Jam², 160mm fork + other suspension questions

[Bert]

Hi, i've got a stock 2021 6.7 Jam² and i would like to improve the handling off the bike. Especialy tight corners, and "trials" like stuff. I'm thinking off changing the forks to a more beefier one than the Recon, but also give it a little more travel for hard hitting stuff. I would like to change the fork for a 160mm thicker one, but i am also conserned that the bike will handle slower with 160mm in the small, tecnical, hairpin type corners. I would like it to be steering faster right already as it is. The offset off the Recon is 42mm, should i look for a fork that has the same offset, or should i buy one with 51mm offset, if i wan't the bike to handle faster? Also, i do not like the stock rear shock, i is just to "bouncy", and i can't find a good tune for my liking, it almost feels like the bike is always riding low in the back. Even though i am not a heavy rider, about 72kg geared up. What aftermarket shock would give a more stable ride?

 

[cablepuller1]

Hi, i've got a stock 2021 6.7 Jam² and i would like to improve the handling off the bike. Especialy tight corners, and "trials" like stuff. I'm thinking off changing the forks to a more beefier one than the Recon, but also give it a little more travel for hard hitting stuff. I would like to change the fork for a 160mm thicker one, but i am also conserned that the bike will handle slower with 160mm in the small, tecnical, hairpin type corners. I would like it to be steering faster right already as it is. The offset off the Recon is 42mm, should i look for a fork that has the same offset, or should i buy one with 51mm offset, if i wan't the bike to handle faster? Also, i do not like the stock rear shock, i is just to "bouncy", and i can't find a good tune for my liking, it almost feels like the bike is always riding low in the back. Even though i am not a heavy rider, about 72kg geared up. What aftermarket shock would give a more stable ride?

I'm riding a hardtail so probably not qualified to answer your question but I have changed out my stock recon for a 20mm bigger fox34, it did make a difference but these changes never tend to be the night and day differences people talk about, they are just subtly better, the extra 20mm is also subtly better, but at no point did I notice the steering slowing, your probably like me and totally overthink these things, the endless YouTube and forum stuff makes it worse, I would buy a secondhand fox34 and try it out, you can sell it easy if you don't like it, the back shock I noticed YouTube video suggests setting between mid and open but still a bit wallowy, maybe also go secondhand on that

 

[sdcoffeeroaster]

Hi, i've got a stock 2021 6.7 Jam² and i would like to improve the handling off the bike. Especialy tight corners, and "trials" like stuff. I'm thinking off changing the forks to a more beefier one than the Recon, but also give it a little more travel for hard hitting stuff. I would like to change the fork for a 160mm thicker one, but i am also conserned that the bike will handle slower with 160mm in the small, tecnical, hairpin type corners. I would like it to be steering faster right already as it is. The offset off the Recon is 42mm, should i look for a fork that has the same offset, or should i buy one with 51mm offset, if i wan't the bike to handle faster? Also, i do not like the stock rear shock, i is just to "bouncy", and i can't find a good tune for my liking, it almost feels like the bike is always riding low in the back. Even though i am not a heavy rider, about 72kg geared up. What aftermarket shock would give a more stable ride?

I think you first need to define what you mean by fast and slow. Yes the longer fork along with less offset will tend to want to "flop" a bit on tight corners but easy to overcome as long as you don't go too far. At higher speeds the 41mm offset can give you that quick steering some are after and more travel means a slightly bigger fork angle so more high speed stability. I came from a 2018 jam2 that had the 34 Rhythm fork, 51mm offset and 140mm travel. I only went up to 150mm, stayed with the 51mm offset, went from 27.5 to 29 on the front and from 2.8" to 2.6" on the back so I'm around 65 deg of fork angle. It might flop a bit more but I can handle it and it has great stability too, sort of the compromise. It has more than enough travel for rocky technical sections and very controlled. If I was more into fast down hilling I might have gone to 160mm travel but I chose the Lyrik Ultimate and it's an amazing fork so I would say quality of the travel is more important than the over all travel which secondary in my mind. And for the same reason that I'm not a really crazy fast all out rider I stuck with the 51mm offset to keep some maneuverability in tight switchbacks which I really enjoy, uphill or downhill. I guess my years of riding observed trials on motorcycles in the 70's influences my preferences today. If I rode more motocross back then and was good at it I might be setting my bike up differently today.

 

[Akelu]

I would like it to be steering faster right already as it is

You could try a shorter stem or cut some length off your handlebars.

 

[sdcoffeeroaster]

You could try a shorter stem or cut some length off your handlebars.

I went from 800mm to 760mm on mine. I am not a large person and that really helped a lot. One other thing about stems. It all depends on if your bars are straight or swept back a bit. If you draw a line across from mid grip to mid grip. That line should be a bit ahead of the axis of the stem. If it's too close the steering can be too twitchy as I found on my bike with the Salsa Bars I use. Somewhere around 30mm offset gives you a lot more slow speed stability. More than that and you're way over the front end too much. I ended up with a 60mm stem because of the Salsa back sweep. With straight bars I could see using around 30mm or so. I think since most are using straight bars these days short 30 mm stems work well. I was surprised that jush going from 50 to 60mm stem gave the bike a much more stable slow speed feeling on the trail. Much less wandering around. I just never like straight bars and love the Salsa bar geometry.

