Hello, I was hoping I could ask some advice of you. From your posts, it seems you were successful in upgrading your Bridgestone to a triple in the front.
I apologize, but this is going to be rather long. I was looking at these links by the way:
Bridgestone Bicycle Catalogue 1986 Bridgestone 400
Bridgestone Bicycle Catalogue 1985 Bridgestone 500
Sheldon Brown on Square Taper Bottom Brackets ISO vs J.I.S.
I'm going touring over this summer, & I'd like to do the same. So I ride a Bridgestone 500, with an SR CRC-100 crankset. It's tapped & ready for a 3rd chainring, but I don't know the appropriate spacers I should get, nor the bolt size.
I know the 400 model has an SR SXC-T301 crankset, which Bridgestone specifically said could take a 3rd ring, but I'm not sure if the crank would use the same spacers or bolts.
However, I'm mostly worried about the bottom bracket – to get enough room to accommodate the 3rd chainring, I'm not sure if the stock spindle is long enough to project out that far.
I was looking at Sheldon Brown's site on this: Sheldon Brown on Square Taper Bottom Brackets ISO vs J.I.S.
, & SR falls under JIS – I'm wondering if the stock bottom bracket is also JIS, & more importantly if it sticks out far enough. I'm hoping that the stock bottom bracket didn't change between the 400 & 500 models much, if at all.
Have you tried mounting a 7 speed cassette instead of the stock 6 speed? That is, without spreading the frame?
On another note, I am also curious if you were able to keep the front derailleur (I already swapped out the rear derailleur for a longer cage) – from my testing, it seemed that the chain would run into the derailleur if I tried to shift to the granny gear. I can't work around this, lest I run the front derailleur into the chain stay, or nonparallel to the chain rings. Did you just swap out the front derailleur? A friend of mine was convinced I just had it maladjusted.
Also, during the trip, I anticipate something might damage my 27" wheels. Because my riding partner is running 700s, I would like to know if we can share spares – I'm told that the 400 model, at least, can take 700s & the brake calipers can still reach down that far. My brakes are the Bridgestone self centering ones.
In addition, do you have enough room between the tires & the brake assembly to mount fenders?
Thank you very much for bearing with me, as I am still a bit of a novice when it comes to bikes – I appreciate the help, & your time & consideration immensely.