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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Strengthening a TTR frame
Post Info TOPIC: Strengthening a TTR frame
RodYorkttr


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Strengthening a TTR frame
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I have read an interesting post regarding the strengthening of a rear sub frame in preparation for carrying weight (clothes/camping/cooking/tool gear) for an extended trip

its here http://ttr250.activeboard.com/t60980288/load-carrying/

Both Moo & TTRfan mentioned potential extra supports to make this possible; but in differing ways.

I can weld and have made racks for the TTR.

With welder in hand..

I see the potential to put a "triangle" brace in the corners where they meet the engine cradle/frame at all four points (top, below the saddle & bottom joining the main frame)

Where/how else might one advise strengthening the frame?..Moo mentioned Lois had a mysterious supporting bar running somewhere...can anyone expand further please or is this a case of me over preparing for situation that is unlikely to happen.(I don't intend to be jumping the bike, but will be riding off road at times)?

Thanks in advance

 

Rod



-- Edited by RodYorkttr on Monday 17th of April 2017 09:45:20 AM



-- Edited by RodYorkttr on Monday 17th of April 2017 09:47:14 AM

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petenz


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use a giant loop..... weight is carryed on the rear of the seat..



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RodYorkttr


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petenz wrote:

use a giant loop..... weight is carryed on the rear of the seat..



...

 Thanks Pete, but wont the weight distribution  be exactly the same(assuming I am carrying the same load)> the same stress loads on the same points?

My racks will have multiple fixing points to the rear frame & rear pillion foot peg, while connected together at the rear to distribute the stress load evenly in the

unlikely event of me crashing

..The previous link found in overlanding the TTR- shows cracked/stress points on frames..I am keen to establish how they got there and to avoid them, if it is caused through excessive weight (excluding my rubenesque body!)



-- Edited by RodYorkttr on Monday 17th of April 2017 10:08:36 AM

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petenz


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Yes and no.... a rack tends to be more rearward... greater leverage on the sub frame...
the sides of a loop are carryed foward lower down....



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TTRfan


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RodYorkttr wrote:

Moo mentioned Lois had a mysterious supporting bar running somewhere...can anyone expand further please or is this a case of me over preparing for situation that is unlikely to happen.

It might be worth messaging Lois on her FB account Rod. She posts there regularly.

Brian



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mossproof


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According to the gentleman who now owns one of Lois Pryce's ttrs, it has no strengthening welded in, but there is more than one!

My rack (the one in the thread) worked perfectly on the Trans Pyrennees trail. I think the straight brace from the passenger footpeg bolt up to the rear end of the grab handle mount on the left hand side of the frame is enough. Admittedly I was only carrying about 20-25kg at most (and this was more than I really needed), but I think the main issue is with the flex of the frame causing fatigue when you're bouncing around and the effective load is doubled or even trebled. The brace takes this flex out of the equation. Maybe some more triangulation on the exhaust side would be advantageous, but I think the real weakness is on the left.

The other weak spots in the frame as shown in Ttrfan's pics, well I suppose you could beef those up a bit for extra insurance just to be sure you've covered the known issues.

A lot is down to weight distribution too - the big bag on top of my rack held only bedding and lightweight tent. The side bags held everything else, and heavy stuff was loaded as low and close to the footpegs as possible to centralize the weight.

Ride safe,

Simon.

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RodYorkttr


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Thank you everyone!..
TTRfan-I will ask her for confirmation,but Mossproof may have the answer, although I wonder why Lois had multiples of TTR's..personally I can't blame her though!
Pete- I agree with you..it's down to weight distribution aslo.
MossP-Your rack is pure inspiration- I have made one out of tubular steel with similar fixing points- although on a TTR Raid, not an OE. , the transfer of force downwards & inwards will be distributed in a similar way.
I recently bought an OE with racks on- the fixing points were in exactly the same position as yours...sinister!
I too had noticed the chance of failure was most likely on the side of the exhaust..I will strengthen & report back
Thanks again!
Regards
Rod

p.s  A kind forum member alerted me to a rack  from Ukraine recently...

It was really sexy...but to ship back to UK...only £260!!



-- Edited by RodYorkttr on Tuesday 18th of April 2017 06:21:43 AM

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leigh


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Moskomoto reckless 80, never need a rack again.

moskomoto.com/products/reckless-80l

There are pics on there of it on a wr250r. Mmmmmmmm

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RodYorkttr


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leigh wrote:

Moskomoto reckless 80, never need a rack again.

moskomoto.com/products/reckless-80l

There are pics on there of it on a wr250r. Mmmmmmmm

 Bit expensive for my needs!,,but thank you.



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mossproof


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I'm flattered!
I suspect the standard exhaust is a structural item, like the old xtz660 tenere, which triangulates the corner and reduces flex on that side.
I think Lois had to sell her bikes post trip in order to eat! (At least in the early days before she became a famous raconteurse/authoress/journalist!)
Ride safe,
Simon.

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leigh


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They are definitely not cheap, but awesome none the less IMO.

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