Converting derailleur bike to internal hub gearing

[Sham69]

Would appreciate views on the possibility of converting a GT Tequesta MTB to a Shimano Alfine SG-7001, 11-speed internal hub gear.

I already have an internal hub geared hybrid bike (SRAM i-motion9) which has proved to be reliable with minimal maintenance - which is what I want from my bikes - so when some components on the GT Tequesta started exhibiting wear, I thought I'd investigate the possibility of converting it to internal hub gearing. I can't stretch to a Rohloff hub but could afford the Shimano Alfine 11-speed (not the Di2 version).

I'd be particularly keen to hear from anyone who has carried out a derailleur-to-internal-hub-gear conversion.

 

[Big John]

I've considered having a bash at doing a similar conversion. I'll watch the thread with interest. I reckon the first thing you'll need to check is will the hub fit between the frame at the back. If I does then I'd imagine it's a goer. You'll need the gear changer and the necessary anchor points for the gear cable on the chain stay. I'm assuming you'd ditch the triple chainset for a single?

 

[Gunk]

Ideally you want single speed type dropouts for an internal hub otherwise chain adjustment is very difficult. That’s why Surly‘s lend themselves to an Internal hub conversion, they have horizontal dropouts.

 

[wakemalcolm]

Some guy rode round the world quite happily with a hub gear and chain tensioner. Main problem I had with my nexus hub was the indexing relied on a return spring rather than the 'pull up pull down' of the rohloff and once the gunk got in the changing quality went.

 

[Sharky]

Is the GT quite an old bike? Switching to hub gears, very achievable, but it will become a bit of a "Triggers Broom" bike, needing new rear wheel, BB, chainset, levers etc. it will lose the essence of the original bike. Nothing wrong with all this, but budget could be getting close or half way to buying something that you are aiming for.

But good luck with your project.

 

[Chris S]

My Raleigh Chiltern had a 3-speed Sturmey Archer hub. The frame got damaged in an accident so I transferred the parts to a Raleigh Routier frame, which originally had 2x5 speed derailleur gears. The frame dimensions were almost identical so it was just a simple switch over.

Make sure your frame's over locknut distance is the same as the hub. If it's only slightly different you can usually add spacers to the axle.

Also check that the hub's sprocket will be in alignment with the chain-ring. If it isn't then the chain will come off when you freewheel. If you're using a traditional 1/8" single-speed chain then it could also break, they're nowhere near as flexible as multi-speed chains.

If your frame has vertical dropouts then you may need to use a chain tensioner to get the chain tension correct. You could also use a half-link chain or a single half-link with a conventional chain. Both are readily available on ebay.

Hub gears usually come with anti-rotation washers to stop the axle rotating. Sturmey Archer ones crumble so I just use conventional steel washers instead. The nuts provide enough friction to stop the axle rotating.

I've attached some pictures of the bike that I built and another Raleigh Routier with deraileur gears.

 

[Sham69]

Thanks for your replies, most helpful.

My GT Tequesta is the bike on the second page from the end (Nimbus paint job):

https://www.mtb-kataloge.de/Bikekataloge/PDF/GT/1990.pdf

I purchased the bike second hand in the early-mid nineties. As I say, I'm currently investigating the possibility of a conversion to internal hub gear - it may not be a go-er as this type of work is always more "involved" than may first appear!

I'm assuming you'd ditch the triple chainset for a single?

Ideally you want single speed type dropouts for an internal hub otherwise chain adjustment is very difficult.

Yes, a single chainset. Chain tensioning shouldn't be a problem because the dropouts are angled (maybe 30 degrees from horizontal, just as they are on my SRAM i-motion9 bike - I'll try and measure though).

You'll need the gear changer and the necessary anchor points for the gear cable on the chain stay.

Yes. I can't find much info on this. Enough sellers, both in the UK and Germany, for the hub gear unit itself but few seem to sell the associated fixing kit and gear shifter unit & cable. I need to investigate more.

Main problem I had with my nexus hub was the indexing relied on a return spring rather than the 'pull up pull down' of the rohloff and once the gunk got in the changing quality went.

I can relate to that. Same thing happened to my i-motion9. It's also a spring return and when the gear cable outer plastic sheathing started to deteriorate (letting in rain water which subsequently rusted the flexible metal sheathing beneath), gear change became stiff/unresponsive.
New shifter with gear cable sorted it.

Switching to hub gears, very achievable, but it will become a bit of a "Triggers Broom" bike, needing new rear wheel, BB, chainset, levers etc.

One way or another, it will soon need quite a few components replaced and most of them are Suntour and not easy to source (possibly can be sourced but a bit of searching required). Would probably need to buy pre-owned stuff - a bit of a risk.

Also check that the hub's sprocket will be in alignment with the chain-ring.

I've run into this problem many years ago when I wasn't even aware there could be an issue. I couldn't source a genuine Suntour chainring replacement on a tourer bike so bought one that had the same fitments and it didn't "line up" well with the freewheel (from memory, I think the chainring lined up with the second highest gear rather than one of the middle gears and objected when I selected the lowest gear). I think this is a difficult issue to predict and I'm unsure how I can ensure I don't get a problem.

Make sure your frame's over locknut distance is the same as the hub.

Fortunately, I measured the width between the dropouts and it's 134mm so I think it's probably 135mm which is the same as the Alfine hub.

I need to do more "research" before I'm able to work out the entire parts cost.