Dura-Ace 7700 Bottom Bracket

The Octalink one:

It is meant to be a sealed cartridge assembly- but mine seems to be clicking heavily after one trip through the rain on Tuesday.

Admittedly it was really coming down on Tuesday afternoon, but I have ridden through similar downpours without killing a bottom bracket in one go.

Should I be looking at the BB as the culprit here, and if so is there anything that I can do other than to change it for a new one?

If I do change it for a new one is there any way of beefing up the seals?

water wouldn't make it click, I shouldn't think...

sounds like it needs a clean and regrease, and re-assembly. unlikely that you should be ditching the whole BB! the bearings are needle rollers, not cartridge.
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/BB/EV-BB-7700-1657B_v1_m56577569830610606.pdf

On my road/rollers fixed I use the 105 octalink BB, much cheapness and has sealed cartridge bearings. Nowhere near as smooth or free-running as the DA, but it hardly matters on the road.

Clean and regrease I can do- good news!

I have the bog standard available in every Evans Lithium grease, however the grease in the BB looked a lot lighter than that- what would you recommend Rob?

yeah, it is a light grease..not sure what's available
http://www.sjscycles.co.uk/product.asp?pf_id=16935&src=froogle ?

sounds like people knacker the bearings when fitting these BBs too tightly, which isn't surprising. Mine has only been wet once (unavoidable when doing my L2 track course at welwyn in the pissing rain) and I cleaned around the seals later but didn't take it apart, it's been fine and will get a service this winter.

The dura ace grease is great stuff, can be pickup up at the HH jumble or various other places. Great for BB's and Wheels.

http://www.totalcycling.com/index.php/product/parts_accessories/lubricants/dura_ace_gease.html

sounds like people knacker the bearings when fitting these BBs too tightly, which isn't surprising.

Ah.

I was not sure how tight to do mine up- seems to be (in the absence of knowing a torque setting etc) a case of doing it up until the axle will not rock, then a tiny bit more for luck. I was so unsure I actually took it downstairs for the CyclesUk mechanic to have a look at- he pronounced it fine, but it def sounds like knacked bearings to me.

How do you know how tight to do these up so I don't knacker the next one?

As mentioned, this is not a cartridge type BB-set.
Don't let it fall, because the tiny balls and needles will be all over the place.
The BB is a real nightmare.
When you can afford it, replace it by a 105 or, even better, Ultegra one (very hard to get, out of production, lighter than 105).

Dura Ace grease: yeah, right great stuff. But preferably the grease they carried in the early 1990's. I think that was one of the best types of bike grease ever. Meanwhile, Shimano has another type of grease.
If you still want the original, look for this: Autol Top 2000. This is what Shimano used for their green Dura Ace grease.

I was not sure how tight to do mine up- seems to be (in the absence of knowing a torque setting etc) a case of doing it up until the axle will not rock, then a tiny bit more for luck.

NOOOOO!

do it up till it gets tight, then back off 1/8 of a turn, it should be as loose as possible without rocking.

read the destructions:
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_1TG0H_001/SI_1TG0H_001_En_v1_m56577569830646804.pdf

Dutch Cheese- I had thought it to be a cartridge?

Shimano Dura Ace 7700 Bottom Bracket
Precision engineered Dura-Ace 7700 Bottom bracket for road Octalink splined system
22 mm diameter chrome-moly hollow pipe billet axle reduces weight
Splined interface provides a more rigid crank assembly compared to tapered counterparts
Compound bearing structure - ball and needle bearings support the spindle to reduce flex
**Maintenance-free sealed cartridge design prevents corrosion and is easy to install
**Average weight 173 grams

68mm / 109.5mm
English Thread

NOOOOO!

do it up till it gets tight, then back off 1/8 of a turn, it should be as loose as possible without rocking.

read the destructions:
http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_1TG0H_001/SI_1TG0H_001_En_v1_m56577569830646804.pdf

Sounds like the problem was not rain, simply my overdose of Fail on the RTFM front.

Bugger.

Neil,
http://www.wiggle.co.uk/p/cycle/7/Shimano_105_5500_Octalink_Bottom_Bracket/4000000771/

might save a lot of hassle, depending on how you price your time. fit and forget.

Thanks Rob- shame that I seem to have wrecked a £60 bottom bracket by being an idiot.

At least I now have something mechanical to blame for my piss poor performance at the track.

keep it and order new bearings?

I feel a visit to Brixton Cycles coming on.

I hear that they keep an atavistic ginger coloured man lurking in a greasy pit there who can commune with bicycles and their component parts.

7710 (the NJS variant) is sealed 7700 is not

http://businesscycles.com/tbb-shim.htm

And at $87.50 not bad value either.

Why would a track version be sealed and a road version not?!

the track one isn't "sealed" but it does have seals. not sure about the NJS one, pretty sure mine isn't one of those but haven't checked. NJS bikes are used outside, in all weathers...

Fair point, I had thought that would apply to road bikes also.

I'll see if I can service/get it serviced, and if not the 105 seems sensible as it is cheap as chips.

And at $87.50 not bad value either.

Why would a track version be sealed and a road version not?!

Shmn's intension was to make a very lightweight and stiff BB-set.
The cartridge type is havier. Don't know about the stiffness, but for sure the durability is lots better. Probably the drag/friction is a lot lower, too.

Anyway, Octalink is a general design failure.
Better go back to square taper.

Anyway, Octalink is a general design failure.
Better go back to square taper.

I completely disagree with this!

I'm not throwing my 7710 cranks in the bin so the whole Octalink/Square taper argument is rather invalid.

I still think that the engineering principles behind Octalink/ISIS etc as a step on from square taper are sound ones.

Sell your DA's to me, I have a some lovely sugino 75s to PX :-)

I completely disagree with this!

how so? proprietary. and not tapered.

how so? proprietary. and not tapered.

Because it offers better performance. It allows for a stiffer, lighter BB. The DA 7710 is the benchmark track crank.

Guy do you think we will see the BB30 standard being adopted by track frames/kit makers?