I thought I had seen the info on here before, but can't find it. Have a 28 swinger on my 21 frame.
Thanks
Jeff

Yes they are....
_________________
MC21SP - Roth-tax
CBR400 - track
MC21R - sold
MC21SP - sold

Jeff

just be careful with some of the after market ones. The Wilber MC28 shock that I got with a remote reserve fouled the frame on my MC21. I had to get the remote banjo attachment to the shock moved from the side to the rear of the shock body.

Any one have any idea why they have a different part number if they are the same?

I am about to get mine rebuilt on my MC28, but seeing as I have a MC21 rear shock laying around I was going to get that one done and then just swap them over...providing they really are the same....or would I be best just to get the MC28 off and have that done rather than infecting my bike with MC21 parts?

They are interchangeable (I have a 28 sp shock on my 21) but they do differ slightly, the lower spring retaining collar is different so I guess they would have a different part number.

Leigh you definetely dont want to infect your 28 with a 21 part, I've had to stop you doing that once this week already

Yeah, take it easy Leigh, you'll make a fast bike if you're not careful.
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread

Fast...is that possible with a 28 .

My front forks have a weep so thought I may as well get them done properly while I am at it. Rear shock is pretty shot as well so may as well get that done at same time.

Bike should be pretty much sorted once the suspension is done. Then its pretty much ready for Cadwell.

There seems to be a slight difference, my Penske shock on my 28 slight hits the airbox and required a slight mod but worked fine, on the 21 it fits perfectly..the shock from Penske was tested on a 21 so I guess thats the reason. Ohlins Japan sells some very limited number of racing shocks and they are both listed as the same for the 21 and 28

I have two side by and they are very similar and all dimensions appear the same, the difference (as Paul says) is the spring mount at the bottom.

I will get a picture up tomorrow of both side by side if anyone is interested?

Yes Watfordhorn, that would be nice...!!!

Here they are side by side. The MC28 one has just come back from K-tech.

The MC21 version is one I picked up from ebay a couple of years ago...and is no longer required, and before anyone comments it did not get that dirty on any of my bikes!