Chain length dilemma: Who to believe?

[Jeremy McCreary]

Thanks in advance for any help in resolving my chain length dilemma:

Go with (a) the seemingly successful length used by the LBS who put on my last SRAM EX1 e-MTB chain, or (b) the much longer chain implied by the SRAM instructions?

Bike is a 500W hub-drive with substantially lowered 1x gearing for my hilly terrain. Low gear is now 42/40 (back/front).

The LBS installed the current EX1 ~1,200 miles ago. Result: Derailleur arm at ~5 o'clock in low gear with excellent shifting performance with my Deore derailleur, Deore cassette, and narrow-wide chainring.

Due to my salty/sandy riding environment and, shall we say, less than stellar maintenance practices, that EX1 now needs to be replaced. Tooled up to do it myself with another EX1. (Retaining current cassette and chainring, as they show no significant wear.)

Plan A was to use the old length and resized the new EX1 accordingly. Then read the SRAM MTB chain instructions to look for gotchas. And lo and behold, SRAM seems to be implying a length at least 10 links longer!

How could that possibly be?? Any compelling reason to go with SRAM over previous success?

 

[Tars Tarkas]

No real idea myself, but you know what works and 10 is a lot of extra links! I'll be interested to see where this goes....

TT

 

[JGcycle]

Here's some helpful info on determining chain length:

 

[nutdriver]

The derailleur hanger in the 5 o'clock position in 1st gear does seem like the existing chain length may be a bit short. What is the hanger position when the bike is in high grade?

I would be inclined to try the longer length first to see how the bike shifts. It is a lot easier to shorten further as needed than it is to lengthen again.

 

[Jeremy McCreary]

Here's some helpful info on determining chain length:

Many, many thanks! That video led me to my oversight: The SRAM instructions meant for the sizing step to be performed in low gear with the chain bypassing the derailleur cage but didn't say so in the text.

And I failed to notice this important little detail in the accompanying diagram. Duh!

Once I followed the diagram, the SRAM and LBS lengths agreed. Mystery solved!

Lessons learned from this adventure:
1. RTFM (read the "fine" manual) isn't always enough. Gotta give the diagrams a close look, too.
2. You may never forget how to ride a bike, but you can definitely forget how to work on one — especially when that was way back in the Late Bronze Age.
3. So watch the relevant Park Tool video beforehand.
4. Hand sanitizer wipes are great for degreasing hands.

Bike was down for 10 days as I gathered parts and tools and got this discrepancy resolved. So great to be riding again!

 

[PedalUma]

The fastest way is to wrap the new chain around the ring and first on the cassette and to add an inch. Works like a charm. I did this on two bikes today. One guy was spinning out on his cassette so we installed a 58-t chainring. He was bedridden with long covid for two years. The bike has been a life saver. Now he won't be ghost pedaling as he regains strength.

 

[ronaldrodgers]

@Jeremy McCreary - Thank you for starting this thread!

 

[Jeremy McCreary]

One last question, please: The new SRAM chain came with some pretty sticky grease on it, but I plan to use Rock "N" Roll (RNR) cleaner/lube going forward.

Start the RNR now or wait till the chain's due for a lube?

 

[fooferdoggie]

One last question, please: The new SRAM chain came with some pretty sticky grease on it, but I plan to use Rock "N" Roll (RNR) cleaner/lube going forward.

Start the RNR now or wait till the chain's due for a lube?

I clean it off its a huge dirt attractor. I put it on a bottle with some water based degreaser and hot water and shake it around till it's clean. The hot water makes all the difference. I tried boiling the chain once and the gunk got super sticky and was almost impossible to get out of the pan.

 

[fooferdoggie]

Now this reminds me of the first time I had to change the timing chain on our tandem. thats the chain that goes between the front and back cranks. New chain was too large and one less link way too small. I finally looked it up and found tandems has an eccentric bottom bracket that will rotate to tighten out loosen the chain. mine has two 6mm bolts under the bike to loosen then a rod in the hole on the bottom bracket and peddle forward or backwards just a little to adjust chain tension. was sure a hassle the first several times. but now its easy I have to do it a few times with each chain as it wears it loosens up the tension.

