Does the Hollowtech II Ultegra R8000 crankset need to use spacers?

I just converted my bike from Praxis to Shimano (finally I have the whole groupset!). I had to replace the BB and cranks (duh) for this upgrade, I bought both brand new. Neither came with any spacers, I've installed the cranks and there was some rub on the front derailleur and the crank arm, which I've alleviated by turning in the front derailleur limit screw however it's awfully close.

Reading online there seems to be a lot of conflicting advice, this post says I need 3 spacers (2R, 1L), same with this post. Others say this crankset needs no spacers (3rd comment). My old Praxis cranks were wider and did have a single spacer on the drive side so maybe I should add one to the new setup.

But the question then is how many do I add, what size do I buy, where do I buy from. I've found 2 vendors (Amazon, eBay) that sell 2.5mm spacers for 68mm bb (my bb is 68mm), is that right? do they need to be Hollowtech II spacers? will any old one do?

Is the bike safe to ride without the spacers? it's going into the shop in a week to have the threaded brake reservoir screw removed & replaced + new front caliper so I will only be riding it on the trainer this week, should I sack my training off for a week to wait for spacers to arrive and fit before putting any miles on it? I've done a test ride and the bike is riding well, alot smoother than the praxis (probably because those bearings where knackered) and all gears appear to be indexed and performing as i'd expect.

  • What is the make/model of your frame? Commented Jun 12, 2020 at 22:07
  • 2018 Specialized Roubaix Comp, i contacted Specialized and gave them the serial number and the frame accepts a 68mm BSA English threaded BB. I went with the Shimano SM-BBR60
    – Axemasta
    Commented Jun 12, 2020 at 22:09
  • Do you mean the inside of the drive side crank is close to the derailleur, like in this question... bicycles.stackexchange.com/questions/66941/… ?
    – Swifty
    Commented Jul 13, 2020 at 18:10
  • Yes it was doing just that, I replaced the gear cable and took my time aligning the mech which i'd never noticed was not running parallel to the chainrings. Many happy hours of riding have passed! :)
    – Axemasta
    Commented Jul 13, 2020 at 20:16

1 Answer 1


Shimano hollowtech comes in various sizes. The links you posted was for a mountain bike. Mountain bike crank spindles are for 73mm frames, so they need spaces for 68mm frames.

Shimano road crank spindles are for 68mm frames. A BSA (normal British threaded) bottom bracket, doesn't need any spacers, you just thread the cups on and then put the cranks in.

I suggest you watch a tutorial on how to put on a bb and crankset and make sure you follow the manufacturers torque and grease recommendations. When in doubt, get a local bike shop to fit it or take in some food and drink for them and ask them to have a quick look so double check your work.

Also, Shimano have excellent online document on which have all of this information and more. I think your BB and crank should have come with instructions on all of this, unless they've stopped physically including.

  • Ok thanks for the info, the frame is a BSA threaded 68mm, confirmed by manufacturer & obviously the fact I fitted a 68mm bb. I watched plenty of tutorials and read documentation beforehand and saw no spacers on the road bikes. Everything was torqued to manufacturers specs, and I used plenty of grease. I'm just a little concerned the cranks are too close to the front deraileur, can I add a spacer? I'm hoping that won't have a negative effect. If I have that option it would be fab. Since the bikes in the shop soon I will get them to once it over but I'm confident in my work :)
    – Axemasta
    Commented Jun 12, 2020 at 21:43
  • Do not add a spacer. You have to re calibrate the front mech if you have changed cranksets. Have you done that since changing from the Praxis cranks?
    – abdnChap
    Commented Jun 12, 2020 at 21:52
  • I only adjusted the outer limit, pulling it back in. The gear shifts well and felt great on the stand and on the bike so I havent really touched it
    – Axemasta
    Commented Jun 12, 2020 at 22:03
  • 1
    My roadie is a Trek w/ a 68mm BB shell. I upgraded to Ultegra this year (R6800 for the crank and front der. BB is BBR60. No spacers required for a road crank in a 68mm shell. There is very little clearance between R. crankarm and the front der, but shifting is good and I'm trimming where I would expect. Suggest doing your front derailleur set up from scratch, paying particular attention to parallelism FD outer plate to outside plane of large chainring adjusted w LOW limit screw initially.
    – Jeff
    Commented Jul 14, 2020 at 18:40

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