Very tiny clearance between crank spider and chainstay.

Cinelli Mash Parallax with Sugino DD75.
The clearance between chainstay and crank spider is awfully too close, it's less than 1mm, should I worry?

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hashtag aero

way too aero though

if thats the chainring bolts, i'd just give them a quick filing just to give you more clearance.

@user71349 yeah, that's the chainring bolt boss. Even if I file all of them, clearance will still be around 1mm, which is awfully too small.

I found a thread about the same issue on the fixedgear subreddit: https://www.reddit.com/r/FixedGearBicycle/comments/4ck3h9/crank_arm_spider_and_chainstay_clearance_should_i/?ref=share&ref_source=link

Spacer behind the RH end of the cassette (cup if old-school) and bb shell

@HarmanMogul from what I understand, spacers are not recommended. In fact, the only spacer that comes with the cranks is a tiny one for the LH to avoid the crank arm rubbing against the BB (that also comes with a warning «use only if strictly necessary»)

another picture where it looks even more dramatic

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Yeah that's going to fuck the chainstay. Can you space the BB?

@Sumo is that a good thing to do though? What spacers would I need? See my comment above about the spacers that come with the crankset.

The risk is it that by using spacers you won't have enough threads engaged and the cranks get damaged/fall off.
Your options are:

• Space the drive out out slightly (not recommended)
  
• Crimp the chainstay (not recommended)
  
• Get different cranks, maybe ones that have a square taper bb (expensive).
  

Thanks @Sumo. I wonder if anyone from the forum has had the same experience with the Mash Parallax and ended up fitting. I am ok with buy different cranks, but I can't try all possible combinations until one fits well :/
I was wondering how large in terms of clearane is the Dura Ace 7710.

I had this issue with the v1 mash works, with Sugino DDs, ended up using square taper bb as per @Sumo

@HousecatHST on my v1 mash work, the chainring was hitting on the chainstay as well with the omnium, ended up going square taper myself. What crankset did you use?

Option 1:You can use a spacer on the Drive side BB cup but you would have to face off the same amount of the BB shell on the non-drive side to maintain correct bearing pre-load.

Option 2: Dent the chainstay

Option 3: Get a square taper BB/Crankset

If the frame is old, just ding the chainstay. Or get someone else to do it if you're squeamish! Not on a new frame however.

It's a new frame :/
About option 3, will Sugino 75 (not DD) work? Anyone willing to swap? :D I am half-serious.
I see that that square taper BB that comes with Sug 75 is 109mm long. How do I know that's going to be enough? Will that be compatible with, say, Shimano BB-UN that are longer, like 113?

Cheers!

You keep asking about crankset, but any crankset that uses a square taper BB can be made to work, as square taper BBs have different axle widths.

You could swap your sugino 75 DDs for normal 75s that run a square taper, then make sure the BB you buy is wide enough.

EDIT - Seen your response. You can use any width BB. Thats why everyone is recommending them :/

indeed :/ just a minute ago I asked if anyone is willing to swap :))

The back of the crank bolt is meant to settle inside. That's why they are knurled. You gotta tighten them.

Duke, you're a legend. I mean, I knew that already, but now.. a superlegend. I owe you a couple of pints.

Thanks everyone, drama is over, Duke is a superlegend, life is good again.

I ended with some campag record pista, the clearance is still tight, but never had any problems.

New clearance after stuffing those bosses into the crank (@ekudduke's comment).
Much better, right?

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