I had this with a MM super gravity casing, could not get it on for love nor money, ended up going to LBS, and when I picked the wheel up they told me they had never had such a mission. Came off easy enough 6 months later though - I think sometimes you just get tyre thats going to be a bastard due to manufacturing tolerance.
No way I can get a 2.5 DHF front tyre on rim. Anyone done this?
- Thread starter Doug Stampfer
- Start date
Well, with all my advice in an earlier post I Decided to update my experience after I had a real outing today.
Fitted Maxxis 29 x 2.5 Assegai DH casing with MAXXGrip compound and Rimpact inserts to my Trek Rail 7.
Standard rims with the Bontrager rim strip in the middle. This is actually a pain, mainly as you can’t get both beads of the tyre into the centre depression, only the one bead at a time. This means getting the 1st bead on is relatively easy, getting the second one on was more of a battle and despite pushing the 2nd bead into the centre as much as possible I still needed leavers to get it on the rim.
But it wasn’t that easy........
I started off with the 1st bead, went on relatively easy, but then put the insert into the tyre and proceeded to try and get the 2nd bead on. Tried for ages, pushed the bead in to the centre as far as ai could but gave up and failed. Took the insert out and eventually got the 2nd bead on but no insert. What I worked out was that in order to get the insert into the tyre and the 2nd bead on the rim I needed to 1st inflate the tyre without the insert and push both beads out onto the rim and pop them into position.
Now with both beads popped onto the rims outer edges I could let the air out and gently just ease the 1 bead off the rim and slide the insert into the tyre. With the other bead still popped out to the edge of the rim it left room for the tyre insert and the 2nd bead to fit into the centre depression (1st time the other bead was taking up this space but now it was popped out to the edge and there was more room). Managed to get the 2nd bead on with leavers and pump the tyre up to 50psi popping both beads out into position.
Now let the air back out, took out the valve core and syringes in the sealant. Magic milk is pretty good, doesn’t dry out and can be topped up if you like. pumped the tyre back up and hey presto, job done.
1st tyre 1.5hrs, 2nd tyre (knowing what to do) 20 mins. Hope this helps someone.
One final observation, When you replace the Bontrager rim strip with tape you run the risk of moving or unpeeling the edge when you use tyre leavers and this can cause leaks. I found that if you can leave the Bontrager strip in place it is more robust and doesn’t get damaged by leavers like sticky rim tape does.
Good luck.
Fitted Maxxis 29 x 2.5 Assegai DH casing with MAXXGrip compound and Rimpact inserts to my Trek Rail 7.
Standard rims with the Bontrager rim strip in the middle. This is actually a pain, mainly as you can’t get both beads of the tyre into the centre depression, only the one bead at a time. This means getting the 1st bead on is relatively easy, getting the second one on was more of a battle and despite pushing the 2nd bead into the centre as much as possible I still needed leavers to get it on the rim.
But it wasn’t that easy........
I started off with the 1st bead, went on relatively easy, but then put the insert into the tyre and proceeded to try and get the 2nd bead on. Tried for ages, pushed the bead in to the centre as far as ai could but gave up and failed. Took the insert out and eventually got the 2nd bead on but no insert. What I worked out was that in order to get the insert into the tyre and the 2nd bead on the rim I needed to 1st inflate the tyre without the insert and push both beads out onto the rim and pop them into position.
Now with both beads popped onto the rims outer edges I could let the air out and gently just ease the 1 bead off the rim and slide the insert into the tyre. With the other bead still popped out to the edge of the rim it left room for the tyre insert and the 2nd bead to fit into the centre depression (1st time the other bead was taking up this space but now it was popped out to the edge and there was more room). Managed to get the 2nd bead on with leavers and pump the tyre up to 50psi popping both beads out into position.
Now let the air back out, took out the valve core and syringes in the sealant. Magic milk is pretty good, doesn’t dry out and can be topped up if you like. pumped the tyre back up and hey presto, job done.
1st tyre 1.5hrs, 2nd tyre (knowing what to do) 20 mins. Hope this helps someone.
One final observation, When you replace the Bontrager rim strip with tape you run the risk of moving or unpeeling the edge when you use tyre leavers and this can cause leaks. I found that if you can leave the Bontrager strip in place it is more robust and doesn’t get damaged by leavers like sticky rim tape does.
Good luck.
