HELP with 1991 Diamondback Ascent
paoloernestogallardo
Posts: 1
Hi,
I'm new in bikeradar and wanted to get some help on converting my old bike frame.
I have a 1991 DB Ascent and wanted to convert it to a dropbar with brifters. I recently got hold of a Shimano Claris 2400 set (brifters, RD and FD). It also came with a FSA Gossamer Crankset (CKM-6100 and a Mega Exo BB). I also got Dia-Compe 986 cantilever brakes since the dual pivots won't fit my setup.
I had my LBS put in the parts and things were going great. Hit a bit of a snag installing the crankset as the BB needed a spacer so that my left arm won't hit the chainstays. But then one of the mechanics said that my spindle was too short. It was a road type and I needed an MTB one, he said. (I'm guessing this is because the BB was a 68mm and my BB shell on the frame was a 73mm).
Anyway while riding home, my left arm crank suddenly fell out. So I had to push my bike and walk home (LBS was already closed by the time I left them).
I wanted to know what would cause this? I'm guessing its because of my BB?
Should I replace my BB with a 73mm? Or would I need to replace the whole crankset?
If replacing my BB would be the solution, would any BB be compatible with the FSA cranks?
Thanks! (sorry, im such a noob).
The following photos are my old bike setup and the new one (still being rigged though).
As well as photos of the FSA crankset.
I'm new in bikeradar and wanted to get some help on converting my old bike frame.
I have a 1991 DB Ascent and wanted to convert it to a dropbar with brifters. I recently got hold of a Shimano Claris 2400 set (brifters, RD and FD). It also came with a FSA Gossamer Crankset (CKM-6100 and a Mega Exo BB). I also got Dia-Compe 986 cantilever brakes since the dual pivots won't fit my setup.
I had my LBS put in the parts and things were going great. Hit a bit of a snag installing the crankset as the BB needed a spacer so that my left arm won't hit the chainstays. But then one of the mechanics said that my spindle was too short. It was a road type and I needed an MTB one, he said. (I'm guessing this is because the BB was a 68mm and my BB shell on the frame was a 73mm).
Anyway while riding home, my left arm crank suddenly fell out. So I had to push my bike and walk home (LBS was already closed by the time I left them).
I wanted to know what would cause this? I'm guessing its because of my BB?
Should I replace my BB with a 73mm? Or would I need to replace the whole crankset?
If replacing my BB would be the solution, would any BB be compatible with the FSA cranks?
Thanks! (sorry, im such a noob).
The following photos are my old bike setup and the new one (still being rigged though).
As well as photos of the FSA crankset.
0
Comments
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The spindle in the crankset is too short, it's designed to go on a 68 mm BB shell and that's the bottom line. So when you mount it, there is not enough purchase for the left crank, which inevitably falls off. You need a MTBike crankset or even better you could get hold of a square taper road chainset and install a square taper bottom bracket for 73 mm shellsleft the forum March 20230
