Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Classic & Vintage (https://www.bikeforums.net/classic-vintage/)
-   -   This crank is too close, right? (https://www.bikeforums.net/classic-vintage/1318930-crank-too-close-right.html)

vwguy 02-25-26 05:49 PM

This crank is too close, right?
 
This is the '98 Trek 8500 I picked up last week, it has full XT except for the crank which he replaced with a 52/42/30 FSA Tempo, doh!

There is about only 3 mm of clearance from the chain ring and the crank arm to the chain stay, that is too close, correct?

https://cimg9.ibsrv.net/gimg/bikefor...93011b62a3.jpg

bulgie 02-25-26 06:07 PM

No, that's probably fine. You could try riding it and stop if it contacts, unless the paint is too precious to risk it?
Most BB spindle/bearing units allow you to space it over to the right a little with a spacer under the fixed cup, if you feel it necesary. Theoretically could make t hit on the left though.

Aubergine 02-25-26 06:36 PM

I have a couple bikes that have 1.5-2 mm spacing between the crank and stay. As long as it's put together square and tight, you'll be ok.

Reynolds 02-25-26 06:40 PM

Looks OK to me.

ascherer 02-25-26 07:13 PM

Does it work? If so, go ride.

P!N20 02-25-26 07:14 PM

Tire needs a shave

stemwinder 02-25-26 08:32 PM


Originally Posted by P!N20 (Post 23702433)
Tire needs a shave

I think that's their "winter coat".

Never really considered the crank/chainstay gap, just for the halibut went and checked all mine (which are original as far as I know) and the gaps are at least 3x to what the OP is showing. I can't imagine anything could ever get caught in that gap, so it's not a safety issue either.

rando_couche 02-25-26 09:14 PM

Ride it as is, and if it starts hitting the stay, put a 1.0 or 1.5 mm spacer under the fixed cup.

SP
Newport OR

randyjawa 02-26-26 03:40 AM

Works for me. No worries there.

nlerner 02-26-26 06:26 AM

Low Q ftw!

oneclick 02-26-26 08:22 AM

No foul, no harm.

neil0502 02-26-26 08:24 AM


Originally Posted by rando_couche (Post 23702496)
Ride it as is, and if it starts hitting the stay, put a 1.0 or 1.5 mm spacer under the fixed cup.

Am I thinking about this wrong? Wouldn't you actually need a longer spindle?

ETA: In thinking about it, I understand why this would work. My gut tells me I'd probably go the spindle route first, if I could.

ETA2: Just noticed bulgie s post above. I guess this is, in part, where my head is at on this one.

obrentharris 02-26-26 11:48 AM

My only caution is about the distance between the chainrings and the stay if you are going to be riding this in the mud. It appears from the photo that any chain suck could easily lift the chain into rather brutal contact with the stay.
Brent

dddd 02-26-26 04:51 PM

A spot of clear tape should highlight any near-contact with the arm before it ever interferes with the paint itself.

I had this issue on the non-drive side of my Raleigh Team 753 Technium after I installed early-70's Stronglight cranks on a Mavic bottom bracket.
The left arm has less metal surrounding the taper, so is more-easily torqued to where the arm moves inward towards the chainstay.
I re-installed the arm using a bit less bolt torque and with Loctite on the threads, so I have about 2mm now after also shaving a bit of metal from the pedal eye.


All times are GMT -6. The time now is 10:31 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.