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4

Welcome to BB standards hell...... you are about to learn far more than you wanted to about bicycle gearing cranks and chain rings.....The only spec I could find on these was the 1999 model, which used a Shimano BB-UN52, 113mm spindle BB Shell Width 73mm - its pretty common and typical of that era MTB. Your idea of another crank set is a possible ...


0

I'd like to swap the crankset out - it's a Shimano Sora 30/42/52T (FC3303). For example, I have seen a Shimano Ultegra with the same 30/42/52T (FC6503) on Craigslist. Are there any specific details I need to be aware of matching up? The main detail you will have to watch out for (as indicated by Kibbee) is whether the two cranks use the same ...


2

Based on your photos, take the other crank arm off, pull the whole bottom axle unit out attached to the welded side. and fit a new cartridge bottom bracket. Cost is not small but its not huge either - certainly cheaper than cranks. Cup and cone bottom brackets are old tech, and cartridges are far superior. If you're lucky, you can now work on unmounting ...


3

This frame either uses a BB386 Evo "standard" or a Pressfit 30 "standard". You can determine which by measuring the width of the frame at the BB shell. If 86.5mm it is BB386Evo. If 68mm it is Pressfit 30. If it is a Pressfit 30(68mm shell) this BB is a direct fit for the Shimano crank without extra spacers. this is the PF30 version of the BB30 bottom ...


7

The core problem is that you need the thread on the bottom bracket axle to attach the new crank, and that will have probably been damaged by your welding. If you can get the bolt out after unwelding, it might be possible to keep the current BB. If your BB is this style, you might be able to cut the crank off, leaving enough of the bolt to weld on a small ...


1

From what I can see the various "MegaExo" BB labels refer to the spindle size and crank fixing, rather than the size of the shell in your frame. There will be subtleties with frame clearance, but that's something for Giant rather than the BB or crankset people. From that website I got this screenshot: You will need a HollowTech II BB, or some that's ...


2

A loose crank arm can damage both the bottom bracket and the crank arms. In your case, since you've run the crank arm til it fell off the bike, it is likely you ruined the bottom bracket. If your crank arm is loose, immediately stop and tighten it. You will need to likely get a new bottom bracket and possibly yet another new crank arm. Replacing a bottom ...


19

I haven't seen one of those before, but it looks as though it could stop the chain dropping between the bottom bracket shell (the bike frame) and the crankset if you ever drop the chain off the inside of the small ring. When that happens it can be tricky to get it back out, and if the chain is oily you end up with that oil everywhere (mostly on your hands ...


-2

If its 3-4.5mm thick then looks like a spacer ring - this is adjacent to the biggest cog, so when fitting a 7 speed cassette to an 8 speed freehub the spare space is taken up. Normally they're made of aluminium, but plastic would be fine too. There are no large stresses on this part. If you don't need it then remove it. The bit to watch is that the lock ...


0

The FC6603 seems to use a standard 130 mm BCD 52t chainring for the outer ring, unlike the special ones used on some other Ultegra/Dura-ace cranksets. You can buy such rings from most major brands. Look for ones marked 10 speed or 11 speed.


1

The only measurement for a bottom bracket you can do with the bottom bracket still on the bike is to do the shell width, which is the width of the frame where the bottom bracket installs. In order to measure the spindle length, you need to remove the cranks and then measure the spindle length. There is no guarantee that the spindle is symmetric or the width ...


1

I would say on this bike you can install any cheapest aluminum crankset, cheapest front derailleur and a friction (non indexed) shifter, where the crankset will be the most costly part (about 30$) and a few dollars for derailleur and shifter (each). So if you able to do the work byself you will end under 50$ for all that upgrade (but those should be done ...


3

First, regarding the crank's bottom bracket recommendation: The crank uses a square taper bottom bracket spindle, and would not be compatible with the Shimano Hollowtech II BB that may be currently in the bike. You could swap out to a BB-UN50 or BB-UN70 from Shimano in a 68x115mm size, to fix the crank/BB compatibility issue if that is the case. That ...



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