Author Topic: Baby steps towards my third bike (Read 10300 times)

fyrstormer · « **on:** February 22, 2016, 02:40:29 pm »

I bought some new bike parts today -- a Shimano Nexus 8-speed internal-gear hub, and two sets of front and rear roller-brakes. (apparently spare parts are hard to come by, and roller-brakes are engineered so all of the friction surfaces wear out at about the same time, so people generally just replace the entire brake assembly after years of use.) I'll get a front hub once I know what kind of interface the front roller-brake uses, and I'll get a shifter once I know whether or not the 8-speed hub kit I bought came with a shifter. (the listing was unclear.)

Why did I get comfort-bike parts? Well, I don't ride as hard as I used to, I already have two kick-ass mountain bikes, and I'll probably never buy a road bike because I just can't ride a bike with no suspension or off-road capability at all, so the experiment will be installing these parts on a mountain-bike frame. I'm thinking maybe a Santa Cruz Superlight, but I'll have to play it by ear once I see how the rear hub and rear roller-brake will mount to the frame. (the front roller brake has a disc-mount adaptor, which makes things much easier.) I've wanted to try this experiment for about 18 years now, ever since I first started shopping for upgrades for my Pro-Flex, and now seems like as good a time as any to start actually getting the parts I need. (specifically, getting the drivetrain and braking parts while I can still get a matching set -- the manufacturing world has a way of discontinuing pretty much every product I like, and I've been letting this idea simmer on the back burner for almost two decades, so it's time to make a move while I still can.)

Yes, it will be heavy. Oh well. My Pro-Flex weighs 30 pounds, so it's not like I won't know how to handle it.

swamp monkey · « **Reply #1 on:** February 24, 2016, 03:31:33 pm »

Yes . parts are hard to find .
i'm looking for parts myself.
Nexus inter 7 sg 7c21 along with shifter .
need for pars and rebuild a set i have .
looking to build a cruiser myself

fyrstormer · « **Reply #2 on:** February 24, 2016, 09:25:35 pm »

Quote from: swamp monkey on February 24, 2016, 03:31:33 pm

Yes . parts are hard to find .
i'm looking for parts myself.
Nexus inter 7 sg 7c21 along with shifter .
need for pars and rebuild a set i have .
looking to build a cruiser myself

Nexus 8-speed hubs are available on eBay for about $180. Some kits include shifters, brake levers, and a rear roller brake. My project is more complicated because I want to put a roller brake on the front, too, and Shimano seems to have discontinued roller-brake-compatible front hubs. I found some on a Dutch website called InternetBikes, but they only ship to Europe, so I got the help of someone here to buy a couple and ship them to me in the US.

Of course, if you're content to use a disc brake on the front, that isn't a problem, because Nexus 8-speed rear hubs are still widely available -- and if you want a disc brake on the rear too, you can get the Alfine 8-speed rear hub, which is compatible with Shimano Centerlock discs (or a 6-bolt adapter).

orange · « **Reply #3 on:** February 26, 2016, 06:23:34 am »

I use Alfine 8 with mixed results. First 2 hubs broke within 6 months each, 3rd hub seems to be better built and is slightly different - I think they made some changes ie. gears work the right way (thumb push ->1st gear, finger pull ->8th gear, originals were like rapid rise action) and it seems a little more durable.

Great when working! I like the lack of maintenance.

fyrstormer · « **Reply #4 on:** March 01, 2016, 02:23:37 am »

What kind of riding were you doing when you broke the Alfine 8 hubs? (they have the same internals as the Nexus 8 hubs, btw.)

fyrstormer · « **Reply #5 on:** March 01, 2016, 07:05:21 pm »

The rear hub arrived today. It looks like it uses the Rapid-Rise shift pattern, where the cable is tightened to upshift. I suppose it doesn't really matter on a hub that can be shifted regardless of wheel rotation or drivetrain load, but it will take a little getting-used-to as far as tuning the shifter to work just-right.

orange · « **Reply #6 on:** March 02, 2016, 08:43:24 am »

General mountain biking - nothing particularly hardcore though as I run rigid.

fyrstormer · « **Reply #7 on:** March 03, 2016, 12:53:36 pm »

Ah. Well, I guess we'll see how mine holds up over time. Once I drop the coin to actually build a bike for it, that is.

I was thinking about maybe converting my Pro-Flex to use this system, since I've got the Christini to handle off-road riding tough enough to benefit from AWD...but then the Pro-Flex wouldn't really be usable as a mountain bike anymore, since these hubs are really intended for road/path/singletrack use. Also, the Pro-Flex is pretty much perfectly dialed-in now, and I don't think I want to shake that up.

fyrstormer · « **Reply #8 on:** March 04, 2016, 01:57:50 am »

Put together the hub, brake, sprocket, and shifter today, just to test-fit everything and see if I need to buy any additional small parts. Man, that is one solid hunk of metal. Feels sturdy.

orange · « **Reply #9 on:** March 08, 2016, 06:55:12 am »

Hope it works out for you.

Just be gentle on the shifts, don't power through them like a derailleur, just slacken off slightly.

fyrstormer · « **Reply #10 on:** March 08, 2016, 02:12:41 pm »

I don't power through shifts on my derailleur bikes either, so there shouldn't be much of a change in my riding habits.

In other news: UGH, the front roller brake I ordered has apparently been discontinued for EIGHT FREAKING YEARS, and the disc-caliper-tab adaptor it requires is basically impossible to find. None of the brakes I ordered came with one. So I have three front roller brakes and no way to mount them. Thanks, Shimano, for leaving information about a discontinued product on your website without any notification that it's discontinued.

orange · « **Reply #11 on:** March 10, 2016, 07:07:27 am »

It was just this comment that made me point out the reduced pressure when shifting, "I suppose it doesn't really matter on a hub that can be shifted regardless of wheel rotation or drivetrain load".

No luck on ebay for the parts you need?

fyrstormer · « **Reply #12 on:** March 11, 2016, 04:35:42 am »

I think I found a place in Germany that can sell me the parts I need. I'll have to wait until I open the box to confirm it actually contains what I need.

fyrstormer · « **Reply #13 on:** March 19, 2016, 04:49:14 pm »

The brake parts showed up from Germany today. Just what I needed. Now I'm just waiting on a retaining nut and the roller-brake/internal-gear-hub assemblies will be complete.

Sadly they will then be promptly stuffed in a box until I have the money and space to build another bike. I've been busy blowing every spare cent on RC car stuff for the past couple years, so it will be a while before this project gets off the ground. At least I've got the parts that will be hard/impossible to find later on, though.

fyrstormer · « **Reply #14 on:** April 03, 2016, 02:26:56 am »

The core drivetrain components are complete.

Special thanks to Colin for helping me get my hands on some parts that I couldn't have shipped directly to me in the US.

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Author Topic: Baby steps towards my third bike (Read 10300 times)