kmcrawford111

Hello everyone,

I am considering converting one of my bikes, a Swobo Dixon, from using an iMotion-9 IGH to a rear derailleur. There is currently no derailleur hanger, but I have read about some hangers that can be added by attaching to the axle. I would prefer that to drilling into the frame (Aluminum). I've attached a picture of the rear hub area. Would such a conversion be possible on this bike considering the design of the stays, etc.? If so, can someone point me to suitable parts to buy? A hanger that is compatible with typical derailleurs would be ideal. I would probably be using a freehub, and I'd prefer to be able to have a wide range of sprocket sizes. The dropout spacing is 135 mm. The chainline of the IGH is 48.8 mm, and it seems to me that this should work fine with a standard freehub wheel build, based on what I've read at sheldonbrown.com.

Yes, I know my chain is rusted. Any advice would be greatly appreciated!

FBinNY 

There might be adapter derailleurs or hangers made for folks like you wanting this change, but IMO Most bikes with track dropouts are ill suited to derailleur conversion.

bobotech

I would really just consider getting a different frame. Even a 100 dollar Nashbar frame would be much easier to build up and would be fine. You could put a claw style derailleur hanger on there somehow I bet though. Wouldn't be optimal though.

Kimmo 

If you have a 135mm frame there, I say go for it, if you're not worried about having one of those ugly claws on there.

Would be a bit of a PITA removing and replacing the wheel with the derailleur having to come off too though.

To do it right* you really need a rear-opening claw, and I'm not sure such a thing exists. Although it wouldn't be very hard to make one.


*Actually, do to it right you use a frame that has an integral derailleur hanger (and IMO that goes for the front too), but I can see you're not too fussed about the aesthetics.

I don't believe a claw necessary hurts indexing, but I wouldn't be surprised if a typical one is a little too flexy for 10s.

Then again, what with the expense of buying all the parts... you might as well just get another bike. Grab a nice used one that just needs some TLC.

cny-bikeman

Although there are good arguments above not to pursue your idea I see three concerns that have not been addressed.

• The fender stay and bolt may interfere with a claw adapter being mounted, even with the axle all the way forward.
• The claw adapter is designed to mount at a downward facing angle (to match the typical forward facing dropout angle) in order to place the derailleur at an optimal position under the cogs. Your dropout is horizontal, which would force the derailleur much farther forward.
  
• The seat stay ends are quite large and may protrude enough to interfere with the chain when on the small cog, especially if they protrude inward the same as they do on the outboard side.
  

Kimmo 

Good calls.

I considered the angle, but figured it'd prolly be alright... and not an issue for a custom claw.

Burton

If thats really a 135mm rear hub spacing the conversion is pretty straightforward. Personally I'd skip the add-on hanger idea altogether and go with you original axle mounted idea.

Absolutely no conversions or work needed to the frame.

You will need both an axle mounted rear derailleur and a rear hub built or modified to accept an axle mount derailleur. Shimano Hone components are perfect for the job. Watch the derailleur selection as they are available in both vertical and horizontal dropout mounts. You obviously want a horizontal mount. They're also available in high normar or low normal configurations. These are discontinued items that originally retailed here in Canada for about $130CDN and can now be picked up for about $30.

Same story for the rear hub. Hone hubs are still available if you want to build your own wheel. Alternatively replacement axle kits are available (an extra long 10mm solid axle with cones and nuts) and will replace the axles on most Shimano hubs. The freehub on a Hone was originally the same part number as an XT. Pick up whatever's cheaper thats available.

I'm currently running that on several bikes - less the horizontal dropouts of course, and was interested in a bombproof setup fot touring / transportation myself. It works very nicely.

Kimmo 

I was of course thinking that was one and the same with using a claw, but before pooh-poohing you, I googled, and what do you know.

Blow me down. And not just one new setup, but there's another too:

Where will it end?

cny-bikeman

Direct Mount is way too pricey, but the Hone systems in not quite as bad - although at about $50 or so shipped it's certainly not cheap.

