Jufimbo

Howdy. I'm spinning out down here in Flat NOLA on the 42:17 (freewheel) stock drivetrain. I've bought a 46 chainring, but am concerned about chainline. Has anybody else upped the chainring on their san jose and had problems with this? I would like to put the new ring on the outside but I'm pretty sure I'd need a slightly shorter spindle.

Live2Die

San Jose... Yesterday's news, Red wings for the cup!

thequickfix

If you put the new chainring in the same place, it will not change the chainline. If there is not enough chainstay clearance and you have to put the chainring on the outside of the spider, then you will be moving the chain out ~5mm, and you would want to get a shorter BB spindle.

roadfix

Sure you can try to bring in the cranks closer by using a shorter spindle. Problem with that is sometimes the crank arms will not clear the chain stays......but that all depends on the crankset and the frame itself (especially frames that take wide tires).

Jufimbo

yeah, I removed the bashguard and want to put the new ring on the outside. I haven't pulled my cranks yet to see if my BB is symmetrical (I've heard that the stock sugino bb isn't) and was hoping to save myself some time, see if anybody else had performed the same operation on a San Jose.

timdoug

Just curious, but I don't understand the problem. Why can't you just change the chain ring, I don't see why that would cause any problems.

Jufimbo

There won't be. You're right, that's what I will do. The functionality of the thing comes first, obviously. I just want to know what I would have to deal with to put the new ring on the outside of the spider. If it is a simple matter of a $30 bb with a shorter spindle, then I'll start shopping around. Otherwise, I'm not going to cry about the ring being on the inside.

mattface 

It's a simple matter of a $30 bb with a shorter spindle. Assuming of course you can GET one with a shorter spindle. If your current bb happens to be a 103mm spindle you're pretty much screwed, because that's as short as they come.

neverjared

Jeez, you guys are being so helpful! What is this? The Roadie Forum?

Jufimbo

Heh heh.

Aeroplane

The questions are about one of the few "bfssfg-approved" complete bikes, not a crappy conversion.

tinydr

Good luck jufimbo... I hope the alignment isn't too far off... your legs must be on the verge of catching on fire trying to spin that gearing in the Crescent city (while not going anywhere very quickly).

One probably ignorant question... could you not go with a smaller cogged freewheel?

Harris seems to have a 15 tooth that might work. Admittedly you may still be spinning out a bit, but at least it would be an improvement.

Jufimbo

I reckon I could...what would that do for me? Haven't done all my homework yet.

tinydr

well... it would give you more gear-inches, albeit less than the 47 tooth chainring... but it would mean you could stick with the 42 and not have to worry about chainline.

Jufimbo

Right. Well I've already purchased the 46 toother, so I'll deal with it one way or the other. If it has to stay on the backside of the spider, so be it. But it sounds like that would have been a viable option. I've been itching to replace the stock chainring anyway as part of a general de-blacking effort. There is a lot of black componentry on a stock San Jose, IMO.

tinydr

fair enough, I hope it works out ok...

honestly you may or may not find you'll want to change the freewheel as well... I run 47 x 16 fixed and its pretty easy to spin out.

Jufimbo

No kidding. Alright, will keep that in mind. Thanks for the tips!

Jufimbo

Ok, so I put the 46 teeth on my cranks and got a sparkling new sram chain. And now my chainline is certainly off. I couldn't put the new chainring on the inside where the old one was, as it scraped the stay. So...my today's question is this: Does anybody know the stock bottom bracket size on the san jose? I don't have a crank puller and it isn't listed on the Bianchi site. Any chance at all its 107?

Jufimbo

Ok, for anyone else searching for it, the stock bottom bracket on a 2008 Bianchi San Jose is...68 x 110.5. Pain in the *****. Mine was a tange. not sure if yours will be. I ordered a Sugino 103 from the Ebay and I hope that will help my effed chainline. I know that Shimano and Tange are basically the same thing, but can anybody tell me anything about the Sugino cartridge bb? Was it worth the extry $5 to get the name?

dmg

Yeah, you shoulda got a (much cheaper) Dura-ace 15 tooth cog, left the ring alone and increased your gear inches on the cheap. Oh well. In my experience all name-brand sealed BBs are good.

{edit}... oh, wait, freewheel. Eh, you could only go down to a 16t, and then you'd be SOL when that was too small. I guess overall you're better off - bashguards are lame.

chrism32205

get a new rear wheel or buy a pista if you want something faster

bbattle

I went the other way and put a 15T cog on the back. Cheaper and quicker.

Jufimbo

Right. I thought about getting a 15t from Harris for the back (after it was suggested here) but I'm crossing my fingers that this 103 will bring the chain in to 'well-enough.' Say, with all this talk about cogs, I have been wondering about the mechanics of increasing gear inches with a chainring vs. cog. Are there any performance differences? More pressure on different parts of the leg? Thx for all the advice BTW.

somepetalhead

same thing in 2020... the bottom bracket and cranks that wont hit the stays but remain in the 42mm chainline is a major pain in the ass!