Eric4

Greetings. I'm moving to an area with rougher mountain roads and would like to convert my single speed IRO Phoenix to something more capable.


Pros:

• The frame is is in good shape, 4130 chromoly, and comfortable to me!
  
• Can fit 38mm wheel
  
• Rack and fender mounts
  

Cons:

• 120mm rear hub spacing. After calling the local shop, I was told they can cold-set the frame to 135mm spacing for about $100
  
• Horizontal dropouts which means no derailleur hanger, but braze-ons for an IGH...should I go that route?
  
• No disc brakes, which seem to be standard on most modern gravel bikes.
  

I'm not in a huge rush on the build, and can be patient to purchase the right parts.


Looking for some input!

rosefarts

I converted a SS mountain bike into a 1x10 last summer. It worked fine. It already had 135mm spacing.

What kind of mounts do you have for the brakes? If you have posts for canti's or V brakes, you'll be fine. If you run calipers, you'll be limited to about 28mm tires.

There are companies out there that make bolt on converters to mount disc brakes. I don't know if they work. They exist.

I tore that bike down to build my gravel bike. I still have the horizontal dropout converter. It's the one that goes on the Santa Cruz Chameleon but it'll fit just about any horizontal dropout and give you the ability to put a derailleur on. It's like $55, I'll sell you mine for $25.

Eric4

The bike unfortunately is mounted for caliper brakes. I've got a long reach Cane Creek on the front, which works alright... A new/used front fork with large tire clearance and disc mounts would be easier for front brakes

I'll do some research into the disc brake adapter for the rear.
Thanks for the offer on the dropout converter. You'll be contacted if I jump into this conversion!

shoota 

Lots of thoughts here. And they all lead back to the same conclusion.. you're going down a rabbit hole that you shouldn't be going down. Not only will this wind up being just as expensive as selling it and buying a real gravel bike but it will also be less capable.

Question: what's the point of cold setting the frame? I'm assuming it's to put a mtb disc wheel in there but you have caliper brakes.. so just keep your current wheels.

Buying a new fork? Not cheap. Cause then you you have to buy a caliper, rotor, and disc wheel.

I mean really nothing about this makes sense to me, I guess that's what I'm getting at. Unless I'm missing something.

edit: I just assumed you were staying SS but maybe that is incorrect? You didn't specify but that would be good info to know.

Eric4

Fitting disc brakes may be overkill on this build. I was wanting to cold set the frame to open it up to a 1x11 setup or for an internally geared hub. The frame has cable routing for an IGH

You're possibly right shoota, it may be easier to get what I can for my SS and purchase something gravel specific

50voltphantom

My 2 cents: Run front & rear brakes, 35 or 38mm tires, gear it somewhere around ~40:19 and just get out there and ride it that way until you can get a dedicated machine. I rode gravel on my Steamroller for 2 years that way and had tons of fun.

pizzamania

I second this. I have ridden many happy gravel miles on a 120 spaced, caliper-braked single-speed. I like 42:17 or 42:18 as a ratio so when you're not on gravel it isn't so slow, but that's totally a personal choice.

I'd just throw some fat tires and a gear you like on there and have fun. if you end up feeling a constraint of some kind you can def upgrade later, but what you have is more than capable.

50voltphantom

Exactly. Modern dual-pivot calipers work excellent (especially with good aftermarket pads). I started out running 42:17 but found I was mashing it much more than I needed to on the flats for the type of gravel roads I have around me so I found a lower gear was better, and actually faster.

HTupolev

40:19 on 700x35 tires is around 57 gear inches...

I think it depends on what the OP means by "rougher mountain roads." Around me, most of the gravel is mountain forest roads.

Last week I did a gravel ride in the foothills around Sultan Basin Road in Western Washington. 6800 feet of climbing in 57 miles. It included features such as a half-mile stretch that averaged about 13%, and a 1.2-mile stretch averaging a hair over 9%. I was the strongest climber in the group, but even with a 22-inch gear available (24-28 on 53mm 26ers), I was often getting much more mashy than I'd like, and once I had to briefly hop off the bike because I wasn't able to maintain smooth enough power delivery for rear wheel traction on the rough loose surfaces.
On a single 57" gear, it pretty much wouldn't have been a bicycle ride, but a slow and janky duathlon.

shoota 

All the more reason to have gears. I think it's safe to say SS is not for me, I just don't get it lol.

rosefarts

Fwiw, you can get a used CX frame on Craigslist for $150-$400. Often comes with a few useful parts.

Eric4

Thanks everyone. I'll probably make some simple changes to the bike and see how it rides.

Currently it's setup 46/15, so maybe a replacement 19 tooth freewheel?

I was able to find an 8 speed IGH that fits in 120mm track spacing. Sturmey Archer X-RF8 (W) , which may be the best bet if I find that I need gears. For now, I'll get the bigger tires, better brakes, and a better geared freewheel.

50voltphantom

ymmv

fietsbob

IGH.. can go in your frame as is ..
In addition New , is a planetary 3 speed crank Efneo GTRO.
3 speeds by having a gear box between the crank and chainring, physically a 28t, with 2 overdrive gears,
effectively a 40 & 50t.. chainring turning faster than the crank arms..
chain does not shift off the cog or chainring, so you can adjust chain tension as with your SS.





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