justinzane

I would like to experiment with a very wide range double -- say 28/48/guard, 30/50/guard, or similar. I've seen lots written about the TA-Specialites Pro Vis 5 aka Cyclotouriste:
- Parts For Old French Bikes from Harris Cyclery
- The Velo ORANGE Blog: TA "Cyclo Touriste" Cranks Redux
- Spécialités TA - Transmission classique
- PRO 5 VIS Chainrings

These sound like a great option; however, they are not readily available or inexpensive. They also seem to work best with a derailler from a third party as has been discussed elsewhere on this site.

I've got Suntour Barcons shifting a cheap riveted 28/38/48 with a Shimano Tourney level FD. The crank arms seem to be separate from the chainrings on a square taper BB, though I do not have a crank puller to check. I'm wondering what the least expensive way is to try the above mentioned setup -- or perhaps a more "normal" 32/48 or 34/50, understanding that the front shifting will not be super smooth. If I really like it, I can invest in more expensive and better kit. If not, I do not want to throw away lots of money. I'm also hoping to avoid the rivets in the future. Can anyone suggest some parts that might fit this particular bill? The crappy riveted chainrings have me confused -- I do not know how much of my existing setup I have to junk to replace them.

---- edit ----

To be more clear; I have a set of perfectly working, if heavy, crank arms. I have a perfectly working square taper (JIS, probably) BB. Is there any way to get the spider separate from a crank arm? Almost everything I see has the spider integrated into the right arm, which may make sense from a strength and weight perspective, but means that to replace the spider you replace the arm. Is there any way to just buy the rings and spacers and spider?

Batavus

TA knock offs by Velo Orange. Uses a JIS BB, which can be had cheap Cranks are still not cheap, but you really can't go cheaper than the riveted cranks you have now.

strock 

If you can find a used Anlun Aero crankset, it will have the same 50.4 BCD as the TA and take the same rings. But you can set up a wide-range double (with or without a guard) on pretty much any triple crankset. Just put the small ring in the inner position and the big ring in the middle position.

JohnDThompson 

The SunXCD (reborn SunTour) crank might also be an option:



Cranks ? SunXCD - Bicycle Components

fietsbob

I'm seeing that spider adapter is not round, inside , so may not be compatible with TA outer chainrings unless the hole is similarly modified with a File.


Another potential... 2/3 of a triple(w bolt on chainrings ), use the middle of the crank as the big chainring-location, + the granny gear.

clengman

A used 110 74 BCD triple would be an affordable way to start. You can go down to a 24t small ring. I have a Takagi triple taken off an 80s mountain bike that I'm planning to use for this kind of experimentation. Troubling I'm having is finding nice looking small (40/42, 44/46) 110 bcd chainring guards to take up the outer chainring position.

I've also done a lot (probably way to much) of pouring over gear calculators trying to come up with an ideal (for me) gearing setup that is widish, but cheats towards the low end, has somewhat close steps and has a convenient shift pattern. I thought that a super wide crankset like what you're talking about might be good, but I'm starting to feel like that kind of thing is not really necessary with a wide range 8 or 9 speed cassette. If you want to keep a 5 speed rear, it's a lot more useful.

Right now I'm leaning towards something like a 44/34 crankset (on a regular old 110 bcd compact crank) with a wideish 8 or 9 speed cassette in the 12-28, 11-30, 11-32 range. It'll give me similar or slightly wider range as my old 52/39 14-32 touring setup. It has close enough ratios on the rear that I won't have to shift the front to get close-step shifts. The two chainrings are close enough that I can use a front shift without changing the back at all to make a moderately large jump, say to change from climbing seated to climbing out of the saddle or vice versa. Front shifts will be much smoother and I won't need any exotic parts.

A 46/30 with a close ratio rear is another possibility that would give me similar range, but with closer steps and less overlap, but that's as big a jump on the front as I can really justify for myself. I'm thinking more overlap isn't necessarily a bad thing. Makes changing from low to high range more easier, and makes shift patterns very convenient.

dsbrantjr

A chainring with the teeth removed makes a fine bashguard and can often be had for nothing if the teeth are worn out.

bikemig 

The sugino xd 600 triple is a fine crank and the price is good since it can be had with BB for around $125. More expensive options include the VO TA copy. Looks very pretty but tough to find chainrings for it. VO has a poor selection of chain rings for its crank on its own website the last time I checked and when available are expensive. A better option might be the offering from IRD as chainrings will be easier to find for it (94bcd): IRD Defiant Wide Compact Road Double Crank Set (46-30T)

94 bcd chainrings are available from a variety of sources.

justinzane

Oy! I really like the look of the Velo Orange stuff. But,
$110 for the cranks plus
$055 for the big ring plus
$030 for the small ring plus
$022 for the bolt kit plus
$007 for the chain plus
$005 for the spacers
---------
$229 for the whole shebang!

