Di2 / Trek BB & Crank questions

vdu7x
vdu7x Posts: 48
edited December 2011 in Workshop
Posted on the tri bike forum but no answers so hope it's ok to post here.

I've recently bought a Trek Speed Concept 7.8 which comes with Sram Force Cranks. (53/39)
http://www.trekbikes.com/us/en/bikes/ro ... oncept_7_8

I did the 70.3 Ironman UK this year and was glad I had a triple on my Madone. I'm hoping to have a go at IM wales but that's pretty lumpy too and I know there is no way on God's earth that I'll manage on a 53/39 crank.

(Before anybody flames me, I know it's a much higher end bike than my fat tubby ars* deserves but OMG it's so pretty!)

I'm also thinking of possibly upgrading to Ultegra DI2 when the TT kit comes out.

So my options seem to be to change the Sram Force crank to the compact version of the same or to change to an Ultegra crank in anticipation of a future upgrade to ultegra Di2.

Questions:
If I decide to go for a Sram compact crank, do I need the BB30 version or the GXP version?
If I change to an Ultegra crank, do I have to change the BB?
Is it daft to try to add upgrade to Ultegra Di2 TT when it comes out with a Sram crank?

Trek say this the bike is BB86.5 - What spec BB would I need if I had to change it for Ultegra?
Very confusing but I think that BB30 means ID of 30mm and BB86.5 means BB width of 86.5!?

Comments

  • moonshine
    moonshine Posts: 1,022
    I understood that there are no plans to launch Ui2 TT kit.... TT setup was being limited to Di2.
    correct me if i am wrong
  • vdu7x
    vdu7x Posts: 48
    Lots of web pages suggesting it's in the pipeline.

    >>Like Dura-Ace, Ultegra will also be getting an optional satellite shifter for TT and triathlon riders.

    http://www.bikeradar.com/gear/category/ ... -11-45107/
  • moonshine
    moonshine Posts: 1,022
    ok, cool... wait & see.. i think i recall my info coming from an article in the Comic a while back which was an interview with Shimano which said it was n't going to triclke down in TT - perhaps it was a cost vs niche area. I don't know.

    It isn't of any real consequence to me tho as my Ridley Dean is fully internal cabled anyway and i've emailed Ridley ro see if i can run Di2 and there answer is no as they can't get the Dean to work properly with it. I think i would beed to drill my frame to make it fit and i'm not overly keen on that.
  • moonshine
    moonshine Posts: 1,022
    this post seems to confirm no immediate plans for Ui2 TT shifters
    http://www.timetriallingforum.co.uk/ind ... opic=63975 - not yet anyway
    "have just spoken to the Shimano Rep and he has confirmed that there will not be an Ultegra TT set up, there is a launch of some new Ultegra products at the end of Feb at a trade show, but this will not filter to us until Summer next year, Ultegra TT Di2 might be included, he doesnt know yet.

    But there will be a Dura Ace wireless TT set up some time next year but will no doubt be pricey"