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-   -   Fixie build Help (https://www.bikeforums.net/showthread.php?t=1202288)

CTony 05-22-20 01:17 PM

Fixie build Help
 
Decided to convert 70s Motobecane bike into fixie bike came with steel rims.Have extra.Weimann wheel-set
canít find hub brand. 5sp freewheel QR.I would like to use nuted/ wingnut axles is this possible?and would I have redish rear wheel.Or would it be easier to purchase fixie rear wheel setup with flip flop and fixed gear so I donít have to dish wheel.Any Guidance.Thanks
N

Litespud 05-22-20 03:12 PM


Originally Posted by CTony (Post 21490925)
Decided to convert 70s Motobecane bike into fixie bike came with steel rims.Have extra.Weimann wheel-set
can’t find hub brand. 5sp freewheel QR.I would like to use nuted/ wingnut axles is this possible?and would I have redish rear wheel.Or would it be easier to purchase fixie rear wheel setup with flip flop and fixed gear so I don’t have to dish wheel.Any Guidance.Thanks
N

You're going to have to replace the axle for a longer one - and get a solid axle at the same time. I'm not sure that you'd need to redish unless you wanted to, or your chainline with the fixed sprocket was way off. However, that still leaves you with the potentially larger problem of running a fixed sprocket on a freewheel hub ie without a left-hand-threaded lockring to prevent the sprocket from spinning off. You could try loctiting the sprocket in place, but I don't know how secure that would be, and I certainly wouldn't trust such a setup. In your shoes, I would simply buy a purpose-built fixie wheel

frizzen 05-22-20 04:10 PM


Originally Posted by CTony (Post 21490925)
Decided to convert 70s Motobecane bike into fixie bike came with steel rims.Have extra.Weimann wheel-set
canít find hub brand. 5sp freewheel QR.I would like to use nuted/ wingnut axles is this possible?and would I have redish rear wheel.Or would it be easier to purchase fixie rear wheel setup with flip flop and fixed gear so I donít have to dish wheel.Any Guidance.Thanks
N

You need to buy a longer axle and nuts, that's easy. The long spacer on the right side of freewheel hubs is a major weakness, so moving some spacers around to get the wheel more centered (and re-dished) and fixing the chainline is highly desirable. Axle nuts are surprisingly expensive. They are a very fine pitch thread and you can't buy them at the hardware store.

I've been using a freewheel hub on a fixed gear bike for years without problems, but if you are going to do skids or stunts you better spring for a real track hub. My bike is 114mm dropout spacing (old 3-speed) and I don't want to mess with it. Track hubs are 120mm.

FastJake 05-22-20 04:26 PM

I don't really understand what your question is. But it's absolutely safe to Rotafix a cog onto a freewheel hub without a lockring. The leverage you can achieve is enough to rip the threads clean off the hub if you overdo it. Skidding the rear wheel will not loosen the cog. I've ridden nearly 30,000 miles on Rotafixed cogs and never had one come loose, due to my preference for quick release instead of a nutted axle.

ljsense 05-22-20 07:56 PM

Back in 1994, I was a bike mechanic at my home town shop on a quaint main street, and I built up something exotic at the time -- a fixed gear bike with a true track rear wheel, which of course was a tubular. The only problem was there was no lock ring. That stuff was scarce back then. But the collective wisdom was that I could tighten it hard enough so that it was not necessary. It's possible that my technique, at age 18, was not good enough. I thought it was leveraged on there to the point that the threads were about to break. But lo and behold at the end of the summer, I was coming down a hill and I felt myself spin off the cog under hard braking using the only stopping force I had -- the chain, naturally, as I was a purist. I remember a lot of things well. The first time I read Anna Karenina. The birth of my kids. But that moment was also right up there. There I was going down a hill with no brakes. You really feel like the captain of your soul at such a moment. I remember deciding that I could not delay, that I would only go faster. I steered into a deep grassy culvert ditch, plunging down then up over it and into a wooden picket fence. I dislocated my thumb and had a crazy row of bruises across my chest but the overwhelming shock was -- WOW, I'M OK.

I would never ride a bike (again) without brakes if the wheel didn't have a lockring.

frizzen 05-22-20 09:03 PM


Originally Posted by ljsense (Post 21491635)
I would never ride a bike without brakes if the wheel didn't have a lockring.

I would never ride without a front brake. I drove down a hill in a car once without brakes (not on purpose). Scary stuff.

mrrabbit 05-23-20 09:01 AM


Originally Posted by CTony (Post 21490925)
Decided to convert 70s Motobecane bike into fixie bike came with steel rims.Have extra.Weimann wheel-set
canít find hub brand. 5sp freewheel QR.I would like to use nuted/ wingnut axles is this possible?and would I have redish rear wheel.Or would it be easier to purchase fixie rear wheel setup with flip flop and fixed gear so I donít have to dish wheel.Any Guidance.Thanks
N

Just answered this question in a post only two days ago...

http://www.mrrabbit.net/docs/freewhe...OLD_sizing.pdf

And yes, if you convert an existing 5 speed hub, you'll need to redish the wheel. Luckily for you, the current hub probably has 120-122mm spacing, no changes needed there. Just set dimension A to 21mm-21.5mm on the gear side, fill out the rest for 120/122 using the non drive side, Then redish the wheel.

That's if there's enough threading overhead / underhead available for the spokes.

=8-)

CTony 05-23-20 12:26 PM

Hello All.Just want to say Thank You To everyone that responded and sharing their knowledge.


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