Wednesday, May 18, 2011

Up Until 2:45am Working on New Gearing

I picked up my new wheel yesterday and was so excited to install it! After finishing up the installation, I remembered I needed to swap out my corresponding shifter to an 8-speed (from 7) to operate the new 8-speed cassette. Being me, I didn't want to rest until I finished. Needing at least 5 hrs of sleep to operate normally, I hit the sack at 2:45am.

So how did all this happen?

Assuming products of the same manufacturer would make compatible parts, I tried to get all my components together last night only to find out this afternoon that they do not work together!

The SRAM MRX Comp 8-speed shifter has a 2:1 ratio. The ratio comes from how much tension the cable makes based on a single gear shift of the shifter. The ratio needs to match the rear derailleur that it operates. The derailleur I have is the stock SRAM 3.0. I only learned recently that it has a 1:1 ratio, meaning it is not compatible.

What a waste of $12.

Amazon has some good prices and with the Prime membership that ships stocked items in 2 days, I guess I sometimes get overly excited and button happy - mouse button that is, which translates to quick purchases.

So the question now is do I get a new shifter or a new derailleur? I really like the grip shifts as opposed to the index shifting or rapid shifters, so I'm leaning towards replacing the rear derailleur with a compatible one.

However, I just remembered that Mike gave me a twist shifter a couple weeks ago. I wonder if it's a 1:1 ratio one. If it is and it's an 8-speed, it'll work! It'll be silver and won't match the other side, but at least it'll work - if it does.

On my trip to Monterey to pick up the SRAM 3x7 IGH, Andy also gave me a couple high end shifters (with faded numbers) and a nice derailleur to go with it. Both are supposedly high end and after doing some research found that the components combined are sold for an excess of $120. That's a lot compared to the $12 shifter I got from Amazon, eh?

Spend additional monies and buy either a shifter or a derailleur.

I'll give the first two options a try when I get home and will report back later.


Okay, it's later. I didn't have the parts for Option 1 so I dug up the XTR derailleur that Andy got me and it works! It's got 1:1 ratio. After 40 minutes of adjusting, the chain finally moves through all the cogs. It can still use some tuning, but for now this'll do. I didn't have enough time to take it around for more than a few runs up and down the block.

So far the trike rides fairly well considering the extra weight of the new wheel. I'm pleasantly surprised. I won't be able to gauge the performance difference accurately until I take it for my routine ride. Another variable worth noting is the new Marathon tire that replaced the lighter weight Marathon Racer.


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