Front end quandary?

dragonlogic · Post by **dragonlogic** » Tue Jul 07, 2015 8:42 pm

Finally decided to start re building the TRX (assaulted by a VW golf 9 months ago). Pretty sure the forks are bent so whilst my wrists are probably not up to riding before next year it may be time to upgrade. I understand my options are thundercat forks that will slot in to my yokes or an r6 front end? How much more hitting is required for this mod and do people think it's worth it. Is the increase in braking significant?

Having failed to get a replacement original fairing I'm looking at having the original one plastic welded, keeping the red tank, spraying the wheels red and the plastics Matt black. Might even hand polish the swinging arm whilst I have the time.

Onward and upwards,

Appreciate any titbits.

Ceri

Stu99 · Post by **Stu99** » Tue Jul 07, 2015 10:29 pm

Can't comment on the R6 front end conversion, but I have done an early(98-01) R1 front end conversion as I believed it was the most straight forward.
By front end I am including everything from handlebar to wheel.
Apart from the R1 front end all you need is to have a steering stem made to R1 spec at the bottom and TRX spec at the top, as well as a reducer pressed into the R1 top yoke.
Somewhere on this site I have posted a diagram showing all dimensions.
As with any forks, they will be optimal if sprung and valved to suit the application and whatever you weigh.

The difference between the front ends is like chalk and cheese.

If you really want to up the ante on braking, add a Brembo m/c to the R1 bluespots and you will be impressed.

Be aware though, that if you wrists are suffering from your accident this mod will put you in a more aggressive posture and you may need an aftermarket clip on to raise the bar height a bit.

Hope that helps you some.

trixynut · Post by **trixynut** » Wed Jul 08, 2015 11:12 am

Don't forget the YZF750 USD forks front end conversion.

Its the easiest to do: just needs a stem swap, plus your speedo drive will work, as will TRX brakes or upgraded blue spot brakes with a little filing of the lower fork leg.

Search the forum...

andyaber · Post by **andyaber** » Wed Jul 08, 2015 3:06 pm

Hi Ceri

I'm just up the road from you and have an R1 front end on mine if you want to meet and have a look. It's also got LSL riser clip ons to ease my old bones.

Give me a shout.

Cheers, Andy.

dragonlogic · Post by **dragonlogic** » Wed Jul 08, 2015 4:06 pm

That's all great advice. The yzf sounds a good plan as least amount of hassle and I'm doing it on a budget so anything I can re use is great thanks trixynut. Be good also the keep the speedo as its only got 21,000 on the clock. Where by Cardiff are you Andy and I'll come up for a spin? Be good to meet another biker in the area.

Really annoying having this weather and no bike.

Thanks and enjoy all

andyaber · Post by **andyaber** » Wed Jul 08, 2015 5:41 pm

Hi Ceri

I'm in Caerphilly.

You're more than welcome to call up or we can go/meet out and about.

I'll pm you some details.

Cheers, Andy.

cobbadiggabuddyblooo · Post by **cobbadiggabuddyblooo** » Thu Jul 09, 2015 4:24 am

You can do a simple axle mod using R1 forks and just use your Trx front wheel, calipers and discs. Speedo drive can be retained, you just need to be careful to align the speedo drive if you remove the front wheel at any time. Or you can fix a small locator for it to slide into on the bottom of the fork leg.

Multitudes of trees can be used from a number of bikes too, not only yamaha but 600-1litre bikes with a 50mm top-54mm bottom tree. ( yzf 750 uses a 56mm bottom)
Yzf uses 320mm discs too if you choose an axle mod/trx wheel on the yzf so another expense and overkill as not really needed on the Trx.
The damping on the yzf 750's with the early forks only have rebound with no compression damping but mid 90's had compression too but still an improvement over stock.

Other option is fitting emulators / gold valves to your std forks which are a quite a good improvement and cheaper option for $350 fitted.
For most just day to day riding this is a great option and value for money.
Look at how many road bikes still run right side up forks.
Your gold valves your slow and fast compression is dealt with via the adjustable shim stack and holes around the edge of the stack, with rebound dealt with via your oil viscosity.

http://www.racetech.com/page/title/Emul ... ng%20Guide
Run the correct spring rate for your weight is the cheapest and easiest step.

dragonlogic · Post by **dragonlogic** » Fri Jul 10, 2015 10:52 am

That's great advice. I have decided to go the whole hog and strip down entire bike. Engine needs a good clean and a lick of paint and I'm toying with the idea of a red frame. Planing a variant of the original red Black colour scheme. Once I have the engine out I Will take the forks off and have them checked to see if they are bent, if not I may very well upgrade them instead. It all depends what bits are around at the time I suppose.

