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Difference between Vintage Dia Compe Center-Pull Brakes

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Difference between Vintage Dia Compe Center-Pull Brakes

Old 09-07-17, 06:01 PM
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Don Buska 
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Difference between Vintage Dia Compe Center-Pull Brakes

Does anyone know what the difference is between the two brakes shown below? I think the Gran-Compe (Lower Photo) version is their model GC-610 or at least that's what is shown on Velobase. The other is probably the original DC-610 model (Upper Photo). They look the same except for the sticker. Both indicate "Drop Forged" and also have the 5583 stamped on the back side. Sorry I don't have the Gran-Compe in hand to view side-by-side at the moment.

Naturally Dia-Compe has newer versions using the same 610 model number just to confuse things more. Wonder why they'd do that??

Inquiring minds want to know





Thanks,
Don
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Old 09-07-17, 06:11 PM
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Yes, one was made when red was cool, the other (probably later) when they felt black was cooler.

Note, the black one seems to have higher polish. So better polish plus cooler black graphics and the same brake can now be spec'd OEM on a better bike.
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Old 09-07-17, 06:26 PM
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I was gonna' say one was left and the other right, but I changed my mind. They look symmetric. Maybe one is front and the other rear, but we can't really tell from those pics, can we? Let's go with the red/black scenario.
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Old 09-07-17, 06:32 PM
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Gran Compe is Dia Compe's "luxury" brand.

Kind of like Cadillac is GM's, or Lexus is Toyota's or Acura is Honda's.

As mentioned- it's polished better with nicer looking decals. There may be a difference in some of the other hardware. For the same reason you'd choose Dura Ace over 600 or XT over LX or Superbe Pro over Cyclone...
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Old 09-07-17, 07:00 PM
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Originally Posted by The Golden Boy View Post
Gran Compe is Dia Compe's "luxury" brand.
Yep I was aware of that. However, when you get to the later 80's side-pulls the difference between Gran Compe versions and the others are quite noticeable, well beyond paint, polish and stickers. Perhaps someone has an early 80's or late 70's Dia Compe catalog that might have their description of the difference.

I would think that Dia Compe was above a simple cosmetic change. Maybe as a whole set, i.e. the Gran Compe version only came as a set with better quality levers and QR hardware. I've seen a couple full sets like that on eBay selling for the $100+ level. Here is a picture of a set. Notice how snazzy the levers are with the built in QR. Those are not the levers I've seen on the many bikes I've owned or seen with the red labeled Dia Compe Center-Pulls.



BTW, I have a set of NOS Gran Compe brakes only coming to me, so I'll be able to do my own review in a real side-by-side next week.

Regarding the Front or Rear brake-ness for those I pictured, Don't pay any attention to that. I was just giving an example, as I know better than ask such a question without pictures Plus, in center-pulls like these it's mainly just the attachment bolt length...

Don

Last edited by Don Buska; 09-07-17 at 07:24 PM.
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Old 09-07-17, 07:11 PM
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Yes,the GC was the luxury version. It was buffed and clear anodized, whereas the standard DC was not. It is also often seen with recessed hex bolts. The catalogue also claims a 12g weight difference, with the GC being heavier. The weight difference might be totally in the hardware but Shimano had a similar case with their identical appearing Tourney and Dura-Ace centre-pulls. In that case,I have read that there was an alloy difference, so that's a possibility that I wouldn't rule out. While the castings appear identical, they might also be slightly beefier, which could account for extra weight. If you really want to know, you could disassemble a sample of each and do a comparison with a good weigh scale.
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Old 09-07-17, 07:41 PM
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Originally Posted by T-Mar View Post
Yes,the GC was the luxury version. It was buffed and clear anodized, whereas the standard DC was not. It is also often seen with recessed hex bolts. The catalogue also claims a 12g weight difference, with the GC being heavier. The weight difference might be totally in the hardware but Shimano had a similar case with their identical appearing Tourney and Dura-Ace centre-pulls. In that case,I have read that there was an alloy difference, so that's a possibility that I wouldn't rule out. While the castings appear identical, they might also be slightly beefier, which could account for extra weight. If you really want to know, you could disassemble a sample of each and do a comparison with a good weigh scale.
Thanks T-mar. I have some Gran-Compe versions arriving next week. So I will do the side-by-side and weight measurements too. I'll report it back here. I was feeling things out if ever anyone had done the footwork in the past. As always Tmar you provide some very useful and insightful information. BTW, the "new" 610's from Dia Compe have those Allen head bolts and really nice engraved logo. They'd look great on a vintage bike, except they just ain't vintage
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Old 09-08-17, 04:52 AM
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I have these Gran Compe Center Pulls.



