Home Chat General Chat

Compatability and Chainsets and the 70.3

Well after a rather painful experience at the weekend doing the 70.3 course at Wimbleball I have decided to take TriLife's advice and change my dinner plate chainset to a compact.

My first thought is to whip off the Bonty RaceLite that is on there and swap it for an Ultegra or Ultegra SL one but I had a sudden thought - I have seen adverts for Fulcrum and other brands - what are the compatibility issues?? Can you do this with cassettes as well the SRAM 11-28 looks good with those hills at a fraction of the cost of shimano.....

Also is there a big difference in normal Ultegra and SL versions?



Oh and if you are doing the course (and have not had a chance to get there) have a read of my blog for my experience of it!


  • danny_sdanny_s Posts: 235
    I have a million questions about the course if you don't mind...

    Did you decide what you were going to go on for gearing... I was thinking that I'd stick with 53/39 on the front and go 11-27 or 12-28 on the back. I'm not a hugely strong cyclist, but I think that going slightly more power, less 100rpm spins up the hills works better for me on a long ride. My hamstrings seem to bounce back better on the run if they've not been winding it up the hills for 3+ hours. Thoughts?

    My understanding of the difference between Ultegra and SL is just a prettier finish and about 60g over the whole drivetrain. Not worth worrying about unless you've already got everything else ultra-light and don't want to shell out for DA. I'd just worry about a SRAM casette with a Shimano chain... it might not be the smoothest ride and you may have to change your chain as well, but I'm no expert. Ask your LBS who you trust not to try and gouge you.

    Is there any chance you could post your GPS data for the run? I'd love to see the elevation profiles just so I can get an impression about what grades to look forward to.

    Sounds to me like you're pretty ready to race this any day now, just got to wait another 5 weeks before they'll let us!

  • combatdwarfcombatdwarf Posts: 258
    Hi Danny_s

    I would seriously suggest having a look at the data dump on my blog when I put it up later (ran out of time last night!!) I found with a 53/39 and a 16-27 (I was trying something out) that on the steepest hill (hill 2) that my RPM was around 35-40ish and HR was >190 - it is really quite steep and just keeps going.

    There were a lot of us with 53/39 or 54/39 on the training day and those with 50/34 did so much better spinning up the hills (i.e. keeping somewhere near 70-80rpm) - I would really recommend getting a cassette with 25 or 27 outer as the second section is a beast....

    I would also advise having something small on the inner (i.e. a 11 or 12) as on the big descents you end up just freewheeling without it (a 16 is soo not enough)

    On the run route it is very back and forth for the initial bit (I suppose to give the crowd something to watch (i.e. the elites) whilst us mere mortals are still out on the bike!) with a fairly stiff hill in the middle. Underfoot it is grass 20%/road 20%/gravel 30%/track 30% I would guess.

  • combatdwarfcombatdwarf Posts: 258
    As requested I have now added in some GPS data for the route - have a look at my blog below
  • danny_sdanny_s Posts: 235
    Thanks you're a hero! The run doesn't look as bad as the bike, just kind of gradual small rolling hills. The cycling just looks worse and worse...

  • combatdwarfcombatdwarf Posts: 258
    I agree - but that big hill is steeper than it looks from the GPS - if you are a good runner you will find it okay - also practice off road running as there is lots of it!. The bike has a really nice section in the middle though which will give some recovery and the bit after the hills is quite good too - but watch out for the last rise before transition as you come at it off a huge hill (down to the bridge) which gives you a false sense of security
  • combatdwarfcombatdwarf Posts: 258
    So I am still looking for an Answer on this one - are different makes compatible on the chainsets/chainring end???

    thanks Iain
Sign In or Register to comment.