed the noise of the new Al idler.



Not expensive - I found them on Ebay, 10 off, delivered for £1.48


METRIC NITRILE RUBBER O-RINGS 3.1 MM DIAMETER, 44 or 45mm ID

http://www.ebay.co.uk/itm/131108205412