Long Distance Cycling - Identify this touring bike part?

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View Full Version : Identify this touring bike part?


netsirk
10-07-07, 11:01 PM
Hi everyone,

first time poster, long time lurker :-)

I picked up a Miyata 1000 this week after watching craig's for about a year (finally in my size!) and I'm in the process of stripping it down, cleaning it up, and then I'll likely repaint the frame (it's scratched to hell) and reassemble in time for Spring.

I typically ride in 100-300km events for charity or to prove that I'm insane and I'm hoping to get some real distance and some touring in next year. There were two things on the bike that I hadn't seen before and I figure you guys might be able to help me out.

I came across a part on the drivetrain-side chainstay that I couldn't figure out, it's the rectanglular 'ring' that the chain is resting on.

Thanks!


netsirk
10-07-07, 11:03 PM
And the rear cassette has a 32t cog... what the heck!? Is that for climbing straight up?

Fishy
10-08-07, 12:02 AM
I think it's called a Mega 7 freewheel - Shimano came out with them six or seven years ago. Works pretty well - I bought my in-laws a couple of Giant Sedonas back then and they were equiped with that "mega range" 34t.

They seem to be pretty reliable even in the salt/sand Cape Cod environment and the 34t works well for getting a pair of portly senior citizens up the hills coming back from the beach. (They ain't called granny gears for nothing.)

For your purposes, you can use that gear for frantic 50-yard sprints to exhaustion at 250 rpm. Helps build fast-twitch muscle, I tell you!


AverageCommuter
10-08-07, 02:53 AM
I'm pretty sure that the "ring" normally has one end of a strip of rubber (or rubberized cloth, I've never touched one myself) attached to it. I can't recall how the other end attaches but the piece of rubber is meant to be a chainstay protector.

LWaB
10-08-07, 05:20 AM
I don't agree with Average Commuter, the item he is thinking of are usually installed in pairs and are mounted closer to each end of the chainstay.

You are already using it exactly as designed, a chainrest when you take the wheel out and an anti-chainslap protector when the wheel is in.

netsirk
10-08-07, 09:30 AM
For your purposes, you can use that gear for frantic 50-yard sprints to exhaustion at 250 rpm. Helps build fast-twitch muscle, I tell you!

LOL! I think that's a Chris Carmichael workout called "blurry-legs" or something no?

netsirk
10-08-07, 09:35 AM
You are already using it exactly as designed, a chainrest when you take the wheel out and an anti-chainslap protector when the wheel is in.

Excellent, and I wasn't even trying!

I am going to have to repaint the frame though, no dents or damage but the finish is destroyed. I'd like to keep the decals somehow or just recreate them. Is there anywhere I can just buy them?

Thanks for your help guys, that little thingy was puzzling my brain!

gosmsgo
10-08-07, 10:09 AM
HEY,

Dont call them granny gears.

I have a 22 up front and a 30 in the back that I use quite often.

Of course that is when I am using the model 96 bikesatwork trailer with 300 plus #'s on it going up a hill.

netsirk
10-08-07, 10:22 AM
I think I will learn to respect my 30x34 gearing the day I do that :-|

http://www.bikechina.com/images/tbernst.jpg

supcom
10-08-07, 05:20 PM
The metal ring is a chainstay slap guard. Simple and effective.

Cave
10-09-07, 01:38 AM
Do a google search on decals, or ask in the framebuilder forum.

I know Harris Cyclery has some vintage Gitane decals (I might decide to repaint my fixxie after all...)

Sixty Fiver
10-09-07, 02:19 AM
Those gears are made for extreme climbing...

Shimano didn't originate the idea of the mega range freewheel as you can find many older examples of freewheels that also have some pretty huge cogs and many of these come from a time when many bikes ran doubles and a larger rear cog offered some much needed lower gearing.

If you are riding a loaded touring bike in the mountains, a gearing like this made sense.

The megarange freewheels were also used on mountain bikes to offer that incredibly low bailout / climbing gear and I ran one for a time with a single 34 tooth ring up front... I could climb damn near anything despite not having a granny ring.

I recently found a 14-32 Suntour freewheel and used it on a Miyata I built up for a young lady I know...her bike runs a simplified 1 by 6 drive with a 48 tooth ring up front and the 48:32 is a low enough gear for her to handle all her climbing needs.

LWaB
10-09-07, 05:26 AM
Suntour used to make a 14-38t 5sp freewheel, the AG.

thechamp
11-14-07, 01:28 AM
Looks like half the mount for one of these (http://www.velo-orange.com/ruslgu.html). Is there a break in the paint where the other one might have been?
And I was spinning 24front 34 rear last weekend. Unloaded but steep as all get out.

LWaB
11-15-07, 01:13 AM
...which is what AverageCommuter suggested in post #4.