 

[Bert]

Rear shock, i think i'll look for a replacement 2nd hand, like suggested, problem i have is that i have a medium size frame, wich limits my choice in replacement shocks a lot. Can't use a shock with a can. What got me wondering the most regarding the fork. Focus states on there website that the fork has a 51mm offset. Yet my bike came delivered with a 42mm offset fork. For short slow hairpin turns, i feel that is handles like a boot. Since i'm not keen on the fork, that is why i was wonderening if it would be better to go with the 51mm offset when replacing the fork. Are there other members over here that got there 2021 Jam² delivered with 42 offset forks? Like suggested, i am going to try it with making the handlebars smaller.
@sdcoffeeroaster , i've got a bit off a trials motorcycle background aswell, maybe that is why i'm so picky on the slow tight steering? + are you using 27.5 in the back and 29 in the front wright now?

 

[sdcoffeeroaster]

@sdcoffeeroaster , i've got a bit off a trials motorcycle background aswell, maybe that is why i'm so picky on the slow tight steering? + are you using 27.5 in the back and 29 in the front wright now?
[/QUOTE]
Cool, I rode a Cotton (minarelli engine, 170cc), Montesa, Ossa, Kawasaki and a 1974 326 Bultaco, my favorite. I only had the Bultaco about a month before somebody stole it but my last ride with it was my best ever Amateur class finish at 2nd. I rode and extensively modified the Kawasaki (was a Kawasaki service mgr/mech back then) later but it was never as good. I even rode an event out here with Sammy Miller when he visited SoCal. Yes I am using reverse mullet but the bike came with plus 2.8" setup.

You might like this article: Exploring the Relationship Between Handlebar vs Stem Length - Pinkbike

 

[sdcoffeeroaster]

@sdcoffeeroaster , i've got a bit off a trials motorcycle background aswell, maybe that is why i'm so picky on the slow tight steering? + are you using 27.5 in the back and 29 in the front wright now?
[/QUOTE]
Cool, I rode a Cotton, Montesa, Ossa, Kawasaki and a 326 Butltaco, my favorite. I even rode an event out here with Sammy Miller when he visited SoCal. Yes I am using a reverse mullet (and 2.5-2.6" front and 2.6" rear) but the bike came with plus 2.8" setup.

 

[Bert]

I am still riding trials motorcycles for fun, and sometimes a local club championship. That and mtb's is how i spend most off my spare time.
Anyway, contacted Focus about the fork offset thing, since there website states, in all the tech documents i can find it should have 51mm, but mine got delivered with 42mm forks. See what they have to say. Also planning on switching the wheel first to test with a 27.5 in the back, and see if this does anything to better the steering.

 

[sdcoffeeroaster]

I am still riding trials motorcycles for fun, and sometimes a local club championship. That and mtb's is how i spend most off my spare time.
Anyway, contacted Focus about the fork offset thing, since there website states, in all the tech documents i can find it should have 51mm, but mine got delivered with 42mm forks. See what they have to say. Also planning on switching the wheel first to test with a 27.5 in the back, and see if this does anything to better the steering.

Great. I do miss competing in Trials but it's not the sport it used to be around here. Bernie Schrieber gave a school recently out in the dessert north of me and it was 105-110 F that day. I almost took my ebike since another rider from here, Mark Eggar, was going to visit but just too hot. Wish I had gone anyway though. This was pre-Covid too. Both of them are old school riders and top in the US in their day. Mark rode for Honda and Bernie of course was the only US World Champ. They are all old like me now, lol...just a few years younger.

I think all of these changes will be very subtle and you might not even notice a single one alone except in certain sections that might be slightly different, easier or harder.

 

[sdcoffeeroaster]

@sdcoffeeroaster , i've got a bit off a trials motorcycle background aswell, maybe that is why i'm so picky on the slow tight steering? + are you using 27.5 in the back and 29 in the front wright now?

Cool, I rode a Cotton (minarelli engine, 170cc), Montesa, Ossa, Kawasaki and a 1974 326 Bultaco, my favorite. I only had the Bultaco about a month before somebody stole it but my last ride with it was my best ever Amateur class finish at 2nd. I rode and extensively modified the Kawasaki (was a Kawasaki service mgr/mech back then) later but it was never as good. I even rode an event out here with Sammy Miller when he visited SoCal. Yes I am using reverse mullet but the bike came with plus 2.8" setup.

You might like this article: Exploring the Relationship Between Handlebar vs Stem Length - Pinkbike
[/QUOTE]
After I posted this I re-read the article and checked my own bike since I recently had the bars off. Dahhh, almost zero effective stem length...no wonder I've felt like I was wandering around on the trail too much! I rotated the bars up slightly to about 20mm effective stem length and wander gone!!!

 

[themoon]

On my 2018 M-sized Jam2 stock 140 mm reckons came with 51 offset. Swapped them for 140 DT Swiss F535, with 44 offset. To be honest, did not notice all that much difference in steering, although the fork is definitely much better.

Then installed MegNeg for rear shock, stock Deluxe. The change was instantly noticeable - rear wheel feels much more stable and planted, it does not bounce as much during jumps.

My latest upgrade was Zeb 160 mm. I feared that the bike would feel unbalanced now, with 160 front / 140 back, but so far does not seem the case. Really like the fork too, although I'm yet to ride it on really aggresive trails

 

[Bert]

Well, updates so far are, found a new unused RT3 shock on ebay, replaced mine, bike felt instantly more planted. Bought an unused "new" Lyrik also, with a 160mm travel, +51offset, intstalled it, but have not been able to test it yet, since i'm still waiting for the required brake mount adapter. I also ordered a 27.5 rear wheel, but unfortunatly, it does not fit so need to send it back. It came with the wrong freehub.