Doug Stampfer
Well-known member
- Thread starter
- #33
Good stuff. SO you cant push the opposing bead up against the opposing rim with the insert in & use the centre of the insert for the second bead? I didn't have a proper look at the insert, how does it slide in & out? I thought it would have to be glued or like to keep the air in?
With the Assegai DH tyre the beads or too tight to push to the outer side of the rim by hand, they really ping into position when you inflate the tyre so I can’t see anyone being able to push them over by hand even without an insert (the inset I use is made by Rimpact, similar to cushcore).
As for the Bontrager rim strip, I haven’t looked closely at that either. Seems to be pretty well fixed, doesn’t move at all, could be glued but I don’t know.
As for the Bontrager rim strip, I haven’t looked closely at that either. Seems to be pretty well fixed, doesn’t move at all, could be glued but I don’t know.
Shane(NZ)
Active member
Have you had a chance to ride?
What pressure do you run? is the main gain to run low psi?should get massive grip
The DH tyre is pretty tough on its own.
Haven't had a chance to ride yet, only down the road. Seriously sticky tyres, they kept flicking little stones up in the air as I rode along.
I weigh 105KG without gear so wanted security of not flatting and good grip. The original Bontrager XR5's were not so grippy on the trails I ride. I ride Brechfa, Abergorlech and Cwm Rhaeadr in South Wales mostly and its a limestone shale which can be quite sharp. 1st trip out on the trails with the Bontragers and cut the sidewall, also didn't like the grip at all.
I expect I can ride low 20's PSI front and mid 20's rear. I contemplated not using the Rimpact inserts but decided I wanted the ability to ride back out of the woods rather than push what could be 10k in some circumstance. Hopefully will get out on the weekend sometime.
Used tape on my last wheel set and no real issues, just found that the tape peeled back a bit sometime on the edges. I've not come across the Bontrager system before so I decided best leave alone and work with it.
Shane(NZ)
Active member
I have a 29 2.5 DD assegai up front, it picks up little stones all the time, haven't noticed this on any other tyres. I'm 115kg plus bike run 22-24psi front.
I have a 27.5 2.6 exo+ assegai for rear, not fitted yate, been raining near 4 weeks in NZ(chch) suns and today but dont think many trails well be open.
Enjoy ?
I managed to get out for a short trip last night. Not a great trail to properly test the tyres but noticed that the Assegai’s are definitely grippy/sticky. They are also definitely heavy, probably add about 1kg between both front and rear tyres over the stock ones. It was noticeable. Also I noticed that they rolled slower as well. But the main thing for me is robustness and overall I’m really pleased.
Doug Stampfer
Well-known member
- Thread starter
- #41
Burped the front tyre today on a drop with sharp corner under it & as I flew gracefully through the air to inspect the foliage of some of our native trees I noticed that the front tyre was flat. I tried pumping up the tyre with my hand pump but no good.
Would I have been able to fit a tube inside the tyre with the plastic insert? I am contemplating carrying one now but only if it will work. If it doesn't work I'll get rid of the insert & tape it instead.
I did manage to pump it up at the carpark with some cable tied around the perimeter of the tyre & carried on riding
Would I have been able to fit a tube inside the tyre with the plastic insert? I am contemplating carrying one now but only if it will work. If it doesn't work I'll get rid of the insert & tape it instead.
I did manage to pump it up at the carpark with some cable tied around the perimeter of the tyre & carried on riding
what do you mean by "insert"? With a normal tubeless setup it is easy to install a tube, just a bit messy. I have my pump in an old sock - I used that (the old sock) to get most of the sealant out.
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You'll be talking about Bontrager's plastic rim bed. I think yes you would be able to fit a tube, but maybe not the easiest doing it trailside. The rim bed makes it harder to fit tyres anyway, although it does make it easier to air the tyres up tubeless. But if you think you're going to need to throw a tube in on a semi-regular basis it might be easier to take the rim bed out and just have it taped. I used to dread changing tyres on my Bonty rims
Doug Stampfer
Well-known member
- Thread starter
- #44
So after burping my front tyre last big ride & walking out with a flat I've been thinking of getting rid of the rim strips & taping so I can throw a tube in if it happens again. I have some questions
Before I do this are the valves used with the bonty rim inserts normal tubeless or special for the rim inserts? Can I reuse them with just tape.
