Tank Slap - Motorcycle Forum

Anybody done this mod ?

Need to replace the chain and sprockets on the sp2 so was considering going for a 520 conversion.

Anyone got any feedback ?

Personally I've never seen the point for a road bike. I've asked in the past when I've been changing move but on both occasions I've been told it's not worth it unless I'm going to be swapping sprocket sizes around - there's supposed to be more choice in 520

I did it to my track 675, but tbh I couldn't tell the difference, theoretically you get lighter unsprung weight and less power absorption by the chain, but it's only going to be noticeable on a stopwatch or by an "Alien" imho.

From what I've seen it's only really worth it if you do the 520 conversion as part of a raft of improvements to get a usable increase in performance, otherwise you're paying a lot of money for a chain and sprockets that'll stretch and wear (especially on a big V twin) and will be knackered faster than a decent aftermarket item.

Cheers Kwacky.

Yes most of the weight saving benefit is in the alloy sprockets tbh. The chain is about 400 grams lighter but as unsprung mass it's similar to loosing 2.5 kg of the sprung mass of the bike.

I know it sounds of little benefit but I have reduced the bikes weight by 20 kg and a lot of that was from numerous small savings as after a few big weight savings you have to start looking for the little losses.

Deegee wrote:I did it to my track 675, but tbh I couldn't tell the difference, theoretically you get lighter unsprung weight and less power absorption by the chain, but it's only going to be noticeable on a stopwatch or by an "Alien" imho.

From what I've seen it's only really worth it if you do the 520 conversion as part of a raft of improvements to get a usable increase in performance, otherwise you're paying a lot of money for a chain and sprockets that'll stretch and wear (especially on a big V twin) and will be knackered faster than a decent aftermarket item.

The race spec 520 chain Im looking at has the same tensile strength as the recommended road 530 chain so it won't wear any quicker.

Plus it will still be even better than the oem chain specification and I only do about 600 miles a year on the SP so the chain will be good for 20 years whatever I get.

An Afam -8 520 chain (highest spec) has exactly the same tensile strength as the -7 530 chain.

Can't remember the units but there both 4180 tensile strength.

As part of an overall weight saving exercise and on a well maintained and low usage road motorbike I can't see why you wouldn't do it IMO

Cheers Kwacky.

Yes most of the weight saving benefit is in the alloy sprockets tbh. The chain is about 400 grams lighter but as unsprung mass it's similar to loosing 2.5 kg of the spring mass of the bike.

I know it sounds of little benefit but I have reduced the bikes weight by 20 kg and a lot of that was from numerous small savings as after a few big weight savings you have to start looking for the little losses.

The only difference I noticed was the sprocket wore out much much quicker, but at 600 miles a year that's never going to be a problem.

Personally I will never put an alloy sprocket on a road bike again but only because of the mileage.

Blade, didn't those tests show that the tensile strength was the same but the 525 was able to withstand the test for longer?

Afam is quality kit. I get excellent mileage from mine.

I think 520 on the SP2 makes sense if you're looking at an overall weight loss plan.

I don't know Kwacky. I got the figures from the afam catalogue. I assume the testing is to a defined standard to allow comparison otherwise it is meaningless imo.

@Monty. Did you use a hard anodised alloy sprocket as I got 12000 mile out of one on the Blade and it still had life remaining.

I got well over 10,000 on my last set of Afam chain and sprockets and that's with winter riding. The front had started to hook out.

Blade, it's effectively a yank test to simulate the loading and unloading on a chain.

Mine where Afam and I didn't get any chain stretch and yes hard anodised.

Felt like riding a wizards sleeve after a few thousand miles

Kwacky wrote:I got well over 10,000 on my last set of Afam chain and sprockets and that's with winter riding. The front had started to hook out.

Blade, it's effectively a yank test to simulate the loading and unloading on a chain.

Yes I know what a tensile test is but you implied there was a difference in time. That I don't know, the catalogue just gives a tensile strength nothing is mentioned about duration of test or too what standard it was performed.

Do yiu have more informaion ? Or a link to where you found this info it sounds very interesting

I'll look it up when I get home.