Dura Ace 7/ 8 Speed Cranks

[rusty bodie]

does anyone know if you can fit dura ace 8 speed cranks on to the traditional 7400 bb axle? was the 8 speed bb a cartridge type?

thanks!

 

[stringfellow1946]

7400 groupset is 7 or 8 speed as I have 7 & 8speed D/tube shifters & 8 speed STI levers. So a 7400 BB 112mm will fit those cranks.
Basically Shimano just kept updating parts of the 7400 series groupset, i.e. Dual pivot brakes, Brake levers with return springs, etc also there are 2 different front Gears depending weather you use 8 Speed STI Levers or 7 speed D/T shifters.
The 7410 cranks came with a cartridge BB 103mm also Shimano updated the following parts as well. 7410 cartridge bearing headset, 7410 SPD Pedals, The 7410 long round seat post etc etc.
Hope that helps

The next major Dura Ace update was the all brand new DA7700 9 speed groupset
Chris

 

[rusty bodie]

Re:

i can't thank you enough for that information!! my memory isn't as good as it once was but it all came flooding back with your reply!


many thanks!

 

[latman]

7402 and 7410 were both DA 8 speed cranks but only 7402 fitted the traditional style axle (there is a cartridge BB for it now too)

 

[rusty bodie]

Re:

i have never owned a "top end" cartridge bb unit, only the cheaper ones and they all seem to dry up within a short period of time. traditional bb units ie cups and axle type generally run forever if maintained properly - is this the case with the high end sealed type or are they just as bad as the cheaper one's for "drying" up?

 

[bm0p700f]

The 7410 8 speed cranks use a 103mm axle. The BB for this is 180g! Also the 7410 cranks are 586g. That what I have gone for a bit lighter than the 7402 axle and BB.

I have never had a cheap square taper BB dry up they just go on and on. The UN91 is light and will last for a very long time so will the BB-7410. Tange Seiki LN-7922 BB with the alloy cups, hollow axles weighing 240g and costing about £25 is a very good modern alternative.