# IGH Conversion Questions



## escapedturkey (Oct 8, 2015)

I'm planning to ride in a more rainy climate.

Three main questions:


How do I know if my bike can accommodate an IGH?
Is it possible to convert to an IGH that's equivalent to F: 36/22 R: 34/11?
Can you suggest a brand/model/wheel less than $500?

I'm mainly interested in lower gears to tackle hills and haul stuff. I ride slow anyways.

My current setup is grip shift 2 x 9 with SRAM X.7 9-Speed and grip shift with 26-inch wheels.

Is there a grip shift compatible IGH system?

I've been using this site for gear calculations - Bicycle Gear Calculator

When I compare in the gear calculator to include my front derailer, it warns of 'high torque.' Are they saying it'll burn out the IGH? Or what exactly does that mean?

I know, lots of questions.

Thanks for any help.


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## Surestick Malone (Jan 24, 2004)

- You'll need to make sure the spacing between the dropouts in the frame matches the hub as well as the axle type (Standard QR or bolt-on axles only for IGH at this point) but I'm guessing 2x9 is standard QR. 
- Some IGHs are limited to a certain minimum input gear ratio to prevent putting too much torque through the hub. "Burning it up" isn't the issue so much as breaking parts. Some people here have had no issues running a lower gear ratio while some seem to have issues no matter what they do. You can probably go a bit lower if you're light and easy on your equipment but you'd be voiding any warranty. 
- With a $500 budget Rohloff is out but the Sturmey Archer and Shimano hubs below Alfine 11 should be within your budget. Remember to budget for, at the very least, spokes, a wheel build, chain, new cog, and a new chainring assuming you're re-using the rim & nipples to keep it cheap. 
- I don't think the Shimano hubs have gripshift style shifters but Sturmey Archer might? The one advantage to Gripshift is you can shift more than one gear at a time, the Shimano shifters are one push for one gear so shifting from one end of the range to the other requires a lot of pushes, it's noticeable going from derailleur gears where, at least for downshifting, you can shift several cogs at once. 

Make sure your hub matches your brakes (get a disc brake hub if your bike has discs) and has the right number of spoke holes. 
Remember you're going to have to figure out some way to prevent the axle turning (Shimano uses anti-turn washers in the drop-outs, I think Sturmey Archer uses a lever arm against the left chain-stay). 
Also, if you have a full-suspension bike you'll need a chain tensioner. 

You're not going to get the gearing range from a gear hub with your budget that you are getting from your 2x9. 

I have a commuter bike with an Alfine 8 and a belt drive. It's nice, the lack of maintenance is a plus but not a big one, the shifting isn't as seamless as a good derailleur set-up and the big gap between the 5th and 6th gears is annoying. It works on the road as a commuter but I wouldn't want it off road. 

Have you considered one of the lower cost 1x drivetrains? I don't think the hub-spacing changed from 9 speed to now. If you get one with an 11 tooth small cog (as opposed to a 10 tooth) you can use your existing freehub body (so no building a new wheel) and you'll get all the low range you want based on your chainring size.


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## escapedturkey (Oct 8, 2015)

Surestick Malone said:


> Have you considered one of the lower cost 1x drivetrains? I don't think the hub-spacing changed from 9 speed to now. If you get one with an 11 tooth small cog (as opposed to a 10 tooth) you can use your existing freehub body (so no building a new wheel) and you'll get all the low range you want based on your chainring size.


I'm going to check out that option. Based on everything you said, sounds like an IGH conversion be might too much of a hassle and not provide the benefits I'll need, especially since I'll be encountering steep hills.

Thank you for your in-depth analysis and insight. Very helpful! :thumbsup:


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## Ailuropoda (Dec 15, 2010)

escapedturkey said:


> I'm going to check out that option. Based on everything you said, sounds like an IGH conversion be might too much of a hassle and not provide the benefits I'll need, especially since I'll be encountering steep hills.
> 
> Thank you for your in-depth analysis and insight. Very helpful! :thumbsup:


Unless you go with a Pinion (12 or 18 speed) or a Rohloff (the undisputed King of IGHs) you just won't get the gear range to come close to a 2x9.

The Pinion C1.12 (the most common choice for mountain bikes) has a gear range of 600 percent. I can assure you that the low gear is stupid low and the high gear is pretty tall.

The Rohloff is close with 526 percent and you can pick chainrings and sprockets to optimize the setup for how you ride. i wanted lower gears on mine and sacrificed some top-end speed.

But 500 bucks isn't a lot considering everything you'll need. As Surestick Malone suggested, a 1x system might do the trick. They're reliable, easy to service, and pretty cheap now. I think you can get a complete SRAM NX Eagle setup for about $375. That is a phenomenal price for what you get and they work perfectly. I can hardly tell the difference between NX and the pricy XO1 which is four times the prices.

The NX cassette does not need an XD driver and will fit on a Shimano freehub. This will give you 12 speeds and a 520 percent gear range.

I love IGHs but they're not the optimum solution for everything.

https://www.backcountry.com/sram-nx...7_k_&msclkid=19602cfa0f7414b69ec573af64add567


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## Weinerts (Feb 3, 2011)

I built my Pugsley up with a Sturmey Archer 5 speed - and it has been a blast - I don't care about trying to make it like a 2X9 or whatever drive train - I just ride it. 

right now - it is has a 22 X 18 on it and it gives me good mountain bike speeds (about 10 mph on the flats) and climbing beef. Really fun. 

The biggest problem is removing the rear wheel to change the tire.. it is a bit messy.


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## escapedturkey (Oct 8, 2015)

Ailuropoda said:


> I think you can get a complete SRAM NX Eagle setup for about $375. That is a phenomenal price for what you get and they work perfectly.


That looks like a great option. Thank you. :thumbsup:


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