Dropped the fairing off to be plastic welded the other day as I could not find a stock fairing for love nor money.

Will sit Down in the next few days and figure a few things out including how to post pic's on here (I've seen the section, just need the time to read it)

Most of the bike is stripped, will try and get some pic's up here to keep you all informed.

Thanks for all the help all, hoping to be back on the road next summer.

cobbadiggabuddyblooo wrote:You can do a simple axle mod using R1 forks and just use your Trx front wheel, calipers and discs. Speedo drive can be retained, you just need to be careful to align the speedo drive if you remove the front wheel at any time. Or you can fix a small locator for it to slide into on the bottom of the fork leg.

Multitudes of trees can be used from a number of bikes too, not only yamaha but 600-1litre bikes with a 50mm top-54mm bottom tree. ( yzf 750 uses a 56mm bottom)
Yzf uses 320mm discs too if you choose an axle mod/trx wheel on the yzf so another expense and overkill as not really needed on the Trx.
The damping on the yzf 750's with the early forks only have rebound with no compression damping but mid 90's had compression too but still an improvement over stock.

Other option is fitting emulators / gold valves to your std forks which are a quite a good improvement and cheaper option for $350 fitted.
For most just day to day riding this is a great option and value for money.
Look at how many road bikes still run right side up forks.
Your gold valves your slow and fast compression is dealt with via the adjustable shim stack and holes around the edge of the stack, with rebound dealt with via your oil viscosity.

http://www.racetech.com/page/title/Emul ... ng%20Guide
Run the correct spring rate for your weight is the cheapest and easiest step.

cobbadiggabuddyblooo · Post by **cobbadiggabuddyblooo** » Fri Jul 10, 2015 11:42 am

This gives you an idea on the axle mod.
The 17mm axle is not the std 17mm trx axle but I have an idea its a swing arm pivot axle from a DT. Any 17mm axle will do if long enough so easily sourced from a wreckers. I had mine made up at a motorcycle engineering shop who does nothing but bike mods and frame straightening. I have 2 wheel spacers as I chose not to use the original speedo drive.

Rich · Post by **Rich** » Fri Jul 10, 2015 9:16 pm

If you want a modded axle to fit R1 forks (98-2000) to trx front wheel I have one in the shed. Just pay post and it's yours - or wait until Wales play Uraguay and collect it from the stadium

petetrx · Post by **petetrx** » Sat Jul 11, 2015 12:24 am

What's the going rate for a set of used R1 forks? There are some on fleabay for $ 400. Is that in the ballpark?

cobbadiggabuddyblooo · Post by **cobbadiggabuddyblooo** » Sat Jul 11, 2015 3:58 am

What year are they???
Early 98-2001 are slightly longer and run 135mm travel( they have that in place on their efforts to keep the front wheel on the ground & 30mm offset) 02-03 are back to 120mm travel and a little shorter but the offset on the trees is 30mm, the same as the Trx. Later models only have a 25mm offset.
The yzf trees have 30mm offset but the bottom tree fork hole is 2mm wider.
Check the calipers as they changed to radial around 06 ????
Not really needed tho for the Trx and disc size changed around there somewhere too.
04 I think they went to 320. There is a few obscure models mid/late 00,a they used a 310mm ??? may be the R6.
$300- $400 is a good price for early forks in good nick.
Easily cost you that price if you got some from the US too.

petetrx · Post by **petetrx** » Sat Jul 11, 2015 4:22 am

Forks on eBay are 01, so I spose that's about on the money then.( $400)

cobbadiggabuddyblooo · Post by **cobbadiggabuddyblooo** » Sat Jul 11, 2015 5:08 am

Yes you should be able to utilise your Trx wheel, discs, calipers, 2000-20001 still run 135mm travel, no issue, fork tubes are slightly thicker wall and improved internals from the 98-99 model.
02 onwards they went to a 43 mm fork too.
The power output of the Trx really isn't going to need any of the bling factors of the later model forks.

Take them to a suspension specialist and for a couple of hundred$$ he'll rebuild them and change the damping curve and possibly spring rate to suit the Trx and your weight.

Do a bit of fishing around and you can find a set of trees from a number of bikes/models with a matching offset and raised clip ons get you close, just a little more forward to the Trx riding position.
No need to run yzf750 (10mm) dog bones , either Std or at most 5mm shorter is ample.

Info I have jotted down from my conversion ..
98-99...745mm fork length from the c of axle to top of fork.
Trx.......765mm fork length from c axle to top of clip on( not the top of fork leg)

Hence the 1, 1/2" raised clip ons to allow for the top tree thickness and fork length as the clip ons sit under the trees.

But if you just run the std r1 clip on I'd suggest running the std trx dogbone.

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