The stock TLR frame is not that bad really, and we have never had any problems with cracking on bikes being ridden in the UK twin-shock championship. I would guess that the cause of any cracking is likely to be related to bikes with stock suspension (very poor) being ridden in serious competition, and suspension bottoming out becoming too much for the frame after a while.
I know you comitted to riding vintage this year and so far kickin` ass. But do really take that pile with you everywhere!!!!!!!!! Take a reflex with you to a flat track. Portable, variable speed, off road chair? Just add Tecate cup holders.
I'am VERY SUSPICIOUS about the physical coherences between a Honda Reflex standard suspension and a probably better suspension, depending cracks to frames as the force on earth with: 9,81 m/s² is everywhere the same? But You never know may be here we will discover in the answer a new Nobel prize Or the increasing of hernaited disks? Very interesting thread in epic as in scientific matter, I might consider to get one of these Honda 4-strokes for my personal mental training too ???
A TLR running in a UK championship series currently, has modern 38mm forks, and special long travel rear shocks. The rider has already broken two 4140 front spindles, even though the bike has modern forks fitted. This being the case its very easy to see how problems with an ERW frame, when used in extreme conditions (Reflex suspension in serious competition for instance) might occur. Most of the rear suspension forces are going to be directed into areas where the wishbone frame tubes are joined to the tank tube. Bikes which are forcefully bottomed out, or have been ridden very hard in the past, will almost certainly have crack damage on these welds. Solution is to TIG weld the cracks, and fit rear suspension that works better.
Using 38mm forks on twinshocks is illegal in Germany as this is not a contemporary component for this class, you will be excluded from classic competitions with this setup. In my experience you only can take serious obstacles and steps with a good suspension, with a "sponge bob" type suspension it will plain and moving said: not work. When it not work there is no big risk to crack something beside going downhill down steps ... but in my limited empirical knowledge you only can go down in a section after you have before got up hill or vica verce of course.
Like it or not damage to frames is greatly increased when old twin-shock bikes are being used in serious modern competition, and are still fitted with 30 year old suspension that doesnt work that well. Its astonishing that many riders are quite prepared to spend considerable amounts of money on new frames, alterations to motors etc etc, but when it comes to suspension a low price and trick looking appearance, seem to be much more important than parts which work properly.
I don't care what other people sometimes do for silly things so where is the beef? I might feel sad about the absent of the right use of resources, if we can assume any "feeling's" in that matter. Certainly any novice and beginner route in modern trials competitions is OK for a used twinshock, there you find rarly larger steps or obstacles. Anyone riding in expert class in modern trials with old unprepared weared out twinshock bike, well should at least ask him self if he is really in the right place. For getting fun with outright junk the easiest way to do is using it just to ride for fun! Also in likewise events that are held for these type of bikes like classic trials. Riding the bike in modern events is tremendous exhausting. I personal leave this to masochists or likewise orientated people ... Mmmh haven't heard, read or seen this, not in TC, not at trialforum not in reality! Most riders - and me too - are very picky about the suspension of their bikes.
Most TS riders here in the UK use 30 year old front forks, and rear units which are based on a design 30 years old. From the same perspective everyone uses modern tyres, and some have highly modified motors, and even modern frames which have been recently manufactured. Just dont get the reason why suspension always seems to be an afterthought, and why very few seem to understand how important this is on a TS bike?
We have been having `FUN`! At our local event We do not have enough vintage riders. So some ride the novice line, a few ride amatuer, and I usually ride Intermediate to try to be fair. It sure is hard to beat an old time rider that rides the novice line well. At the end of the day we combine our scores to make up our twinshock class. As far as I`m concerned we are all winners because we are just having FUN.
Do what you wan't but don't try to ride in most classic events on the continent with an hybrid bike that has fitted not contemporary parts, there are exeptions like shocks, handlebars, ... even the Spaniards have changed the rules here. It is no problem to rebuild a worn out fork, the betors are quite good when they in as new condition again. Certainly it is a problem to rebuild most of the original non rebuildable rear shocks, but there are already good shocks as an replacements available and this is legal even on the continent. IMHO the problem are the costs for a rebuild of a fork, take 200 - 250 for an aligned, rechromed and polished pair of stanchions that are just these 1/10mm bigger in diameter to compensate the wear of the lower outer tubes. Then machining the outer tubes, another 100 , to get them round again. All in all around 350 - 500 will you have to spend to rebuild a pair of forks. That is may be the reason some guys use newer once. To the design of a twinshock rear suspension. It is a twinshock!, The obstacels and steps got higher after the twinshocks with the monos because with these monos and their progressive rear shocks you can climb much higher difficult steps with ease then with a twinshock. One of the reasons its wasted time to ride twinshocks in modern events in higher classes in my opinion.
Sadly those making various parts "illegal" by their "rules" dont seem to understand that its often less costly to fit things like modern forks, which work better and can be found used for maybe half the cost of rebuilding badly worn originals. By the same token these people would probably accept modern frames, which provide far more of an advantage than 38mm forks, and are certainly something that gives an edge to anyone with money to spend. As to rear shocks, a TS bike fitted with modern shocks made by people like Willbers, Ohlin, or Maxton, if the rear geometry is right, performs far better than anything fitted with the cheaply made and rather crude shocks which are popular for TS trials currently. The situation in Spain seems almost as ridiculous as here in the UK, in that highly modified Spanish machines, with modern chrom moly frames, and very special motors costing around £3k to build, are being used in classes supposedly intended for authentic machines with original type spec.
