sprockets

I've just bought a single speed bike that I want to convert to an internal hub geared bike. At first this seemed like the easiest bet but it just occurred to me that I may have to braze on some parts to the bike. Fortunately it's a steel frame so it's possible if I have to, I just want to know if I have any other options. I've never done this before, does anyone have a link to a site with information on how to braze stuff to a bike frame (or even a generic brazing info site)

Thx.

sprockets

Is it possible to just solder the parts necessary for the gear cable to the frame or will it not be strong enough?

This is a pic of the bike I will be converting:

dbg

The cablehousing from the shifter can go all the way to the hub. On one of my builds I used a hose clamp to to attach a cablestop on the chain stay. I then had bare cable between the downtube cablestop and the chainstay stop. On all subsequent internal hub builds I just used plastic cable ties to hold the housing all the way from shifter to hub based cablestop. That works just fine.

sprockets

Great news, thank you. I picked up the bike last night, the over locknut dimension looks like it's just a hair under 110 mm. Any opinions on what the max OLN dimension I can use without cold setting? I should mention that this is on a 20" wheeled bike so the rear fork is shorter than normal.

JanMM

track-style horizontal dropouts should be ideal for your project

jjciiijs

I do not see you having to weld or soder anything. There are cable housing holders that clamp around tubes and you can run the housing to the hub. or you can use zip ties to hold the housing

Dan Burkhart 

You did not specify which hub you are looking at, but given the constraints of your dropout spacing, you are probably best to go wit Sturmey Archer. The 8 speed non braked version is 124mm, but I think I remember Sheldon saying that he narrowed one down considerably by using skinny nuts and spacers.
Gearing wise, the SA is a good choice for small wheel bikes, as gear 1 is direct, and the rest are overdrives. This means you can achieve normal speeds without an oversize chainring.
I would suggest, however that you consider the SA SRF5 5 speed hub. It has a decent ratio range, and in the 171.2 mm axle version, has an OLD of just 113.7 mm. I installed one of these in my commuter, and I have been very happy with it.
Cable attachment is simple, as the cable stop is on a bracket fastened to the axle.
https://tinypic.com/fullsize.php?pic=...&capwidth=true
As for routing the cable from shifter to cable stop, zip ties work just fine.
This one has direct in the middle of the range, so it should work with your current chainring.

MichaelW

In the olden days, braze-ons (ie silver soldered additions) were for high end bikes. Everday machines used clamp-on cable guides and stops. You can still pick these up from some vintage/small-parts places.
eg
https://www.theoldbicycleshowroom.co....pair-382-p.asp
https://www.firstflightbikes.com/shifters.htm
https://loosescrews.com/index.cgi?c=C...d=430630720109

reverborama

I use colored zip-ties on mine. Works great.

My dropout spacing was 126, the hub was 130 so I just spread it. Rode it like that for a year and it worked fine. Cold set the frame to 130 a couple of months ago. Still works great but changing tubes on the rear wheel is a bit easier now.

tcs

The Sturmey-Archer X-RF8 model IHSFXDCSAA1 uses a 155mm long axle and has a factory OLD of 116mm. If you gently discussed acceptance of this hub with the pictured frame, I doubt you'd have to do any cold setting.

HTH,
TCS

Dan Burkhart 

Right you are, and it comes in 28 spoke drilling too, so it's a good fit for a 20" wheel.

wroomwroomoops

Most gear hubs can be spaced out nicely with washers. Just put the same amount of equal width washers on both sides, and you're golden.

One thing you didn't mention is, what type of brakes you expect to use? Geared hubs have, very often, roller, drum or coaster brakes. So before you ask: no, you don't need braze-ons for either of those. If it's a roller or drum brake, you can just zip-tie the cable to the frame where necessary.

sprockets

This looks like my best option, the only problem I have is trying to find one. The LBSs in Toronto claim that their distributors will not order one unless they can be sure to sell 10. I've had trouble finding them online as well.

K6-III

Shoed be able to get one from www.aebike.com

Grand Bois

Adding washers won't make the hub narrower.