Chain tension - vertical dropouts

[Alistair]

Hi,

I'm just putting together a basic singlespeed as a training tool/commuter. I work in carlton and see so many around that i've decided to have a go myself...

Firstly, it is anti-hipster, so fashion isn't a consideration. I have got an alloy road frame that i've hacked up a bit and painted. The advantages were that it is very light, cheap and a good size.

The main issue is that it has vertical dropouts. I'm happy to run a chain tensioner from the rear derailleur hanger, but someone was trying to talk me out of that and saying something about a "magic gear calculator" or something. I've googled it and i'm not convinced that it will work, or be safe.

Am i better off sticking to plan A and running a tensioner? The plan is just to go single speed - i think fixed would be a bit trendy... If i'm better off with a tensioner, can anyone recommend one?

Thanks

[brauluver]

http://www.bikeradar.com/gear/category/ ... ioner-9341

[boyracer]

or

buy my white industrie ENO eccentric hub for 130mm vertical drop out frames. make an offer.

[brauluver]

or

buy my white industrie ENO eccentric hub for 130mm vertical drop out frames. make an offer.

MMMMMMM, nice clean look with less moving parts/friction, best of both worlds.

[jaseyjase]

or

buy my white industrie ENO eccentric hub for 130mm vertical drop out frames. make an offer.

this

[MiG]

So, you're doing this for training but fixed is too trendy despite being better for training. Riiiight. I guarantee you're gonna be coasting when you shouldn't but I guess that's the price of anti-trend trendiness. SS is for the worst kind of hipster, the one that can't even ride properly (not saying you can't, just pointing out who you're aligning yourself with).

[Alistair]

It is more that I don't want to ride fixed on the road. It is just something that was recommended to help with strength and fitness for mtb

I don't think I'm going to be coasting up hills, which is where it will make me work harder?

[MiG]

In my opinion converting to SS for training is like getting a sex change but keeping a beard; a useless halfway point with more cons than pros. I could understand if comfort was the aim, but you specifically said training.
You can mount a granny gear for hills and coast down the other side. Weak Fixed will punish you for choosing lazy gears. Plus it feels nice. Why don't you want to use fixed on the road? I commute fixed.

[brauluver]

Do whatever you feel comfy with Alistair.The chances are if you buy a flip/flop rear you will experiment with fixed when the mood takes you.

[familyguy]

Magic gear calcs arent great. I tried two with the same input and got one link difference. One was too tight to even fit, lucky I tried the longer one first. Here's the result:



Too slack for fixed. Most roadies seem to fit neatly between every possible magic gear combo. Go the Eno and you can flip flop and keep MiG happy

Jim

[Alistair]

That was basically what i was interested in. The hub could be a good answer, but i wasn't set on fixed and it won't be cheap. I think a light, fast, simple single speed will do everything i want it to

I will be going with a decent gear too - the trip to work is a gradual uphill, but coming home is downhill and i don't want to be spinning out the whole way.

This is the frame anyway. I've just painted it, spent a while wetsanding and i'm pretty happy with how it is looking

[boyracer]

G'day Alistair.
120 clams and postage will get you one of the best hubs money can buy! It is polished alloy. Google 'White Industries ENO' . Your gunna have to buy/build a wheel anyhow. I would never run a spacer kit and jockey on a dished freewheel hub...not ideal for bullet proof commuter, especially as your a big bloke. Looks ugly too when you've spent all that time grinding and sanding to remove all extraneous crap. Hub is 32 hole flip-flop with track nuts (theft proof), meaning it is fixed one side and threaded for a BMX style freewheel on the other. I ran it fixed with a 1/8th cog/chain. This holds more lube and is stronger (and much cheaper) than 3/32 so lasts for years literally. My commuter fixed does 150 a week,rain or shine, and has been going for 2 years on its drivetrain. Def' recommend you have a go at fixed if you want to build strength/ endurance/ suplesse which is all important on those lung busting MTB climbs. This hub allows you to have both. Run a freewheel, say a 16(common) one one side and a 15 or 14 track cog on the other for your downhill run! My commute is the other way...bugger. The only problem with fixed comes when you value style over safety and go brakeless. yeah i got a brakeless track bike but i don't ride it every day. And us big lads look ridiculous in rolled up skinny jeans!
Hub hasn't seen a lot of use, was on my LOOK roadie as spare commuter!! I have since built a steel roadie for my spare bike and its 120mm spaced. I can buy new ends from WI to resize it but i have a Campy high flange wheelset on steelie and it looks just right.

