shabby cranks: painted vs anodised vs polished

[nsew]

Image01999.jpg

Before Deore XT existed, the best shimano MTB kit was Deore DX, and the DX cranks were polished not anodised. Needless to say they can be repolished ad infinitum.

cheers

Deore XT (Deer Head) was introduced in 1983 (indexed XT II in 1987). Deore DX was introduced in 1990. Both sets of cranks are ‘light alloy anodised’ according to Mombat http://mombatbicycles.com/Shimano.htm#1990 and both can be polished ad-infinitum. As I understand it XT M730 (and Dura Ace of the period) are cold forged - an expensive process that results in a greater strength alloy. Apparently so expensive that Shimano dropped it from their manufacturing process in 1994.

[nsew]

It’s interesting that in those early MTB days Shimano designed stuff specifically for MTB and ‘Long Distance Touring’. The two were deemed mutually compatible. I believe this ad shows the ‘gunmetal grey’ crankset which was an option, long before XTR incorporated it.

[edit. That’s a Deore crankset)

http://www.disraeligears.co.uk/Site/Shi ... age_9.html

[Brucey]

you can't meaningfully 'repolish' anodised surfaces without either removing the anodised layer or renewing it, because it is a hard layer achieved by chemical conversion. The anodised layer is locally removed by wear and when this happens it invariably looks dreadful (eg campag cranks above).

It is possible to renew an anodised coating but I have never heard of it being done on cranks. I know that process conditions are critical if a good colour match is to be maintained; it isn't clear to me that you would be able to 'repair' worn anodising without it being obvious where the wear had been afterwards, unless the old anodising is removed from the part entirely.

FWIW the first Deore groupset was designed as a touring groupset (for bikes with dropped handlebars) before the MTB was a commercially important thing. Flat bar shifters were also included (as an afterthought, more or less) and this allowed the use of Deore bits on MTBs. The first deore thumbshifters have a large barrel and have a 'retrofriction-esque' feel to them (without breaking SunTour's patents), courtesy of a strong biasing spring inside the shifter. I have always presumed that the shifter barrel is as large as it is in order to allow the spring to be as large and powerful as it needs to be. I have a theory that these shifters are also the reason that the shift ratio of MTB triple front derailleurs is different from that of 'road' front derailleurs; the barrel on the deore shifters is fat enough that it would be hard work to operate a road triple FD with them.

cheers

[nsew]

Then I believe you’re referring to the non anodised Deore MT-60 cranks. I believe Shimano 600 was the first Shimano group marketed as ‘Touring’. Here’s a polished XT-M730 crankset and a 600 touring ad. But yes, fine grit and elbow grease is required.

[Brucey]

Shimano had obviously sold parts for touring before, but Deore was the first shimano touring ensemble designed from the ground up; this is the first version (1981?)



No thumbshifters here (when first announced), but they were in the published catalogue. The RD and FD in this group has blue and green colour flashes on it, and like most parts in this group, is now pretty rare. I don't recall if the cranks were anodised or not.

FWIW MT60 series parts were introduced piecemeal, and only got called/became part of a DX groupset later on. So some MT60 parts were, I think, available as early as 1987.

cheers

[nsew]

Can you identify the crankset in this 1982 video? https://youtu.be/8D2p7zxVsFo

[nsew]

It’s a confusing time. Flat bar Deer Head, drops Deore.

[Brucey]

Didn't deer head come out the year after Deore…? Actually I think you are right, there must have been an earlier XT crank with a 110/74 pattern but I don't know what the model number was. It doesn't seem to have been in the FC-DE** series, anyway, and I can't (not that I have looked exhaustively) find mention of it amongst FC-M*** either. I certainly don't remember being offered one when I went shopping for a MTB in 1987, but maybe they just didn't make many or something. IIRC I came away with a MT60 crankset on that bike. (BTW I bought another (fairly unmolested) 1987 MTB a while ago and it has M700 gearset together with a MT60 brakeset. It has a stronglight crankset, but I don't think this is very meaningful; being a Peugeot, that would be a common substitution anyway I suppose, along with French hubs etc, even if there was a similar shimano crankset available).

The crankset in the video looks slightly different from others (eg in the webs between the crank and the spider?), appears to be anodised (although you can't be certain, obviously) and it doesn't have the embossed 'shimano' marks seen on later XT cranks like the ones you showed upthread (of which I think I have a worn set somewhere; if I find them I'll take a photo which will be an interesting comparison). Could it be a prototype I wonder? -there is no branding on it...?

IIRC stripping anodising at home typically involves either caustic oven cleaner and lots of elbow grease, or even more elbow grease and fine SiC abrasive, which soon degrades, being only slightly harder than the surface you are trying to remove. Is there an easier way, I wonder? Those polished XT cranks in that picture may have been a labour of love...?

cheers

[nsew]

Yes 110 / 74. 600EX is an interesting group that was the first to introduce SIS (6sp) as a d/t shifter.