Retro Grouch 

Valparaiso! What do you need gears for? I remember doing a 50 mile ride in the Valparaiso area and the biggest hill we climbed was where the road went over the railroad tracks.

HillRider

It's like riding in southern Florida where I need two gears: with the wind and against the wind.

fietsbob

>>> FWIW Lots of DaHon folding bikes used the regular derailleur mount in a rear opening dropout.


But , why not get the better IGH?

Replace the iMotion-9 IGH, with a Rohloff for more gear Ratios, & wider range
.. if that is your desire..

The German company made them for Mountain biking in the first place..

I use the whole 526% range of mine, where I live..

Burton

$50 ain't cheap enough for a derailleur and hub**********? Where could you get anything else even close to that quality for even twice the price?

The last Hone rear mech I bought was $25 and $15 shipping. The rear hub complete was $30 and free shipping. Conversely the Halo Spindoctor hubs were about $125 each and the conversion axle alone was $35. I'm thinking that anyone moving from an IGH probably will want a 9 or 10 speed drivetrain which rules out a Tourney hanger mount anyway. Even just a Deore rear mech would run around $50 and still needs some way to attach it.

krome

Isn't that a pretty well regarded IGH? What is your motovation? Hub shot? Need more gear range? Seems the thing to do would be to add a front derailler and a second chainring. Then you just need a chain tensioner, which should be much easier to install.

kmcrawford111

Thanks so much, everyone. Much appreciated!

krome,

My motivation is that I'm planning on doing an ebike conversion (front hub) with a target cruising speed of 25 MPH, which will probably require different mechanical gearing to work efficiently with pedalling. I'm going to be replacing my handlebar at the same time (with one that will fit me better), and my experience hasn't been all that great with the iMotion-9. I know some people love IGH, but mine frankly hasn't been maintenance-free as advertised (and I mean beyond cable adjustment, which I have no problem with).

1. I've had the entire unit replaced already, and the LBS mechanic who worked on it said the inside of the original one was "trashed" inside. To be fair, I had the LBS work on it first because I broke the plastic part where the cable exits the hub, which was entirely my fault. But the trashing the LBS mentioned was unrelated. Except when the hubs were less than a year old, I've always had some slippage in gears 5-6, no matter how much I adjust. I spent a great deal of time trying to find out how to lube the thing even though it's touted as not needing that, at least for years. It wasn't until just recently, some 4 years after buying the bike, that I learned I can lube theough the disc brake rotor bolt holes.

2. It seems it's discontinued anyway. As this bike is used as a regular commuter, especially in the winter (when I use the unassited road bike less), that means I may need to convert eventually anyway.

3. The weight of the IGH doesn't seem to outweigh the *claimed* lack of needed maintenance.

4. I like to be able to fix things myself. With a derailluer, I can see what's going on.

As I was saying, the conversion is likely going to "want" higher gearing. After further thought the RD alone probably won't get me there, because I'll still have the midsize chainring.

What I'm leaning towards now is just seeing how things go as-is, and probably installing a larger single crank accordingly. When I *need* to replace the iMotion-9, I'll consider those Shinano Hone parts, or MAYBE another IGH for 135mm spacing. I remember reading that the Gripshift for my iMotion is specific to the hub, though - this is why I was thinking about doing the conversion now, with the new shifter on the new handlebar.

The Hone parts do sound like the better option, since the different IGH option likely will change the chainline.

bobotech

Why don't you just consider the easiest and probably cheapest solution which is replace the frame? Then you can get all normal easy-to-get standard parts that aren't all that expensive? Just seems the simplest way.

Like i mentioned above, the Nashbar fames are cheap and quite nice and have good reviews from a lot of people including members here.

Burton

If you plan on an e-bike conversion with a front motor make very sure the fork will handle it. Torque arm or an equivalent will be required.

Not sure why you think higher gearing will be necessary but if so cranks from folding bicycles are available with chainrings of up to 64T in size and will bolt right on. Of course that might compromise your ability to push that thing around WITHOUT a motor assist.

krome

Now that you've commented on the hub, I think I remember the Sachs/SRAM 7 speed was the really well regarded one, well regarded as far as durability. I have a couple laying around but haven't really used them yet. I've been very pleased with my Shimano Nexus 8, but I've only got a years worth of time on it thus far.

