WTD: 9 speed (Octalink) Crankset

tonytiger81

Well my chainset decided to destroy itself this weekend so i'm looking to source a 6500 ultegra or 7700 dura ace 9 speed chainset, or 105? 170mm cranks. It's this or buy a new groupset as these things seem to be getting too rare for my liking.

TheDocMan

I've a 6500 9sp Ultegra Octalink 53/39 but it's 172.5 in silver
Or 5500 105 53/39 172.5 in black.
If you check my posts you'll find pictures etc under "Chainsets & freehubs clear out" from about a month ago. Regards.

tonytiger81

Thanks DocMan. I should mention that I'm about 5' 7. Is there a big difference between 170 and 172.5? I've only had 170s on any bike i've ever owned.

TheDocMan

I've used 175 and 172.5 over the years and never noticed any difference.
Technically longer crank gives greater leverage but then needs more effort. Your talking 2-3% either way so.
Of note though is you'd need to lower your saddle hight by 2.5mm if you fitted longer crank.

tonytiger81

Interesting point! But would my knee at the top of the upstroke be more bent if the crank is longer and my seat is lowered? :-S

paul a newman

have an octalink 105 c set, 170 and bb in excellent condition, E40

TheDocMan

tonytiger81 wrote: »

Interesting point! But would my knee at the top of the upstroke be more bent if the crank is longer and my seat is lowered? :-S

Yea it would but I wouldn't like to be trying to measure it. Somewhere between 0.8 and 1 degree depending on your lenght of leg.

tonytiger81

Before I decide, any pics of the 105?

paul a newman

am not the most technical ! can send you a whats app pic later, around 3, if you pm your no

tonytiger81

@ paul_a_newman: those cranks do look pretty fresh. I guess it's better all round if i stick with the crank size i know best rather than mess around with saddle height etc. so i'll go with the 105 cranks. Thank you TheDocMan for your quick reply also.

paul a newman

will root out the BB on sat Tony, and get back to you