 

[Jeremy McCreary]

I clean it off its a huge dirt attractor. I put it on a bottle with some water based degreaser and hot water and shake it around till it's clean.

Thanks! Too late for that now, unfortunately. Something I can do without removing the chain?

 

[fooferdoggie]

Thanks! Too late for that now, unfortunately. Something I can do without removing the chain?

you can take th echain off and do it. a chain cleaner or spray degreaser will do it too though it takes more time. Now I do them ahead so they have time to dry. I go through maybe 8 chains a year. this works well but it stinks and gets spendy. maybe 1/2 a can to get that gunk off the chain. https://www.amazon.com/Finish-Line-Speed-Degreaser-18-Ounce/dp/B00PANI4O6/ref=sr_1_5?crid=397SXT9JYBH6&keywords=bike+chain+degreaser+spray&qid=1707539971&sprefix=chain+spray+deg,aps,187&sr=8-5
this version works well too https://www.amazon.com/gp/product/B000AAEDC6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[rob feature]

One last question, please: The new SRAM chain came with some pretty sticky grease on it, but I plan to use Rock "N" Roll (RNR) cleaner/lube going forward.

Start the RNR now or wait till the chain's due for a lube?

Most experienced riders I know say this is the best it will ever get in regards to chain lube. That in mind, I just put it on and ride it. Seems to last for hundreds of miles before needing any care. Whenever shifting gets a little finicky, that's when I clean and apply my favorite lube. The important part is what's in the links - not on the outside. That said, anything that holds dust has the potential to accelerate wear on the exposed parts. I personally don't sweat that though as dust is going to stick to whatever you put on there as soon as you start riding.

 

[smorgasbord]

I’m late to this thread, but since you have a Shimano Deore derailleur you should follow Shimano instructions, not SRAM. Some of the wide range SRAM derailleurs might have different chain length requirements.

 

[BikerG]

Now this reminds me of the first time I had to change the timing chain on our tandem. thats the chain that goes between the front and back cranks. New chain was too large and one less link way too small. I finally looked it up and found tandems has an eccentric bottom bracket that will rotate to tighten out loosen the chain. mine has two 6mm bolts under the bike to loosen then a rod in the hole on the bottom bracket and peddle forward or backwards just a little to adjust chain tension. was sure a hassle the first several times. but now its easy I have to do it a few times with each chain as it wears it loosens up the tension.

Back in the day we used half-links to get chain tensions dialed in. Half-links were (still are?) popular with fixed gear and single speeds with non-horizontal dropouts.

 

[PedalUma]

@Jeremy McCreary,
I use an old peanut butter jar with laundry soap and water to strip the packing gunk off a new chain. It is amazing how much black crud comes off. Stuff such as Simple Green works too. Then I like to soak it in another jar of nano wax. The dry lube does not attract grit. With a quick link, removing a chain for this purpose is easy. Reinstall it off the chainring so you have slack.

 

[Gionnirocket]

Next time you boil it.. add some olive oil, carrots and a few sprigs of parsley.

 

[PCeBiker]

@Jeremy McCreary,
I use an old peanut butter jar with laundry soap and water to strip the packing gunk off a new chain. It is amazing

I'm gonna try that for my third cleaning,..

The plastic peanut butter jars are great.
The lids seal.
This is my old jar lid. The vacuum caved in the lid instead of leaking.

 

[PCeBiker]

Next time you boil it.. add some olive oil, carrots and a few sprigs of parsley.

I've got everything I need to make a really tasty Vegan Chain Lube,..

 

[Slaphappygamer]

I've got everything I need to make a really tasty Vegan Chain Lube,..


View attachment 171031

“California Blend” good choice