From Velobase;
I've researched the origins of this crank and have found that it was used both with the Deore XT group as referenced by Mombat.org, but also with the Shimano 600EX group as the model number would suggest.

http://velobase.com/ViewComponent.aspx? ... 8&Enum=115

https://si.shimano.com/pdfs/ev/EV-FC-62 ... -0650I.pdf

[nsew]

Here the seller lists as XT-M700 - check out the pedal axle and the half-step touring configuration. https://www.ebay.co.uk/itm/124504877653

Vintage Shimano Deore XT Crankset w/Plattform Pedals

These old Shimabo Deore XT cranks and pedals have been sitting on the shelf for years waiting for a bike to come in that would need them. Rather than have them sit unused any longer we've decided to get them out on the road so here they are.

The crankset was used on early touring and mt. bikes. It is a triple configuration with a wide range of gears. The neatest part of the whole set (beyond those old Deore markings) is the platform pedals. They were way ahead of the time providing a large area for your shoe to contact the pedal. They also had a huge pedal axle which effectively lowered the pedal on the crank.

It's quite hard to find a complete set of these cranks and pedals and neither can really be used without the other due to the axle size. We've solved the problem by listing everything together so don't miss out!

[Brucey]

that appears to be a FC-DE** crankset, but I'm not exactly sure which one (there are about six different models, mainly with only slight differences)

Probably FC-DE31, being a triple with those ring sizes?

cheers

[Brucey]

Yes 110 / 74. 600EX is an interesting group that was the first to introduce SIS (6sp) as a d/t shifter....

https://si.shimano.com/pdfs/ev/EV-FC-62 ... -0650I.pdf

There was a version of 600-EX prior to that; the index version is 600-EX-SIS. IIRC it was the first group to use the 'standard' shift ratio in the rear mech; Dura Ace 7400 had 6s indexing in 1984, but that used a different shift ratio. IIRC most of the 600EX-SIS group became available in late 1986 (including FC-6207, the double chainset which went with it) but the techdoc above for FC-6206 triple appears to be dated 4/87 so it may have been a later addition.

Interestingly the BB spindles for use with FC-6206 appear only to support 'road' chainlines; leastways there is only correction for BB shell width and number of chainrings.

IIRC FC-6207 is embossed 'shimano 600EX' near the pedal eye, but in the same place FC-6206 says just 'shimano' which may be because it was meant to be used in more than one groupset. The crankset in the video doesn't have such markings, so it is still a mystery.

cheers

[PH]

‘Touring’. Here’s a polished XT-M730 crankset and a 600 touring ad. But yes, fine grit and elbow grease is required.

That's so pretty, I don't know if there's any anodising that shiny, even if so it won't stay that way long.

[nsew]

that appears to be a FC-DE** crankset, but I'm not exactly sure which one (there are about six different models, mainly with only slight differences)

Probably FC-DE31, being a triple with those ring sizes?

cheers

The date code on the eBay Deore is Feb 81 which points to at least a 1980 design and looks for all the world like a take on the TA Cyclotourist that I understand was a popular early mtb crankset. The mystery crank in the video looks suspiciously like the Sugino AT of that era. I wonder why they didn’t use the Deore as that was what featured in all the Deer Head XT marketing.

[Brucey]

You are right the mystery crank does look like the Sugino crank. Sugino pioneered the 110/74 format I believe. It is quite possible that shimano were having a change of tack regarding cranks at about that time; IIRC Takagi (who I think had made most good quality shimano branded cranks previously) were still selling their cranks under their own brand but at about that time they were bought out by shimano lock stock and barrel and only made for shimano subsequently. Possibly this move was prompted by (or caused) supply problems... who knows? It is possible (bearing in mind it was only a year between Deore and 'Deer Head') that the launch of the first Deore groupset was delayed for some reason, and crank supply problems might have been it?

Date marks on shimano parts are interesting; parts made by subcontractors (which would have included cranks back then) are often on long lead times and/or made in batches so date marks may be well ahead of sale or release dates . Occasionally I have seen a shimano component where there are three separate date marks; one each (in the metal) for major components (which may have come from a subcontractor) and a third, later one, usually on a sticker, which presumably denotes when the assembly was produced.

The FC-DE** crank series were indeed based on the TA (also Stronglight/Nervar) bolt circle pattern. IIRC the comparative lack of dedicated MTB cranks meant that as late as ~1982/83 the specialized stumpjumper was fitted with TA cyclotouriste cranks; (after that they made their own, or rather sugino made them for spesh).

FWIW there is a nice write-up of the first Deore group here;

https://bikeretrogrouch.blogspot.com/2014/07/deore-first-touring-gruppo.html

FWIW around that time I had no strong urge to buy shimano cranks; the dyna drive pedals seemed an obvious blind alley (and they were; you could still buy dyna drive AX cranks, heavily discounted, -complete with threaded adaptors for normal pedals- at least five years after they stopped making them). But you couldn't buy dyna drive pedals, because few managed to ride a full season on them without them wearing out. Later they succeed in putting me off with biopace chainrings. They were the first things to be removed from the 1987 MTB I bought.

cheers