ak08820

I have a what appears to be a dark green colored 1993 Bridgestone MB-4. It is missing the crankset.
According to BikePedia the original one was Crankset Sugino TGP, 24/36/46 teeth.
What would be a good inexpensive replacement for this?

Thanks in advance.

Bill Kapaun

24/36/46 is a bit of an odd bird-

Since you don't have the original crank, you can't check to see if larger rings will clear the chain stay, so "fudging" in that direction could be problematic.
2x/3x/44 tends to be a pretty available combination and probably your best bet if you can't find anything in 46T.
Just Google mountain bike cranks.

You MOST LIKELY will have to get a new BB (Bottom Bracket)
Older cranks tended to use much longer spindles than the newer cranks.
The crank will fit on, but the FDER probably won't reach the largest ring.

BTW- It appears that has a triple butted frame, so that's VERY desirable!

HillRider

That's right, it is unusual but I used to have a '93 Trek 7000 aluminum frame rigid/hardtail MTB that came with a Deore LX 110/74 BCD crank with that exact chainring combination.

It also had the oddest cup-and-cone bottom bracket since the spindle had been installed with the longer end toward the nds. I discovered this at the first overhaul and when I tried to correct this "mistake" the nds crank arm hit it's chainstay. I later installed a UN-7X cartridge bottom bracket and had to use a 127 mm spindle length to get the nds crank arm to clear the chainstay. Despite the longer ds extension, the bike still shifted decently.

dsbrantjr

Rivendell Bike has a very nice Sugino crankset with the same 46/36/26 lineup: https://www.rivbike.com/product-p/cr1.htm
I recently put a Shimano Acera FC-M361 42/32/22 on an old MTB and replaced the large ring with a 46T Origin8 one and it shifts fine; I shimmed the large ring out 1.2mm to keep the chain from rubbing it when in the middle ring. You may be satisfied with the 42T ring as-is.

bikemig 

I just put a stronglight 99 crankset with english cups on my 1993 XO-2; go figure. There is no reason not to mod that bike to your heart's content as long as you're not worried about the C&V thought police, :


A sugino is an excellent choice for that bike. You can pick up a sugino xd 600 for a little over $100 if you shop around, https://www.treefortbikes.com/product...FYFhMgodVWMAgw

You could pick up a nashbar branded triple for $59.99 which will be fine for that bike and the price is certainly hard to beat if you don't lose sleep over steel inner chainrings (I never have but ymmv): https://www.nashbar.com/bikes/Product...2_502057_-1___

mieklein

I just purchased a '93 Bridgestone MB-4 myself. I know this thread is very old but do you still have that bike? Did you ever find a replacement for the Sugino crankset? The bike I purchased has all original parts but the crankset might need to be replaced. I would love to discuss with you if you still have this bike.

Bill Kapaun

Why might it need to be replaced?
If just a worn ring, you can buy replacements. Usually not economically feasible if you have to replace all 3.
Ditto for the BB.

mieklein

I appreciate the advice. You are right, it is only a worn ring. I was also just informed that the bike did not originally come with front suspension. It has a RockShox Quadra 21R that is apparently aftermarket. Does adding a front suspension to a bike that was designed without one change the geometry of the bike? It is loose in the head tube but I believe it must just need a headset adjustment.

ak08820

I still have that frame but it is still left alone and not worked on.

mieklein

Did you ever find the a replacement crankset?

ak08820

No, but I may have one around when needed.