Don Buska

On a current build, high-end 1984 Araya Frame (post to come when completed) with chromed Suntour Superbe Pro dropouts, I am seriously considering using a last generation Suntour Sprint (SP) 9000 series derailleur (RD-SP10) instead of my normal go-to Superbe or Superbe Pro line up. For some reason I just find that dark gray paint contrast with the polished aluminum really appealing vs the solid polished aluminum look of the SB model. Recently I acquired the aforementioned Sprint rear derailleur and was immediately taken by how close it resembled the Superbe Pro (SB) RD-SB00 derailleur. Rating wise they are both Accushift Plus index capable with the same specs for sprocket/chain ring tooth-count range. In fact initially they both used the same down-tube shifters (SL-IP00). I decided to make a side-by-side physical comparison of the two units to see exactly how they differed.

Both of the derailleurs used here are date code CG (July 1986), so it provides a sound comparison platform.



Weight: The catalogs indicates the SB at 194g and the SP at 204g. Only a 10 gram difference. However, this is where one of the significant difference between the two come into play. As delivered the SB uses their seal bearing pullies, whereas the SP uses the older brass bushing style. On my digital scale the bearing version weighs in at 14grams each and the older style are only 10grams each. So any derailleur that gets fitted to the sealed bearing pullies will automatically see an 8g increase in weight! You will notice in the pictures that I have the pullies reversed as I plan on using the SP with bearing pullies on my build. However, please realize if both derailleur's used the same style pullies their weight difference would increase to 18 grams!

First regarding the items that are the same:
- Critical Dimensions are the same:
Pulley-to-Pulley Spacing
Parallelogram pivot point spacing
L-H Adjuster Spacing
Lower Knuckle Size
- Both use Stainless Steel bushing pins on the Parallelogram.
- Use the exact same pulley cage.
- Both are dual spring pivots. ( Frame and Cage pivot bolts)
- Identical cable mounting system. Albeit the SB has a tension spring on the barrel adjuster where the SP does not.




Where they are different:
- The upper knuckle is noticeably beefier on the SP model (about 3mm wider at the widest point)
- The Parallelogram cage is beefier on the SP model. You can see that in the top down picture. The thinnest point of the cage back-wall is around 4mm on the SB, while it is 5.5mm on the SP.
- As mentioned previously the SB came standard with sealed bearing pullies, the SP did not.
- Pulley mounting bolts are aluminum on SB version and chrome plated steel on the SP version.



Functionally these two derailleurs are so close in specifications that I personally feel I won't be sacrificing performance using the SP model on my current build. In Frank Berto's excellent 1988 book 'Complete Guide to Upgrading Your Bike' he rated both versions as VG (Very Good) on their index and friction shifting ability. The interesting difference is that Frank only gave the SP a G (Good) for Rigidity and Longevity while the SB got VG. You would think that the slightly beefier build of the SP would be more rigid.

I would be interested in others opinions and experiences with these two derailleur. I am using another RD-SB00 on my 1986 Fuji Special and it works flawlessly index shifting a Suntour 7-speed Ultra freewheel (12-24). BTW, I will be doing another 7-Speed index (12-23) on this upcoming Araya build.

If any one has and is willing to sell the matching front derailleur (FD-3900 Clamp Mount Version) I would be interested. However, only clean versions with the SPRINT labeling on the cage being fully intact. I will be using another Suntour front derailleur on the build until I can locate the matching family member.

Another aside, I will be using the matching CB-7600 brakes on this build so that gray-polished aluminum contrast look will continue to that portion as well. Albeit with older style Superbe non-aero levers.

SJX426 

Great comparison! Thanks for sharing the info!

Wileyone 

I am a really big fan of Suntour. But I actually prefer the 1st Generation Superbe to the later Pro series. To me it has a Timeless C&V look to it. On a recent Fuji build I weighed the 1st generation rear Derailleur at 190 grams (that was after all the Crud was removed).

Vintage_Cyclist

I'm running a Superbe Pro RD that came OEM on my 1984 Trek 760, originally with a Suntour 13x24 6 speed freewheel.

Needing a little more range for my old knees, I got it running with a 13x28 7 speed Shimano Uniglide cassette on a temporary wheel set. After I rebuilt a set of wheels, using the original Sprint hubs, I had it running with a 13x28 6 speed Suntour Ultra freewheel, which has since been replaced with a Shimano 13x28 7 speed Hyperglide freewheel.

All of the above in friction, of course, running smooth as butter.

