Monday, October 15, 2012

Brahma gets new chain and cogs

I bought Brahma roughly 1.5 years ago. And, I have put 1500-odd miles on it. I recently noticed that changing gears using the derailleur was getting to be a bit problematic. I adjusted the derailleur as best as I could, but it still would act weird.

So, I put the El Chain Stretch-O-Meter on it and found that it was 80+ in a few links and 100 in a few. So, I said I would get the chain replaced.

Having never replaced a chain on the Brompton before, I decided I would go to the LBS; went to REI and had Jerry take a look at it.

Jerry and I agreed that it was time to replace the chain. So, we replaced the chain with a 3/32" SRAM PC 1071 chain.
So, the chain is replaced. All is well, right? Not really!

I read on the Brompton Forum on Facebook that I should also replace the cogs and the chainring at the same time, when I replace the chain. So, I ordered 2 sets of cogs and a spare chain from Foldabikes. I ordered the 2nd chain, as a back-up. The chain at REI wasn't cheap. I don't complain about REI, because of their exceptional service, but the chain was a bit pricy - $53. So, in a few days, the cogs and the spare chain arrive. Foldabikes has a SRAM chain that will work for this purpose, a 3/32" chain, for about $20. The saving grace is that REI does not charge a lot for the installation. Plus, I like the techs at REI. Now, if I only had a car mechanic that I can trust...:)

Luckily not enough wear in the chain ring to warrant replacement.

Off to REI again. Only this time, it is to get two things taken care of: 1) install the new cogs and 2) take some links off the new chain, so that there is less slack.

Jerry and I measured the rear cogs, the old ones, using another widget for indication of wear; they were worn. So, we replaced the rear cogs, with the new ones from Foldabikes.

Jerry took 4 more links off the chain. Now, I think I have about 98 links. Now, there is very little slack when I fold Brahma.
You would think I would be done, right? Well, all is well, for the most part. There are two other things that I noticed that I am investigating:

  1. When in the lowest gear, I was told that the chain tensioner should be at about a 20-degree angle from the chain stay.
  2. There is a slight kink in the SA indicator chain. I think this is making chaining to the highest gear a bit difficult. I have to push harder than usual.
HELP POR FAVOR!
I am not certain if #1 above is a must. If you know, please leave me a comment.

I plan to get a couple of spare indicator chains ordered and replace the one that's bent and keep one as a spare.

I have to wonder if the quality of SA has gone to the dogs. I have a 30+ year old bike, the Raleigh Twenty, which also has a 3-speed SA hub, with the same kinda indicator chain. That old indicator chain is rock solid.


Finally, some arithmetic to keep my mind sharp :)
Have a Great Week!

Peace :)

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5 comments:

  1. $53 for a chain? That's expensive! A 3/32 chain is what you needed. You could have even gotten away with a single speed chain for 12 bucks. The 10 speed chain is for a 10 speed rear cassette, not an internal geared hub setup like the one you have. Shifting problems in this case would have to do more with the hub than the chain and cog. Chains and cogs do wear over time, but they can also be very resilient. I have about 3,000 miles or so on my Raleigh sport road bike and everything shifts properly as long as it's dialed in.

    It never hurts to get a second opinion, those are my 2 cents. I'm a professional bike mechanic and restorer of old bicycles.

    -Johnny

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    Replies

    1. Hi Johnny:
      Thanks for stopping by.
      I am not too hung-up on the $53.
      I don't relish blowing my savings, but I got charged almost nothing for the installation of the chain, taking links off , installing the cogs, etc. Best of all, I got to learn how to do it as well.

      I have a bunch of miles on my other bikes, whose chains haven't worn out.

      I have not just only the SA Hub, but I also have a 2 extra gears, outside of the SA hub.

      And, you may be right about the slipping. I will have to check everything else is properly working.

      FIrst, order of business though is replacing the indicator chain.

      Peace :)

      Delete

  2. Great write-up Chandra! Just curious, are you running aftermarket crank gears? I was doing some maintenance on my chain this weekend (blog post coming soon), and found out I was running a 7-speed gear? Did you get a 10-speed chain because of availability or the aftermarket gears (or other)?

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    Replies

    1. Hi Fernando:
      I use a Schlumpf Speed Drive instead of the traditional chain ring.
      I have a 6 speed Brompton; 3 speed SA hub and a 2 speed derailleur.
      I suppose adding the Schlumpf makes it a 12 speed.

      I bought the 10 speed chain, because it was recommended to me.
      I typically buy good quality things. I was told SRAM is a great product.
      I have no reason not to believe that.
      I thought single speed chain was only for a fixed gear or a single speed bike.
      That's why, given I have the 2 speed derailleur, I bought the SRAM 1071 10 speed chain.

      Subsequently, I have learned that you can buy a cheaper chain, even from a Brompton dealer.
      It has to be a 3/32" chain. That will do!

      Plus, the chain that came with my Brompton, did not have a quick link.
      The new chain does.

      As noted in the post, I also changed the rear cogs also.

      After I got the chain installed, I bought a spare chain and a set of spare rear cogs.

      I am curious about your 7 speed. I will be looking for your post about it.

      Peace :)

      Delete

    2. Oops, I should clarify... it is a SRAM chain that says 7 SPD, which I would assume is a chain sized for a 7-speed. Not really all that exciting.

      Delete

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