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I've bought myself a new bike (BTwin Riverside 120) and I've taken it out for a couple of spins as of yet.. When speeds go above, say, 20-25 km/h (12-16 mph) (I'm giving a rough estimate based on what strava told me), there's a distinct vibration of sorts that I feel when I'm pushing onto the pedal to propel the bike forward, and the lagging foot (I really don't know the appropriate word, if any that exists) doesn't feel any vibration even at high speeds. The vibration does not happen on speeds around 10 km/h (6mph) at all though.. What can be the reason for this? Is that normal?

Pardon me for being stupid but I'm just speculating here, can it be that the air cutting through my shoe soles is causing me to feel the vibration on my foot? (I may be pedalling wrong).

The saddle height is lower than what it needs to be for my height because the bike's primary use is done by someone shorter than I. I say that because my foot is mostly not parallel to the ground when I'm pedalling, it's mostly pointing up.

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  • My guess is that something in the drivetrain is rubbing and transmitting through the chain when it's under higher tension because you're pedaling harder.
    – Adam Rice
    Oct 8 '20 at 15:06
  • Could higher chain tension transmit road buzz better?
    – Paul H
    Oct 8 '20 at 16:05
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    Probably the chain on the cogs. Oct 8 '20 at 16:39
  • Detecting vibration or noise is always tricky. Proceed by elimination and methodically. When does it happen? On which surface? While pedalling? Freewheeling? Tyre pressure? Change one thing at a time. If possible, exchange components with those from another bike (a mate's). Have a mate ride yours....
    – Carel
    Oct 8 '20 at 17:42
  • @Carel happens on flat roads (on roads that have stone studs for better grip as well as on roads that are absolutely smooth). While pedaling, and on the down stroke only. Tyre pressure was maintained at the recommended level. I sadly don't have anyone whom I can exchange it with and try..
    – Timon
    Oct 8 '20 at 18:07
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You may be feeling vibration coming from worn bearings in either the pedals or bottom bracket. Something this is only discernable when applying greater force to the pedal and crank - which would explain why you feel it in the down stroke but not return stroke.

Manually turn the pedals feeling for excessive resistance, 'notchiness', clicks or play. Do the same for the cranks. If you can slip the chain out of the front derailleur cage and off the chainrings it makes it much easier to feel any problems when turning the crank, because there is no drag or vibration from the chain.

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    It's a new bike so I honestly doubt the bearings will be worn out.. The bike has no front derailleur. I'm sorry I couldn't really understand what you asked me to do after taking the chain out of the derailleur cage and chainrings (it's got a single chainring).. Basically take the chain off and then try to turn the pedals and looks for signs you mentioned? I tried doing that but there was nothing that I'd categorize as unusual.
    – Timon
    Oct 8 '20 at 17:48
  • Slight vibration in high gears sometimes happens due to small number of teeth engaging with the chain. Try turning the bike upside-down and pushing the offending pedal by hand. Oct 9 '20 at 1:19
  • @Jeremy, it's a 11-34 drive with a 36 teeth crank. So is this vibration at high gears a "normal" thing or do I need to take my bike back to the shop and get it repaired?
    – Timon
    Oct 10 '20 at 4:39
  • It's not a fault - when you are using the 11 tooth sprocket, only 4 or 5 teeth are going to be engaging with the chain, so under pressure it might "grind" a bit. When you find which gears you use most, you might want to increase the chain ring & alter some of those rear sprockets - but its not cheap and down to personal choice / terrain you ride on. Oct 10 '20 at 14:24
  • @Jeremy, altering isn't exactly a choice for me at the moment.. Its a new bike so if any component has trouble, the shop will happily replace it. I'm thinking of taking it to the shop and having someone from the workshop have a look at it
    – Timon
    Oct 12 '20 at 7:03

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