Don Buska

I love to spread the joy I run the first generation Superbe Pro (RD-3100) on my 1980 SR 10-Speed and my 1980 Fuji Newest. So not a stranger to their excellent friction side versions either. I agree the first gen has it on the looks side for sure, along with the Cyclones out at the same time. FWIW, the RD-3100 is only 169 grams due to the use of the aluminum pivot bolts,yet it uses the exact same body as the non-pro RD-2100 version.

Ex Pres 

What were you doing with that pie-plate freewheel on there? they came with a 12-21 (7s)
And everything shifts so quietly on those close-range shifts that you almost wondered if you had.

dddd

I believe that neither of these derailers are of the dual-sprung-pivots type (where the derailer pivots both control chain tension and B-tension as the range of gears is used.


Notice that once the derailer is installed, there is no movement at all at the "B" or mounting bolt pivot, since the chain tension pulls the body forward to make hard contact with the adjusting screw.
I think it may have been a patent issue, but as it is the spring in the B-pivot only pulls the derailer back when the wheel is being removed, not while riding.
I discovered back in the day that with the B-screw removed, that the two pivots could allow the derailer body to swing about in the same way as a Shimano or Simplex derailer does, but I did have to adjust the spring tension balance between the cage pivot and the B-pivot to achieve this. I recall tinkering with the cage pivot, actually disassembling the cage from the derailer while out on some solo bike rides, in order to find the right spring tension adjustment that allowed the two pivot springs to balance and to improve shifting on my relatively large-range cassette (I respaced a Hyperglide cassette for Accushift indexing).
My theory at the time was that Suntour intended for shops and racers to be able to do this modification so that their derailers could perform more like Shimano's without violating any patents.
My Specialized Epic with 7s Command shifters still has the modified Superbe Pro derailer on it, though currently it's working with an Accushift freewheel instead of with my modified SRP titanium cassette.
I sure spent a lot of time trying to keep my older Epic competitive with the newer bikes and their STI levers, at the time it weighed 18lbs with pedals and using Araya CTL370 clinchers on NukeProof Titanium hubs. It remains a very nice-riding bike, feels quick as a cat!

Vintage_Cyclist

Original owner must've swapped it out.

Don Buska

You are probably correct on the details of the upper spring in the mounting knuckle. Here is the text from the Suntour Sprint 9000 and Superbe Pro Leaflets, " On the Sprint 9000 (or sub Superbe Pro for the other leaflet) we've added a second tension spring (at the mounting bolt). This allows the guide pulley to remain at the optimum distance from each freewheel cog, regardless of freewheel tooth differential. The results is shifting precision of such a high order you have to experience it to believe it." Their words not mine I just indicated for comparison purposes that they were both "dual spring pivots", which is true as both positions do have that spring loading. Considering the original 1st Gen Superbe (RD-2100/3100) doesn't have a spring nor even the B adjuster screw.

I also agree with your assessment that on these derailleurs it mainly keeps the whole derailleur body firmly resting against the b-screw stop. I vaguely remember reading somewhere, possibly a Berto writing, that one of the Suntour engineers said that the mount spring was never really needed on the Suntour derailleur because of the slant parallelogram,or at least that's how I remember it

"My theory at the time was that Suntour intended for shops and racers to be able to do this modification so that their derailers could perform more like Shimano's without violating any patents." - What a wonderful observation. You indeed have a great deal more experience than me and some really great experimentation under your belt. Thanks for the wonderful insight.

"My Specialized Epic with 7s Command shifters still has the modified Superbe Pro derailleur on it, though currently it's working with an Accushift freewheel instead of with my modified SRP titanium cassette." - My 86 Fuji is using those Command Shifters with the above Superbe Pro and an Accushift rated 7-speed Winner Pro. It's shifting the 12-24 extremely well.

Don Buska

Since my original post earlier this year I have discovered one additional and important difference between the Suntour Superbe Pro RD-SB00 and Sprint RD-SP10 Rear Derailleurs. On the SB00 a thrust bearing is placed between the guide pulley cage and the main body on the stainless pivot bolt. The SP10 does not have this bearing! Per the 1988 Superbe Pro Leaflet this 'eliminates cage play and reduces cage rotational friction.

The Golden Boy 

Thank you for this! (and sorry I missed this thread when you posted it)

My Sprint is it's original bag and my Superbe Pro has been on 2 bikes, but is now resting in a box- I always thought they were identical, save the pulleys- for some reason, I didn't think there were such glaring differences- that bulkier knuckle stands out once you know it's there.