[Alistair]

Sounds good. Can you PM me some payment details and i'll transfer some cash. A single speed kit is going to cost something anyway and i don't like bodges

[Boognoss]

White Industries

Purveyors of all SS gear that is dead sexy.

[rustychisel]

looks like you're all over this Alistair, and it's the right decision. The ENO eccentric is dead sexy and magic gears can work, sort of, with some judicious filing of the dropouts, but using an ENO is a much better idea in the long run. Why?

Chain stretch, to put it simply. As you can see from FamilyGuy's bike the difference between good tension and poor tension is about 2mm adjustment in the dropouts... not easy sometimes. Get it right at first and within a couple of months you'll find the chain has stretched - significantly - and you need the extra adjustment. To get the right magic gear you often need a half-link in the chain, but they're often difficult to find and don't fit all chains. Thus, if you use a half link you're constricted as to choice of chains. It can work, but it's a bit fraught. The ENO obviates a lot of those difficulties, just watch out for

1) width OLN of hub and frame
2) enough cam adjustment on the frame
3) possible difficulty in running a rear brake with ENO (but I only use front brake).

Hope this helps.

Oh yeah, you can buy the Eno from US websites for less than what boyracer was originally asking, but don't tell him that For the price he's asking now, I'd be all over it like a fat kid on a custard tart.

[Boognoss]

Forgot to add, there is an Australian importer/reseller. I've dealt with them once and they were great. Probably buy cheaper OS but I couldn't be bothered this time .

www.definitivecycles.com.au

[Alistair]

I didn't even look to see what it was worth overseas.

The rear brake thing is interesting too, and occurred to me as i was going to sleep last night. I have only used disks recently, and stopped riding road bikes as i was so unhappy with the crap brakes - does just the front brake stop you ok?

I didn't want a bodge anyway, and even with this i still have spent nothing on this bike. The cranks were $40, the frame $50, $25 for a can of colour/clear/sandpaper and i have bars, wheels, a fork and headset already. The only question now is whether to build a new wheel, or stick this hub into one of the cheap ones i have.

[rustychisel]

here's a thread we prepared earlier

http://www.bicycles.net.au/forums/viewt ... 12&t=24980

[boyracer]

Oh yeah, you can buy the Eno from US websites for less than what boyracer was originally asking, but don't tell him that For the price he's asking now, I'd be all over it like a fat kid on a custard tart.

US postal service used to fund a cycling team or something like that....probably from all the money they made shipping things to australia!!!

[Alistair]

I don't know what to take out of that thread! Currently the front brake on my mtb is making a horrible noise, so i'm barely using it... that said, it is good to know it is there.

My other concern is what kind of brake lever to use if i only had a front. I have drops, and wanted conventional aero levers. I'm not a fan of those ones near the stem... the ones i was going to use might be odd with only one though! I might have to look into it

[Alistair]

Also, can i ask a stupid question? I have a fairly basic wheel which i was planning on using, but now i am going to use this other hub. Is it possible to get a bike shop to swap the hubs over easily? What should i expect to pay?

[boyracer]

flange diameter of ENO is 48mm, centre to flange 32mm from memory. was built 2x. Google 'spokecalc' and find your current hub measurements. or sheldon brown.

[Alistair]

I would never run a spacer kit and jockey on a dished freewheel hub...not ideal for bullet proof commuter, especially as your a big bloke.

Another stupid question... how do you know i'm a big guy? You are right as i'm 6'4, but i don't think i have said that anywhere!

[boyracer]

you look so peaceful when you're asleep....

[rustychisel]

you look so peaceful when you're asleep....