Pradd

Hi there guys,

I have been trying to install today my new Sugino 75DD crankset on my Cinelli Tipo Pista and it seems it has not enough clearance, the chainring bolt touches the chainstay.
The crankset came with no spacer. What should I do? Should I get some BB spacers? Would it change the 42mm chainline?? I apologize for the noobie question. I am an avid rider but a shifty mechanic.

Thanks!

Scrodzilla

In my experience, the Tipo Pista has clearance issues with a lot of cranksets.

Adding a cup spacer to the drive side will increase the chainline by the thickness of the spacer but a couple of mm is really nothing to worry about. You don't NEED a 42mm chainline.

Pradd

Hey thanks so much for your answer. What size of a spacer do you recommend me to use? A friend of mine told me there should be 3mm of distancing between the crank and the chainstay, due to torsion when pedalling... should I use a 3mm spacer?

Scrodzilla

One of my bikes has about 2mm between the crank arm and chainstay. I've never had a problem.

BB spacers are cheap. Pick up a 2mm and a couple of 1mm so you can experiment.

Pradd

Thanks mate. I really appreciate your help.

Scrodzilla

REDMASTA

since the tipo is steel you can also dimple the chainstay a bit. had this done to my sword to clear bigger tires and also for more clearance of my omnium cranks.

i imagine the extra clearance you need is very little, id just wrap some painters tape around chainstay and carefully work that small area with a ball peen hammer till the spider clears. id personally rather do this than run spacers.

Scrodzilla

Bad advice. The Tipo Pista is aluminum.

Unlike Omniums, using spacers on a Sugino Direct Drive crankset is 100% acceptable.

REDMASTA

my bad, i was thinking of the tutto for some reason. scrod is right, don’t hammer away on your aluminum frame.

Pradd

Just wondering, why is it not acceptable to use spacers one Omnium? Just yesterday a friend sent me a picture of his Leader with spacers on Omnium.

Scrodzilla

It's amazing how many people do this without actually thinking about the simple physics of it and end up with ruined bottom brackets and/or crank arms. No spacers on Omniums, ever.

Because the non drive side crank arm on a GXP crankset installs using just one bolt instead of a pre-load/pinch bolt system, it needs to bottom out on the the shoulder of the axle to seat properly. Using a spacer to increase clearance basically "shortens" the spindle protruding through the non drive side and doesn't allow the arm to be installed to the correct torque without crushing the bearings. Either that, or you're riding around with a loose non drive side arm.

Pradd

I see, my friend has been riding for years like that, I wonder how the bearings survived.
Another question, what kind of spacers should I use? Crank spacers or hollowtech spacers? I have noticed that Sugino sell crank spacers to surpass the clearance. In fact, my crankset came with two plastic 0,5mm crank adjust spacers with a note to use them in the left crank if there is play or the crankset touches the metal part of the BB. I have tried to used them both on the right crank, which helps with the clearance, but them the left crank has a metal sounds. I think it touches the metal external cup, I am not sure.

Scrodzilla

Getting a stock Sram GXP bottom bracket to last years is a magic trick in itself.

Personally, I would use bottom bracket spacers between the drive side cup and the frame.

boom

As an anecdote - I have a 1mm spacer on the drive side of a SG75 DD2 BB that measures out to be a 43mm chainline, which seems to be required in order to produce a Q factor that is symmetric around the centerline of the bike, but my hub dimensions and cog thickness also produce a measured 43mm chainline in the rear (with no spacers) so all is well I guess.

veganbikes

On my Langster with the DD crankset I haven't even measured and don't really care. The crank fit on with my Wheels MFG BB and spins smoothly and that is all I care. I used a chainline gauge once in my life and that was on a really poorly made geared Dutch bike where the chain was on the BB in the middle cogs because it was so poorly aligned. I don't even know if Park Tool makes one still but I haven't seen one for sale luckily one of the guys at the shop is a tool collector and has that old thing.

Scrodzilla

I honestly can't even remember the last time I measured the chainline on one of my own bikes. People who stress out about that **** are hilarious.

Pradd

Hei, I informed my fried about this and he brought the Leader 725 to my place to do some service to the BB. He had one 2’5mm spacer on the right side of the BB and two 2’5mm spacer on the left side. We removed and clean and everything and just left the right side spacer due to clearance with the chainstay. Nevertheless, I tried to tight the self extracting bolt the more I could, but the cranks had a lot of play. At the end, to solve the play, I had to put another 2’5mm spacer on the left sidE. Could you help me figure out why has this happened?

Pradd

Well, I am recently getting into mechanics and I have read a lot of information regarding the chainline. So I am not necessarily stressed but I want to do a good job and leave my bike as perfect as I can. In the end I have ordered 3 0,7mm Shimano spacers. I will try to play with them to see if I can solve the chainstay clearance issue with just 0,7 or 1,4mm extra chainline.
I promise not to stressed a lot about it, tho 😄

Scrodzilla

Yup, you crushed the bearings. I'm surprised they still spin.

Also, GXP bottom brackets don't need any "service". Leave the damn thing alone before you break it more.