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Old 09-08-17, 10:18 AM
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Originally Posted by Michael Angelo View Post
I have these Gran Compe Center Pulls.
Any documents with those? I'd be interested in their age, i.e. date of manufacture. My guess would be late 80's
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Old 09-08-17, 10:51 AM
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Those are New Gran Compe, specifically NGC450. They go back to at least 1986.
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Old 09-08-17, 11:15 AM
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@Don Buska , I have a set of the Dia-Compe levers with the integrated QR on one bike, and they are indeed nice to use: VeloBase.com - Component: Dia-Compe 154
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Old 09-08-17, 11:38 AM
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Originally Posted by Don Buska View Post
Any documents with those? I'd be interested in their age, i.e. date of manufacture. My guess would be late 80's
Earlier. 1981 or possibly before. Those are GC450 - the short reach version. They were the cool touring brakes just before cantilevers came back into fashion. I remember that the '81 (and 82?) Univega Specialissima came with those brakes.
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Old 09-08-17, 02:08 PM
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Originally Posted by ThermionicScott View Post
@Don Buska , I have a set of the Dia-Compe levers with the integrated QR on one bike, and they are indeed nice to use: VeloBase.com - Component: Dia-Compe 154
Yeah I have ones like yours too (154's). Those in that pictured set are even snazzier. That ornate artwork on the release with the black fill on the word (RELEASE). They must be a GC version of the 154's. I've yet seen one so nice.

BTW, that set is on eBay now. The seller is also including QR hangers and QR straddles. Naturally the later items were not part of the original kit as three points for quick release would be a bit much Those levers have real 'gum' hoods with the Dia Compe logo too! Really nice set, but a bit to expensive for my projects. The brakes would be more valuable that my whole bike However, if anyone has $150 burning a hole in your pocket here's an opportunity to really snaze up that vintage road bike. You could even keep some of those QR parts for other projects.
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Old 09-08-17, 02:11 PM
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Originally Posted by Salamandrine View Post
Earlier. 1981 or possibly before. Those are GC450 - the short reach version. They were the cool touring brakes just before cantilevers came back into fashion. I remember that the '81 (and 82?) Univega Specialissima came with those brakes.
Thanks much appreciated and noted.

Don
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Old 09-08-17, 05:22 PM
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Comparison Summary

Dia Compe 610 DC (Dia Compe) va GC (Gran Compe) Physical Comparison Results

Well I forgot I had a single rear GC brake on the way that arrived in todays mail. I have several old DC versions lying around so I was able to sit them down for a side-by-side comparison. Here are some of my observations:

1) The GC are indeed a much better finish, i.e. so much smoother. As T-Mar indicated the GC is a very nice clear anodized finish.

2) Even with several differences to report here they weighted exactly the same. I removed all the mounting washers, spacers and nuts and both came in at 130.5 grams. BTW, the through frame bolt lengths are the same. Strange that T-Mar found a slight catalog spec'd difference. The weight was also a surprise considering they are constructed a bit different.

3) The Mounting Bolts are different. The DC model has only a wedge fit head that keeps the mounting bolt from turning when attaching the mounting nut. Holding the brake assembly while tightening the nut is what keeps it in place. On the GC version their is an added extension to the bolt head. It has the wedge head as before with additional flats on the extension for a open-end 10mm wrench. So it offers the user a secondary means of holding the brake assembly in place while tightening the nut. See the side-by-side picture below (note the DC versions bolt is pushed back a little from it's normal secured position):



4) The anchor holes for the transverse (straddle) cable ends are slightly larger on the GC version. GC measured 7.6mm while the DC version was 7.4mm. Your can see the slight bit of play around the ends in the comparison picture below. Of note on the DC version my ends were frozen in place and I will need to use a bit of penetrating oil to free them. The structural dimensions of both the DC and GC Arms are the same, except for these forged Anchor Holes! The DC version is noticeably bulkier.



5) There is a rotational forged Pin and Slot mechanism that assists the Outer Arm and Inner Arm rotation when opening and closing. The interesting situation here is this Pin-Slot system is used on the cheaper DC version and is absent on the GC. The following two pictures illustrate the difference. Note that the Pin is on the back of the outer arm and the slot, which can't be seen in the pictures, is on the front side of the inner arm.





So, in conclusion and as others have expected, the Gran Compe version is by far a better finished specimen. However, from an operational standpoint you probably won't see much difference. If you want to spend the extra money to snazzy up your vintage Dia-Compe center-pull braked bike, and yet stay in the correct time period, the GC upgrade might make your day. This is especially true if you also go with the higher end levers that probably came with the GC brakes.

It's always fun to investigate these things. For me it keeps the technical side of this hobby/sport interesting. Any additions would be appreciated.

Great day to all - Don

Last edited by Don Buska; 09-08-17 at 06:05 PM.
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Old 09-08-17, 08:53 PM
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I have those black label Gran Compe brakes on my 79 Centurion Pro Tour, with brazed-on mounts. Previously, I had a pair of Weinmann 610s on there. The Gran Compes are noticeably stiffer and brake better.




You never know with pricing on this old stuff. I was able to pick these up for ten bucks (with the roller hangers) on eBay. They were totally covered in mud and the seller was apparently just trying to get rid of them for whatever he could get.
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Old 09-08-17, 09:40 PM
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Originally Posted by Vintage_Cyclist View Post
I have those black label Gran Compe brakes on my 79 Centurion Pro Tour, with brazed-on mounts. Previously, I had a pair of Weinmann 610s on there. The Gran Compes are noticeably stiffer and brake better.

