Are 15"/380mm shocks TOO long?

[Scott S]

I have a 1980 550E "bitsa bike" I'll be building from leftover parts. I'm told that the 550 can benefit from longer shocks, but that usually means something around 14"/360mm.

I found a set of modern shocks in 15"/380mm length. Is that TOO long?

I also have Sonic springs and emulators for the forks.

[posplayr]

I had Ohlins with 35mm of extension. 15" is probably the absolute max, make sure you slide your triple clamp to the top of the forks.

[Steve]

Make sure you adjust your chain properly.

The chain will be at its tightest when the front sprocket shaft, swingarm pivot and rear axle are in a straight line. With your longer shocks, you might have to slip the shocks off their mounts to lift the wheel to that position (with bike on the centerstand), but do that once to adjust the chain for proper slack, then put the shocks back onto their mounts and measure the resulting chain slack. Use THAT as your "adjust to" measurement to ensure the chain does not bind up because it's too tight.

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[Scott S]

I haven't bought the shocks yet. I'm afraid they're just a little bit TOO long.

[Nessism]

Too long unless the bike is modded (my opinion.)

[mmattockx]

I have a 1980 550E "bitsa bike" I'll be building from leftover parts. I'm told that the 550 can benefit from longer shocks, but that usually means something around 14"/360mm.

I found a set of modern shocks in 15"/380mm length. Is that TOO long?

I also have Sonic springs and emulators for the forks.

What length are the OEM shocks? I wouldn't go more than 1" over on the length personally.


Mark

[Gorminrider]

Gee you might not be able to use centerstand-it might be off the ground and side stand will give more lean too but nobody here now knows so why not "mock it up" with a jack under frame to see. ...It won't duplicate spring sag so you'll have to guess at this....

Steve's got a good point so you'll have to leave more sag when adjusting the chain too.
Making a dirt bike?

[posplayr]

Gee you might not be able to use centerstand-it might be off the ground and side stand will give more lean too but nobody here now knows so why not "mock it up" with a jack under frame to see. ...It won't duplicate spring sag so you'll have to guess at this....

Steve's got a good point so you'll have to leave more sag when adjusting the chain too.
Making a dirt bike?

Best to mock-up with those cheap eBay shock extenders. Might need two sets. Would not trust to ride but for sags tests should survive.

[bwringer]

I wouldn't do it. Anything over an inch longer and the handling starts to get pretty weird.

[posplayr]

https://www.walmart.com/ip/Unique-Bargains2Pcs-Shock-Absorber-Height-Extension-Extender-for-Yamaha-Motorcycle-Suspension/734851212?wmlspartner=wlpa&selectedSellerId=571&adid=22222222227113984301&wl0=&wl1=g&wl2=c&wl3=233439657993&wl4=pla-383128126707&wl5=9030230&wl6=&wl7=&wl8=&wl9=pla&wl10=111838760&wl11=online&wl12=734851212&wl13=&veh=sem