Classic & Vintage - Stronglight 700a bottom bracket
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11-28-08, 02:25 PM
i've got a stronglight 700a catridge bottom bracket. see the velobase entry here (http://www.velobase.com/ViewSingleComponent.aspx?ID=9c2d8c4b-3030-41c9-802c-2ccb31ada9c2&Enum=119).
the description from a 70s stronglight catalog says 'its preadjusted and lubricated for life"
well, mine has minimal play. i've seen replacement parts (bodies or shells) on ebay for these and was wondering if there is way to service them. anybody have experience with them?
update: some research shows that the mavic 600 series bottom brackets were made by stronglight . these strongly resemble the 700a. in the 1979 mavic catalog at wool jersey (http://www.wooljersey.com/gallery/v/broderir/Catalogs-Posters/MAVIC/1979-11/Page+14.jpg.html?g2_GALLERYSID=638b43dff694feb5d88003135eec93f9), the 600 R.D. is advertised as "adjustable, can be taken to pieces". any ever service a mavic 600 before?
11-28-08, 03:13 PM
I have a Stronglight unit at home, not sure if it's this 700A or another model, but all-alloy except for the steel spindle IIRC. I have not serviced it but I'll check it out tonight and post if I learn anything. My guess is that the cartridge bearings are pressed into the shell and usually can be pressed out and replaced, this would be the typical set-up. Slight chance you might need a special tool, but I usually have employed a big vise or giant C-clamp and some deep-well sockets to do "press work".
11-29-08, 02:10 AM
thanks. the stronglight catalog references tools 710 and 720 for catridge bb adjustment. the mavic catalog mentions tool ref. 670. stronglight ref. 720 looks like it could be a combination of a pin spanner and freewheel remover or park tool BBT-18 (to be used with a wrench). the 720 can be vaguely seen here (http://www.flickr.com/photos/stronglight/2290805988/in/set-72157603969281091/)
i start to think that once mounted, the cups can be removed with a pin spanner or the 720/670 to access the bearing catridges, but i'd like confirmation on this before attempting it myself. this picture (from a current ebay auction) shows that this likely possible:
11-29-08, 05:29 AM
ok. so after some tinkering with the tools i have, here is what i found:
- the left side cup (with brand and thread markings) is adjustable and removable. in order to adjust the tension on the spindle the BB has to be mounted.
- the right side cup seems to be fixed to the shell, or mine is just super tight. the mavic catalog shows the model 602 with a removable right cup, but who knows. what threw me off is that my right cup has holes to accept a pin spanner. the holes appear to be self made and not factory, since they are a bit offset, not at all symmetrical. perhaps this was done in order to thread the bb without the manufacturer's suggested tools (i.e ref 720). using a pin spanner from the left would likely be counter-productive and thus loosen the spindle.
at any rate, i was able to tighten the spindle down. and it is good to know that when the bearings do go, it can be serviced. then it will just be a matter of finding the correct cartridge bearings that fit! gotta love french projects. :thumb:
11-29-08, 09:10 AM
Below is my catalogue page showing the early Stronglight 700 series cartridge bearing set - from around 1984. The axle assemblies shown below on that page are for Titanium and Steel axle versions with cartridge bearings... but with more conventional cups which just snap onto the outer edges of the cartridges. I believe these same basic axle assemblies are also used in the model 700 sealed version.
I must admit I am a bit confused. I assumed the 700a was not threaded to the frame, and was just held in place by the flange on the right side and the lock ring on the left, and I would guess the right side "cup" was threaded inside the 700a shell - just as it might be threaded to a frame. BUT... since there are threads shown all along the outside of the shell in the catalogue image, perhaps this entire casing threaded through the bottom bracket shell of the frame from the right side.
The Stronglight Professional type 710 tool here (http://www.flickr.com/photos/stronglight/2291064500/in/set-72157603969281091/) is actually a rather massive and complex shop tool which serves several functions: 1. a bottom bracket thread "tap"... 2. a "facing" tool for both BB and head tube edges... 3. a headset press. The recommendation of using this tool implies the need to thread the BB shell of the frame all the way through to ensure a clean and consistent thread to accept the 700a sealed unit. [WHEW!]
A larger size image is HERE (http://farm3.static.flickr.com/2296/2286295691_8b0fb4eb68_b.jpg)
... and much larger size HERE (http://farm3.static.flickr.com/2296/2286295691_206d37166f_o.jpg)
11-30-08, 02:02 PM
thanks for chiming in. the truth is that i don't know for sure that it is a 700a. the velobase entry for that model closely matches mine. my bb more resembles the mavic 602 than the one in your catalog. notable differences are that both left and right sides use a lock ring (and the lockrings are even different diameters). the right cup doesn't have flats. the shell is not entirely threaded either (although at first look it seems so)
see the attachment for a closer look.
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