Mixte 700->650b conversion. IGH & dynohub rebuild...

Ok already went over some of this in the 650b thread but the project has grown and may be of interest to some as I've noticed a few forumengers using alfine hubs and servicing shimano igh is basically the same procedure for all models. Anyhoo, I built up a mixte for my wife a few years ago from a miyata road frame. Clearances are very tight and 23mm 700c tyres are the biggest that'll fit under the mudguards so the ride is a bit bumpy, and she also wants a more upright position and to lose the coaster brake. So to make me a happy tinkerer and her a happy commuter I've decided to convert it to 650b wheels with new bars. Bought a cheap nexus 7 wheel with roller brake locally, rims, long reach brakes and bars from sella-berolinum.de and scavenged a broken shimano dh3n80 dynohub from a wheel and have replaced the internals using spares from bicicli.de. God bless ze Germans and their web shops. Here's the bike currently.

I tore the dynohub apart using youtube instructions and managed to fit the new internals without trouble. €34 is way cheaper than a new hub, obvs. I can't find the pics now but will post them later. I also stripped off the roller brake from the nexus hub and cracked it open. Sadly no before pics but believe me it was dirty and greasy as hell on the outside. You basically pull the shifting stuff and the sprocket off the DS, pop off two big dustcaps and then undo locknut + cone on the NDS to free the internals from the hub shell. As you can see in the pics it looks fine inside!

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Then time to wipe hub internals off and soak it in transmission fluid for a while.

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Blackened grease is due to metal having grated off things during the breaking in period. Has to go as it's abrasive. This hub had never been serviced. I have some of shimanos special igh grease inbound for the pawls and gear bits, and shall also put a goodish amount of marine grease on bearings and under seals as per Sheldon's recommendations.

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Last bit about the IGH. Couldn't make myself put it back together without taking it apart properly first. You can see a bunch of metal dust inside in one of the pics, the first attachment is actually the last pic, after cleaning and before rebuilding. Very satisfying process putting it back together, felt a bit like a watchmaker. Got a plastic dust cover for the rollerbrake side as I'll be putting rim brakes on this build.

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Here it is, ready for wheelbuilding. In case anyone is wondering, the dust cover for the rollerbrake is the same for 7 & 8 speed hubs, just not listed as compatible anywhere.

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how long did it take you to strip and rebuild?
I've had a few of these over the years mainly nexus 8 and alfine 8 but I've never been brave enough for a complete strip and rebuild.

About 1-1.5 hours unless you count all the time I spent researching and buying stuff (oil, grease, dustcap) before actually starting. As you say, the fear of fucking it up is pretty intense. Next time (hopefully not for another year or two) it'll be much quicker.

Edit: I had printed out step by step instructions that I got from Sheldon's igh pages. I watched three youtube vids before starting.

It's an impressive feat, I think, so well done. I've got a broken N8, broken by me doing some long over due maintenance, so have a crack at stripping that.

Have you thought about a fitting oil port? This guy details the thought process and implementation.
http://www.astounding.org.uk/ian/hubgear/oilport.html

I've never been in the situation of needing a new rim so never had the opportunity to retrofit one.

Good luck it's an interest project.

Thanks, it wasn't that hard with the service manual at hand tbh. Just had to let the fundamentals of the procedure seep through my wooden brain before actually doing it.

Re oil port I've definitely thought about it but the shell of the 7 speed hub is different (no bulge) so couldn't think of a good place to put it in.

Slow progress. Some boring wheelbuilding pics. Here's the rear being laced.

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Rims look like they'll kill you instantly. But according to da interweb they won't - some guy toured extensively on a pair. The manufacturer punches the holes in the inner wall.

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Nailed it

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Front wheel laced

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Tensioned and trued rear. Nailed front logo too. RIP Sheldon, great site.

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Looks mint!

Yes, they do. I've got a pair and have done L'Eroica and more on them and I'm still alive though :)

Yes, they do

I assume you mean they won't. Kill you, that is :-) I'm rather fond of my wife after all.

No no, I meant, they do look like they'll kill you.

If looks could kill...

I love your wheel building jig. So functional.

Thanks, it's not a exactly a precision instrument but has worked ok for a few years. Built it from scrap wood and a few metal bits which I think were supposed to hold our stove in place somehow but I forgot to attach them when I installed it ;)

Final voyage in 700c guise. A bit worried when she said she really liked it so we took a detour through some rough gravel and request for fatter tyres is now confirmed.

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Frame almost stripped.

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Given the good ol' linseed oil treatment inside.

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