Saturday, January 21, 2012

Sanyo Dynohub Install

Sanyo H27 Dynohub

My commute to work often entails riding in the dark, especially during these short days of Winter, either my ride in is in the dark, or the ride home. On a bad day, I could be in the dark both ways. So, I've always needed a light for commuting. Over the years I've tried many battery powered lights, beginning with the old square wonder lights of the late 70s!

Bicycle lighting wasn't ever of huge interest to me until recently. I've found that the technology has improved tremendously over the last few years. Probably the most important development has been the introduction of LED bulbs. These are so much more efficient than the old incandescent bulbs, it has really revolutionized the field. 

A few years ago I finally decided to invest in a better quality light, and found a Sigma Pro on sale at Nashbar for over 50% off. This is a really fine battery powered light. And it's built extraordinarily tough, with an aluminum body. It's small battery pack has a good life span, and the LED puts out a strong beam.
Motobecane with the Sigma Pro LED

I have been interested in generator hubs and these too have seen some exciting developments take place over the last few years. Combined with the advances in LED bulb technology, they are looking like a great combination for reliable bicycle lighting.

Dynohubs are actually quite an old idea, Sturmey Archer having produced one many years ago. More recently, Schmidt developed their SON, followed by Shimano's nice dynohubs. Now, Sanyo has produced one, the H27, which is now available at a very economical price. I decided I wanted to experiment with this new system

The Sanyo can be found online as low as $35, shipped! I decided on the Busch & Muller Lumotec Lyt N LED headlight, which I purchased from Longleaf Cycles. Now, the reason the Sanyo was so cheap was that it is only the hub itself, you do not get a Q/R skewer or even the plastic connector for the headlight leads. The skewer I had lying around, the connector I purchased with the headlight from Longleaf, they're cheap.

Lumotec installed.

I laced the hub(32 hole) to a nice shiny Sun CR18, and installing the light was pretty easy, I had to remove one spacer to allow enough room on the brake bolt for the sturdy stainless steel rod bracket.

The tricky, (and if I say so myself), brilliant part of the install was the wiring. I dreaded having to zip-tie the wire from hub to light. I then noticed that the Motobecane's fork had small vent holes on the inside. These were just big enough to allow the 2-wire lead to pass through!

Inside top of fork; notice the wire passing through the vent hole.

The process of actually feeding the wire down the fork and fishing it out the tiny hole at the bottom was long and trying. But, after about 20 minutes of careful prodding I finally snagged the lead with a small wire hook I fashioned from thin wire:

Got it through!! Also in the picture is the wire used to fish the leads through the hole.

Man that was tricky, but really worth it, the installations is really clean. Now with the wires run, it was a simple process of slipping the supplied connector ends onto the headlight leads, then stripping the wire ends and installing them into the connector and then into the hub.

Connector installed in the hub.

I gave the hub a spin, and like magic, light! At low RPM's the light kind of flashes on and off rapidly, but at any speed at all, you've got a good steady beam. I haven't had a good chance to use the light, my last commute was not dark enough to really examine the beam, but it looks pretty good. Time will tell.

Motobecane with Sanyo H27 and Lumotec Lyt N

I like the look of the installation, the light mounted at the fork crown looks good, and my handlebars are clean now, with no clamp cluttering them up!

I added a tailight, here's the link.

Monday, January 16, 2012

How many times do you patch a tube?

How many is too many?

The other day I was in the garage, about to pull my Surly LHT off its hook for a ride. As I always do, I first squeezed the tires to check inflation. Ugh, back tire was flat! Well, this bike has Pasela tires but without the Tourguard belt, so it's not a huge surprise when I find a flat. 

So, off came the wheel and out came my patching supplies. I buy 1 inch Rema patches by the hundred in a box for my workshop. Also a tin of rubber cement, sandpaper. A recent addition is a tire "pencil" I found at NAPA autoparts recently, (to mark the location of the hole in the tube). Finally, a pair of steel tire levers, (steel really is the only appropriate material for a tire lever).
Tools of the trade.
And off to work I go. After taking out the tube, I found a hole and patched it. Pumping a little air into it revealed a second hole, so I patched that one too. When I was finished the second patch, I sat back and looked at the tube. I realized I had put 13 patches in this guy over the years! Holy moly! Oh well, I stuck the tube back into the tire and went riding.

