Knocking sound from BB area

Rik08

Member
Joined
Jan 9, 2021
Messages
68
Reaction score
22
Location
Leamington
So my E150rs has started to make an occasional knock/tap sound from bottom bracket area, I know there is no BB, Amy ideas ? Only when pedalling, motor on or off, not all the time and more when loaded then spinning freely (so it wouldn’t do it on bike stand), 550 miles in
 
⚡ EMTB Pro Go Pro — Living Intelligence Reports, exclusive discounts & ad-free Up to 25% off Peaty's, PEMBREE, Magicshine & more · Ad-free browsing · Pro badge See the deals →
So my E150rs has started to make an occasional knock/tap sound from bottom bracket area, I know there is no BB, Amy ideas ? Only when pedalling, motor on or off, not all the time and more when loaded then spinning freely (so it wouldn’t do it on bike stand), 550 miles in
Check to see if the chain ring locking nut is tight , the bosch gen 4 is known for it. Just grab the ring and give it a jiggle, if there's movement there's your problem
 
Check to see if the chain ring locking nut is tight , the bosch gen 4 is known for it. Just grab the ring and give it a jiggle, if there's movement there's your problem
That’s all tight ! I’ve ordered a lock nut removal tool so I can take chainring off to get to bottom swingarm bolt to check torque of it !
 
Last edited:
I’ve seen a few people on facebook have a knocking noise which they thought was their BB but it turned out to be a loose bolt that holds the rear shock in place. Worth checking this.
 
Few different threads in Bosch section. Try this one see if it sounds familiar.

 
So checked all the linkages are still at 24nm, removed and greased seat, bars removed and cleaned, so making the noise, sometimes it’s a creaking noise, some times just a metallic feel, only when pedalling so driveline related surely? Wd40’d the linkages earlier, Next up remove pedals and fit so cheapo clip less I have, after that I’m running out of ideas, it’s not the clutch or the downhill rattle in freewheel, I’m worried bearings in motor are on way out after 600 miles !?
 
Without hearing it, it's hard to judge. Have you tried riding and pulling a control cable taut at the bar, in case its rubbing inside the frame.
 
Ok so after much investigation! Chainring found to be loose (but only just happened as I’d checked it before !), cranks removed, cleaned, motor mounts checked - lower 2 behind plastic cover on non drive side moved about half a turn each, rest were tight. Cranks regreased and refitted, tested and still the random knocking sound ! Front QR removed, cleaned, greased refitted, rear axle tightened (was tight), most likely candidate was the seat post, pulled this out as far as I could, a lot of dust, cleaned up as best as I could. Took bike out tonight, nice and quiet !! How do I get seat post out ?
 
had this on my e150rs, turned out it was a faulty bearing on the pivot of the swingarm by the rear mech
bearing felt really rough considering it was only a couple of months old, quite difficult to trace. No noise downhill orwhen freewheeling or bouncing but bad under load climbing. sounded really creaky /clonky like the frame had a weld broken of something. got it replaced under warranty and cured everything.
 
Keep reading
    Browse all

    Similar Threads

    Community Stats

    Since 2018
    672K
    Messages
    41,512
    Members
    Join 30,000+ Riders, it's free!
    Back
    Top