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SRAM Rival 1 and 73mm bottom bracket

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17K views 7 replies 4 participants last post by  RS VR6  
#1 ·
Hey everyone,
I recently bought a Kona sutra frame which I am currently building up into a crosser. Originally I wanted to set it up with a complete SRAM Rival 1 groupeset, but the cranks don't seem to fit the bottom bracket. Can someone confirm that - or am I doing something wrong and the cranks actually should fit?
The bottom bracket housing measures 73mm, and is fitted with a Truvativ GXP Team BB. The spacers also seem to have been put in place (this was already don't by my LBS from where I got the frame). The information in regards to whether the Rival 1 cranks should be fitting or not seem to be varied - some ppl say it should fit, others say it shouldn't. My experience say it doesn't - as in, with the current constellation (I.e. with the spacers in the BB) the spindle is to short. Is it true that SRAM Rival cranks only go with 68mm BB? And if so, why does Kona build crossers with a 73mm (more like MTB) BB?
Any help or input is appreciated. I am a woman by the way, so please help me understand this without using gobbledy**** language...:)
 
#3 ·
It could just be that the spindle is too short. Rival is traditionally a road groupset and the crank is probably designed to fit a 68mm BB. All the tech docs from SRAM for Rival 1 are all filed under "road".
 
#4 ·
Right, so Gravelbike says that the spacers should go out - but I am not sure...the bike store put the spacers in already traditionally, so one would assume that they know what they do and that the spacers are supposed to be in there. I know there is some confusion about whether spacers are supposed to be in or out with a 73mm BB GXP. So, in or out?

And RS VR6 says what I also heard from some other ppl - Rival's spindle is too short and only designed for road bikes. So, do all road bikes have 68mm BB?
 
#5 · (Edited)
Rival 1 is actually more towards CX, I put the shifter etc 11s group on my road bike because I wanted 1x11.

The answer is really simple:

Take a ruler, measure the bottom bracket housing. Likely it's 73mm. Bike shop was too stupid to measure and check first obviously. Remove the spacers, install the cranks and go ride.

Bottom brackets are mostly stated 68/73. Cranks may be different (road shorter than mountain). Road bike frames shouldn't have spacers in most cases.

And actually iirc my road bike which is a trek 1.2 is 68 but ultegra bb Sora crank, no spacers iirc.

Sent from my XT1565 using Tapatalk
 
#6 ·
I took the Rotor 3D crank from my Cervelo S2 with a 68mm BB and tried it in my mountain bike with a 73mm BB. The spindle was too short. I thought I'd be able to swap spiders and run it on the MTB...no go. I also called Rotor and they told me the mountain crank has a longer spindle. The vast majority of road bikes are 68mm.
 
#7 · (Edited)
Ok, I measured again the bottom bracket housing, it is definitely 73mm, like stated earlier on.
I also took apart the bottom bracket. Now, there is a small black plastic distance tube between the two cups. With this black thing, you must use the two spacers on either side of the cups as otherwise there would be a gap between the cups and the bottom bracket housing. Now, I though I could leave out the black distance tube, as well as the spacers, then the crank would fit. But this is not the case either, the crank spindle is still too short.

Also, the when I check the bike components website from where I purchased the crank set (I bought the complete group set though) https://www.bike-components.de/de/SRAM/Rival-1-GXP-11-fach-Kurbelgarnitur-p43828/
it states only BSA 68mm for the bottom bracket, and not BSA 73. Does this mean that it only fits 68mm bottom bracket housings, or did they just forget to write down the BSA 73 measure because it is more typically used for road bikes/ cross bikes which pretty much always have a 68mm bottom bracket housing?

In other words, I guess I have answered my own question...the SRAM Rival crank set does not fit into a 73mm housing, no matter if spacers are left in or out.
Any additional comments/advice are appreciated.