This got me to thinking, how many people even patch tubes these days? I remember when working in a bike shop years ago, that we would never patch a customer's tube, it just wasn't cost effective even then, what with labor and then you've got to wonder if the patch will hold, etc. Nowadays, with the armored tires most people use, flats may be so rare that lots of riders don't bother. Just keep some spare tubes around and replace as needed.

Of course, being a cheap bastard, I just can't go that way. Plus, I think I've gotten pretty good at patching. You just need the proper equipment. Rema patches are the best. Always work well and stick on as they are supposed to. Getting a bottle of rubber cement is a good idea. Tubes of glue always dry out. 

Once I apply the patch, I'll wrap the tube in a rag and press the patch in a vice for a few minutes, just to make sure it sets. Then, I always stick the patched tube into the tire, and take the unpatched tube out for my spare. I think having the patch pressed against the tire walls helps set the patch, plus you will know for sure that the patch is good. A successfully patched tube is every bit as reliable as an new tube.

5 of the 13 patches on this tube!
So really, there is nothing wrong with a 13 patch tube, maybe a little weight. The one thing that would stop me from continuing to use a tube is if I have to patch over another patch. Things start to get a little dicey. But in this case, every patch is well spaced, and all are holding well.

Monday, January 2, 2012

Super compact crank for the LHT

Shimano "STX" crankset. 42X32 chainwheels.

I'm a big fan of compact cranks, the cranks with the 110mm BCD, (bolt circle diameter). This is a very useful size for road riding and gives you the ability to set up a pretty low low gear and still have a high gear approaching 100 inches. Lately I've been interested in the super compact cranks, like the old TA Cyclotourists and now Velo Orange has introduced it's Gran Cru with a 50.4 BCD that uses the same pattern as the old TA cranks. I'll probably have to pick up one of those some day.

Anyway, I was mulling over these cranks when I remembered an old mountain bike crank I had bought years ago from Nashbar. It was a clearance sale, naturally, so I got this crank for a song. The Shimano STX 5 pin crankset. These super compacts were the standard for mountain bikes in the mid 90s, but as the style in mtn cranks shifted to 4 pin, these became passe. Added to this was the fact that these were 170mm  arms which are not as popular as longer arms. 

Anyway, I got these a long time ago and have never really used them. Tried to use them on an occasional mtn bike build but I always suspected the the InterGlide (IG) sprockets wouldn't work well with non IG chains. At any rate, they sat in my parts bin for a long time. But after considering the possibilities offered by this small BCD, I decided to investigate the compatability. Finally found a reference to the IG from Sheldon Brown,(who else?), which stated that the IG would work fine with SRAM chains. 

So what the heck? I decided to make a super compact double, by removing the inner granny gear. An unusual feature of the STX is that this sprocket is bolted to the middle cog, not to the spider. 

I tried a couple of different bottom brackets, finally settling on a 110mm UN54. There is ample clearance for both the crank arms and the sprockets on my Surly LHT. But no more room for the spider on the BB spindle!
Lot's of room for sprockets and crankarms, but the inner face of the spider is getting close to the BB!

If you had a bottom bracket you could slide around a bit, like a Phil Wood, I bet you could get away with a 108mm. With the stock 32 and 42 chainwheels, there is no threat of scrapping the chainstays. I'm sure a 46 could fit, and I have ordered one. I thought I would have a problem with the front derailleur, I could not lower it enough to get it within the 2mm's I would usually set it at, the tail of the derailleur hits the chainstay! I got it as low as I could. Testing on the stand seemed to show no trouble shifting or loosing the chain.

Note the large distance between big chainwheel and derailluer.

Took the LHT out on a little jaunt to Lincoln and back to test out the new crank. It is working very well! I have to say that I really enjoyed the 42 tooth big ring. I could easily go over Sierra College hill in it, of course, back in the day, a 42 was my small ring on my Nouvo Record equipped bikes! Shifting was excellent, so much nicer than with a triple, especially if you're a retro-grouch friction shifter like me. With a 32 in the back, this actually gives me a double with a 27 inch low. If you need anything lower than a 27 inch gear, you should be walking anyway.  

Also, the IG teeth have not become a factor at all. The SRAM 8-spd chain I use works fine.

I have a 46 tooth chainwheel on order to fit this crank, so I will have some higher gears, and the gap between the front changer and sprocket should not be an issue any more. But it will probably be a while before I put it on, I could get used to a 42 for my big ring!