Edit: One of my Sachs 7 speeds has a busted planetary gear carrier. But it was broken when I purchased it, so I'm not sure what the circumstance of its demise. It was a drum brake version, so I purchased it with the intent of getting it fixed.

kyselad

Personally, I'd also be inclined to go this route. Probably more like $200 if you went with a Nashbar disc-friendly frame and fork and then moved everything over, but I'm sure you could make a good chunk of that back flipping the Swobo frameset on CL ("super track star commuter frameset!"). The IGH setup seems well suited to a winter commuter, so I'd probably just try a more reliable hub if it were mine. But I do understand the advantage of having a simple, readily serviceable derailer setup, in which case why start by making things needlessly non-standard right out of the gate?

fietsbob

Why not just buy a turn key E Bike , if the goal is to have one? Asia is a Price leader there too..

conversions, factoring in labor and parts will cost More.

kmcrawford111

fietsbob,

I don't like the style of the overwhelming majority of turnkey ebikes. Most of them look too much like beach cruisers or town bikes, and neither is suited to my commute. Plus, their components generally suck as far as I can tell. Even the Stromer - which I generally like - has Sora components, and it's $3-4 K. Despite my reservations about my iMotion-9, the bike on the whole has been solid, and I know it works well as a winter commuter - and I believe it still will with this conversion. The only other issue I have is that the handlebars feel uncomfortable now after being used to my road bikes, but I hope to remedy that during the conversion. I'm out to get a quality ebike to replace most of the ~50% of commuting I do with my truck now. I don't have any confidence that any bike costing less than my conversion will do that.

Plus, I'm looking forward to the project.

kmcrawford111

I know I'm reviving an old thread here, but I came across this today:

https://www.biketoolsetc.com/index.cg...tem_id=SU-550I

This seems to be EXACTLY what I was looking for. If this truly will allow me to use a standard RD, this would be great. Not sure what the small part is for, though. Can anyone enlighten me as to any possible reason this wouldn't work for my application?

I've done the eBike conversion, and the gearing works well enough for now, but it could stand to be higher. The iMotion-9 continues to act up despite my fussing with its adjustment and lubrication. I've thought about going to an iMotion-3, which is still in production, but I would prefer a reliable RD.

What I don't understand about some of the components listed above i.e. Shimano Hone is: why would a certain hub be required to work with that (Hone) RD? What is different about that hub? It seems to me the spacing must be the same, or at least similar to any other 135mm hub. And wouldn't limit screw adjustments compensate for whatever small differences (vs. a more typical RD setup) there might be?

EDIT: I understand that this part would make removing the rear wheel much more of a hassle... at least compared to an integrated-hanger setup. But I'm not sure it would be (at least much) more of a hassle than it is now with the IGH, and I use Schwalbe Marathon Plus tires, which have worked so well for me over many thousands of miles that I basically don't worry about flats. I've never had one with these tires.

EDIT 2: Maybe that smaller part is used to keep the hanger attached to the dropouts when removing the wheel (and for extra support)? That would be sweet...

cny-bikeman

You might want to look way back at post number 5

unterhausen

#nothingistrue

kmcrawford111

Thanks for your responses. I very much appreciate your insight. I did re-read that post.

* 1: If there is a small amount of interference, I don't see a problem with grinding off a little of the material on the hanger there to make it fit.

* 2: I don't doubt that having the RD further forward isn't optimal, but the design of this part (the one I just listed) doesn't follow suit. I would hope if it didn't work as advertised, it wouldn't be for sale.

* 3: I just looked at the inside of the seat stays, and they don't protrude inwards. If they did interfere with the chain on one or more sprockets, couldn't I simply adjust the H limit screw accordingly, and not use (and maybe not even install) those sprockets? I don't need many gears, but I do want a wide range - low for bailing me out if the electric system fails and I have to go uphill, and high for pedaling when the electric system is working. My understanding of freehubs is that they allow a good deal of flexibility in gearing.