|mavic sealed bottom bracket questions?||naff geezer|
Jan 28, 2002 7:37 AM
|pimping an old frame and have taken it off and it seems to spin smooth but i figure i should service it before replacement.
a) what's inside - cartridge bearings?
b) what taper cranks would it fit? it had dura-ace 7400 series cranks - can i use a set of 7402's?
c) came off easy - any special instructions to replace it?
d) why did its popularity wane? it looks to be a cool little unit which is suited for many purposes.
d) as it is on a italian frame but with a french sounding name (montagner- pasarella) and the fact that the headset (shimano 105) is impossible to tighten/adjust (by me or my lbs - appears fine) properly can i assume that maybe my italian frame is french threaded? if so any ideas for a good/cheap fix for a headset?
ideas or input appreciated
|re: mavic sealed bottom bracket questions?||TJeanloz|
Jan 28, 2002 8:04 AM
|1. Cartridge bearings inside the BB, not much (anything) you can do for them.
2. If a Shimano crank came off, a Shimano crank can go back on.
3. Put it back in just like you took it out.
4. Mavic got out of the groupset market after the ZAP fiasco and MTN bike parts fiasco, and has yet to really jump back in. They stopped making headsets and bottom brackets along with the rest of the groups so they could focus on hubs and wheels.
5. I think it's very unlikely that you have a french threaded frame. If it's new enough to have a 105 headset, it isn't likely french. It was probably an italian thread that was milled specially for the Mavic BB (this was a fairly standard operation for bike shops to do).
|Mavic Bottom Brackets||Nessism|
Jan 28, 2002 8:16 AM
|I'm not sure if Mavic made different models but their most common bottom brackets used chamfered lock rings to hold the bottom bracket into the frame. The bottom bracket shell on the frame needed to be cut with a special chamfer cutting tool before the cartidge could be installed. These were great for doing frame repairs where the bottom bracket shell threads were damaged. Just cut the chamfer on the frame and slam in the catridge unit. Due to the way the unit is held into the frame, a very high torque is required to get the lock rings tight enough. As I recall, a special tool may be needed since a common spanner may not be strong enough.|
|re: mavic sealed bottom bracket questions?||paul3d|
Jan 28, 2002 12:15 PM
|First off how did you take it off? Did you unscrew the brown chamfered rings? or did you simply take a spanner to cap and unscrew. Once you remove the cap, just take a rubber mallet and tap the axle out. This will bring out a set off sealed bearings. To take the other bearing out remove the cap and take a "drift" and reach in and tap out.
Its not that hard. The only problem is when you put them back in you will need a special tool to tap the sealed bearings back in. I think a large socket that just fits inside the shell and kisses off the outer rim of the bearing unit should work ok.
If you did remove the lock rings, they will need to be installed tight since they compress against the frame. There is a special tool that fit in the notches. Two should be used. Keep in mind that this will effect your chain line.
Hope I haven't scared you.
|no, enlightened me actually||naff geezer|
Jan 28, 2002 1:14 PM
|borrowed the tool from the lbs to take the chamfered fixing rings off. as i had no idea what was in there i was surprised to see the mavic item and thought how nifty and well made it appeared.
the sealed bearings part should be straightfroward to replace and fit. might get my lbs to tighten it in the frame as i want to get it torqued down right. mine has two little nodes similar to what a few older freewheels have where two prongs on a spanner look to fit in to unscrew the ends. but ill see what a little tapping brings. my chainline was/is pretty good.
i cant wait to open it up. i never thought a bottom bracket could draw as much interest in me as this one did. (maybe i need a life, huh?)
thanks to you and the others that have responded. oh, by the way even tho the lbs had the tool they still didn't know what to do with it and what sort of bottom bracket it was. that's funny.
|no, enlightened me actually||paul3d|
Jan 28, 2002 1:40 PM
|Just remember that when you tighten the lockrings you have your chainline set. If you screw too much on one side it will move the entire unit to that side, therefor move your chainline. Also, Those holes are for the spanner. Unscrew them and tap the axle out to get to the sealed bearings.
I just removed my Mavic bottom bracket from my frame. The threads of the frame are all rusted up and will need to be retapped to handle a Campy Chorus bb. the bottom bracket was still in great shape. Smooth..
|no, enlightened me actually||jordan|
Feb 2, 2002 2:52 PM
|Paul-If that Mavic BB is for sale I am interested in buying it.Thanks for any reply.|| |