Good replacement rear hub?

Discussion in 'Friction Drive' started by bikejock, Mar 14, 2016.

  1. bikejock

    bikejock Member

    Hey all, I ran into a problem when I was out on my friction drive MTB the other day. My cassette freehub is loose & effects pedaling slightly. It seems to shift fine but on the 6th to 8th speed I notice the loose caseette as I pedal. I took it to the shop & had the freehub overhauled but the casette still seems loose on 6th-8th speeds.

    I think what caused my freehub body to become loose was having my friction drive roller pressing too hard on my rear wheel causing stress on my rear hub & driving at speeds 25-30 MPH when using the engine. From what I gathered, bicycles are typicaly designed to travel between 5-15 MPH at most & arent really meant to go between 25-30 MPH. So I may as well try an upgraded rear freehub.

    I use a Giant Reval 29er with a formula disk rear hub is 32 hole & designed to fit a PG830 8 speed cassette & the standard 6 hole disk brake rotor. The stock Shimano stuff seems pretty low grade & doesn't seem to be able to handle higher than normal bicycle speeds. So, can anyone reccomend me a good sturdy high speed rear MTB hub that can handle friction drives better?

  2. HeadSmess

    HeadSmess Well-Known Member

    so somehow your weight (lets say 180lb) plus the bikes weight is less load than the friction drive roller pressure? me thinks not... you would be bending the axle first, anyway. axles always bend first.

    ridden plenty of bikes without engines that can easily hit 60km+, or about 45mph for you guys... so speed isnt an issue or there wouldnt be such things as downhill mountainbiking or the tour de france...

    loose cassette...has it been assembled correctly, is it missing say, a shim washer? has it been tightened correctly? is it possible that a tooth is damaged, or the derailleur is sticky, or out of index? it wasnt serviced at all and one of the (outer would be my guess) bearings is on the point of collapse?

    you should be able to pick a loose sprocket or three (and arent the final three sprockets threaded and are what holds the cassette together anyway?) just by poking the thing.

    you could try a different bikeshop ;) get someone that knows what theyre doing. or learn the skills yourself. not that hard, dismantling a freewheel, cleaning it out, greasing it and reassembling. you may need one or two fancy tools to get the thing apart, admittedly. cheaper than a new hub still...

    yes, shimano has gone downhill since the 80's or so... shame. they used to be good.

    maybe you could get rid of the new, fancy, weak stuff and go for the old, bulletproof, reliable stuff? whats wrong with only 5 speeds?

    oh, and last thought... any chain damage, and or, is it the correct chain for an 8 speed hub anyway?
  3. bikejock

    bikejock Member

    I weigh about 160 & my bike is a pretty light weight MTB. It has a hardtail alloy frame. I think the kit adds about 20 lbs & the bike I think weighs rohghly 10 lbs. The chain should be the correct one. I replaced it with the same as stock 8 speed KMC chain after about 1000 miles. Everything in the pedal drivetrain seems true except the loose freehub body.

    I think an axle bending from the pressure of the friction drive pushing on my rear wheel is what could have damaged the freehub body. I was still kinda trying to find the sweetspot. Plus I like to rase the mount off the wheel so I can pedal without any resistance or noise. After I get my freehub body fixed I might mark the sweetspot with a paint marker so I know how much pressure the friction drive roller should be put on my rear wheel to prevent future damage.

    The problem isn't very noticeable when I use my engine but I do like to pedal for exercise I can still pedal & shift fine & the chain doesn't slipp off the cogs. I might try to replace the freehub body myself or take it to a different bike shop.
  4. JunkyardDog

    JunkyardDog Active Member

    I weigh 240 and use a friction drive. I have it on a decent bike now, but have run it on a cheap Walmart cruiser. I have not had any damage to anything. IMO, friction drive puts less stress on the rear wheel than chain drive. The problem you are having is a bicycle problem and not related to the motor. Any bicycle shop should be able to fix it. I would not tell them you are using a motor, most bike shops don't like that. Oh, and by using a 29" wheel, you will need a slightly larger than normal roller. The larger wheel will lower the gear ratio slightly.
  5. bikejock

    bikejock Member

    I use the Staton inc. kit with the largest drive roller available & a Honda GX35 engine which offers enough power for my needs. So far the loose freehub/cassette isn't very noticeable when I keep it in 1st through 4th gear when I pedal. Those are the gears I stick to when I go up hill anyway. Lately, I mostly have been using my pedals to go up steep inclines since friction drives struggle going up hill. I only have one or two inclines I have to deal with on my commute anyway so its not a big problem at the moment.

    So far I have had no problems when I use the motor. It's been a very reliable kit so far. One of the best I had. The quality of the hardware far surpasses anything from China. I only ran into a clutch problem which was easily fixable with a new clutch rotor. The bike shop is well aware of the fact I have a motor on it but they can look past it since it's a rack mounted setup that can easily be separated from the wheel by lifting it above using the quick release rod. It being light weigh makes it even easier for a shop to work on. If any seirious work on the bike is reqired I don't mind removing it completly as it only takes under an hour to do so.
    Last edited: Mar 20, 2016
  6. HeadSmess

    HeadSmess Well-Known Member

    the tyre size has absolutely NOTHING to do with the gear ratio with friction drive.

    the roller acts as if its driving on the ground itself, the tyre is just an "idler" gear, doing nothing but reversing rotational direction...

    what he is saying is most bikeshops have this absolute HATRED of anything with an engine attached to it, that still claims to be a bicycle... its not about it being in the way, its that it challenges their sense of "purity" and they dont like the smell of petrol in their "oh so high class" shop...

    they could just be using you as a source of easy revenue... people that know no better are easy targets... educate yourself!
    what proof have you actually got that they serviced ANYTHING other than their saying so? and how much did it set you back? hence why i recommend you do this work yourself. you know whats done, you know whats what, and theres only yourself to blame if anything goes pear shaped... and face it, bikes are DEAD SIMPLE to work on...why pay some lycra wearing fool to do it?

    and, like i said and the bikes combined weight, plus g-forces when you hit the odd pothole, are FAR IN EXCESS of what the FD setup will produce...besides, the FD would push the wheel out of the dropouts first ;) just think of the forces involved when someone lands a 10' jump badly, yet doesnt bend or break ANYTHING. (i used to jump my BMX with an FD setup on it :p)

    noone else has this issue, meaning it is NOT the FD at is the hub, or whoever "services" the hub.
  7. bikejock

    bikejock Member

    I decided to learn how to do the work myself. I ordered a proper replacement hub body & the proper tools for the job. I already learned how to do basic things like tuneups myself thanks to tutorial videos on YouTube. The hub overhaul at the bike shop only set me back $25 but I think it was only overhauled but the freehub body was not replaced as it should have been.

    I should have done the replacement of the hub body in the beginning myself but my rear hub probably was in need of an overhaul as it does work better but the freehub body still needs to be swapped. I'm still kinda new to bike maintenance & repair but I have learned a good amount of info already thanks to the internet & YouTube.

    There are a fair amount of bad roads I end up going over & maybe going over those bumps at 20 to 25 mph proabably wasnt good for it. Next time I find myself going over rough roads I'll have to remember to reduce my speed to 10 to 15 mph to reduce damage risks. I think my next build will most likely be a full suspension bike. I currently have my engine on a hard tail Giant MTB with front suspension only.
  8. bikejock

    bikejock Member

    I paced an order for a new rear hub. Turns out the reason my hub failed after about 1k miles was because it was a stock Giant brand hub designed to work with Shimano parts. I ordered a Shimano Deore hub that is supposed to be a step up in quality compared to my stock hub.