I know that this is quite reasonable in the world of quality cycling components. However, it is WAY beyond what I can afford for "experimental" parts that I am not absolutely sure that I want to use long term. To be more clear, I'm looking to experiment with this if and only if I can find parts in the two digit range.

Thanks, though... Something more to drool over.

justinzane

Thank you. I was thinking that that would be the way I go since I can pop a guard ring in the outer spot or convert back to a triple if I want. I am truly stumped by one thing, though...

I have a set of perfectly working, if heavy, crank arms. I have a perfectly working square taper (JIS, probably) BB. Is there any way to get the spider separate from a crank arm? Almost everything I see has the spider integrated into the right arm, which may make sense from a strength and weight perspective, but means that to replace the spider you replace the arm.

Is there any way to just buy the rings and spacers and spider?

clengman

It's uncommon to have a spider that's not integral to the right crank arm. Yours is almost certainly not two pieces. You should be able to get a used 110/74 bcd triple and a couple chainrings for well under $100.

fietsbob

it is a compromise to lower costs swaging on the big ring , then bolting on the other one was done .

if you got a bike with more expensive parts , then the 2 rings bolted to the spider, integral

forged out in the making of the right crank arm.

justinzane

That is almost perfect. Unfortunately, I'm having trouble finding them at much under $200 for just the arms. And, that is not anywhere near my "experimental" budget. I could get a Shimano 105 complete crankset and a couple of extra chainrings for that money.

I really appreciate the suggestion, as it is just what I want. I'm simply too poor to consider it.

justinzane

I'm sorry to be ignorant, but could you suggest a product line for me to look for that should be in that range on sale or used? In my searching, I've come across lots of separate spiders that are expensive, but most of the affordable stuff is either riveted or seems to be ISIS, Octalink, or some other non-compatible thing.

clengman

Buy this: Vintage SR Sakae CX Cranks 170mm Triple 110mm 74mm BCD Square Taper | eBay

And a 46t chainring. Bang. Done.

clengman

I like it! Thanks!

Metacortex

Nervar cranks are another TA alternative: VeloBase.com - Component: Nervar 631/633

Here's an example set up with TA rings: The Smut Pedaller: Not finished yet

They can often be found inexpensively on eBay: Vintage Nervar 631 633 Crankset Crank Arms 170mm BSA | eBay

Airburst

The chainrings are almost certainly swaged onto the crank arm. Only a few BMX cranksets with splined BB spindles have a chainring that's not attached to the crank arm, and those are still only available.

JohnDThompson 

Good point. Often much more reasonably priced than TA, and you don't need a proprietary puller.

Batavus

I eventually found a second hand Stronglight 49d (same BCD as TA cyclotouriste) for a steal, so that's the way I did it. The only trouble I had was figuring out which JIS BB would give me correct chainline for a fixed set up (113 mm, by the way) as it is supposed to take a ISO BB.

So trawl the internet and go second hand to save some bucks. And indeed you have to be aware that both the TA and the Stronglight take a proprietary puller (which I happened to have before I bought the crank).

justinzane

I understand, I think. I'm not quite sure where that leaves me when deciding what to shop for. For an inexpensive way to experiment with different front chainring setups, should I look for crank arms with integrated spider?

And, since torque from the left crank is transferred through the bottom bracket no matter what, why does the spider not connect to the spindle to get torque from both arms instead of having the spindle transfer torque from the left crank through the right? Just the ability to save weight and ease manufacturing by casting/forging the spider and right arm as one?

justinzane

Looks good, though that 30T is quite worn, so I'd be looking at a 28T and a 48T plus that. Still kinda affordable. But, for some reason or another, perhaps because I setup and accounts ~10 years ago and have not used it since, I cannot convince Pay[st]Nazi[/st]Pal that I should be allowed to actually use my account. So, e-bay is for the most part out. If anyone there would use another payment processor, I'd look at their stuff.

justinzane

Bizarrely, it seems that the rings are all riveted together and that they are attached by splines that open inwards towards the BB. Do not know whether the little ring with the splines is part of the right arm or whether it is separate. Has anyone seen this on cheap cranksets before?

Airburst

That's most likely a result of the swaging process that was used to attach the rings - I've seen a number of lower-end cranksets with swaging marks that look like splines. A picture would confirm it. The ring of metal around the boss (for want of a better word) on the crank that protrudes through the chainrings is similar to a peened-over rivet end in the way it works, it's basically deformed with some sort of tool once the ring has been slipped over it. Something about the way it's done on some cranks leaves those spline lookalikes.

Multiple rings riveted together is nothing new on low-end cranksets either.

justinzane

Ahhh. Makes sense. If I work up the courage to deal with BF on my phone, I post a pic.