[tjet]

Hi dudes,

I'm about to buy a used stock swingarm and have a welder friend modify and extend it.

How much should I extend it?

For reference, below are some wheelbase lengths for various bikes (that I've owned, liked, or lusted over). I was also going to add weight & fork angle, but too much research needed.

• TW200: 52.2"
• XT225: 53.1"
• XT250: 53.5"
• XR250: 55.1"
• TTR230: 54.5"
• TTR125: 50.0"
• YZ250F: 58.1"
• YZ250FX: 58.3"
• YZ250X: 58.5"
• MT-3: 54.3"
• RD400C: 51.9
• GT380: 54.3
• FT400 Ascot?
• XJ550 Seca?
• TZ250?
• DT250: 55.9"
• IT250: 57.0"

Cheers,

Tracey

 

[Ski Pro 3]

The consensus is 2" extension. This really helps with hill climbing, keeps the front tire from lofting. Also plenty of clearance for the ATV tire mod. The extra lever effect from a longer swingarm makes the rear suspension a bit softer.

 

[SEADUB200]

2-3” extension is what most have done for trail-work. More than that & you’re looking at spring/shock replacement, or modifications.

Seems that doesn’t throw the overall geometry too far out of whack to adversely affect handling, except for the better, especially on steeper, loose hill climbs & also if you load on gear or ride 2-up.

Gives it a better balance. Some have reported better trail handling as well with the extensions, as it seems to give you more ability to slide/brake, or rear-steer the bike than the stock setup.

Search “swingarm” & you’ll find this is a pretty well covered topic.

 

[Workingman]

In my opinion 1 3/4 to 2 1/4 on off road is all that is needed on any bike ...

 

[PlacerLode]

The correct answer is……………1 1/2”

I had a 2” extension with ATV tire it was a bit too long IMO

lol there was an old news guy who always answered that way I think it was John McLaughlin

rather than cut and extend the arm I’d build a new rear plate and that way you can even move the axle hole upwards to correct for any change in rake at the head tube created by raising the rear height when you simply extend the tubes

 

[Kingsize]

Agree with everyone here. Probably 2" inches if you are welding. Or get the JNS Engineering one at 3" if you want a bolt on solution. TW200 Bolt-On 3” Swingarm Extension

 

[tjet]

Yeah I got the JNS kit. I've also decided on doing the trailer wheel mod at the same time, but I plan on using a 50-50 tire for steetability.

 

[Fred]

Too much extension and one can get conflict with stock fender on fuel suspension compression. I am happy with a 2" extension. Slightly increased my turning radius which was noticeable on a pair of lock-to-lock turns between boulders on one of my trails where I didn't have the needed extra inch clearance.

 

[reddave]

I have the JNS 3" and I do believe it is just a bit too long. As Fred mentioned, I experienced ATV tire clearance issue with an already shortened factory rear fender. I had to trim off all material beneath the license plate mount and also bend my plate back a bit. I would say that a 2" extension would likely be ideal.

 

[tjet]

Any pics of your JNS adapters installed?

 

[vhortykho]

Search works good. A couple reviews too.

 

[tjet]

Yo i know how to use the search. I was asking the reddave if he had a pic of his install.

 

[vhortykho]

JNS Bolt-On Swing Arm Extension

Guys, please be sure to post details about your chains - either if you extend your current one, or get a new one. I'm hoping to order the exact length chain I need. As I mentioned before, I'm doing a dual sprocket mod at the same time (47/52) while retaining the stock 14T front sprocket. Cheers!

www.tw200forum.com

You have posts above and below his pic.

 

[imlost]

Thought I'd add my 2 cents to this topic and add my opinion on the optimum length of an extended swingarm. I only have experience with a commercially-available swingarm that can be purchased through a website in Japan. I believe this swingarm is 6" longer than stock, and you can see it in the thread I posted about the Stretch Rat bike I purchased, which came pre-modified by the previous owner.

For street riding, I don't experience any negatives in handling. The only thing that is noticeable is the increase in turning radius, which is typically not a big deal on streets. On my bike, the whole fender and back half of the subframe was deleted, undoubtedly for function as well as aesthetics. The seat height grew only a fraction of an inch, which was surprising to me.

If I was going to attempt to ride this bike on trails, I'm certain I would not like the restriction in turning radius. If I was building a swingarm from scratch, I'd only make it long enough for an oversized tire to clear. Anything longer will result compromise in other aspects.

 

[flat4]

My JNS 3 inch extenders are working great for me in tight single track.