Hi all my first post. Just in case this is in the wrong place…er…sorry
I have been looking at getting a new bike and discovered fixies for the first time. I really appreciate the beautiful, uncomplicated, elegant style of them and want to build one. Being a bit of a tech head I have been researching transmissions.
My plans are: I want to combine an aluminum frame with carbon forks (mid 90’s racing frame) Nuvinci n360 infanatly variable hub with a belt drive. I am mainly after getting some exercise and where i live is fairly flat and just want to chuck laps around a local Lake. I came up with that combination as a bit of an experiment and want a tricky looking bike.
I am aware that the nuvinci hub is a little inefficient and heavy but i will compensate by throwing some cash on lightweight stuff on the rest of the build to compensate to some degree, I have heard the nuvinci is as smoooooth as, and almost silent. when coupled with the belt drive should be like silk as a ride.
The frame has 130mm between the dropouts but the hub requires 135 do you think I will get away with that?
I am also aware that I will have to do a bit of engineering on the triangle to get the belt though but know how to do that.
I really think the idea of building a bike rather than going in to a shop is really appealing. Ask me in a month though I may have changed my mind, LOL
Is there any comment on my plans with that combination. I am a newbie and would really appreciate some feedback from more experienced guys who have been doing bikes for years.
How are you planing to get the belt into the rear triangle?
Regarding rear spacing: I know that you can cold-set steel frames to allow them to be used with a different width hub. I’m not sure how smart it would be to do this to an alu frame, as the alu is not as pliant/ fatigue resistant as steel.
With these two things I’d recommend looking to get a steel frame for this build.
It’s the ductility you should be worried about in this case, high strenght aluminium alloys typically have quite low ductility, whereas 4130 or gaspipe are quite ductile, high end heat treated tubesets a little less so.
Aluminium is less fatigue resistant than steel but that doesn’t come into it for cold setting operations.
OP: A bike you that coast is not a fixie
That said there’s nothing wrong with internal gear hubs
I youtube searched “Belt drive frame conversion” first hit was this
this is a stainless fitting being brazed into a steel frame, there are several products like this on the market but i don’t know of any Aluminium ones. you can’t weld aluminum to stainless steel.
Also I’ve never used a nuvinci but apparently they’re quite heavy, I’d consider getting a shimano nexus or alfine hub if you want a belt drive with gears. Note these hubs are not exactly light but appear to be ~1kg lighter than a nuvinci. I’m using a late model nexus (8sp) and it is totally silent when coasting and it’s just as smooth as any other drive train i’ve used. you can also get drop bar shifters for nexus/alfine
On the nexus the hub is 135mm wide but you can substitute the non drive side locknut with a thinner one which will bring the width low enough that you won’t need to cold set a 130mm frame.
Thanks froggy I wll use an aluminium “joiner” yes the nduvincy is heavy but the upside is cadence. Have read a number of reviews about the nexus and Alfine, not that good. I love the idea of infinitely variable linked via a belt have not heard of it b4. Like I said bit of an experiment in smooooooothness. someone used the analogy of the nuvincy with that of tuning the sails of a small yatch.
Nothing ventured nothing gained.
Thanks man
“A bike that coasts is not a fixie” true, mayby its a trixy then.
Everyone starts somewhere. If they had the internet when I started fabricating bodgy awful solutions to problems that do not exist - I wouldn’t have learned anything.
If I had the internet when i was a teenager I wouldn’t have left my room and probably have soiled half a forest worth of tissues.
Whilst I agree we all started somewhere (and that we are a cynical mob, hard to please and baying for newbie blood) few if any of us turned up out of the box planning a nuvinici belt drive home fab. “fixie”. That’s like turning up to a Black Panther Party meeting wearing a Klu-Klux Clan outfit.
Asking for it comes to mind. Quid quo pro with regard to original post and responders this far.