You never know with pricing on this old stuff. I was able to pick these up for ten bucks (with the roller hangers) on eBay. They were totally covered in mud and the seller was apparently just trying to get rid of them for whatever he could get.
Really nice. I'm sure the brazed-on mounts also makes for a better brake mounting. Looks like one nice bike as well.
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Old 09-09-17, 08:59 AM
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FWIW, I've seen the DC version without the pin and slot. I've also seen DC versions with the slot a red, plastic pin.
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Old 09-09-17, 09:16 AM
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Originally Posted by T-Mar View Post
FWIW, I've seen the DC version without the pin and slot. I've also seen DC versions with the slot a red, plastic pin.
It's worth a great deal T-Mar - Thanks. The problem with comparing a limited sampling of either brake is it doesn't take into account manufacturing changes throughout the production life. So I may get an early DC version, but my GC might be a much later version. All the DC's I have here had the pin/slot setup and I do have another NOS set of GC's arriving next week, but that still only accounts for a limited sample of those. Plus the GC's might have been produced near the end of the manufacturing of that particular series, before they really modernized them into the current offerings. Eventually with enough user 'FWIW' posts we will have a true sense of the real difference between the DC and GC versions - the goal

Thanks again, Don
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Old 09-09-17, 09:59 AM
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Originally Posted by Don Buska View Post
Does anyone know what the difference is between the two brakes shown below? I think the Gran-Compe (Lower Photo) version is their model GC-610 or at least that's what is shown on Velobase. The other is probably the original DC-610 model (Upper Photo). They look the same except for the sticker. Both indicate "Drop Forged" and also have the 5583 stamped on the back side. Sorry I don't have the Gran-Compe in hand to view side-by-side at the moment.

Naturally Dia-Compe has newer versions using the same 610 model number just to confuse things more. Wonder why they'd do that??
As has been said, I think the main difference between the std Dia Compe and Gran Compe was the polish. This might seem minor but from production standpoint it adds significantly to the cost. There may have been other small upgrades as well: perhaps better bolts, better pads, etc. But I'm just speculating... Generally it is Toyota vs Lexus.

Could 5583 be the alloy? I know there is a 5083. Possibly more likely to be some production code.

The new GC610 is CNC milled from 6066 rather than forged. They seem to be a little bit beefier, perhaps more akin to the 60s Weinmanns than the 70's version. I don't have them all on hand to compare though. Other than that they are basically the same. I have them on my Mercian and for me they are the perfect brake. They have the pins and slots, FWIW.

I'm sure it's obvious to 99% of forumites, but to be clear, the model numbers of these brakes indicate the reach, not the quality level. GC450 are short reach, DC610 and GC610 are medium reach, and DC750 are long reach.

Dia Compe still makes the GC450 as well as the GC610. They make the 750 too but only in the Dia Compe version. The new DC750 looks the same as the old ones. The new GC450 look exactly the same too, except they lost the fake Gucci 70s style logo and replaced it with script.
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Old 09-09-17, 10:13 AM
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Don, yes, undoubtedly there were various versions over the years, given the long life span. The only definitive data point I can currently give you is that the DC version had the slot and red, plastic pin in 1977. I have another pair from 1975 without the pin and slot. The label is missing but they should be DC version based on the red bushings.
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Old 09-09-17, 10:46 AM
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Originally Posted by Salamandrine View Post
...Could 5583 be the alloy? I know there is a 5083. Possibly more likely to be some production code...
I used to consider that possibility but have my doubts. However, it is almost certainly a JIS standards number, as it is always accompanied by the JIS symbol. JIS covers bicycles under the D (automotive) section of their standards. Consequently, I'm currently leaning to the it indicating D5583 and being a bicycle brake standard. Similarly, all the Suntour derailleur claws exhibit the JIS symbol and 4532, which I believe is actually D4532, a derailleur standard.
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Old 09-09-17, 10:53 AM
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Originally Posted by T-Mar View Post
I used to consider that possibility but have my doubts. However, it is almost certainly a JIS standards number, as it is always accompanied by the JIS symbol. JIS covers bicycles under the D (automotive) section of their standards. Consequently, I'm currently leaning to the it indicating D5583 and being a bicycle brake standard. Similarly, all the Suntour derailleur claws exhibit the JIS symbol and 4532, which I believe is actually D4532, a derailleur standard.
Interesting. Yes, that would seem to be more probable. It makes sense.
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Old 09-09-17, 11:31 AM
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Originally Posted by Don Buska View Post
[I]Eventually with enough user 'FWIW' posts we will have a true sense of the real difference between the DC and GC versions - the goal Don
Nice science Don. You the Man.
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Old 09-09-17, 01:17 PM
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I believe Weinmann first introduced the delrin sheathed stud (guide pin) and slot somewhere between 1967 and 1970. From what I've seen Dia-Compe didn't copy that design until 1977. It was designed to equalize the braking force from the arms.

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