If non contemporaray parts would be allowed where is the border, in terms of equal technical conditions of each bike. This would be very unsporting if someone that want to take part with a bone stock bike has to "conquer" against highly technical pimped bikes that uses parts and constructions that wasn't invented when the rest of the bike was produced. This is a no go in competition as this spoils fair play. Wrong this is against the rules, http://www.ortwinsann.de/D-Cup/Austragungsbedingungen 2012.pdf, modern frames are illegal and heavy modifications for twinshocks frames are fierced discussed, sometimes allowed sometimes excluded! The old shocks are mostly not repairable and by the way some of them did work very well and would do their work even today! As I already wrote the Spaniards have now changed the rules, and as I could follow their news will elaborate their rules from season to season. That the Spanish riders like to pimp their bikes in optical matter is something you have to think away. Anyway stricter rules about a contemporary setup of a bike help's fair play and eleminates unhealthy competition thaughts you take part because you want to meet the other guys and have fun not to win. Here in Germany there often isn't even a referee at the sections, the participants will divide in small groups where each other scores. Cheating or long discussions with this method of ranking will not appear and it is very efficient, no long line up's in front of certain sections. Certainly this will only work if you accept this community and their rules, by doing this you can even have with outright junk a lot of fun. As the "riding quality" between a worn out fork from 1982 and a rebuild one from 1982 isn't so remarkable. We don't have to forget it's a hobby, for hard competition and bla bla bla the people should go to modern trials with modern equipment.
In terms of forks, anyone with a fair amount of money to spend can have a set of 35mm forks which work better than any 38mm production parts currently available. Allowing some modern parts such as forks do mean an inexpensive improvement to suspension, but its not any great advantage in classic events as the sections tend to be on the easy side at most. Reduced cost is the main thing in favour of allowing parts such as forks. Its a good thing that modern frames are banned in Europe. Not the case here in the UK unfortunately, where costly modern frames are already the norm in top level P65, and likely to become the case in TS as well in time, which will mean machine build costs in excess of £6k at a minimum! Difficult to compare performance of shocks unless you have tried modern ones on your TS bike, but the difference is more noticeable than that between a properly set up brand new Ohlins on a modern bike, and a worn out OE part on the same machine. If the Spanish feel its fair to allow recently re-manufactured TS machines using crom moly frames, cartridge forks, many carbon and Ti parts, as well as highly modified motors, to compete in classes intended supposedly for authentic 60s, 70s, 80s machines, then they are following the example of the Scottish "P65" 2 day, where modern Brit twin-shocks compete as "P65's"......................That to me is certainly cheating, but as classic competition in Spain has a lot of interest from very wealthy people, its probably seen as being ok.
Thank you for the kind words. Let's hope it helps. I was gonna ride it today anyway. Besides, neither bike even got unloaded at the races last night. The howling windy duststorm conditions made me just leave 'em in the van. Looks like this thread blew up today. Sorry I was not around to join the festivities, but I was out having. Fun. With. Outright. Junk. It is after all, the name of the thread.
Here I have my doubts, I had to rechrome and align the stanchions for my Bultaco, a "well known" 35mm Betor fork where the chrome was OK (not nice) but sadly the stanchions where bent. I knew the fix will be costly so I looked at craiglists in Europe and found another fork in France for a good price. I bought the second pair and the stanchions of the other fork where straight but the chrome was badly pittet and scratched at some spots, so both pairs got the same treatment here. All for tubes went for processing which was OK as with the double amount of tubes I could get a much cheaper price. Both forks got better seals, new valves, new piston silde bushings, new oil, the lower tubes where overhauled too. The second fork additional got special springs adjustable fork caps and we enhanced the valves inside, (here I had help from the northern KTM racing shop that is very well equiped with all the special tools and machinery they also repair WP and Öhlins forks and shocks). The result was very good, the responding is improved, also the second fork is now really progressive and the spring adjustable, there is a difference in overall performance between them but still the better fork pair is far away compared to a more modern 38mm fork. Due to the diameter increase of the 38mm stanchions and that these forks often have much better guide bushings then the old fashion 35mm. The pair that where mounted to the bike: The second pair from Thônes: After rebuild: Anyway to spend some money in the forks is worth the much better riding, in my experience when forks get weard out you have a soft front, every order you give to the front like steering or weight shift will be either followed in "slow motion" or with a delay, just new seals and oil will not cure this phenomenon. Yep and to be expected! Even a hypermodern pair of shocks will not make the rear as good as most monoshock setups with lever-operation. There are very good Shocks availabe which don't need any lever-operation but these have additonal cartridges, are mostly designed as a monoshock and where will you place the cartridges? The little above standard shocks will work fine IMHO for very good riders. Many bike owner in Spain pimp their ride, they even chrome the frame but also exhausts and engine side cases, if they like it, can afford it let them do it. It really looks often very nice too.