What pressures are you using with DHFs/ DHRs? I'm usually around 18-19psi which gives me great grip over roots but prob the cause of the front burping. I've been watching some guns like Remy on youtube & they seem to run 26-29PSI???
Contemplating cushcores as well. I read somewhere they are only sposed to last the lifetime of 2 tyres??? Thats only 6-8 months or so of good riding on an Emtb. Anyone had any long term feedback from their cushcores?
Before I do this are the valves used with the bonty rim inserts normal tubeless or special for the rim inserts? Can I reuse them with just tape.
What pressures are you using with DHFs/ DHRs? I'm usually around 18-19psi which gives me great grip over roots but prob the cause of the front burping. I've been watching some guns like Remy on youtube & they seem to run 26-29PSI???
Contemplating cushcores as well. I read somewhere they are only sposed to last the lifetime of 2 tyres??? Thats only 6-8 months or so of good riding on an Emtb. Anyone had any long term feedback from their cushcores?
Just remove tubeless valve and put tube in. Pump it up and go. And pump more pressure, 17-18 psi is too low
If you're running exo or exo+ I think your pressures are a bit low. I'm 95kg and ride lots of rooty trails too, I also run 18psi in the front but that's with a DD casing, and I've had no issues at that pressure. I would just keep raising the pressure a couple of psi until the tyre stops burping. Have you considered carrying C02 or a high volume pump like the topeak mountain morph (lezyne do one too) - I found the tyres sit so tight on the Bonty rim strip I could re-seat them with a pump like that. Can't comment on the lifespan of cushcore, but a tyre insert should help prevent burping. However, there are cheaper inserts than cushcore, and for the extra outlay you could just get some DD tyres and save yourself the faff of inserts. I have a feeling the Bonty tubeless valves are shaped to work best with their rim strip, can't quite remember. It is hard to get that rim strip out without damaging it.
I removed the tubes and went tubeless and yesterday replaced my tyres all without removing the bontrager tape. It's tricky but doable by hand.
You need to grab the bulk of the tyre with 2 hands and drag the last section over the rim - don't try and push it bit by bit with your thumbs but drag the last 100mm over all at once if you see what I mean.
You need to grab the bulk of the tyre with 2 hands and drag the last section over the rim - don't try and push it bit by bit with your thumbs but drag the last 100mm over all at once if you see what I mean.
Doug Stampfer
Well-known member
- Thread starter
- #48
Yeah it is quite low I agree. I'm having wrist issues at the moment (not due to bike setup or levers etc) so as well as replacing the airseal on the yari I am thinking about cushcores to run lower pressures for small bump compliance. I also don't want to experiment with the lowest air pressure I can run out in the field if it involves a walk back to the car.
I think for the sake of being able to throw a tube in I'll get rid of the insert but will do some research on the cushcore longetivity.
Doug Stampfer
Well-known member
- Thread starter
- #49
Good grief I bought a tyre pressure gauge & put 21PSI up front & 23PSI back then went for my usual ride. It was horrible. My tyres were skittering off every root & rock & I felt like I had no control at all. I'm baffled how people can ride with higher pressures - surely they are riding gods or like living on the edge.
Those pressures aren't even particularly high compared to what some riders will run, but I agree, I always like to run the lowest pressure I can get away with, not a good feeling to have the tyres skittering and skipping. If you can't run lower without burping, looks like it's some sort of tyre insert for you then?
They're just a lot more experienced than you.
What you weigh, what tyre casings you run and how you ride ALL make a massive diffference to what pressures you need to run.
As a heavier but still reasonably fast, capable and very experienced rider I'd fold the sidewalls cornering ANY 2.5 front tyre with just 21psi and wouldn't get down a fast rocky trail without a dinged rim or any air still in the rear tyre at just 23psi. Pressures that low would be far more sketchy than any tyre skitter. Tyres skittering isn't really an issue if your line choice, weight positioning and speed etc. are good. Most beginners rarely even lean DHFs over onto to the edges peoperly or realise how to control the drift zone before the edge bites properly. for both of these to work properly the tyre requires support. (ie. enough pressure for the casing not to fold)
FWIW I run dual compound (the least grippy maxxis tyres available) exo casing 2.5 Minion DHF upfront at 32psi and another exo casing 2.3 Minion SS rear at 40psi all year round on technical steep loose slippy Scottish DH and Enduro tracks. It's obviously not a super grippy set-up but I'd honestly rather forego grip for the extra acceleration, support and liveliness. I'm not racing tho. Every average alfie on a trail bike you meet these days feels the *need* to have the ultimate grip possible. and yet very few are actually riding quickly.
