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Lower fork clamp

PostPosted: Wed Oct 17, 2018 8:42 pm
by No side stand
I scored this lower fork tree recently, thinking it may have been an all elusive XLR lower. But now I don’t know???
Part number forged on the tree is H664
1” inch stem (didn’t notice that at time of impulse buy) which is 7-11/16” long (196mm).
To give a comparison, the stem on a K and Sporty is about 15/16” diam and 6-15/16” (176mm) long.
It has been machined for K model & Sporty 33.30”mm fork tubes but the centre is 165mm instead of 167mm
It has rake built into the stem like an XLR triple tree.
Anybody know what it is?

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Re: Lower fork clamp

PostPosted: Wed Oct 17, 2018 8:43 pm
by No side stand
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Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 12:16 am
by Ferrous_Head
1 inch stem = Big Twin.

Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 7:52 am
by Mutt
ain't that a Triumph 650 lower tree?

Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 9:50 am
by hugoct
Triple clamps do not affect rake.
The angle of the steering stem determines the rake.
Triple clamps do affect trail.
Triple clamps determine the offset between the steering stem and the fork tubes.
Triple clamps are seen in various offsets, tube diameters, widths between tubes, and with tubes that are parallel to and not parallel to the steering stem.
The XLRTT triple clamp set is not unique to the XLRTT.
The fork stem and bracket and the top bracket are the same for a particular year KR, KRTT, and XLRTT.
The "H" casting number prefix on the steering stem is ubiquitous with period Triumph castings.

Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 6:24 pm
by hayleyl
Looks like a Triumph lower tree to me. Cheers Hayley

Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 7:17 pm
by No side stand
Thankyou to all who helped identify the part. After the suggestions posted, I sent some pics to a friend who sells old Trumpy parts, and he confirms that is old Triumph.
I was ratting through boxes at our second-hand Harley shop looking at fork sliders and triple trees for my XLR projects when I came across that different looking lower clamp. A friend had told me how to identify the lower clamp for my XLR. Apparently the stem leans forward in 45701-52R. When I spotted that clamp and not ever being a Triumph guy, and somewhat prone to impulse buying, all I saw was “stem leaning forward” and it was all over for me. Into my pile it went.
The same friend has lent me the upper bracket 45738-58RA (see picture) for comparison, but he doesn’t have the lower clamp. Can anyone post a picture of the lower clamp that mates to the alloy clamp I have pictured.

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This picture shows the difference between a stock Sporty upper clamp and XLRTT and I guess KRTT part45738-58RA.
appologies on the picture size. Still getting used to the forum.

Re: Lower fork clamp

PostPosted: Thu Oct 18, 2018 7:31 pm
by hugoct
The lower with stem is the same regardless which "R" top clamp you have.

Re: Lower fork clamp

PostPosted: Fri Oct 19, 2018 2:32 pm
by No side stand
hugoct wrote:The lower with stem is the same regardless which "R" top clamp you have.


Hi Hugot. Thanks for your reply. When you say “The lower with stem is the same” I’m hoping you can give a bit more information as I’ve never seen one. What is it the same as?
Steve

Re: Lower fork clamp

PostPosted: Fri Oct 19, 2018 3:56 pm
by hugoct
The lower clamp with stem only came in one "R" iteration.
It doesn't matter if you have the 58R aluminum top clamp or the earlier version.