Intermittant drive when pedalling

Hi folks. Riding home today my bike developed an issue. Whenever I stopped pedalling, so slowing down for traffic and junctions or freewheeling, i would loose drive and be pedalling air and not moving forward. Sometimes I could get the connection back quickly going up and down the gears and sometimes i'd have to stop and walk a bit before I could get the drive back ride some more. Once up to speed and pedalling consistently it worked fine.
I got home and was able to replicate the problem using my hand to spin the pedals so not torque related.
Gear changing is fine. Now I did put a new chain on few days ago, it is the correct chain for the bike (10 speed Tiagra) and it is the correct length based on the number of links of the original chain. The bike was fine for the first half of my ride, the problem started 10 miles from home so i don't think it's related in any way, perhaps i;m wrong.
I'd welcome any more experienced opinions.

Comments

  • Wheelspinner
    Wheelspinner Posts: 6,675
    Busted freehub I’d assume. There are typically three small pawls with little springs which lock into splines under load, and when you coast those pawls just spring out of the way which is what makes the noise.

    Splines worn, or springs busted or both. Depending on hub model, may be a replaceable spare part, and a 10 minute job to swap over. If not, new hub or wheel likely required.
    Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS
  • Thanks for the quick reply Wheelspinner. I was hoping it may be something else but a google search also suggested this.might be the problem. I've only limited experience and the bikes 8 months old but i have been riding it throughout winter, still i'd hope the hub would last a bit longer as i only ride maybe 5 hours a week, perhaps a little over 1000 miles.
    Perhaps I'll contact the bike company and see what they can do, i think the wheels are an in-house brand.
  • masjer
    masjer Posts: 2,613
    A strip, clean and relube with oil might bring it back to life. Sometimes it can just be dirt or grease clogging up the freehub.
  • First.Aspect
    First.Aspect Posts: 16,957
    How cold is it where you ride? I've had grease get too viscous in cold weather before and do this. Shimano hubs are known for it.

    Otherwise as masjer has said, a service could help. If it is a simple hub you can just pull apart do make sure you catch all the bits...
  • MattFalle
    MattFalle Posts: 11,644
    tbh, the freehub may just have come loose and need tightening up - generally cassette off and one 5mm allen key on wach side of the wheel.

    10 min job.

    sometimes its just the simple things.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • First.Aspect
    First.Aspect Posts: 16,957
    A lot of cheap hubs are just press on though. Also, if it is a simple pawl and ratchet system, they will have 5 mm of overlap. Would have to be wildly loose for that to be the issue.
  • orraloon
    orraloon Posts: 13,227
    If bike is only 8 months old, warranty? Get bike shop to sort it out?
  • MattFalle
    MattFalle Posts: 11,644
    A friend has a set of Hunts.

    The free fell iff after that amount of mileage and as we all know although they are cheap parts Hunts aren't cheap, in fact they are wildly overpriced.

    Just thinking it may be worth a look.

    We all know the OP needs some Obermayers to replace whatever he has on there but that goes without saying tbh.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • First.Aspect
    First.Aspect Posts: 16,957
    There are lots of other places available to you MF to expel hot air about Hunt wheels, other than a thread for giving someone some advice. The OP has the wheels he has and the issue is undoubtedly fixable, and easily.
  • MattFalle
    MattFalle Posts: 11,644
    oh - don't misconstrue my posting intentions.

    just saying it could be a loose freehub and using a real world example to back up claim
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • First.Aspect
    First.Aspect Posts: 16,957
    Not sure how a novatec free hub can "fall off". Novatec being a brand that many wheelbuilders use. And a general design that other manufacturers use.

    Pawls can certainly get gummed up though.
  • veronese68
    veronese68 Posts: 27,765
    I think they are Formula hubs used on Boardman and various others that have a reputation for freehubs failing. You can get replacements and I think they need an 11mm Allen key if I remember rightly. Some come with a key.
    But, as 'loon rightly points out, that should be a warranty issue if the bike is only 8 months old.
  • ultramarineblue
    ultramarineblue Posts: 3
    edited March 2022
    Hi all and thanks for all the replies, just a quick update. I have removed the cassette and indeed is it wobbling about a bit. Enough so I should be able to get a video of it to send of and hopefully get a replacement under warranty.
    Meanwhile i'll have a go at tightening it if i have the correct Allen key. Or even if i'm able to.
    Thanks for the replies and advise!


  • racerex
    racerex Posts: 69
    I had the exact same issue with a DT Swiss 240 hub, probably had less than 2,000 miles on those wheels at the time. Had to smack the side of the wheel a couple times to get the ratchet to engage. Pulled the hub off when I got home and found the grease on the ratchet spring was all gunked up and sticky. Just had to clean, re-lube, and reassemble and all was good. Took 5 minutes. Not sure what kind of grease DT Swiss uses at the factory, or if it's their ratchet design, but I had never experienced that on any wheel before.