Rosemount
E*POWAH Elite
40 PSI !!!
Rosemount
E*POWAH Elite
Rosemount.
Dome us all a huge favour and just block me.
Do
To be fair, Gary, 100% whatever works for you! However, although I know dirt jumpers, trials/street riders and the like favour even higher pressures, 40psi is definitely at the higher limit of what most riders would run for trail riding. As you say, rider weight, casings, riding style are all huge factors in deciding the appropriate pressure. I personally get away with running slightly lower pressures on my eeb than I would on my accoustic, because I'm running DD casings that offer really good support. Your "business up front, party out back" setup is fine for more confident riders, but for those less experienced, grip inspires confidence, and will help those riders progress, even if they aren't riding fast or haven't learned to lean their DHFs onto the corner knobs.
Were I on DH casings my pressures would be less for sure. and don't forget I'm only running a 2.3 rear tyre.
I actually run 50/55psi for commuting and that's a mixture of on/off road (but nothibg gnarly). occasionally I'll swing by a local jump spot and hit a few jumps/berms on my way home with those pressures.
On my DJ/4X bike i run 55/60psi (26x2.2 f&r)
I actually run 50/55psi for commuting and that's a mixture of on/off road (but nothibg gnarly). occasionally I'll swing by a local jump spot and hit a few jumps/berms on my way home with those pressures.
On my DJ/4X bike i run 55/60psi (26x2.2 f&r)
Yeah. That's exactly what I was saying TBF.
The way I learned to dial in my tyre pressures, back when I was new to riding, is to inflate to quite a high pressure (over 40psi), and ride trails that are familiar to you. As you ride, reduce the pressure in small increments, noting as you do so the effect this has on the amount of grip and general handling of the bike. The idea is to keep doing this until you can feel a detrimental effect on the bike's handling, e.g. the bike feels unstable in corners, tyres are folding and wallowing , getting rim strikes. Increase the pressure until these symptoms disappear, and this should provide a good baseline pressure to begin with. I don't know if many others have done something similar, but I found it worked well for me. I found it a great way to figure out a good balance between grip and rolling speed, that suited my setup/riding style/trails, as well as learning how different pressures affected bike handling.
If you're looking for maximum grip. Instead of whacking the tyres up to 40psi and riding lots of trails, A really fast way to get decent a base tyre pressure settings is to simply ride the bike on a hard surface and push down through the tyres as hard as you can with the bike leant over (You need to really push down hard though. no pansying about). Gradually lowering the pressure as you repeat this process you'll eventually get to a point where you can feel the tyre fold. At this point you need go back up and add a little more pressure.
As this is a base setting you then can ride familiar trails and fine tune to preference. you'll then only really need to alter pressure up or down by one or two Psi front and rear
As this is a base setting you then can ride familiar trails and fine tune to preference. you'll then only really need to alter pressure up or down by one or two Psi front and rear
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Doug Stampfer
Well-known member
- Thread starter
- #60
Well I supposed there's experienced & experienced. I've actually been mtbing since 89 when I first threw my leg over a Kuwahara at Banff. however over the years I guess I've forgotten more than I've learnt. Actually to be honest the Emtb reawakened in me the love of mtbing. I'm at the stage/age that each ride I think I'm learning something new each time - I wonder if when that stops whether my interest in riding will wane again.If I think about when I started mountainbiking it was new & really out there , those bikes with wide tyres people used to stop & ask about. Then front suspension - wow! Then full suspension like a motorbike, then full suspension that actually worked & now ebikes. I recall each evolution was a game changer.
Back on topic.I was really happy running at 18-19 PSI. The contact with the ground was great, roots & rocks were partially absorbed rather than run over which made for a smoother less effortful, less twitchy, less input, less muscle strained type ride which is what I like. I also know myself pretty well & fast reaction time is something I do not have so have no illusions or desire about being the fastest rider down a trail.
Re the tyre pressures what really surprised me was the major difference I felt just pumping the tyre up to 21&23. I guess it just changed the whole profile of the tyre & how it reacts with obstacles & perhaps the difference isn't as pronounced pumping from there up to 26-29.
I find myself with my style of riding happier at low pressures, however will need to accomodate the inherent problems with those pressures.
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